1
|
Fionda B, Bussu F, Placidi E, Rosa E, Lancellotta V, Parrilla C, Zinicola T, De Angeli M, Greco F, Rigante M, Massaccesi M, Gambacorta MA, Indovina L, De Spirito M, Tagliaferri L. Interventional Radiotherapy (Brachytherapy) for Nasal Vestibule: Novel Strategies to Prevent Side Effects. J Clin Med 2023; 12:6154. [PMID: 37834798 PMCID: PMC10573955 DOI: 10.3390/jcm12196154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/18/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
Interventional radiotherapy (brachytherapy) has become the new therapeutic standard in the management of early stages nasal vestibule tumors; in fact it allows for high local control rates and low toxicity profiles. However, since more and more patients will receive interventional radiotherapy (brachytherapy) as primary treatment, it is desirable to implement novel strategies to reduce the dose to organs at risk with the future aim to result in further lowering long-term side effects. MATERIALS AND METHODS We were able to identify two different strategies to reduce dose to the treatment volume, including the implantation technique (the implant can be interstitial, endocavitary or mixed and the catheters may be placed either using the Paris system rules or the anatomical approach) and the dose distribution within the implant (the most commonly used parameter to consider is the dose non-uniformity ratio). We subsequently propose two novel strategies to reduce dose to organs at risk, including the use of metal shields for fixed organs as in the case of the eyes and the use of a mouth swab to push away mobile organs, such in the case of the mandible. We used two different algorithms to verify the values namely the TG-43 and the TG-186. RESULTS We provided an accurate literature review regarding strategies to reduce toxicity to the treatment volume, underlining the pros and cons of all implantation techniques and about the use dose non-uniformity ratio. Regarding the innovative strategies to reduce the dose to organs at risk, we investigated the use of eye shielding and the use of swabs to push away the mandible by performing an innovative calculation using two different algorithms in a series of three consecutive patients. Our results show that the dose reduction, both in the case of the mandible and in the case of eye shielding, was statistically significant. CONCLUSION Proper knowledge of the best implantation technique and dose non-uniformity ratio as highlighted by existing literature is mandatory in order to reduce toxicity within the treatment volume. With regard to the dose reduction to the organs at risk we have demonstrated that the use of eye shielding and mouth swab could play a pivotal role in clinical practice; in fact, they are effective at lowering the doses to the surrounding organs and do not require any change to the current clinical workflow.
Collapse
Affiliation(s)
- Bruno Fionda
- U.O.C. Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Roma, Italy; (B.F.); (T.Z.); (M.D.A.); (M.M.); (M.A.G.)
| | - Francesco Bussu
- Divisione di Otorinolaringoiatria, Azienda Ospedaliero Universitaria, 07100 Sassari, Italy;
- Dipartimento di Medicina, Chirurgia e Farmacia Università di Sassari, 00168 Sassari, Italy
| | - Elisa Placidi
- U.O.S.D. Fisica Medica e Radioprotezione, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy; (F.G.); (L.I.)
| | - Enrico Rosa
- Dipartimento di Neuroscienze, Sezione di Fisica, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Valentina Lancellotta
- U.O.C. Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Roma, Italy; (B.F.); (T.Z.); (M.D.A.); (M.M.); (M.A.G.)
| | - Claudio Parrilla
- U.O.C. Otorinolaringoiatria, Dipartimento di Scienze dell’Invecchiamento, Neurologiche, Ortopediche e della Testa-Collo, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Tiziano Zinicola
- U.O.C. Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Roma, Italy; (B.F.); (T.Z.); (M.D.A.); (M.M.); (M.A.G.)
| | - Martina De Angeli
- U.O.C. Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Roma, Italy; (B.F.); (T.Z.); (M.D.A.); (M.M.); (M.A.G.)
| | - Francesca Greco
- U.O.S.D. Fisica Medica e Radioprotezione, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy; (F.G.); (L.I.)
| | - Mario Rigante
- U.O.C. Otorinolaringoiatria, Dipartimento di Scienze dell’Invecchiamento, Neurologiche, Ortopediche e della Testa-Collo, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Mariangela Massaccesi
- U.O.C. Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Roma, Italy; (B.F.); (T.Z.); (M.D.A.); (M.M.); (M.A.G.)
| | - Maria Antonietta Gambacorta
- U.O.C. Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Roma, Italy; (B.F.); (T.Z.); (M.D.A.); (M.M.); (M.A.G.)
- Istituto di Radiologia, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Luca Indovina
- U.O.S.D. Fisica Medica e Radioprotezione, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy; (F.G.); (L.I.)
| | - Marco De Spirito
- Dipartimento di Neuroscienze, Sezione di Fisica, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, 00168 Rome, Italy
| | - Luca Tagliaferri
- U.O.C. Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, 00168 Roma, Italy; (B.F.); (T.Z.); (M.D.A.); (M.M.); (M.A.G.)
| |
Collapse
|
2
|
Karius A, Szkitsak J, Strnad V, Lotter M, Kreppner S, Schubert P, Fietkau R, Bert C. On the implant stability in adaptive multi-catheter breast brachytherapy: Establishment of a decision-tree for treatment re-planning. Radiother Oncol 2023; 183:109597. [PMID: 36870607 DOI: 10.1016/j.radonc.2023.109597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/14/2023] [Accepted: 02/24/2023] [Indexed: 03/06/2023]
Abstract
BACKGROUND AND PURPOSE To assess implant stability and identify causes of implant variations during high-dose-rate multi-catheter breast brachytherapy. MATERIALS AND METHODS Planning-CTs were compared to control-CTs acquired halfway through the treatment for 100 patients. For assessing geometric stability, Fréchet-distance and button-to-button distance changes of all catheters as well as variations of Euclidean distances and convex hulls of all dwell positions were determined. The CTs were inspected to identify the causes of geometric changes. Dosimetric effects were evaluated by target volume transfers and re-contouring of organs at risk. The dose non-uniformity ratio (DNR), 100% and 150% isodose volumes (V100 and V150), coverage index (CI), and organ doses were calculated. Correlations between the examined geometric and dosimetric parameters were assessed. RESULTS Fréchet-distance and dwell position deviations >2.5 mm as well as button-to-button distance changes >5 mm were detected for 5%, 2%, and 6.3% of catheters, but for 32, 17, and 37 patients, respectively. Variations occurred enhanced in the lateral breast and close to the ribs, e.g. due to different arm positions. Only small dosimetric effects with median DNR, V100, and CI variations of -0.01 ± 0.02, (-0.5 ± 1.3)ccm, and (-1.4 ± 1.8)% were observed in general. Skin dose exceeded recommended levels for 12 of 100 patients. Various correlations between geometric and dosimetric implant stability were found, based on which decision-tree regarding treatment re-planning was established. CONCLUSION Multi-catheter breast brachytherapy shows a high implant stability in general, but considering skin dose changes is important. To increase implant stability for individual patients, we plan to investigate patient immobilization aids during treatments.
Collapse
Affiliation(s)
- Andre Karius
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany.
| | - Juliane Szkitsak
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Michael Lotter
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Stephan Kreppner
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Philipp Schubert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| |
Collapse
|
3
|
Dose Distribution of High Dose-Rate and Low Dose-Rate Prostate Brachytherapy at Different Intervals-Impact of a Hydrogel Spacer and Prostate Volume. Cancers (Basel) 2023; 15:cancers15051396. [PMID: 36900188 PMCID: PMC10000179 DOI: 10.3390/cancers15051396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/13/2023] [Accepted: 02/21/2023] [Indexed: 02/25/2023] Open
Abstract
The study aimed to compare the dose distribution in permanent low-dose-rate brachytherapy (LDR-BT) and high-dose-rate brachytherapy (HDR-BT), specifically focusing on the impact of a spacer and prostate volume. The relative dose distribution of 102 LDR-BT patients (prescription dose 145 Gy) at different intervals was compared with the dose distribution of 105 HDR-BT patients (232 HDR-BT fractions with prescription doses of 9 Gy, n = 151, or 11.5 Gy, n = 81). A hydrogel spacer (10 mL) was only injected before HDR-BT. For the analysis of dose coverage outside the prostate, a 5 mm margin was added to the prostate volume (PV+). Prostate V100 and D90 of HDR-BT and LDR-BT at different intervals were comparable. HDR-BT was characterized by a considerably more homogenous dose distribution and lower doses to the urethra. The minimum dose in 90% of PV+ was higher for larger prostates. As a consequence of the hydrogel spacer in HDR-BT patients, the intraoperative dose at the rectum was considerably lower, especially in smaller prostates. However, prostate volume dose coverage was not improved. The dosimetric results well explain clinical differences between these techniques reported in the literature review, specifically comparable tumor control, higher acute urinary toxicity rates in LDR-BT in comparison to HDR-BT, decreased rectal toxicity after spacer placement, and improved tumor control after HDR-BT in larger prostate volumes.
Collapse
|
4
|
Takase K, Itonaga T, Mikami R, Irisawa R, Saito K. Dosimetric Superiority of High-Dose-Rate (HDR) Brachytherapy Using a Surface Mold Applicator for Primary Cutaneous Angiosarcoma of the Scalp. Cureus 2022; 14:e25056. [PMID: 35719801 PMCID: PMC9199566 DOI: 10.7759/cureus.25056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2022] [Indexed: 11/05/2022] Open
|
5
|
Variations in hot spots during intracavitary brachytherapy reduces long-term toxicities associated with image-guided brachytherapy. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.109014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
6
|
Palled SR, Radhakrishna NK, Manikantan S, Khanum H, Venugopal BK, Vishwanath L. Dosimetric comparison of manual forward planning with uniform dwell times versus volume-based inverse planning in interstitial brachytherapy of cervical malignancies. Rep Pract Oncol Radiother 2020; 25:851-855. [PMID: 32982589 DOI: 10.1016/j.rpor.2020.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/31/2020] [Accepted: 08/12/2020] [Indexed: 11/26/2022] Open
Abstract
Aim Dosimetic comparison of manual forward planning(MFP) with inverse planning(IP) for interstitial brachytherapy(ISBT) in cervical carcinoma. Background Brachytherapy planning by MFP is more reliable but time-consuming method, whereas IP has been explored more often for its ease and rapidness. The superiority of either is yet to be established. Methodology Two plans were created on data sets of 24 patients of cervical carcinoma who had undergone ISBT, one by MFP with uniform dwell times and another IP on BrachyVision 13.7 planning system with a dose prescription of 600 cGy. Isodose shaper was used for improving conformity & homogeneity. Dosimetric parameters for target and organs at risk (OARs) were recorded. Conformity index (COIN), dose homogeneity index (DHI), overdose index (OI), Coverage index (CI) and dose nonuniformity ratio (DNR) were calculated. Results Mean high risk clinical target volume: 73.05(±20.7)cc, D90: 5.51 Gy vs. 5.6 Gy (p = 0.017), V100: 81.77 % vs. 83.74 % (p = 0.002), V150: 21.7 % vs. 24.93 % (p = 0.002), V200: 6.3 % vs. 6.4 % (p=0.75) for IP and MFP, respectively. CI: 0.81(IP) and 0.83(MFP) (p = 0.003); however, COIN was 0.79 for both plans. D2cc of OARs was statistically better with IP (bladder 54.7 % vs. 56.1 %, p = 0.03; rectum 63 % vs. 64.7 %, (p = 0.0008). Conclusion Both MFP and IP are equally acceptable dosimetrically. With higher dose achieved to the target, for a similar OAR dose, MFP provides greater user flexibility of dwell positions within the target as well as better optimization. Isodose shaper may be carefully used for fine tuning. Larger sample sizes and clinical correlation will better answer the superiority of one over the other.
Collapse
Affiliation(s)
- Siddanna R Palled
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | | | - Senthil Manikantan
- Medical Physicist, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | - Hashmath Khanum
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | - Bindu K Venugopal
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | - Lokesh Vishwanath
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
| |
Collapse
|
7
|
Kumar M, Thangaraj R, Alva RC, Koushik K, Ponni A, Janaki MG. Interstitial high-dose-rate brachytherapy using cobalt-60 source for cervical cancer: dosimetric and clinical outcomes from a single institute. J Contemp Brachytherapy 2020; 12:351-355. [PMID: 33293974 PMCID: PMC7690231 DOI: 10.5114/jcb.2020.98114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 05/18/2020] [Indexed: 02/01/2023] Open
Abstract
PURPOSE To record and report dosimetric and clinical outcomes of interstitial brachytherapy using cobalt-60 (60Co) source in cervical cancer. MATERIAL AND METHODS Seventy patients who underwent external beam radiotherapy with dose of 45 Gy in 25 fractions, followed by interstitial brachytherapy (ISBT) 6.5 Gy × 4 fractions were included into this study. The ISBT applicators were inserted under combined spinal and epidural anesthesia. Computed tomography (CT) simulation was performed and axial CT images were transferred to treatment planning system. High-risk clinical target volume (CTVHR) and organs at risks (OARs) were contoured. Four fractions of 6.5 Gy were prescribed to CTVHR using inverse planning technique. Patients were followed-up for 3 years. Dosimetric parameters and clinical outcomes were recorded and compared with available literature. RESULTS Seventy patients with FIGO stage IIB-IVA were included in the study. The median EQD2 of 2 cm3 of bladder, rectum, sigmoid and D90 CTVHR were 70 Gy (53-75 Gy), 64 Gy (51-71 Gy), 48 Gy (44-72 Gy), and 77 Gy (70-86 Gy), and dose homogeneity index (DHI), dose non-uniformity ratio (DNR), coverage index (CI), overdose volume index (OI), and conformal index (COIN) were 0.58 (0.39-0.78), 0.42 (0.22-0.61), 0.87 (0.59-0.97), 0.19 (0.09-0.30) and 0.74 (0.52-0.85), respectively. Local control rate at 2 years was 87.14%. Eight patients had local recurrence and one patient had lung metastasis. Also, two patients with local recurrence had recto-vaginal fistula. Two patients had grade 2 proctitis (2.8%) and one patient developed grade 3 proctitis (1.4%). There was no grade 2 or higher bladder toxicity. CONCLUSIONS The dosimetric parameters, local control and toxicities of high-dose-rate interstitial brachytherapy in cervical cancer patients treated by 60Co radioactive source are similar, compared to available literature using iridium-192 (192Ir) source.
Collapse
Affiliation(s)
| | | | | | | | - Arul Ponni
- Ramaiah Medical College, Bengaluru, India
| | | |
Collapse
|
8
|
Murakami N, Yoshimoto S, Nakamura S, Uematsu M, Kashihara T, Takahashi K, Inaba K, Okuma K, Igaki H, Nakayama Y, Itami J. Per-oral interstitial brachytherapy catheter insertion for boost in case of recurrent tonsillar carcinoma: dosimetry and clinical outcome. BJR Case Rep 2020; 6:20190059. [PMID: 32201608 PMCID: PMC7068101 DOI: 10.1259/bjrcr.20190059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 12/14/2022] Open
Abstract
High-dose-rate interstitial brachytherapy (HDR-ISBT) is relatively rarely applied for the head and neck cancer. However, its dose distribution is more confined than intensity modulated radiation therapy (IMRT) and can deliver higher dose while sparing surrounding normal tissues. In this case report, the effectiveness of HDR-ISBT as a boost following IMRT for post-operative recurrent oropharyngeal cancer patient was indicated. A 73-year-old male who developed local recurrence after surgery for oropharyngeal squamous cell carcinoma. Salvage IMRT up to 70 Gy concurrent with weekly cetuximab was planned. However, CT taken at 60 Gy found a residual tumor, then, boost HDR-ISBT was proposed. 1 week after 60 Gy of IMRT, HDR-ISBT, 12 Gy in 2 fractions, was delivered under local anesthesia. MRI taken 2 months after HDR-ISBT showed no residual tumor. It was demonstrated that boost HDR-ISBT following IMRT for local recurrence of oropharyngeal cancer was performed safely and showed favorable efficacy.
Collapse
Affiliation(s)
- Naoya Murakami
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Seiichi Yoshimoto
- Department of Head and Neck Surgery, National Cancer Center Hospital, Tokyo, Japan
| | - Satoshi Nakamura
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Masakazu Uematsu
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Tairo Kashihara
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Kana Takahashi
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Koji Inaba
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Kae Okuma
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Hiroshi Igaki
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Yuko Nakayama
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| |
Collapse
|
9
|
Dosimetric comparison of inverse optimisation methods versus forward optimisation in HDR brachytherapy of breast, cervical and prostate cancer. Strahlenther Onkol 2019; 195:991-1000. [PMID: 31482321 PMCID: PMC6811387 DOI: 10.1007/s00066-019-01513-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/08/2019] [Indexed: 11/29/2022]
Abstract
Objective Dosimetric comparison of HIPO (hybrid inverse planning optimisation) and IPSA (inverse planning simulated annealing) inverse and forward optimisation (FO) methods in brachytherapy (BT) of breast, cervical and prostate cancer. Methods At our institute 38 breast, 47 cervical and 50 prostate cancer patients treated with image-guided interstitial high-dose-rate BT were selected. Treatment plans were created using HIPO and IPSA inverse optimisation methods as well as FO. The dose–volume parameters of different treatment plans were compared with Friedman ANOVA and the LSD post-hoc test. Results IPSA creates less dose coverage to the target volume than HIPO or FO: V100 was 91.7%, 91% and 91.9% for HIPO, IPSA and FO plans (p = 0.1784) in breast BT; 90.4%, 89.2% and 91% (p = 0.0045) in cervical BT; and 97.1%, 96.2% and 97.7% (p = 0.0005) in prostate BT, respectively. HIPO results in more conformal plans: COIN was 0.72, 0.71 and 0.69 (p = 0.0306) in breast BT; 0.6, 0.47 and 0.58 (p < 0.001) in cervical BT; and 0.8, 0.7 and 0.7 (p < 0.001) in prostate BT, respectively. In breast BT, dose to the skin and lung was smaller with HIPO and FO than with IPSA. In cervical BT, dose to the rectum, sigmoid and bowel was larger using IPSA than with HIPO or FO. In prostate BT, dose to the urethra was higher and the rectal dose was smaller using FO than with inverse methods. Conclusion In interstitial breast and prostate BT, HIPO results in comparable dose–volume parameters to FO, but HIPO plans are more conformal. In cervical BT, HIPO produces dosimetrically acceptable plans only when more needles are used. The dosimetric quality of IPSA plans is suboptimal and results in unnecessary larger active lengths.
Collapse
|
10
|
Choi CH, Kim JI, Park JM. A 3D-printed patient-specific applicator guide for use in high-dose-rate interstitial brachytherapy for tongue cancer: a phantom study. Phys Med Biol 2019; 64:135002. [PMID: 31170698 DOI: 10.1088/1361-6560/ab277e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A patient-specific applicator guide system (PSAG) for tongue-cancer high-dose-rate (HDR) interstitial brachytherapy (ISBT) was developed by utilizing a 3D printing technique. An effectiveness of the 3D-printed PSAG (3D-PSAG) was evaluated for HDR ISBT. Six patients with tongue cancer were retrospectively selected for this study. For each patient, a total of three virtual clinical target volumes (CTV) requiring the insertion of four catheters (CTV4), six catheters (CTV6), and eight catheters (CTV8) were defined. For each CTV, treatment plans were generated to deliver 45 Gy in nine fractions. The 3D-PSAG was fabricated using a 3D-printer and the patient's CT-images. The resulting 3D-PSAG took the form of a shell conforming to the patient's contours with tubes for catheter insertion. For each CTV, catheters were inserted into the phantom with and without the 3D-PSAG. After that, CT-images of the phantom with the inserted catheters were acquired. Differences between the planned positions and those of the actually inserted catheters were evaluated from the CT-images. Given the actual catheter insertion positions, the dose distributions were reconstructed and analyzed. The maximum positional errors with and without the 3D-PSAG were 0.2 mm and 4.5 mm, respectively. For CTV6, the D 90% values of the original plan, the reconstructed plan with the 3D-PSAG, and the reconstructed plan without the 3D-PSAG, were 48.8 ± 1.7 Gy, 49.0 ± 2.9 Gy, and 45.6 ± 3.3 Gy, respectively. The D 1cc values for the mandible were 51.3 ± 9.2 Gy, 61.6 ± 8.3 Gy, and 81.1 ± 16.7 Gy, respectively. The dose homogeneities in the CTVs into which the catheters had been inserted with the 3D-PSAG were always superior to those into which the catheters had been inserted without the 3D-PSAG. The present phantom study demonstrated the feasibility of more accurate interstitial tongue brachytherapy while simplifying the treatment process by utilizing the 3D-PSAG.
Collapse
Affiliation(s)
- Chang Heon Choi
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea. Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | | | | |
Collapse
|
11
|
Kauer-Dorner D, Berger D. The Role of Brachytherapy in the Treatment of Breast Cancer. Breast Care (Basel) 2018; 13:157-161. [PMID: 30069174 DOI: 10.1159/000489638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Radiotherapy plays an important part in the management of breast cancer. Especially after breast-conserving surgery, external whole breast irradiation, occasionally with an additional local boost, is an integral part of breast conservation. Besides external radiation techniques, brachytherapy (BT) has long been among the treatment options, especially with regard to local boost application. With the emerging implementation of accelerated partial breast irradiation (APBI), BT in general and interstitial multi-catheter BT in particular, are gaining an increasing role in the management of a selected group of early breast cancer patients. APBI is an approach to reduce the irradiated area to the former tumor bed rather than treating the whole breast tissue in patients with a low baseline local recurrence risk. After a variety of phase I-III clinical studies, it is clearly evident that APBI will play a role in the treatment of this selected patient group. In this review, we focus on the clinical development and different available techniques of breast BT and provide a preview of prospects for its use.
Collapse
Affiliation(s)
| | - Daniel Berger
- Department of Radiotherapy, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
12
|
Terribilini D, Vitzthum V, Volken W, Frei D, Loessl K, van Veelen B, Manser P, Fix MK. Performance evaluation of a collapsed cone dose calculation algorithm for HDR Ir-192 of APBI treatments. Med Phys 2017; 44:5475-5485. [PMID: 28750134 DOI: 10.1002/mp.12490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 07/10/2017] [Accepted: 07/15/2017] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Most dose calculations for HDR brachytherapy treatments are based on the AAPM-TG43 formalism. Because patient's anatomy, heterogeneities, and applicator shielding are not considered, the dose calculation based on this formalism is inaccurate in some cases. Alternatively, collapsed cone (CC) methods as well as Monte Carlo (MC) algorithms belong to the model-based dose calculation algorithms, which are expected to improve the accuracy of calculated dose distributions. In this work, the performance of a CC algorithm, ACE in Oncentra Brachy 4.5 (ACE 4.5), has been investigated by comparing the calculated dose distributions to the AAPM-TG43 and MC calculations for 10 HDR brachytherapy accelerated partial breast irradiation treatments (APBI). Comparisons were also performed with a corrected version of ACE 4.5 (ACE 4.5/corr). METHODS The brachytherapy source microSelectron mHDR-v2 (Elekta Brachytherapy) has been implemented in a MC environment and validated by comparing MC dose distributions simulated in a water phantom of 80 cm in diameter with dose distributions calculated with the AAPM-TG43 algorithm. Dose distributions calculated with ACE 4.5, ACE 4.5/corr, AAPM-TG43 formalism, and MC for 10 APBI patients plans have then been computed and compared using HU scaled densities. In addition, individual dose components have been computed using ACE 4.5, ACE 4.5/corr, and MC, and compared individually. RESULTS Local differences between MC and AAPM-TG43 calculated dose distributions in a large water phantom are < 1%. When using HUs scaled densities for the breast cancer patients, both accuracy levels of ACE 4.5 overestimate the MC calculated dose distributions for all analyzed dosimetric parameters. In the planning target volume (PTV), ACE 4.5 (ACE 4.5/corr) overestimates on average V100%,PTV by 3% ± 1% (1% ± 1%) and D50,PTV by 3% ± 1% (1% ± 1%) and in the organs at risk D1cc, skin by 4% ± 2% (1% ± 1%), D0.5cc, ribs by 4% ± 2% (0% ± 1%), and D1cc, heart by 8% ± 2% (3% ± 1%) compared to MC. Comparisons of the individual dose components reveals an agreement for the primary component of < 2% local differences for both ACE 4.5 and ACE 4.5/corr. Local differences of about 40% (20%) for the first and residual scatter components where observed when using ACE 4.5 (ACE 4.5/corr). Using uniform densities for one case shows a better agreement between ACE 4.5 and MC for all dosimetric parameters considered in this work. CONCLUSIONS In general, on the 10 APBI patients the ACE 4.5/corr algorithm results in similar dose distributions as the commonly used AAPM-TG43 within the PTV. However, the accuracy of the ACE 4.5/corr calculated dose distribution is closer to MC than to AAPM-TG43. The differences between commercial version ACE 4.5 and MC dose distributions are mainly located in the first and residual scatter components. In ACE 4.5/corr, the changes done in the algorithm for the scatter components substantially reduce these differences.
Collapse
Affiliation(s)
- Dario Terribilini
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Veronika Vitzthum
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Werner Volken
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Daniel Frei
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Kristina Loessl
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Bob van Veelen
- Elekta Brachytherapy, 3905TH, Veenendaal, The Netherlands
| | - Peter Manser
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Michael K Fix
- Division of Medical Radiation Physics, Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| |
Collapse
|
13
|
Takácsi-Nagy Z, Martínez-Mongue R, Mazeron JJ, Anker CJ, Harrison LB. American Brachytherapy Society Task Group Report: Combined external beam irradiation and interstitial brachytherapy for base of tongue tumors and other head and neck sites in the era of new technologies. Brachytherapy 2016; 16:44-58. [PMID: 27592129 DOI: 10.1016/j.brachy.2016.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/30/2016] [Accepted: 07/01/2016] [Indexed: 11/19/2022]
Abstract
Irradiation plays an important role in the treatment of cancers of the head and neck providing a high locoregional tumor control and preservation of organ functions. External beam irradiation (EBI) results in unnecessary radiation exposure of the surrounding normal tissues increasing the incidence of side effects (xerostomy, osteoradionecrosis, and so forth). Brachytherapy (BT) seems to be the best choice for dose escalation over a short treatment period and for minimizing radiation-related normal tissue damage due to the rapid dose falloff around the source. Low-dose-rate BT is being increasingly replaced by pulsed-dose-rate and high-dose-rate BT because the stepping source technology offers the advantage of optimizing dose distribution by varying dwell times. Pulsed-dose and high-dose rates appear to yield local control and complication rates equivalent to those of low-dose rate. BT may be applied alone; but in case of high risk of nodal metastases, it is used together with EBI. This review presents the results and the indications of combined BT and EBI in carcinoma of the base of tongue and other sites of the head and neck region, as well as the role BT plays among other-normal tissue protecting-modern radiotherapy modalities (intensity-modulated radiotherapy, stereotactic radiotherapy) applied in these localizations.
Collapse
Affiliation(s)
| | | | - Jean-Jacques Mazeron
- Department of Radiation Oncology, Groupe Hospitelier Pitié-Salpêtrière, Paris, France
| | - Cristopher James Anker
- Department of Radiation Oncology, School of Medicine, University of Utah, Salt Lake City, UT
| | - Louis B Harrison
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL
| |
Collapse
|
14
|
Breast Brachytherapy: Interstitial Breast Brachytherapy. Brachytherapy 2016. [DOI: 10.1007/978-3-319-26791-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
15
|
A retrospective dosimetric comparison of TG43 and a commercially available MBDCA for an APBI brachytherapy patient cohort. Phys Med 2015; 31:669-76. [DOI: 10.1016/j.ejmp.2015.05.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 04/28/2015] [Accepted: 05/14/2015] [Indexed: 11/21/2022] Open
|
16
|
MITHRA - multiparametric MR/CT image adapted brachytherapy (MR/CT-IABT) in anal canal cancer: a feasibility study. J Contemp Brachytherapy 2015; 7:336-45. [PMID: 26622238 PMCID: PMC4663214 DOI: 10.5114/jcb.2015.55118] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 09/25/2015] [Indexed: 01/09/2023] Open
Abstract
PURPOSE The aim of this study is to test a novel multiparametric imaging guided procedure for high-dose-rate brachytherapy in anal canal cancer, in order to evaluate the feasibility and safety. MATERIAL AND METHODS For this analysis, we considered all consecutive patients who underwent magnetic resonance/computed tomography image adapted brachytherapy (MR/CT-IABT) treated from February 2012 to July 2014. To conduct this project, we formed a working group that established the procedure and identified the indicators and benchmarks to evaluate the feasibility and safety. We considered the procedure acceptable if 90% of the indicators were consistent with the benchmarks. Magnetic resonance imaging with contrast and diffusion weighted imaging were performed with an MRI-compatible dummy applicator in the anus to define the position of the clinical target volume disease and biological information. A pre-implantation treatment planning was created in order to get information on the optimal position of the needles. Afterwards, the patient underwent a simulation CT and the definite post-implantation treatment planning was created. RESULTS We treated 11 patients (4 men and 7 women) with MR/CT-IABT and we performed a total of 13 procedures. The analysis of indicators for procedure evaluation showed that all indicators were in agreement with the benchmark. The dosimetric analysis resulted in a median of V200, V150, V100, V90, V85, respectively of 24.6%, 53.4%, 93.5%, 97.6%, and 98.7%. The median coverage index (CI) was 0.94, the median dose homogeneity index (DHI) was 0.43, the median dose non-uniformity ratio (DNR) resulted 0.56, the median overdose volume index (ODI) was 0.27. We observed no episodes of common severe acute toxicities. CONCLUSIONS Brachytherapy is a possible option in anal cancer radiotherapy to perform the boost to complete external beam radiotherapy (EBRT). Magnetic resonance can also have biological advantages compared to the US. Our results suggest that the multiparametric MR/CT-IABT for anal cancer is feasible and safe. This new approach paves the way to prospective comparison studies between MRI and ultrasound-guided brachytherapy (USBT) in anal canal cancer.
Collapse
|
17
|
Dosimetric comparison of Acuros™ BV with AAPM TG43 dose calculation formalism in breast interstitial high-dose-rate brachytherapy with the use of metal catheters. J Contemp Brachytherapy 2015; 7:273-9. [PMID: 26622230 PMCID: PMC4643735 DOI: 10.5114/jcb.2015.54052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 06/30/2015] [Accepted: 08/16/2015] [Indexed: 11/17/2022] Open
Abstract
Purpose Radiotherapy for breast cancer includes different techniques and methods. The purpose of this study is to compare dosimetric calculations using TG-43 dose formalism and Varian Acuros™ BV (GBBS) dose calculation algorithm for interstitial implant of breast using metal catheters in high-dose-rate (HDR) brachytherapy, using 192Ir. Material and methods Twenty patients who were considered for breast conservative surgery (BCS), underwent lumpectomy and axillary dissection. These patients received perioperative interstitial HDR brachytherapy as upfront boost using rigid metal implants. Whole breast irradiation was delivered TG-43 after a gap of two weeks. Standard brachytherapy dose calculation was done by dosimetry. This does not take into account tissue heterogeneity, attenuation and scatter in the metal applicator, and effects of patient boundary. Acuros™ BV is a Grid Based Boltzmann Solver code (GBBS), which takes into consideration all the above, was used to compute dosimetry and the two systems were compared. Results Comparison of GBBS and TG-43 formalism on interstitial metal catheters shows difference in dose prescribed to CTV and other OARs. While the estimated dose to CTV was only marginally different with the two systems, there is a significant difference in estimated doses of starting from 4 to 53% in the mean value of all parameters analyzed. Conclusions TG-43 algorithm seems to significantly overestimate the dose to various volumes of interest; GBBS based dose calculation algorithm has impact on CTV, heart, ipsilateral lung, heart, contralateral breast, skin, and ribs of the ipsilateral breast side; the prescription changes occurred due to effect of metal catheters, inhomogeneities, and scatter conditions.
Collapse
|
18
|
Liang B, Zhou F, Liu B, Wang J, Xu Y. A novel greedy heuristic-based approach to intraoperative planning for permanent prostate brachytherapy. J Appl Clin Med Phys 2015; 16:5144. [PMID: 25679173 PMCID: PMC5689981 DOI: 10.1120/jacmp.v16i1.5144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/26/2014] [Accepted: 09/26/2014] [Indexed: 11/28/2022] Open
Abstract
This paper presents a greedy heuristic‐based double iteration and rectification (DIR) approach to intraoperative planning for permanent prostate brachytherapy. The DIR approach adopts a greedy seed selection (GSS) procedure to obtain a preliminary plan. In this process, the potential seeds are evaluated according to their ability to irradiate target while spare organs at risk (OARs), and their impact on dosimetric homogeneity within target volume. A flexible termination condition is developed for the GSS procedure, which guarantees sufficient dose within target volume while avoids overdosing the OARs. The preliminary treatment plan generated by the GSS procedure is further refined by the double iteration (DI) and rectification procedure. The DI procedure removes the needles containing only one seed (single seed) and implements the GSS procedure again to get a temporary plan. The DI procedure terminates until the needles number of the temporary plan does not decrease. This process is guided by constantly removing undesired part rather than imposing extra constrains. Following the DI procedure, the rectification procedure attempts to replace the remaining single seeds with the acceptable ones within the existing needles. The change of dosimetric distribution (DD) after the replacement is evaluated to determine whether to accept or to withdraw the replacement. Experimental results demonstrate that the treatment plans obtained by the DIR approach caters to all clinical considerations. Compared with currently available methods, DIR approach is faster, more reliable, and more suitable for intraoperative treatment planning in the operation room. PACS number: 87
Collapse
Affiliation(s)
- Bin Liang
- Image Processing Center, Beihang University, Beijing.
| | | | | | | | | |
Collapse
|
19
|
Sharma PK, Sharma PK, Swamidas JV, Mahantshetty U, Deshpande DD, Manjhi J, Rai DV. Dose optimization in gynecological 3D image based interstitial brachytherapy using martinez universal perineal interstitial template (MUPIT) -an institutional experience. J Med Phys 2014; 39:197-202. [PMID: 25190999 PMCID: PMC4154188 DOI: 10.4103/0971-6203.139015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/16/2014] [Accepted: 04/16/2014] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to evaluate the dose optimization in 3D image based gynecological interstitial brachytherapy using Martinez Universal Perineal Interstitial Template (MUPIT). Axial CT image data set of 20 patients of gynecological cancer who underwent external radiotherapy and high dose rate (HDR) interstitial brachytherapy using MUPIT was employed to delineate clinical target volume (CTV) and organs at risk (OARs). Geometrical and graphical optimization were done for optimum CTV coverage and sparing of OARs. Coverage Index (CI), dose homogeneity index (DHI), overdose index (OI), dose non-uniformity ratio (DNR), external volume index (EI), conformity index (COIN) and dose volume parameters recommended by GEC-ESTRO were evaluated. The mean CTV, bladder and rectum volume were 137 ± 47cc, 106 ± 41cc and 50 ± 25cc, respectively. Mean CI, DHI and DNR were 0.86 ± 0.03, 0.69 ± 0.11 and 0.31 ± 0.09, while the mean OI, EI, and COIN were 0.08 ± 0.03, 0.07 ± 0.05 and 0.79 ± 0.05, respectively. The estimated mean CTV D90 was 76 ± 11Gy and D100 was 63 ± 9Gy. The different dosimetric parameters of bladder D2cc, D1cc and D0.1cc were 76 ± 11Gy, 81 ± 14Gy, and 98 ± 21Gy and of rectum/recto-sigmoid were 80 ± 17Gy, 85 ± 13Gy, and 124 ± 37Gy, respectively. Dose optimization yields superior coverage with optimal values of indices. Emerging data on 3D image based brachytherapy with reporting and clinical correlation of DVH parameters outcome is enterprizing and provides definite assistance in improving the quality of brachytherapy implants. DVH parameter for urethra in gynecological implants needs to be defined further.
Collapse
Affiliation(s)
- Pramod Kumar Sharma
- Department of Medical Physics, International Oncology Center, Fortis Hospital, Noida, India ; Department of Radiation Oncology, Shobit University, Meerut, Uttar Pradesh, India
| | - Praveen Kumar Sharma
- Department of Radiation Oncology, International Oncology Center, Fortis Hospital, Noida, India
| | - Jamema V Swamidas
- Department of Medical Physics, Tata Memorial Hospital, Parel, Mumbai, India
| | - Umesh Mahantshetty
- Department of Radiation Oncology, Tata Memorial Hospital, Parel, Mumbai, India
| | - D D Deshpande
- Department of Medical Physics, Tata Memorial Hospital, Parel, Mumbai, India
| | - Jayanand Manjhi
- Department of Radiation Oncology, Shobit University, Meerut, Uttar Pradesh, India
| | - D V Rai
- Department of Radiation Oncology, Shobit University, Meerut, Uttar Pradesh, India
| |
Collapse
|
20
|
A brachytherapy plan evaluation tool for interstitial applications. Adv Bioinformatics 2014; 2014:376207. [PMID: 24665263 PMCID: PMC3934649 DOI: 10.1155/2014/376207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/16/2013] [Accepted: 12/24/2013] [Indexed: 11/18/2022] Open
Abstract
Radiobiological metrics such as tumor control probability (TCP) and normal tissue complication probability (NTCP) help in assessing the quality of brachytherapy plans. Application of such metrics in clinics as well as research is still inadequate. This study presents the implementation of two indigenously designed plan evaluation modules: Brachy_TCP and Brachy_NTCP. Evaluation tools were constructed to compute TCP and NTCP from dose volume histograms (DVHs) of any interstitial brachytherapy treatment plan. The computation module was employed to estimate probabilities of tumor control and normal tissue complications in ten cervical cancer patients based on biologically effective equivalent uniform dose (BEEUD). The tumor control and normal tissue morbidity were assessed with clinical followup and were scored. The acute toxicity was graded using common terminology criteria for adverse events (CTCAE) version 4.0. Outcome score was found to be correlated with the TCP/NTCP estimates. Thus, the predictive ability of the estimates was quantified with the clinical outcomes. Biologically effective equivalent uniform dose-based formalism was found to be effective in predicting the complexities and disease control.
Collapse
|
21
|
Kapoor R, Khosla D, Shukla AK, Kumar R, Gupta R, Oinam AS, Sharma SC. Dosimetric and clinical outcome in image-based high-dose-rate interstitial brachytherapy for anal cancer. Brachytherapy 2013; 13:388-93. [PMID: 24211122 DOI: 10.1016/j.brachy.2013.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/28/2013] [Accepted: 09/23/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE To evaluate dosimetric and clinical outcome in patients of anal cancer treated with image-based interstitial high-dose-rate brachytherapy following chemoradiation. METHODS AND MATERIALS Sixteen patients with anal cancer were treated with chemoradiation followed by brachytherapy boost with image-based high-dose-rate interstitial brachytherapy from January 2007 to June 2011. Two brachytherapy dose schedules were used: 21 Gy in seven fractions and 18 Gy in six fractions depending on response to chemoradiation. CT scan was done after placement of needles for confirmation of placement and treatment planning. Target volume was contoured on CT scans. Volumetric quality indices and dose parameters were calculated. RESULTS The mean clinical target volume was 17.7 ± 4.98 cm(3), and the median overall tumor size was 4.2cm (3.4-5cm). The mean values of coverage index, dose homogeneity index, overdose volume index, dose non-uniformity ratio, and conformal index were 0.94, 0.83, 0.21, 0.37, and 0.88, respectively. With a median followup of 41 months (range, 20-67.2 months), preservation of the anal sphincter was achieved in 14 patients. The 1- and 2-year local control rates were 93.8% and 87.5%, respectively. Treatment was well tolerated and none of the patients developed Grade 3 or higher late toxicity. CONCLUSIONS The combination of external beam radiotherapy with interstitial brachytherapy increases the dose to the tumor volume and limits the volume of irradiated normal tissue, thereby decreasing late toxicity. The use of image-based treatment planning provides better dose conformality with reduced toxicity and helps to prevent a geographic miss.
Collapse
Affiliation(s)
- Rakesh Kapoor
- Department of Radiotherapy and Oncology, Regional Cancer Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Divya Khosla
- Department of Radiotherapy and Oncology, Regional Cancer Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
| | - Arvind K Shukla
- Department of Radiotherapy and Oncology, Regional Cancer Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Ritesh Kumar
- Department of Radiotherapy and Oncology, Regional Cancer Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Rajesh Gupta
- Department of Surgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Arun S Oinam
- Department of Radiotherapy and Oncology, Regional Cancer Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Suresh C Sharma
- Department of Radiotherapy and Oncology, Regional Cancer Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| |
Collapse
|
22
|
Holm Å, Larsson T, Tedgren ÅC. A linear programming model for optimizing HDR brachytherapy dose distributions with respect to mean dose in the DVH-tail. Med Phys 2013; 40:081705. [DOI: 10.1118/1.4812677] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
23
|
A case report on bilateral partial breast irradiation using SAVI. Med Dosim 2012; 37:214-20. [DOI: 10.1016/j.meddos.2011.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 07/21/2011] [Accepted: 08/10/2011] [Indexed: 12/25/2022]
|
24
|
Assessment of dose homogeneity in conformal interstitial breast brachytherapy with special respect to ICRU recommendations. J Contemp Brachytherapy 2011; 3:150-5. [PMID: 23346125 PMCID: PMC3551357 DOI: 10.5114/jcb.2011.24822] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 08/25/2011] [Accepted: 09/06/2011] [Indexed: 11/17/2022] Open
Abstract
Purpose To present the results of dose homogeneity analysis for breast cancer patients treated with image-based conformal interstitial brachytherapy, and to investigate the usefulness of the ICRU recommendations. Material and methods Treatment plans of forty-nine patients who underwent partial breast irradiation with interstitial brachytherapy were analyzed. Quantitative parameters were used to characterize dose homogeneity. Dose non-uniformity ratio (DNR), dose homogeneity index (DHI), uniformity index (UI) and quality index (QI) were calculated. Furthermore, parameters recommended by the ICRU 58 such as minimum target dose (MTD), mean central dose (MCD), high dose volume, low dose volume and the spread between local minimum doses were determined. Correlations between the calculated homogeneity parameters and usefulness of the ICRU parameters in image-based brachytherapy were investigated. Results Catheters with mean number of 15 (range: 6-25) were implanted in median 4 (range: 3-6) planes. The volume of the PTV ranged from 15.5 cm3 to 176 cm3. The mean DNR was 0.32, the DHI 0.66, the UI 1.49 and the QI 1.94. Related to the prescribed dose, the MTD was 69% and the MCD 135%. The mean high dose volume was 8.1 cm3 (10%), while the low dose volume was 63.8 cm3 (96%). The spread between minimum doses in central plane ranged from −14% to +20%. Good correlation was found between the DNR and the DHI (R2=0.7874), and the DNR correlated well with the UI (R2=0.7615) also. No correlation was found between the ICRU parameters and any other volumetric parameters. Conclusions To characterize the dose uniformity in high-dose rate breast implants, DVH-related homogeneity parameters representing the full 3D dose distributions are mandatory to be used. In many respects the current recommendations of the ICRU Report 58 are already outdated, and it is well-timed to set up new recommendations, which are more feasible for image-guided conformal interstitial brachytherapy.
Collapse
|
25
|
Dutta S, Sharma SC, Singh R, Kapoor R, Oinam AS, Bhardwaj A, Goswami P. Quality assessment of interstitial implants in high- dose- rate brachytherapy after lumpectomy in patients of early stage breast cancer. Indian J Surg Oncol 2011; 1:294-302. [PMID: 22693381 DOI: 10.1007/s13193-011-0059-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 02/23/2011] [Indexed: 10/18/2022] Open
Abstract
To assess the quality of high dose rate (H,D,R.) interstitial implants in breast cancer by using different volumetric indices and correlating them with skin and subcutaneous tissue toxicity. Out of 15 patients who were selected for interstitial implants after undergoing breast conservation surgery, five were treated radically with 34 Gy in 10 fractions in 5 days @ 3.4 Gy # twice daily and 10 patients recieved boost dose of 12 Gy in 4 fractions @ 3 Gy /# twice daily. The median follow up was 15 months. During each follow up assessment of late skin and subcutaneous tissue toxicity as per RTOG criteria was done . Various dosimetric indices were analysed. Dose Volume Histogram for dose per unit volume of skin for 10cc,5cc,2cc,1cc,0.1cc and 0.01cc was calculated. Best estimates and correlation of toxicity was revealed by assessment of Dose Nonuniformity Ratio(DNR) which also correlated well with geometry defining indices like Uniformity Index (UI).Volumetric assessment of skin dose for less than 2 cc correlated most with toxicity. DNR and UI can help us to assess and correlate late skin and subcutaneous tissue toxicity and thus serve useful to determine the quality of implant.
Collapse
|
26
|
Dose volume uniformity index: a simple tool for treatment plan evaluation in brachytherapy. J Contemp Brachytherapy 2010; 2:71-75. [PMID: 27829848 PMCID: PMC5095264 DOI: 10.5114/jcb.2010.14405] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 06/07/2010] [Indexed: 11/20/2022] Open
Abstract
Purpose In radiotherapy treatment planning, dose homogeneity inside the target volume plays a significant role in the final treatment outcome. Especially in brachytherapy where there is a steep dose gradient in the dose distribution inside the target volume, comparing the plans based on the dose homogeneity helps in assessing the high dose volume inside the final treatment plan. In brachytherapy, the dose inhomogeneity inside the target volume depends on many factors such as the type of sources, placement of these radioactive sources, distance between the applicators/implant tubes, dwell time of the source, etc. In this study, a simple index, the dose volume uniformity index (DVUI), has been proposed to study the dose homogeneity inside the target volume. This index gives the total dose volume inhomogeneity inside a given prescription isoline. Material and methods To demonstrate the proposed DVUI in this study, a single plane implant (breast: 6 catheters), a double plane implant (breast: 9 catheters) and a tongue implant (5 catheters) were selected. The catheters were reconstructed from the CT image datasets in the Plato treatment planning system. The doses for the single, double and tongue implants were prescribed to the reference dose rate as per the Paris technique. DVUI was computed from the cumulative dose volume histogram. Results For a volume receiving a uniform dose inside the prescription isoline, the DVUI is 1. Any value of DVUI > 1 shows the presence of a relatively high dose volume inside the prescription isoline. In addition to the concept of DVUI, a simple conformality index, the dose volume conformality index (DVCI), has also been proposed in this study based on the DVUI. Conclusion The DVUI and the proposed DVCI in this study provide an easy way of comparing the rival plans in brachytherapy.
Collapse
|
27
|
Major T, Fröhlich G, Lövey K, Fodor J, Polgár C. Dosimetric experience with accelerated partial breast irradiation using image-guided interstitial brachytherapy. Radiother Oncol 2009; 90:48-55. [DOI: 10.1016/j.radonc.2007.10.027] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 08/29/2007] [Accepted: 10/18/2007] [Indexed: 11/16/2022]
|
28
|
Assessment of tumor control probability for high-dose-rate interstitial brachytherapy implants. Rep Pract Oncol Radiother 2008. [DOI: 10.1016/s1507-1367(10)60085-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
29
|
Kehwar TS, Akber SF, Passi K. Qualitative dosimetric and radiobiological evaluation of high - dose - rate interstitial brachytherapy implants. Int J Med Sci 2008; 5:41-9. [PMID: 18311328 PMCID: PMC2253950 DOI: 10.7150/ijms.5.41] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Accepted: 02/16/2008] [Indexed: 12/25/2022] Open
Abstract
Radiation quality indices (QI), tumor control probability (TCP), and normal tissue complication probability(NTCP) were evaluated for ideal single and double plane HDR interstitial implants. In the analysis, geometrically-optimized at volume (GOV) treatment plans were generated for different values of inter-source-spacing (ISS) within the catheter, inter-catheter-spacing (ICS), and inter-plane-spacing (IPS) for single - and double - plane implants. The dose volume histograms (DVH) were generated for each plan, and the coverage volumes of 100%, 150%, and 200% were obtained to calculate QIs, TCP, and NTCP. Formulae for biologically effective equivalent uniform dose (BEEUD), for tumor and normal tissues, were derived to calculate TCP and NTCP. Optimal values of QIs, except external volume index (EI), and TCP were obtained at ISS = 1.0 cm, and ICS = 1.0 cm, for single-plane implants, and ISS = 1.0 cm, ICS = 1.0 cm, and IPS = 0.75 to 1.25 cm, for double - plane implants. From this study, it is assessed that ISS = 1.0 cm, ICS = 1.0 cm, for single - plane implant and IPS between 0.75 cm to 1.25 cm provide better dose conformity and uniformity.
Collapse
Affiliation(s)
- Than S Kehwar
- Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | | | | |
Collapse
|
30
|
Polgár C, Fodor J, Major T, Németh G, Lövey K, Orosz Z, Sulyok Z, Takácsi-Nagy Z, Kásler M. Breast-conserving treatment with partial or whole breast irradiation for low-risk invasive breast carcinoma--5-year results of a randomized trial. Int J Radiat Oncol Biol Phys 2007; 69:694-702. [PMID: 17531400 DOI: 10.1016/j.ijrobp.2007.04.022] [Citation(s) in RCA: 233] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Revised: 04/09/2007] [Accepted: 04/10/2007] [Indexed: 12/26/2022]
Abstract
PURPOSE To report the 5-year results of a randomized study comparing the survival and cosmetic results of breast-conserving treatment with partial breast irradiation (PBI) or conventional whole breast irradiation (WBI). METHODS AND MATERIALS Between 1998 and 2004, 258 selected patients with T1 N0-1mi, Grade 1-2, nonlobular breast cancer without presence of extensive intraductal component and resected with negative margins were randomized after breast-conserving surgery to receive 50 Gy/25 fractions WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 x 5.2 Gy high-dose-rate (HDR) multicatheter brachytherapy (BT; n = 88) or 50 Gy/25 fractions electron beam (EB) irradiation (n = 40). RESULTS At a median follow-up of 66 months, the 5-year actuarial rate of local recurrence was 4.7% and 3.4% in the PBI and WBI arms, respectively (p = 0.50). There was no significant difference in the 5-year probability of overall survival (94.6% vs. 91.8%), cancer-specific survival (98.3% vs. 96.0%), and disease-free survival (88.3% vs. 90.3%). The rate of excellent to good cosmetic result was 77.6% in the PBI group (81.2% after HDR BT; 70.0% after EB) and 62.9% in the control group (52.2% after telecobalt; 65.6% after 6-9-MV photons; p(WBI/PBI) = 0.009). CONCLUSIONS Partial breast irradiation using interstitial HDR implants or EB to deliver radiation to the tumor bed alone for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI. Significantly better cosmetic outcome can be achieved with carefully designed HDR multicatheter implants compared with the outcome after WBI.
Collapse
Affiliation(s)
- Csaba Polgár
- Department of Radiotherapy, National Institute of Oncology, Budapest, Hungary.
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Yoo S, Kowalok ME, Thomadsen BR, Henderson DL. A greedy heuristic using adjoint functions for the optimization of seed and needle configurations in prostate seed implant. Phys Med Biol 2007; 52:815-28. [PMID: 17228123 DOI: 10.1088/0031-9155/52/3/020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We continue our work on the development of an efficient treatment-planning algorithm for prostate seed implants by incorporation of an automated seed and needle configuration routine. The treatment-planning algorithm is based on region of interest (ROI) adjoint functions and a greedy heuristic. As defined in this work, the adjoint function of an ROI is the sensitivity of the average dose in the ROI to a unit-strength brachytherapy source at any seed position. The greedy heuristic uses a ratio of target and critical structure adjoint functions to rank seed positions according to their ability to irradiate the target ROI while sparing critical structure ROIs. Because seed positions are ranked in advance and because the greedy heuristic does not modify previously selected seed positions, the greedy heuristic constructs a complete seed configuration quickly. Isodose surface constraints determine the search space and the needle constraint limits the number of needles. This study additionally includes a methodology that scans possible combinations of these constraint values automatically. This automated selection scheme saves the user the effort of manually searching constraint values. With this method, clinically acceptable treatment plans are obtained in less than 2 min. For comparison, the branch-and-bound method used to solve a mixed integer-programming model took close to 2.5 h to arrive at a feasible solution. Both methods achieved good treatment plans, but the speedup provided by the greedy heuristic was a factor of approximately 100. This attribute makes this algorithm suitable for intra-operative real-time treatment planning.
Collapse
Affiliation(s)
- Sua Yoo
- Department of Radiation Oncology, Duke University Medical Center, Box 3295, Durham, NC 27710, USA.
| | | | | | | |
Collapse
|
32
|
Chaswal V, Yoo S, Thomadsen BR, Henderson DL. Multi-species prostate implant treatment plans incorporating Ir192 and I125 using a Greedy Heuristic based 3D optimization algorithm. Med Phys 2007; 34:436-44. [PMID: 17388159 DOI: 10.1118/1.2400827] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The goals of interstitial implant brachytherapy include delivery of the target dose in a uniform manner while sparing sensitive structures, and minimizing the number of needles and sources. We investigated the use of a multi-species source arrangement (192Ir with 125I) for treatment in interstitial prostate brachytherapy. The algorithm utilizes an "adjoint ratio," which provides a means of ranking source positions and is the criterion for the Greedy Heuristic optimization. Three cases were compared, each using 0.4 mCi 125I seeds: case I is the base case using 125I alone, case II uses 0.12 mCi 192Ir seeds mixed with 125I, and case III uses 0.25 mCi 192Ir mixed with 125I. Both multi-species cases result in lower exposure of the urethra and central prostate region. Compared with the base case, the exposure to the rectum and normal tissue increases by a significant amount for case III as compared with the increase in case II, signifying the effect of slower dose falloff rate of higher energy gammas of 192Ir in the tissue. The number of seeds and needles decreases in both multi-species cases, with case III requiring fewer seeds and needles than case II. Further, the effect of 192Ir on uniformity was investigated using the 0.12 mCi 192Ir seeds in multi-species implants. An increase in uniformity was observed with an increase in the number of 0.12 mCi 1921r seeds implanted. The effects of prostate size on the evaluation parameters for multi-species implants were investigated using 0.12 mCi 192Ir and 0.4 mCi 125I, and an acceptable treatment plan with increased uniformity was obtained.
Collapse
Affiliation(s)
- V Chaswal
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | | | | | | |
Collapse
|
33
|
Nose T, Komoike Y, Yoshida K, Koizumi M, Motomura K, Kasugai T, Inaji H, Nishiyama K, Koyama H, Kozuka T, Gomi K, Oguchi M, Akahashi Y, Sumida I, Yamashita T. A pilot study of wider use of accelerated partial breast irradiation: intraoperative margin-directed re-excision combined with sole high-dose-rate interstitial brachytherapy. Breast Cancer 2006; 13:289-99. [PMID: 16929124 DOI: 10.2325/jbcs.13.289] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Accelerated partial breast irradiation (APBI) is generally limited to patients at extremely low risk of local recurrence. The significance of the risk factors, however, depends on the extent of surgery, radiation, and systemic therapy. In Japan, wide excision is generally supplemented by intraoperative margin-directed re-excision if the frozen section examination yields positive results. This approach combined with conventional radiotherapy achieved an excellent 10-year local control rate of 93%, and young age and ductal carcinoma in situ were not risk factors for local recurrence. To reduce the treatment duration, high-dose-rate interstitial brachytherapy (HDRIB) was employed. The first APBI phase I / II trial in Japan was conducted to determine if wider indications for early breast cancer patients were appropriate. METHODS The subjects comprised 20 patients including those with extensive intraductal component (n=7), ductal carcinoma in situ (n=2), positive final margins (n=3), and of younger age (< or = 45 years; n=5). Breast-conserving surgery using an intraoperative re-excision approach was followed by intraoperative implantation of applicators. Sole HDRIB of a 36-42 Gy in 6-7 fractions was delivered postoperatively over 3-4 days. Tumors were staged as follows: cT1 (n=12), cT2 (n=8), cN0 (n=20). Systemic therapy was used in 16 patients (80%). The median follow-up period was 52 months (range, 26-86 months). RESULTS Te five-year crude local, distant control, and Kaplan-Meier cause-specific survival rates were 95%, 95%, and 89%, respectively. Fat necrosis developed in 1 patient. CONCLUSIONS Sole HDRIB with intraoperative margin-directed re-excision was feasible under wider indications compared to other contemporary APBI series, and achieved acceptable and similar results to these series in terms of the local control rate and complications.
Collapse
Affiliation(s)
- Takayuki Nose
- Department of Radiation Oncology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-Ku, Tokyo 135-8550, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Viola A, Major T, Julow J. Comparison of (125)I stereotactic brachytherapy and LINAC radiosurgery modalities based on physical dose distribution and radiobiological efficacy. Radiat Res 2006; 165:695-702. [PMID: 16802870 DOI: 10.1667/rr3529.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The goal of this study was to make a comparison between stereotactic brachytherapy implants and linear accelerator-based radiosurgery of brain tumors with respect to physical dose distributions and radiobiological efficacy. Twenty-four treatment plans made for irradiation of brain tumors with low-dose-rate (125)I brachytherapy and multiple-arc LINAC-based radiosurgery were analyzed. Using the dose-volume histograms and the linear-quadratic model, the brachytherapy doses were compared to the brachytherapy-equivalent LINAC radiosurgery doses with respect to the predicted late effects of radiation on normal brain tissue. To characterize the conformity and homogeneity of dose distributions, the conformal index, external volume index, and relative homogeneity index were calculated for each dose plan and the mean values were compared. The average tumor volume was 5.6 cm(3) (range: 0.1-19.3 cm(3)). At low doses, the calculated radiobiological late effect on normal tissue was equivalent for external-beam and brachytherapy dose delivery. For brachytherapy at doses greater than 30 Gy, the calculated equivalent dose to normal tissues was less than for external-beam radiosurgery. However, the dose-calculated homogeneity was better for the LINAC radiosurgery, with a mean relative homogeneity index of 0.62 compared to the calculated value of 0.19 for the brachytherapy (P=0.0002). These results are only predictions based on calculations concerning normal tissue tolerance. More data and research are needed to understand the clinical relevance of these findings.
Collapse
Affiliation(s)
- Arpad Viola
- Doctoral School, Semmelweis University, 1085 Budapest, Hungary.
| | | | | |
Collapse
|
35
|
Major T, Niehoff P, Kovács G, Fodor J, Polgár C. Dosimetric comparisons between high dose rate interstitial and MammoSite™ balloon brachytherapy for breast cancer. Radiother Oncol 2006; 79:321-8. [PMID: 16730085 DOI: 10.1016/j.radonc.2006.05.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Revised: 04/26/2006] [Accepted: 05/08/2006] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE To make a quantitative dosimetric comparison between treatment plans of multicatheter-based interstitial brachytherapy (IB) and MammoSite brachytherapy (MSB) for breast cancer. PATIENTS AND METHODS Seventeen patients treated with IB and twenty-four with MSB were selected for the study. The irradiations for IB patients were planned using conventional two-film reconstruction technique. Following the implantation each patient was CT scanned, then the planning target volume (PTV) was retrospectively defined on the CT data set, and the original plan was reconstructed (CONV plans). Furthermore, conformal plans were also created by dose optimization on target (CONF plans). The planning for MammoSite applicator was based on CT imaging. The dose distributions were evaluated with dose-volume histograms. The following parameters were calculated and compared: volume of the PTV and its percentage receiving 90, 100, 150 and 200% of the prescribed dose (V90, V100, V150 and V200, respectively), percentage dose covering 90% of the PTV (D90), minimum dose in the PTV (D(min)), maximum dose in the PTV (D(max)) for MSB only, dose homogeneity index (DHI), and conformal index (COIN). To assess the dose to organs at risk maximum point dose to skin, lung and heart was used. RESULTS The median number of implanted catheters for IB was 11 (range: 6-13), the average balloon volume for MSB was 59.1cm(3) (range: 43.4-75.3 cm(3)). The average volume of PTV was 63.4 and 109.6 cm(3) for IB and MSB patients, respectively. The average V90, V100, V150, V200 were 76, 70, 26 and 9% for IB(CONV); 92, 87, 55 and 32% for IB(CONF) and 96, 88, 27 and 3% for MSB, respectively. The average D90 was 72, 94 and 99%, the D(min) was 47, 58 and 67%, respectively. The mean D(max) was 258% for MSB. The average DHI was 0.63, 0.37 and 0.70 for IB(CONV), IB(CONF) and MSB, respectively. D(max) to skin, lung and heart were 45, 54 and 31% for IB(CONV), 50, 55 and 29% for IB(CONF,) 97, 66 and 27% for MSB, respectively. CONCLUSIONS Target volume coverage was better for MSB than conventional IB, and it was comparable to conformal IB. The suboptimal coverage for IB patients is due to radiography based planning, which is unable to provide 3D information of the target. Dose homogeneity was somewhat better for MSB than IB(CONV), but the dose to skin and lung was higher for MSB. The MSB provides dosimetrically acceptable dose plans. The quality of interstitial implants can be improved with image-guided catheter insertions regarding both homogeneity and conformality.
Collapse
Affiliation(s)
- Tibor Major
- National Institute of Oncology, Radiotherapy Department, Budapest, Hungary
| | | | | | | | | |
Collapse
|
36
|
Polgár C, Major T, Fodor J, Németh G, Orosz Z, Sulyok Z, Udvarhelyi N, Somogyi A, Takácsi-Nagy Z, Lövey K, Agoston P, Kásler M. High-dose-rate brachytherapy alone versus whole breast radiotherapy with or without tumor bed boost after breast-conserving surgery: Seven-year results of a comparative study. Int J Radiat Oncol Biol Phys 2004; 60:1173-81. [PMID: 15519789 DOI: 10.1016/j.ijrobp.2004.05.012] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Revised: 05/06/2004] [Accepted: 05/10/2004] [Indexed: 11/19/2022]
Abstract
PURPOSE To report the 7-year results of a prospective study of accelerated partial breast irradiation (APBI) using interstitial high-dose-rate brachytherapy and compare the treatment results with those achieved by standard, whole breast radiotherapy (WBRT), with or without a tumor bed boost (TBB). METHODS AND MATERIALS Between 1996 and 1998, 45 prospectively selected patients with T1N0-N1mi (single nodal micrometastasis), nonlobular breast cancer without the presence of an extensive intraductal component and with negative surgical margins were treated with APBI using interstitial high-dose-rate implants. A total dose of 30.3 Gy (n = 8) and 36.4 Gy (n = 37) in seven fractions within 4 days was delivered to the tumor bed plus a 1-2-cm margin. During the same period, 80 patients, who met the eligibility criteria for APBI but who were treated with 50 Gy WBRT with (n = 36) or without (n = 44) a 10-16-Gy TBB, were selected as controls. The median follow-up for the APBI and control groups was 81 and 83 months, respectively. Local control, relapse-free survival, cancer-specific survival, late side effects, and cosmetic results were assessed. RESULTS The crude rate of total ipsilateral breast failure was 6.7% (3 of 45), 11.4% (5 of 44), and 8.3% (3 of 36) for patients treated with APBI, WBRT, and WBRT + TBB, respectively. The differences in the 5- and 7-year actuarial rates of ipsilateral breast recurrence were not statistically significant among patients treated with APBI (4.4% and 9.0%), WBRT (4.7% and 14.8%), and WBRT + TBB (5.7% and 9.5%). No statistically significant difference in either the 7-year probability of relapse-free survival (79.8%, 73.5%, and 77.7% for APBI, WBRT, and WBRT + TBB, respectively) or cancer-specific survival (93.3%, 92.9%, and 93.9% for APBI, WBRT, and WBRT + TBB, respectively) was found. The 7-year actuarial elsewhere breast failure rate was 9.0% in the APBI group and 8.3% in the control group (p = 0.80). The rate of excellent/good cosmetic results was 84.4% in the APBI group and 68.3% in the control group (p = 0.04). The corresponding rates of asymptomatic fat necrosis were 20.0% and 20.6%. Symptomatic fat necrosis occurred in 1 patient (2.2%) treated with APBI. The incidence of Grade 2 or worse late radiation side effects was similar for both groups (26.7% vs. 28.6%). CONCLUSION Accelerated partial breast irradiation using interstitial high-dose-rate implants, with proper patient selection and quality assurance, yields similar 7-year results to those achieved with standard breast-conserving therapy. APBI does not increase the risk of elsewhere breast failures.
Collapse
Affiliation(s)
- Csaba Polgár
- Department of Radiotherapy, National Institute of Oncology, Budapest, Hungary.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Yoo S, Kowalok ME, Thomadsen BR, Henderson DL. Treatment planning for prostate brachytherapy using region of interest adjoint functions and a greedy heuristic. Phys Med Biol 2003; 48:4077-90. [PMID: 14727752 DOI: 10.1088/0031-9155/48/24/006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We have developed an efficient treatment-planning algorithm for prostate implants that is based on region of interest (ROI) adjoint functions and a greedy heuristic. For this work, we define the adjoint function for an ROI as the sensitivity of the average dose in the ROI to a unit-strength brachytherapy source at any seed position. The greedy heuristic uses a ratio of target and critical structure adjoint functions to rank seed positions according to their ability to irradiate the target ROI while sparing critical structure ROIs. This ratio is computed once for each seed position prior to the optimization process. Optimization is performed by a greedy heuristic that selects seed positions according to their ratio values. With this method, clinically acceptable treatment plans are obtained in less than 2 s. For comparison, a branch-and-bound method to solve a mixed integer-programming model took more than 50 min to arrive at a feasible solution. Both methods achieved good treatment plans, but the speedup provided by the greedy heuristic was a factor of approximately 1500. This attribute makes this algorithm suitable for intra-operative real-time treatment planning.
Collapse
Affiliation(s)
- Sua Yoo
- Department of Medical Physics, University of Wisconsin-Madison, 1530 MSC, 1300 University Ave., Madison, WI 53706, USA
| | | | | | | |
Collapse
|
38
|
Narayanan SS, Goel V, Sarin R, Jalali R, Shrivastava SK, Deshpande DD, Dinshaw KA. Intraoperative high-dose-rate 192Ir radical implant in early breast cancer: a quality assurance and dosimetry study. Int J Radiat Oncol Biol Phys 2003; 56:690-6. [PMID: 12788174 DOI: 10.1016/s0360-3016(03)00015-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the variability in catheter length, geometry, and dosimetric parameters of radical intraoperative high-dose-rate breasts implant during 7-11 days. METHODS AND MATERIALS Simulator X-rays, CT scans, and dosimetric studies were repeated on alternate days in 14 consecutive patients treated with radical intraoperative two- or three-plane nylon catheter high-dose-rate implant (34 Gy in 10 fractions within 5 days). RESULTS Significant variation was found in catheter length, but no major change was noted in implant geometry, homogeneity, or inhomogeneity indexes. A variation in length of >5 mm in one or more catheters was seen in all patients and >10 mm in 11 patients at any time during the implant. Of the 171 catheters in 14 patients, 100 (58%) and 38 (22%) showed a variation of >5 mm or >10 mm, respectively. The variation of >10 mm was reduced from 32% of catheters in the first 5 patients to 17% in the subsequent 9 patients (p = 0.028). Rigid catheter fixation might reduce length variation but may cause skin necrosis if the expanding cavity indents the skin for a long period against the fixation device. A dose homogeneity index of 0.90 (range 0.85-0.92) and dose nonuniformity ratio of 0.20 (range 0.12-0.25) were satisfactory. CONCLUSION The catheter fixation and exit catheter length should be measured daily and if the implant is in situ for more than a few days, orthogonal X-rays and, if indicated, dosimetry should be repeated at least once.
Collapse
|
39
|
Jozsef G, Streeter OE, Astrahan MA. The use of linear programming in optimization of HDR implant dose distributions. Med Phys 2003; 30:751-60. [PMID: 12772981 DOI: 10.1118/1.1564471] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The introduction of high dose rate brachytherapy enabled optimization of dose distributions to be used on a routine basis. The objective of optimization is to homogenize the dose distribution within the implant while simultaneously satisfying dose constraints on certain points. This is accomplished by varying the time the source dwells at different locations. As the dose at any point is a linear function of the dwell times, a linear programming approach seems to be a natural choice. The dose constraints are inherently linear inequalities. Homogeneity requirements are linearized by minimizing the maximum deviation of the doses at points inside the implant from a prescribed dose. The revised simplex method was applied for the solution of this linear programming problem. In the homogenization process the possible source locations were chosen as optimization points. To avoid the problem of the singular value of the dose at a source location from the source itself we define the "self-contribution" as the dose at a small distance from the source. The effect of varying this distance is discussed. Test cases were optimized for planar, biplanar and cylindrical implants. A semi-irregular, fan-like implant with diverging needles was also investigated. Mean central dose calculation based on 3D Delaunay-triangulation of the source locations was used to evaluate the dose distributions. The optimization method resulted in homogeneous distributions (for brachytherapy). Additional dose constraints--when applied--were satisfied. The method is flexible enough to include other linear constraints such as the inclusion of the centroids of the Delaunay-triangulation for homogenization, or limiting the maximum allowable dwell time.
Collapse
Affiliation(s)
- Gabor Jozsef
- Department of Radiation Oncology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.
| | | | | |
Collapse
|
40
|
Monk BJ, Tewari KS, Puthawala AA, Syed AMN, Haugen JA, Burger RA. Treatment of recurrent gynecologic malignancies with iodine-125 permanent interstitial irradiation. Int J Radiat Oncol Biol Phys 2002; 52:806-15. [PMID: 11849805 DOI: 10.1016/s0360-3016(01)02728-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To analyze the outcome of permanent 125I interstitial radiotherapy for unresectable retroperitoneal recurrences of gynecologic malignancies. METHODS AND MATERIALS A retrospective review of 20 patients treated between 1979 and 1993 was performed to evaluate survival and morbidity associated with the interstitial 125I technique. RESULTS Nineteen tumors were located on the lateral pelvic wall and one in the para-aortic region. Eight patients, not previously irradiated, received external beam radiotherapy (EBRT) along with 125I interstitial implants placed at the time of celiotomy. Nineteen (95%) are dead of disease at 1-69 months of follow-up. The median survival was 7.7 months for patients treated with 125I alone and 25.4 months for those treated with both 125I and EBRT. One patient is alive without evidence of disease 69 months after 125I implantation. Fistulas, bowel obstructions, and fatal complications occurred only among patients previously irradiated. CONCLUSIONS When used in a previously irradiated field, 125I interstitial radiotherapy has major morbidity and is unlikely to be associated with cure or long-term survival. In radiotherapy-naive patients with unresectable isolated recurrent gynecologic malignancies, 125I implants and EBRT are feasible and occasionally may contribute to long-term disease-free survival.
Collapse
Affiliation(s)
- Bradley J Monk
- Division of Gynecologic Oncology, The Chao Family N.C.I.-Designated Comprehensive Cancer Center, University of California, Irvine-Medical Center, Orange, CA 92868, USA
| | | | | | | | | | | |
Collapse
|
41
|
D'Souza WD, Meyer RR. Dose homogeneity as a function of source activity in optimized I-125 prostate implant treatment plans. Int J Radiat Oncol Biol Phys 2001; 51:1120-30. [PMID: 11704337 DOI: 10.1016/s0360-3016(01)01802-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE In conventional treatment planning for permanent I-125 prostate implants, it has been suggested that lower seed activities result in more homogeneous dose distributions and also less overdose of the critical structures. We sought to determine if this hypothesis holds by analyzing treatment plans constructed using an automated optimized approach. METHODS AND MATERIALS We studied treatment plans for 10 patients using mixed-integer programming and the branch-and-bound method. Two mixed-integer models (that yielded somewhat different treatment plans) were developed: a "basic" model and a "dose homogeneity" model. For each resulting treatment plan, we examined dose homogeneity (by evaluating the dose non-uniformity ratio [DNR] and the full-width half-maximum [FWHM] of the differential dose-volume histogram [DVH]) as a function of three different source activities (0.35 mCi, 0.44 mCi, and 0.66 mCi). In addition, target coverage and critical structure dose distributions were evaluated. Plans using multiple source activities were also evaluated for resulting dose inhomogeneities. RESULTS The homogeneity model results in a more homogeneous dose distribution than the basic model. DNR is lowered by an average of 42% (standard deviation [SD] = 19%), 39% (SD = 21%), and 33% (SD = 21%) for the 0.35 mCi, 0.44 mCi, and 0.66 mCi seeds, respectively, when the homogeneity model is employed over the basic model. Corresponding average decreases in the FWHM of the DVH for 0.35 mCi, 0.44 mCi, and 0.66 mCi, respectively, are 29 Gy (SD = 28 Gy), 24 Gy (SD = 22 Gy), and 27 Gy (SD = 13 Gy). Seeds of 0.35 mCi and 0.44 mCi result in the lowest DNR and narrower FWHM of the DVH relative to 0.66 mCi seeds. In general, the 0.44 mCi seeds produce greater target coverage and require fewer seeds and needles than the 0.35 mCi seeds. Although 0.66 mCi seeds result in the greatest target coverage, they yield highest critical structure doses. They also yield solutions requiring the least number of seeds and needles. However, the dose distributions from 0.66 mCi seeds are highly inhomogeneous. Multiple source activities in the same treatment plan produce dose distributions that are comparable in homogeneity to 0.44 mCi seed implants. CONCLUSIONS Even when an optimization model that seeks to minimize dose inhomogeneity is employed, all factors involved in seed implants make 0.44 mCi the best activity choice in comparison with 0.35 mCi and 0.66 mCi.
Collapse
Affiliation(s)
- W D D'Souza
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA.
| | | |
Collapse
|
42
|
Major T, Polgár C, Somogyi A, Németh G. Evaluation of the dose uniformity for double-plane high dose rate interstitial breast implants with the use of dose reference points and dose non-uniformity ratio. Radiother Oncol 2000; 54:213-20. [PMID: 10738079 DOI: 10.1016/s0167-8140(99)00170-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE To investigate the influence of dwell time optimizations on dose uniformity characterized by dose values in dose points and dose non-uniformity ratio (DNR) and to analyze which implant parameters have influence on the DNR. MATERIALS AND METHODS Double-plane breast implants with catheters arranged in triangular pattern were used for the calculations. At a typical breast implant, dose values in dose reference points inside the target volume and volumes enclosed by given isodose surfaces were calculated and compared for non-optimized and optimized implants. The same 6-cm treatment length was used for the comparisons. Using different optimizations plots of dose non-uniformity ratio as a function of catheter separation, source step size, number of catheters, length of active sections were drawn and the minimum DNR values were determined. RESULTS Optimization resulted in less variation in dose values over dose points through the whole volume and in the central plane only compared to the non-optimized case. At implant configurations consisting of seven catheters with 15-mm separation, 5-mm source step size and various active lengths adapted according to the type of optimization, the no optimization, geometrical (volume mode) and dose point (on dose points and geometry) optimization resulted in similar treatment volumes, but an increased high dose volume was observed due to the optimization. The dose non-uniformity ratio always had the minimum at average dose over dose normalization points, defined in the midpoints between the catheters through the implant volume. The minimum value of DNR depended on catheter separation, source step size, active length and number of catheters. The optimization had only a small influence on DNR. CONCLUSIONS In addition to the reference points in the central plane only, dose points positioned in the whole implant volume can be used for evaluating the dose uniformity of interstitial implants. The dose optimization increases not only the dose uniformity within the implant but also the high dose volume. The optimization on dose points and geometry provides the most uniform dose distribution. The dose non-uniformity ratio can be minimized by selecting the isodose line of the midpoints between the catheters in the whole volume for the dose prescription, but the dose coverage may not be adequate. For a clinically acceptable plan, a compromise should be made between dose non-uniformity and coverage.
Collapse
Affiliation(s)
- T Major
- Radiotherapy Department, National Institute of Oncology, 7-9 Rath Gy. u., H-1122, Budapest, Hungary
| | | | | | | |
Collapse
|
43
|
Kramer BA, Arthur DW, Ulin K, Schmidt-Ullrich RK, Zwicker RD, Wazer DE. Cosmetic outcome in patients receiving an interstitial implant as part of breast-conservation therapy. Radiology 1999; 213:61-6. [PMID: 10540641 DOI: 10.1148/radiology.213.1.r99oc1861] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To study factors related to breast cosmetic outcome in patients treated with an interstitial implant as part of breast-conservation therapy. MATERIALS AND METHODS One hundred fifty-six patients with stage I or II breast carcinoma who received 50 Gy of external-beam irradiation followed by a 20-Gy interstitial boost were examined. The dose homogeneity index (DHI) was calculated for each evaluable implant and was examined in light of other patient-, treatment-, and tumor-related variables previously demonstrated to affect cosmesis. RESULTS Of the variables examined, both the DHI (P = .021) and the total excision volume (P = .019) were significantly related to cosmetic outcome (excellent vs less than excellent) in a univariate model. In the multivariate analysis, only the total excision volume remained significant (P = .032). The mean total excision volume +/- SD in patients with excellent cosmetic outcome (81.8 cm3 +/- 84.0) was significantly less than that in patients with less than excellent cosmetic outcome (120 cm3 +/- 84). The probability of excellent cosmetic outcome linearly increased with an increase in DHI. The mean DHI was 0.74 +/- 0.12 for the cases with excellent cosmetic outcome and 0.68 +/- 0.10 for those with less than excellent cosmetic outcome. CONCLUSION To achieve optimal cosmesis, DHI should be maximized. The volume of tissue removed, however, remains the most significant determinant.
Collapse
Affiliation(s)
- B A Kramer
- Department of Radiation Oncology, New England Medical Center, Tufts University School of Medicine, Boston, Mass., USA
| | | | | | | | | | | |
Collapse
|
44
|
Tozer-Loft SM, Walton L, Forster DM, Kemeny AA. An improved technique for comparing Gamma Knife dose-volume distributions in stereotactic radiosurgery. Phys Med Biol 1999; 44:1905-19. [PMID: 10473204 DOI: 10.1088/0031-9155/44/8/305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A function derived from the geometry of brachytherapy dose distributions is applied to stereotactic radiosurgery and an algorithm for the production of a novel dose-volume histogram, the Anderson inverse-square shifted dose-volume histogram (DVH), is proposed. The expected form of the function to be plotted is checked by calculating its value for single focus exposures, and its application to clinical examples of Gamma Knife treatments described. The technique is shown to provide a valuable tool for assessing the adequacy of radiosurgical plans and comparing and reporting dose distributions.
Collapse
Affiliation(s)
- S M Tozer-Loft
- Department of Medical Physics, Weston Park Hospital, Sheffield, UK.
| | | | | | | |
Collapse
|
45
|
Wong VY, Leung TW, Wong CM. Relative dose uniformity assessment in interstitial implants. Int J Radiat Oncol Biol Phys 1999; 44:1179-84. [PMID: 10421553 DOI: 10.1016/s0360-3016(99)00129-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Two new indices, the peak index (PI) and the new geometry index (NGI), that quantify implant dose uniformity and quality are presented. Their advantages include independence to absolute treatment dose and high sensitivity compared with other adopted dose-uniformity measures. The applicability of these indices were evaluated through computer simulations and several clinically executed implant cases. Target coverage is assumed to be properly observed and will not be discussed herein. METHODS AND MATERIALS The natural volume-dose histogram serves as the basis of our investigation. The PI and NGI definitions are based on parameters derived from the histogram. Two computer-simulated implants and 12 clinically executed implants, using high-dose rate remote afterloading techniques, are studied. Various indices that quantify the dose uniformity of the implant, namely the quality index (QI), geometry index, as well as the PI and NGI, are computed, and the results are compared. RESULTS The PI demonstrated significantly increased sensitivity (up to 5 times) to dose-uniformity evaluation, compared with the QI. The deduced parameter NGI may thus offer a better measure of implant qualities, allowing a more meaningful assessment and correlation between implant qualities to the treatment results. The PI system also offers a guideline to the design of optimal implant geometry. CONCLUSION The PI overcomes some of the shortcomings of the QI in that it provides more information about the peaking of the natural dose-volume histogram of a particular implant. The PI and NGI may offer better, more sensitive means to assess implant dose uniformity, independent of prescription dose, than other measures.
Collapse
Affiliation(s)
- V Y Wong
- Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong
| | | | | |
Collapse
|
46
|
The relationship between dose heterogeneity (“hot” spots) and complications following high-dose rate brachytherapy. Int J Radiat Oncol Biol Phys 1999. [DOI: 10.1016/s0360-3016(98)00550-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
47
|
Yang G, Reinstein LE, Pai S, Xu Z, Carroll DL. A new genetic algorithm technique in optimization of permanent 125I prostate implants. Med Phys 1998; 25:2308-15. [PMID: 9874822 DOI: 10.1118/1.598460] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Real time optimized treatment planning at the time of the implant is desirable for ultrasound-guided transperineal 125I permanent prostate implants. Currently available optimization algorithms are too slow to be used in the operating room. The goal of this work is to develop a robust optimization algorithm, which is suitable for such application. Three different genetic algorithms (sGA, sureGA and securGA) were developed and compared in terms of the number of function evaluations and the corresponding fitness. The optimized dose distribution was achieved by searching the best seed distribution through the minimization of a cost function. The cost function included constraints on the periphery dose of the planned target volume, the dose uniformity within the target volume, and the dose to the critical structure. Adjustment between the peripheral dose, the dose uniformity and critical structure dose can be achieved by varying the weighting factors in the cost function. All plans were evaluated in terms of the dose nonuniformity ratio, the conformation number and the dose volume histograms. Among these three GA algorithms, the securGA provided the best performance. Within 2500 function evaluations, the near optimum results were obtained. For a large target volume (5 cm x 4 cm x 4.5 cm) including urethra with 20 needles, the computer time needed for the optimization was less than 5 min on a HP735 workstation. The results showed that once the best set of parameters was found, they were applicable for all sizes of prostate volume. For a fixed needle geometry, the optimized plan showed much better dose distribution than that of nonoptimized plan. If the critical structure was considered in the optimization, the dose to the critical structure could be minimized. In the cases of irregular and skewed needle geometry, the optimized treatment plans were almost as good as ideal needle geometry. It is concluded that this new genetic algorithm (securGA) allows for an efficient and rapid optimization of dose distribution, which is suitable for real time treatment planning optimization for ultrasound-guided prostate implant.
Collapse
Affiliation(s)
- G Yang
- Department of Radiation Oncology, SUNY at Stony Brook 11794-7028, USA.
| | | | | | | | | |
Collapse
|
48
|
Merrick GS, Butler WM, Dorsey AT, Walbert HL. Influence of timing on the dosimetric analysis of transperineal ultrasound-guided, prostatic conformal brachytherapy. RADIATION ONCOLOGY INVESTIGATIONS 1998; 6:182-90. [PMID: 9727878 DOI: 10.1002/(sici)1520-6823(1998)6:4<182::aid-roi6>3.0.co;2-u] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Postoperative computed tomography (CT)-based dosimetric analysis of transperineal ultrasound-guided conformal prostate brachytherapy provides detailed information regarding the coverage and uniformity of the implant. However, there is no generally accepted standard for the optimal timing of the postoperative dosimetry. This report details dosimetric analysis and the effect of timing based upon CT and orthogonal film evaluation for ten unselected patients implanted with either iodine-125 (125I) or palladium-103 (103Pd). Within 2 hours after implantation, patients underwent a CT scan and the first of four sequential sets of orthogonal films. Subsequent orthogonal films were obtained on days 3, 14, and 28 postimplant. CT-based dosimetry revealed coverage of the prostate to the prescribed minimal peripheral dose (mPD) at 93.1 +/- 3.6% of the volume, the prostate volume receiving 150% of mPD was 38.2 +/- 8.7%, and the urethral and rectal doses were 114 +/- 12% and 78 +/- 19% of mPD, respectively. The implanted seeds seen on orthogonal films acted as markers for temporal changes in prostate dimensions, and the standard deviation of each dimension was used as input in an ellipsoidal volume calculation. Seed coordinates were self normalized to the center of gravity of each two-dimensional view and were measured relative to the linear regression line in the superior-inferior direction. The reproducibility of the anteroposterior (AP) film setup in terms of temporal variation in the angle of the regression line was markedly better than that of the lateral films, 1.8 degrees +/- 1.2 degrees vs. 4.3 degrees +/- 2.6 degrees, respectively. Dimensional contraction from day 0 to day 28 averaged 11.3% in the superior-inferior direction, 8.5% in the AP/PA (posteroanterior) direction, and 2.5% in the right-left lateral direction. This translated into a volume change of 20.9% (ranged 11.6-31.6%), which was determined by using the ellipsoid method. The half-life for edema resolution was 10.6 +/- 1.8 days (range 8.6-14.3 days). However, because of variability in the degree and extent of edema and its rate of resolution, we believe that it may be futile to define a single point in time as the most accurate indicator of the postoperative dose distribution. Rather, it may be preferable to accept universal standardization of timing and methodology for CT-based postoperative dosimetry, which would facilitate comparison of results between centers and maximize the information content of that single measurement. We conclude that day 0 represents the optimal time, because dosimetric evaluation at that time minimizes patient discomfort and inconvenience (a catheter is already in place), provides information about edema when it is near its maximum extent, and provides prompt closure of the learning loop and, as such, hopefully will result in improved implantation techniques and results.
Collapse
Affiliation(s)
- G S Merrick
- Schiffler Oncology Center, Wheeling Hospital, Wheeling Medical Park, West Virginia 26003, USA.
| | | | | | | |
Collapse
|
49
|
Merrick GS, Butler WM, Dorsey AT, Walbert HL. Prostatic conformal brachytherapy: 125I/103Pd postoperative dosimetric analysis. RADIATION ONCOLOGY INVESTIGATIONS 1998; 5:305-13. [PMID: 9436248 DOI: 10.1002/(sici)1520-6823(1997)5:6<305::aid-roi7>3.0.co;2-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Widespread replication of the favorable long-term results of prostatic conformal brachytherapy achieved by the Seattle group requires evidence that the technical quality of their implants is achievable elsewhere. Preplanning with a modified uniform loading algorithm using low activity seeds produces virtually no regions within the planning volume at less than the prescribed dose and no interconnected volumes between seeds at double the dose. The operative procedure stabilizes the prostate and locates the prostate targets, needles, and seeds and their relationship to the bladder and rectum using transverse and longitudinal ultrasound as well as contrast enhanced fluoroscopy. A detailed postoperative dosimetric analysis of patients with clinical T1/T2 adenocarcinoma of the prostate gland who underwent transperineal ultrasound conformal prostatic brachytherapy from March through June 1996 was performed. The analysis involved 7 consecutive patients implanted with 125I seeds and 5 consecutive patients implanted with 103Pd seeds. Median coverage to the full minimal peripheral dose (mPD) was 96% (range 80-99%) of the prostate volume. At 80% of the mPD, median isodose coverage was 100% (range 91-100%) of the prostate volume. Regarding hot spots to critical structures, the median maximal urethral dose was 175% of the mPD (range 115-227%) and the median maximal dose to the anterior rectal mucosa was 105% of the mPD (range 83-133%). Analysis of postoperative dose-volume histograms has shown that our maximal dose surface to any volume greater than 5 cm3 is 203% (range 175-247%). These results indicate that good quality transperineal ultrasound prostatic conformal brachytherapy can be accurately reproduced in a community hospital setting and that biochemical no evidence of disease (NED) results and local control rates will be comparable to those of the Seattle group with no unexpected urethral or rectal complications or side effects.
Collapse
Affiliation(s)
- G S Merrick
- Schiffler Oncology Center, Wheeling Hospital, WV 26003, USA.
| | | | | | | |
Collapse
|
50
|
Anacak Y, Esassolak M, Aydin A, Aras A, Olacak I, Haydaroğlu A. Effect of geometrical optimization on the treatment volumes and the dose homogeneity of biplane interstitial brachytherapy implants. Radiother Oncol 1997; 45:71-6. [PMID: 9364634 DOI: 10.1016/s0167-8140(97)00143-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE The isodose distributions of HDR stepping source brachytherapy implants can be modified by changing dwell times and this procedure is called optimization. The purpose of this study is to evaluate the effect of geometrical optimization on the brachytherapy volumes and the dose homogeneity inside the implant and to compare them with non-optimized counterparts. MATERIAL AND METHODS A set of biplane breast implants consisting of 84 different configurations have been digitized by the planning computer and volumetric analysis was performed for both non-optimized and geometrically optimized implants. Treated length (TL), treated volume (V100), irradiated volume (V50), overdose volume (V200) and quality index (QI) have been calculated for every non-optimized implant and compared to its corresponding geometrically optimized implant having a similar configuration and covering the same target length. RESULTS The mean TL was 74.48% of the active length (AL) for non-optimized implants and was 91.87% for optimized implants (P < 0.001). The mean QI was 1.83 for non-optimized implants and 2.17 for optimized implants (P < 0.001). The mean V50/V100 value was 2.71 for non-optimized implants and 2.65 for optimized implants (P < 0.001) and the mean V200/V100 value was 0.09 for non-optimized implants and 0.10 for optimized implants (P < 0.001). CONCLUSIONS By performing geometrical optimization it is possible to implant shorter needles for a given tumour to adequately cover the target volume with the reference isodose and thus surgical damage is reduced. The amount of healthy tissues outside the target receiving considerable radiation is significantly reduced due to the decrease in irradiated volume. Dose homogeneity inside the implant is significantly improved. Although there is a slight increase of overdose volume inside the implant, this increase is considered to be negligible in clinical applications.
Collapse
Affiliation(s)
- Y Anacak
- Department of Radiation Oncology, Ege University Faculty of Medicine, Izmir, Turkey
| | | | | | | | | | | |
Collapse
|