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Abstract
Plain pelvic radiographs are commonly used for a variety of pediatric orthopedic disorders. Lead shielding is typically placed over the gonads to minimize radiation exposure to these sensitive tissues. However, misplaced shielding can sabotage efforts to protect patients from excessive radiation exposure either by not covering radiosensitive tissues or by obscuring anatomic areas of interest, prompting repeat radiographic examinations. The goal of this study was to determine the incidence of misplaced shielding for pelvic radiographs obtained for pediatric orthopedic evaluation. Children 8 to 16 years old who had an anteroposterior or frog lateral pelvic radiograph between 2008 and 2014 were included. A total of 3400 patients met the inclusion criteria, and 84 boys and 84 girls were randomly selected for review. For both boys and girls, the percentage of incorrectly positioned or missing shields was calculated. Chi-square testing was used to compare the frequency of missing or incorrectly placed shields between sexes and age groups. Pelvic shields were misplaced in 49% of anteroposterior and 63% of frog lateral radiographs. Shielding was misplaced more frequently for girls than for boys on frog lateral radiographs (76% vs 51%; P<.05). Pelvic bony landmarks were often obscured by pelvic shielding, with a frequency of 7% to 43%, depending on the specific landmark. The femoral head and acetabulum were obscured by shielding in up to 2% of all images. The findings suggest that accepted pelvic shielding protocols are ineffective. Consideration should be given to alternative protocols or abandonment of this practice. [Orthopedics. 2017; 40(4):e623-e627.].
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Cuaron JJ, Harris AA, Chon B, Tsai H, Larson G, Hartsell WF, Hug E, Cahlon O. Anterior-oriented proton beams for prostate cancer: A multi-institutional experience. Acta Oncol 2015; 54:868-74. [PMID: 25591937 DOI: 10.3109/0284186x.2014.986288] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Proton beam therapy (PBT) for prostate cancer generally involves the use of two lateral beams that transverse the hips. In patients with hip replacements or a previously irradiated hip, this arrangement is contraindicated. The use of non-lateral beams is possible, but not well described. Here we report a multi-institutional experience for patients treated with at least one non-lateral proton beam for prostate cancer. MATERIAL AND METHODS Between 2010 and 2014, 20 patients with organ-confined prostate cancer and a history of hip prosthesis underwent proton therapy utilizing at least one anterior oblique beam (defined as between 10° and 85° from vertical) at one of three proton centers. RESULTS The median follow-up was 6.4 months. No patients have developed PSA failure or distant metastases. The median planning target volume (PTV) D95 was 79.2 Gy (RBE) (range 69.7-79.9). The median rectal V70 was 9.2% (2.5-15.4). The median bladder V50, V80, and mean dose were 12.4% (3.7-27.1), 3.5 cm3 (0-7.1), and 14.9 Gy (RBE) (4.6-37.8), respectively. The median contralateral femur head V45 and max dose were 0.01 cm3 (0-16.6) and 43.7 Gy (RBE) (15.6-52.5), respectively. The incidence of acute Grade 2 urinary toxicity was 40%. There were no Grade≥3 urinary toxicities. There was one patient who developed late Grade 2 rectal proctitis, with no other cases of acute or late ≥Grade 2 gastrointestinal toxicity. Grade 2 erectile dysfunction occurred in two patients (11.1%). Mild hip pain was experienced by five patients (25%). There were no cases of hip fracture. CONCLUSION PBT for prostate cancer utilizing anterior oblique beam trajectories is feasible with favorable dosimetry and acceptable toxicity. Further follow-up is needed to assess for long-term outcomes and toxicities.
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Affiliation(s)
- John J Cuaron
- Memorial Sloan Kettering Cancer Center and Procure Proton Therapy Center , Somerset, NJ , USA
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Georg D, Hopfgartner J, Gòra J, Kuess P, Kragl G, Berger D, Hegazy N, Goldner G, Georg P. Dosimetric considerations to determine the optimal technique for localized prostate cancer among external photon, proton, or carbon-ion therapy and high-dose-rate or low-dose-rate brachytherapy. Int J Radiat Oncol Biol Phys 2014; 88:715-22. [PMID: 24521685 DOI: 10.1016/j.ijrobp.2013.11.241] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 11/19/2013] [Accepted: 11/22/2013] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. METHODS AND MATERIALS Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior-posterior) and 8 mm (superior-inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ((192)Ir) and LDR-BT ((125)I) were D(90%) ≥34 Gy in 8.5 Gy per fraction and D(90%) ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose-volume parameters were extracted. RESULTS Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose-volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D(mean) around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. CONCLUSION Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques were clearly superior in terms of BW, RW, and normal tissue sparing, with lowest values for HDR-BT.
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Affiliation(s)
- Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria.
| | - Johannes Hopfgartner
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
| | - Joanna Gòra
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
| | - Peter Kuess
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
| | - Gabriele Kragl
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
| | - Daniel Berger
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
| | - Neamat Hegazy
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
| | - Gregor Goldner
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
| | - Petra Georg
- Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
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Tao Y, Lefkopoulos D, Ibrahima D, Bridier A, Polizzi MDP, Wibault P, De Crevoisier R, Arriagada R, Bourhis J. Comparison of dose contribution to normal pelvic tissues among conventional, conformal and intensity-modulated radiotherapy techniques in prostate cancer. Acta Oncol 2009; 47:442-50. [PMID: 17906985 DOI: 10.1080/02841860701666055] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
High-energy external radiotherapy has become one of the most common treatment in localized prostate cancer. We compared the difference of dose distribution, mainly at the 5-30 Gy dose level, in the irradiated pelvic volume among three modalities of radiotherapy for patients with prostate cancer: conventional, conformal and intensity-modulated radiotherapy (IMRT). We selected six patients with prostate cancer treated by conformal radiotherapy at the doses of 46 Gy to PTVN (prostate and seminal vesicles), and 70 Gy to PTV-T (prostate). The conventional technique": an 8-field arrangement was used; the conformal technique 4 fields with a boost through 6 fields. For IMRT, a five-beam arrangement was used. Dose-volume histograms (DVH) were analyzed and compared among the three techniques. The IMRT technique significantly increased the pelvic volume covered by the isodose surfaces below 15 Gy as compared with the conventional and conformal techniques. The mean absolute increase for the pelvic volume included between 5-30 Gy for the IMRT technique, was about 2 900 ml as compared with the conventional technique. However, IMRT significantly reduced the irradiated volume of the rectum in the dose range of 5 to 40 Gy, also significantly reduced the irradiated volume of bladder and femoral heads, and obtained a similar or improved isodose distribution in the PTVs. In addition, the use of IMRT slightly increased the relative dose delivered to the body volume outside the pelvis, as estimated by the use of specific software. A long-term follow-up will be needed to evaluate potential late treatment complications related to the use of IMRT and the low or moderate irradiation dose level obtained in the pelvis and in the whole body.
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Affiliation(s)
- Yungan Tao
- Department of Radiotherapy, Institut Gustave-Roussy, Villejuif, France.
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Cornu O, Libouton X, Naets B, Godts B, Van Tomme J, Delloye C, Banse X. Freeze-dried irradiated bone brittleness improves compactness in an impaction bone grafting model. ACTA ACUST UNITED AC 2009; 75:309-14. [PMID: 15260423 DOI: 10.1080/00016470410001240] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Defatted bone chips with or without freeze-drying and irradiation have mechanical advantages as compared to fresh-frozen controls in in vitro models of impaction. These improved results have been ascribed to replacement of viscous bone marrow by saline and embrittlement of the freeze-dried bone by irradiation. MATERIAL AND METHODS To determine which of these hypotheses is correct, we compared the development of stiffness and compactness of morselized bone graft that had been: 1) fat-reduced with saline, and 2) fresh-frozen, solvent-detergent defatted, 3) freeze-dried irradiated and 4) not irradiated. We used 12 osteoarthrotic femoral heads to prepare these four batches of morselized bone, and impacted 18 samples from each batch in a cylinder. The frozen bone grafts were tested after thawing at room temperature for 2 hours and the freeze-dried grafts were tested after 30 minutes of rehydration. We monitored the development of compactness and stiffness of the material during impaction. RESULTS The stiffness of the freeze-dried irradiated bone was greater than that of the other three series after 10, 50 and 150 impactions. The freeze-dried bone chips that were not irradiated and the chips defatted with saline alone were less stiff than the fresh-frozen control after 150 impactions. INTERPRETATION The brittleness of freeze-dried irradiated bone, caused by loss of the capacity to absorb energy in a plastic way, increases the compactness and stiffness of the morselized grafts. Washing bone with saline alone or treating bone with solvent-detergent but no irradiation had no similar mechanical advantage and the bone did not impact better than fresh-frozen undefatted bone in our model.
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Affiliation(s)
- Olivier Cornu
- Orthopaedic Research Laboratory, Université Catholique de Louvain, Brussels, Belgium.
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Pereslytskikh PF. [Formation of ossification nucleus in the femoral head in hamsters exposed to laser radiation]. Morfologiia 2008; 134:68-72. [PMID: 19241874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The purpose of the study was to detect the relation between the formation of ossification nucleus in the epiphysis and the ingrowth of vessels into it, using laser radiation of femoral heads. The study was performed in 30 golden hamsters, 20 of them starting at 10 days after birth were exposed to daily irradiation of the right hip joint (during 3-80 days). The left joint was used as control. The radiation was performed with Agnis laser device (radiation power--2 mW, impulse frequency--2500 Hz, exposure duration--8 min, optical fiber diameter--4 mm). Femoral bones of experimental and control animals were histologically studied at days 13 till 90. Laser radiation was found could delay vessel growth from diaphysis into epiphysis for up to 13 days, and the beginning of ossification nucleus formation in the femoral head--for up to 5 days. This suggests the direct relation of the development of bone ossification nucleus in the epiphysis and growing of vessels into its cartilage, since no other factors retarding the vessel growth and formation of bone nucleus were used.
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Santanam L, He T, Yudelev M, Forman JD, Orton CG, Heuvel FV, Maughan RL, Burmeister J. Intensity modulated neutron radiotherapy for the treatment of adenocarcinoma of the prostate. Int J Radiat Oncol Biol Phys 2007; 68:1546-56. [PMID: 17674984 DOI: 10.1016/j.ijrobp.2007.04.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 04/11/2007] [Accepted: 04/12/2007] [Indexed: 11/19/2022]
Abstract
PURPOSE This study investigates the enhanced conformality of neutron dose distributions obtainable through the application of intensity modulated neutron radiotherapy (IMNRT) to the treatment of prostate adenocarcinoma. METHODS AND MATERIALS An in-house algorithm was used to optimize individual segments for IMNRT generated using an organ-at-risk (OAR) avoidance approach. A number of beam orientation schemes were investigated in an attempt to approach an optimum solution. The IMNRT plans were created retrospectively for 5 patients previously treated for prostate adenocarcinoma using fast neutron therapy (FNT), and a comparison of these plans is presented. Dose distributions and dose-volume histograms (DVHs) were analyzed and plans were evaluated based on percentage volumes of rectum and bladder receiving 95%, 80%, and 50% (V(95), V(80), V(50)) of the prescription dose, and on V(60) for both the femoral heads and GM(muscle) group. RESULTS Plans were normalized such that the IMNRT DVHs for prostate and seminal vesicles were nearly identical to those for conventional FNT plans. Use of IMNRT provided reductions in rectum V(95) and V(80) of 10% (2-27%) and 13% (5-28%), respectively, and reductions in bladder V(95) and V(80) of 12% (3-26%) and 4% (7-10%), respectively. The average decrease in V(60) for the femoral heads was 4.5% (1-18%), with no significant change in V(60) for the GM(muscle) group. CONCLUSIONS This study provides the first analysis of the application of intensity modulation to neutron radiotherapy. The IMNRT technique provides a substantial reduction in normal tissue dose in the treatment of prostate cancer. This reduction should result in a significant clinical advantage for this and other treatment sites.
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Affiliation(s)
- Lakshmi Santanam
- Department of Radiation Oncology, Washington University, St. Louis, MO 63110-1093, USA.
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Guckenberger M, Pohl F, Baier K, Meyer J, Koelbl O, Flentje M, Vordermark D. Influence of rectum delineation (rectal volume vs. rectal wall) on IMRT treatment planning of the prostate. Strahlenther Onkol 2007; 182:721-6. [PMID: 17149579 DOI: 10.1007/s00066-006-1566-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Revised: 08/18/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the delineation of either the rectal volume (RV) or the rectal wall (RW) in intensity-modulated radiotherapy (IMRT) for prostate cancer: influence on dose distribution to the targets and organs at risk (OARs) was investigated. MATERIAL AND METHODS For ten patients with localized prostate cancer IMRT treatment plans were generated with the RV, wall including the filling, and the RW without the lumen as OAR (plan-RV and plan-RW), respectively. Two different IMRT treatment- planning systems (TPS) were utilized. The influence on target coverage and sparing of OARs was investigated. RESULTS No influence was seen on target coverage and sparing of the bladder and femoral heads. Doses to the RV were significantly reduced in plan-RV for all evaluated dose levels: maximum 26% and 17%, respectively, in both TPS. The dose distribution to the RW was not significantly different between plan-RV and plan-RW. CONCLUSION The different delineation of the OAR rectum significantly affected the inverse IMRT treatment-planning process. The use of the RV as OAR resulted in improved dose distributions to the RV. Therefore, it is suggested using the RV as OAR in IMRT treatment planning of the prostate.
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Vassiliev ON, Kry SF, Kuban DA, Salehpour M, Mohan R, Titt U. Treatment-planning study of prostate cancer intensity-modulated radiotherapy with a Varian Clinac operated without a flattening filter. Int J Radiat Oncol Biol Phys 2007; 68:1567-71. [PMID: 17544596 DOI: 10.1016/j.ijrobp.2007.04.025] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 04/05/2007] [Accepted: 04/06/2007] [Indexed: 02/07/2023]
Abstract
PURPOSE To assess the feasibility of intensity-modulated radiotherapy for prostate cancer using photon beams from an accelerator operated without a flattening filter; and to determine potential benefits and drawbacks of using unflattened beams for this type of treatment. METHODS AND MATERIALS Intensity-modulated radiotherapy plans were generated for 10 patients with early-stage prostate cancer. For each patient, four plans were generated: with and without the flattening filter, at 6 and 18 MV. The prescription dose was 75.6 Gy to 98% of the planning target volume. The number of beams, their orientations, and optimization constraints were the same for all plans. Plans were generated with Eclipse 8.0 (Varian Medical Systems). RESULTS All the plans developed with unflattened beams were clinically acceptable. In terms of patient dose distributions, plans with unflattened beams were similar to the corresponding plans with flattened beams. Plans with unflattened beams required fewer monitor units (MUs) per plan: on average, by a factor of 2.0 at 6 MV and 2.6 at 18 MV, assuming that removal of the flattening filter was not followed by recalibration of MUs. CONCLUSIONS Clinically acceptable intensity-modulated radiotherapy plans for prostate cancer can be developed with unflattened beams at both 6 and 18 MV. Dosimetrically, flattened and unflattened beams generated similar treatment plans. The plans with unflattened beams required substantially fewer MUs. The reduction in the number of MUs indicates corresponding reduction in beam-on time and in the amount of radiation outside the target.
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Affiliation(s)
- Oleg N Vassiliev
- Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030-4009, USA.
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Jereczek-Fossa BA, Cattani F, D'Onofrio A, Cambria R, Kowalczyk A, Corallo A, Vavassori A, Zerini D, Ivaldi GB, DeCobelli O, Orecchia R. Dose distribution in 3-dimensional conformal radiotherapy for prostate cancer: Comparison of two treatment techniques (six coplanar fields and two dynamic arcs). Radiother Oncol 2006; 81:294-302. [PMID: 17113670 DOI: 10.1016/j.radonc.2006.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 09/15/2006] [Accepted: 10/03/2006] [Indexed: 11/16/2022]
Abstract
PURPOSE To compare dose distribution for two techniques of 3-dimensional conformal radiotherapy (RT): 6-field technique (6F) and 2-dynamic arc therapy (2DA). METHODS AND MATERIALS Thirty nonmetastatic prostate cancer patients were included. In each patient, two treatment plans were prepared: with six coplanar fields (45 degrees , 90 degrees , 135 degrees , 225 degrees , 270 degrees , 315 degrees ) and with two dynamic lateral 100 degrees -wide arcs (40-140 degrees , 220-320 degrees ). Dose-volume histograms (DVHs) were computed and mean area under curve (AUC) values were calculated for the DVHs of Planning Target Volume (PTV), rectum, urinary bladder and femoral heads. Doses given to 30% of rectum (DR(30)), to 60% of rectum (DR(60)), to 50% of bladder (DB(50)), to 50% of femoral head (DF(50)) and to 95% of PTV (DPTV(95)) were reported as a percentage of the total dose. RESULTS Mean DR(30) and DR(60) for 6F and 2DA were 75.8%, 51.5% and 72.2%, 37.2%, respectively. Mean DB(50) for 6F and 2DA were 68% and 64.2%, respectively. Mean right DF(50) for 6F and 2DA were 35.4% and 45.5%, respectively. Mean DPTV(95) for 6F and 2DA were 99% and 99.2%, respectively. Mean AUCs of DVHs of rectum and urinary bladder were significantly higher for 6F (this was more evident for small PTV and in the intermediate dose range). Mean AUC of DVHs of PTV and femoral heads were significantly higher for 2DA. CONCLUSIONS Both 6F and 2DA offer good dose distribution for PTV. 2DA allows for significantly better sparing of rectum and urinary bladder with slightly worse femoral head dose distribution. Further study is warranted in order to establish the clinical relevance of these differences.
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Mell LK, Kochanski JD, Roeske JC, Haslam JJ, Mehta N, Yamada SD, Hurteau JA, Collins YC, Lengyel E, Mundt AJ. Dosimetric predictors of acute hematologic toxicity in cervical cancer patients treated with concurrent cisplatin and intensity-modulated pelvic radiotherapy. Int J Radiat Oncol Biol Phys 2006; 66:1356-65. [PMID: 16757127 DOI: 10.1016/j.ijrobp.2006.03.018] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 02/04/2006] [Accepted: 03/01/2006] [Indexed: 11/28/2022]
Abstract
PURPOSE To identify dosimetric parameters associated with acute hematologic toxicity (HT) and chemotherapy delivery in cervical cancer patients undergoing concurrent chemotherapy and intensity-modulated pelvic radiotherapy. METHODS AND MATERIALS We analyzed 37 cervical cancer patients receiving concurrent cisplatin (40 mg/m(2)/wk) and intensity-modulated pelvic radiotherapy. Pelvic bone marrow (BM) was contoured for each patient and divided into three subsites: lumbosacral spine, ilium, and lower pelvis. The volume of each region receiving 10, 20, 30, and > or =40 Gy (V(10), V(20), V(30), and V(40), respectively) was calculated. HT was graded according to the Radiation Therapy Oncology Group system. Multivariate regression models were used to test associations between dosimetric parameters and HT and chemotherapy delivery. RESULTS Increased pelvic BM V(10) (BM-V(10)) was associated with an increased Grade 2 or worse leukopenia and neutropenia (odds ratio [OR], 2.09; 95% confidence interval [CI], 1.24-3.53; p = 0.006; and OR, 1.41; 95% CI, 1.02-1.94; p = 0.037, respectively). Patients with BM-V(10) > or =90% had higher rates of Grade 2 or worse leukopenia and neutropenia than did patients with BM-V(10) <90% (11.1% vs. 73.7%, p < 0.01; and 5.6% vs. 31.6%, p = 0.09) and were more likely to have chemotherapy held on univariate (16.7% vs. 47.4%, p = 0.08) and multivariate (OR, 32.2; 95% CI, 1.67-622; p = 0.02) analysis. No associations between HT and V(30) and V(40) were observed. Dosimetric parameters involving the lumbosacral spine and lower pelvis had stronger associations with HT than did those involving the ilium. CONCLUSION The volume of pelvic BM receiving low-dose radiation is associated with HT and chemotherapy delivery in cervical cancer patients undergoing concurrent chemoradiotherapy.
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Affiliation(s)
- Loren K Mell
- Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL 60637, USA.
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Wang WH, Tsuji H, Ishikawa H, Tsujii H, Kamada T, Mizoe J, Li YX. [Comparison of treatment planning by carbon ion radiotherapy and by intensity-modulated radiotherapy for prostatic adenocarcinoma]. Zhonghua Zhong Liu Za Zhi 2006; 28:836-9. [PMID: 17416005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
OBJECTIVE To evaluate the potential benefit of carbon ion radiotherapy (C-ion RT) through comparison with photon intensity-modulated radiotherapy (IMRT) in dose distribution for prostatic adenocarcinoma. METHODS In randomly selected 5 patients, treatment planning of C-ion RT (4 coplanar beams) and IMRT (7 coplanar fields) were worked out by computer working station. In order to make a meaningful comparison, it was defined that the 95% isodose surface had to cover 100% of the PTV in each plan; all dose was given as normalized dose with the definition of the minimum dose of the PTV being equal to 95% of prescribed dose. Dose-volume histograms (DVHs) of the tumor and organ-at-risks (OARs) were calculated. Volume irradiated more than or equal to some specified doses, conformity index ( CI) , and inhomogeneity coefficient (IC) of each treatment plan was compared, respectively. RESULTS With C-ion RT, the mean irradiated volumes (in %) of the rectum were significantly smaller than that with IMRT except for 95% dose level, and C-ion RT could provide complete protection to the posterior rectal wall. In addition, C-ion RT could also remarkably reduce the dose to the bladder, femoral heads and non-target normal tissues at each dose level. Dose conformation and homogeneity in the target volume of C-ion RT were better than that in IMRT (mean CI50%, 3.36 vs. 5.04, mean CI95%, 1.20 vs. 1.46, mean IC, 0.03 vs. 0.12). CONCLUSION Compared with IMRT, C-ion RT can obtain better dose distribution, and may reduce tumor recurrence and radiation-induced complications in prostatic adenocarcinoma.
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Affiliation(s)
- Wei-hu Wang
- Department of Radiation Oncology, Cancer Hospital (Institute), Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100021, China
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Lee CT, Dong L, Ahamad AW, Choi H, Cheung R, Lee AK, Horne DF, Breaux AJ, Kuban DA. Comparison of treatment volumes and techniques in prostate cancer radiation therapy. Am J Clin Oncol 2006; 28:618-25. [PMID: 16317275 DOI: 10.1097/01.coc.0000172281.32437.d4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare dose-volume histograms (DVHs) for 3 target volumes (group 1, prostate + seminal vesicles + pelvic lymph nodes; group 2, prostate + seminal vesicles; group 3, prostate only) to determine the difference in dose to normal structures (rectum, bladder, and femoral heads) while controlling for target dose using 3-dimensional conformal radiation therapy (3DCRT) versus intensity modulated radiation therapy (IMRT). METHODS Ten patients with localized prostate cancer were randomly selected. 3DCRT and IMRT planning were done to deliver 75.6 Gy to the prostate, 50.4 Gy to the pelvic nodes, and 55.8 Gy to the seminal vesicles at a standard fractionation of 1.8 Gy. An additional plan delivering 75.6 Gy to the seminal vesicles using IMRT was run. DVHs were compared for 3DCRT and IMRT. RESULTS In all 3 groups, the percent rectum receiving > or =70 Gy, > or =60 Gy, and > or =40 Gy was significantly less for IMRT than for 3DCRT. Increasing target volumes, as necessary for pelvic nodal irradiation, overall did not result in higher rectal doses for IMRT. With 3DCRT, however, larger target volumes did increase the amount of rectum irradiated. Similar results were obtained for the femoral heads whereas results for the bladder were mixed. CONCLUSION When compared with 3DCRT, IMRT delivered equivalent or higher doses to the target volume with greater sparing of critical organs. Because dose-volume parameters have been shown to relate to toxicity, IMRT would appear to be the favored technique for prostate cancer radiation, particularly with regard to nodal treatment.
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Affiliation(s)
- Catherine T Lee
- Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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14
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Zheng G, Ballester MAG, Styner M, Nolte LP. Reconstruction of Patient-Specific 3D Bone Surface from 2D Calibrated Fluoroscopic Images and Point Distribution Model. ACTA ACUST UNITED AC 2006; 9:25-32. [PMID: 17354870 DOI: 10.1007/11866565_4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Reconstruction of patient-specific 3D bone surface from 2D calibrated fluoroscopic images and a point distribution model is discussed. We present a 2D/3D reconstruction scheme combining statistical extrapolation and regularized shape deformation with an iterative image-to-model correspondence establishing algorithm, and show its application to reconstruct the surface of proximal femur. The image-to-model correspondence is established using a non-rigid 2D point matching process, which iteratively uses a symmetric injective nearest-neighbor mapping operator and 2D thin-plate splines based deformation to find a fraction of best matched 2D point pairs between features detected from the fluoroscopic images and those extracted from the 3D model. The obtained 2D point pairs are then used to set up a set of 3D point pairs such that we turn a 2D/3D reconstruction problem to a 3D/3D one. We designed and conducted experiments on 11 cadaveric femurs to validate the present reconstruction scheme. An average mean reconstruction error of 1.2 mm was found when two fluoroscopic images were used for each bone. It decreased to 1.0 mm when three fluoroscopic images were used.
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Affiliation(s)
- Guoyan Zheng
- MEM Research Center, University of Bern, CH-3014, Bern, Switzerland.
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15
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Butler AM, Morgan DAF, Verheul R, Walsh WR. Mechanical properties of gamma irradiated morselized bone during compaction. Biomaterials 2005; 26:6009-13. [PMID: 15958242 DOI: 10.1016/j.biomaterials.2005.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2004] [Accepted: 03/09/2005] [Indexed: 10/25/2022]
Abstract
This study examined the effects of gamma irradiation on the compressive properties of morselized cancellous bone from human femoral heads. Twelve bone samples, mean age of 68 years (range 92-39), were divided into 3 groups (N=12) of varying irradiation level (0, 15 and 25 kGy). Each specimen was compacted in a controlled fashion in steps of 0.5 mm at 0.5 mm/min (up 12 mm). The load and stiffness increased with compaction, but this relationship was not linear. There was no statistical significant difference in the compacting load or stiffness between groups (p>0.05) until the last 1 mm of compaction, where the 25 kGy group were significantly stiffer compared to controls but not different to the 15 kGy group. This may be due to decreased interlocking of bone particles caused by higher irradiation levels resulting in a stiffer graft.
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Affiliation(s)
- Adam M Butler
- Orthopaedic Research Laboratories, University of New South Wales, Prince of Wales Hospital, Sydney, Australia
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16
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Abstract
UNLABELLED We retrospectively analyzed the prognostic factors related to the failure of acetabular components after total hip arthroplasties in radiated hips. Eighteen hips from 12 patients who had primary arthroplasties were followed up for a mean of 58 months (range, 20-139 months). The patients' age, total radiation dose, latent period, presence of infection, and the type of the acetabular component were examined as possible predictors of failure using the Cox proportional hazard regression. Multivariate analyses showed that a longer latent period was the most important risk factor for failure, increasing 1.72 times when the latent period was greater than 1 year, after adjusting for other predictors. The latent period might be helpful for clinicians in choosing a treatment method for patients. LEVEL OF EVIDENCE Prognostic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.
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Affiliation(s)
- Myung-Rae Cho
- Department of Orthopaedic Surgery, School of Medicine, Daegu Catholic University Hospital, Daegu, Korea.
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17
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Eagle MJ, Rooney P, Lomas R, Kearney JN. Validation of Radiation Dose Received by Frozen Unprocessed and Processed Bone during Terminal Sterilisation. Cell Tissue Bank 2005; 6:221-30. [PMID: 16151961 DOI: 10.1007/s10561-005-7479-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Accepted: 05/17/2005] [Indexed: 10/25/2022]
Abstract
Fresh frozen femoral heads (FH) and frozen processed bone (FP) are widely used as a source of allograft bone. The FP bone and some of the FH are terminally sterilised by the National Blood Service Tissue Services (NSBTS), via application of a minimum 25 kGy gamma radiation dose. To comply with the Guidelines for the Blood Transfusion Services in the United Kingdom (2002), frozen musculoskeletal tissue must be maintained below -40 degrees C during storage and transit. In practice, NBSTS stores bone long-term in -80 degrees C freezers. During transport for irradiation, a temperature of circa -79 degrees C is maintained by packing the bone in dry ice. An evaluation of the radiation dose received by bone has previously been made via dosimeters located within the tissue and dry ice, however, some evidence suggests that low temperature can influence the accuracy of the dosimeter readings. The aim of this study was to determine the actual radiation dose received by FH and FP bone during the irradiation process. This was accomplished by comparing radiation dose readings from dosimeters placed in dry ice with dosimeters placed in a dry ice substitute of similar dimensions and density i.e., polytetrafluoroethylene (PTFE) at ambient temperature. New packing formats were developed for both FH and FP bone such that 15 FH or 3 kg of FP bone could be irradiated in one transport box at any given time in a standardised fashion. The data show that low temperature consistently increased dosimeter readings 10--27%, and that radiation dose always fell within the range of 25--40 kGy (FH=25.1--35.7 kGy; FP bone=25.2--32.4 kGy).
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Affiliation(s)
- M J Eagle
- Tissue Services R&D, National Blood Service, Longley Lane, Sheffield S5 7JN, U.K.
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18
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Abstract
The aim of this study was to investigate the ability of Australian centres to produce high-dose intensity modulated radiation therapy (IMRT) prostate plans, and to compare the planning parameters and resultant dose distributions. Five Australian radiation therapy departments were invited to participate. Each centre received an identical 5 mm-slice CT data set complete with contours of the prostate, seminal vesicles, rectum, bladder, femoral heads and body outline. The planning team was asked to produce the best plan possible, using published Memorial Sloan-Kettering Cancer Centre prescription and dose constraints. Three centres submitted plans for evaluation. All plans covered the planning target volume adequately; however, only one plan met all the critical organ dose constraints. Although the planning parameters, beam arrangements and planning systems were different for each centre, the resulting plans were similar. In Australia, IMRT for prostate cancer is in the early stages of implementation, with routine use limited to a few centres.
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Affiliation(s)
- M Skala
- Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Health Service, Liverpool, New South Wales, Australia.
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19
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Brown PD, Kline RW, Petersen IA, Haddock MG. Irradiation of the inguinal lymph nodes in patients of differing body habitus: A comparison of techniques and resulting normal tissue complication probabilities. Med Dosim 2004; 29:217-22. [PMID: 15324919 DOI: 10.1016/j.meddos.2003.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2003] [Accepted: 12/17/2003] [Indexed: 10/26/2022]
Abstract
The treatment of the inguinal lymph nodes with radiotherapy is strongly influenced by the body habitus of the patient. The effect of 7 radiotherapy techniques on femoral head doses was studied. Three female patients of differing body habitus (ectomorph, mesomorph, endomorph) were selected. Radiation fields included the pelvis and contiguous inguinal regions and were representative of fields used in the treatment of cancers of the lower pelvis. Seven treatment techniques were compared. In the ectomorph and mesomorph, normal tissue complication probability (NTCP) for the femoral heads was lowest with use of anteroposterior (AP) and modified posteroanterior (PA) field with inguinal electron field supplements (technique 1). In the endomorph, NTCP was lowest with use of AP and modified PA field without electron field supplements (technique 2) or a 4-field approach (technique 6). Technique 1 for ectomorphs and mesomorphs and techniques 2 and 6 for endomorphs were optimal techniques for providing relatively homogeneous dose distributions within the target area while minimizing the dose to the femoral heads.
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Affiliation(s)
- Paul D Brown
- Division of Radiation Oncology, Mayo Clinic, Rochester, MN, USA.
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20
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Abstract
The purpose of this work was to develop a robust technique for planning intensity-modulated radiation therapy (IMRT) for prostate cancer patients who are to be entered into a proposed hypofractionated dose escalation study. In this study the dose escalation will be restricted to the prostate alone, which may be regarded as a concurrent boost volume within the overall planning target volume (PTV). The dose to the prostate itself is to be delivered in 3 Gy fractions, and for this phase of the study the total prostate dose will be 57 Gy in 19 fractions, with 50 Gy prescribed to the rest of the PTV. If acute toxicity results are acceptable, the next phase will escalate doses to 60 Gy in 20 x 3 Gy fractions. There will be 30 patients in each arm. This work describes the class solution which was developed to create IMRT plans for this study, and which enabled the same set of inverse planning parameters to be used during optimization for every patient with minimal planner intervention. The resulting dose distributions were compared with those that would be achieved from a 3D conformal radiotherapy (3DCRT) technique that used a multileaf collimator (MLC) but no intensity modulation to treat the PTV, followed by a sequential boost to raise the prostate to 57 Gy. The two methods were tested on anatomical data sets for a series of 10 patients who would have been eligible for this study, and the techniques were compared in terms of doses to the target volumes and the organs at risk. The IMRT method resulted in much greater sparing of the rectum and bladder than the 3DCRT technique, whilst still delivering acceptable doses to the target volumes. In particular, the volume of rectum receiving the minimum PTV dose of 47.5 Gy was reduced from a mean value of 36.9% (range 23.4% to 61.0%) to 18.6% (10.3% to 29.0%). In conclusion, it was found possible to use a class solution approach to produce IMRT dose escalated plans. This IMRT technique has since been implemented clinically for patients enrolled in the hypofractionated dose escalation study.
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Affiliation(s)
- J H Mott
- North Western Medical Physics and Clinical Oncology, Christie Hospital NHS Trust, Manchester M20 4BX, UK
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21
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Vastel L, Meunier A, Siney H, Sedel L, Courpied JP. Effect of different sterilization processing methods on the mechanical properties of human cancellous bone allografts. Biomaterials 2004; 25:2105-10. [PMID: 14741625 DOI: 10.1016/j.biomaterials.2003.08.067] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Use of new sterilization methods applied to human bone is likely to affect both the mechanical and biological properties of human cancellous grafts. The mechanical properties of the transplanted bone inevitably determine the short- and mid-term results of the orthopedic procedure performed. The aim of this study was to compare, under similar conditions, the mechanical effects of gamma irradiation, lipid extraction, and treatment with 6M urea on trabecular bone samples, through conventional mechanical tests and measurement of the ultrasound wave propagation rate. Deteriorations measured for gamma irradiation and lipid extraction were low: 2.4% and 2.5%, respectively, for ultrasound propagation wave measurements. They were clearly significant for protocol including 6M urea, corresponding to a loss of 30% in values measured in the control sample for the stress to failure, inciting prudence when grafted bone is used for support in orthopedic assembly. High consistency in the results obtained between travel time of the ultrasound wave, easily done, and measurement of stress to failure through conventional tests, favor the use of ultrasound protocol, described as a quality test performed on bone grafts in the tissue bank before distribution and implantation.
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Affiliation(s)
- L Vastel
- Bone Tissue Banking, Cochin AP-HP, Service de Chirurgie Orthopédique A, Hôpital Cochin, AP-HP, 28 rue du Faubourg Saint Jacques, 75014, Paris Cedex 14, France.
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22
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Luxton G, Hancock SL, Boyer AL. Dosimetry and radiobiologic model comparison of IMRT and 3D conformal radiotherapy in treatment of carcinoma of the prostate. Int J Radiat Oncol Biol Phys 2004; 59:267-84. [PMID: 15093924 DOI: 10.1016/j.ijrobp.2004.01.024] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2003] [Revised: 01/15/2004] [Accepted: 01/19/2004] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Intensity-modulated radiotherapy (IMRT) has introduced novel dosimetry that often features increased dose heterogeneity to target and normal structures. This raises questions of the biologic effects of IMRT compared to conventional treatment. We compared dosimetry and radiobiologic model predictions of tumor control probability (TCP) and normal tissue complication probability (NTCP) for prostate cancer patients planned for IMRT as opposed to standardized three-dimensional conformal radiotherapy (3DCRT). METHODS AND MATERIALS Segmented multileaf collimator IMRT treatment plans for 32 prostate cancer patients were compared to 3DCRT plans for the same patients. Twenty-two received local-field irradiation (LFI), and 10 received extended-field irradiation (EFI) that included pelvic lymph nodes. For LFI, IMRT was planned for delivery of 2 Gy minimum dose to the prostate (> or =99% volume coverage) for 35 fractions. The 3DCRT plans, characterized by more homogenous dose to the target, were designed according to a different protocol to deliver 2 Gy to the center of the prostate for 37 fractions. Mean total dose from 35 fractions of IMRT was equal to mean total dose from 37 fractions of 3DCRT. For EFI, both IMRT and 3DCRT were planned for 2 Gy per fraction to a total dose of 50 Gy to prostate and pelvic lymph nodes, followed by 2 Gy per fraction to 20 Gy to the prostate alone. Treatment dose for EFI-IMRT was defined as minimum dose to the target, whereas for EFI-3DCRT, it was defined as dose to the center of the prostate. TCP was calculated for the prostate in the linear-quadratic model for two choices of alpha/beta. NTCP was calculated with the Lyman model for organs at risk, using Kutcher-Burman dose-volume histogram reduction with Emami parameters. RESULTS AND CONCLUSIONS Dose to the prostate, expressed as mean +/- standard deviation, was 74.7 +/- 1.1 Gy for IMRT vs. 74.6 +/- 0.3 Gy for 3D for the LFI plans, and 74.8 +/- 0.6 Gy for IMRT vs. 71.5 +/- 0.6 Gy for 3D for the EFI plans. For the studied protocols, TCP was greater for IMRT than for 3D across the full range of target sensitivity, for both localized- and extended-field irradiation. For LFI, this was due to the smaller number of fractions (35 vs. 37) used for IMRT, and for EFI, this was due to the greater mean dose for IMRT, compared to 3D. For all organs, mean NTCP tended to be lower for IMRT than for 3D, although NTCP values were very small for both 3D and IMRT. Differences were statistically significant for rectum (LFI and EFI), bladder (EFI), and bowel (EFI). For both LFI and EFI, the calculated NTCPs qualitatively agreed with early published clinical data comparing genitourinary and gastrointestinal complications of IMRT and 3D. Present calculations support the hypothesis that accurately delivered IMRT for prostate cancer can limit dose to normal tissue by reducing treatment margins relative to conventional 3D planning, to allow a reduction in complication rate spanning several sensitive structures while maintaining or increasing tumor control probability.
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Affiliation(s)
- Gary Luxton
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305-5847, USA.
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23
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Milecki P, Piotrowski T, Dymnicka M. The comparison of radiotherapy techniques for treatment of the prostate cancer: the three-field vs. the four-field. Neoplasma 2004; 51:64-9. [PMID: 15004663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Our purpose was to compare the three-field and the four-field planning techniques in patients with localized prostate cancer. Twenty patients with localized prostate cancer stage (T1-T2N0M0) were chosen for the analysis of treatment plans. Simulation and CT planning were performed in all cases in the supine position with a "comfortably" full bladder. The planning treatment volume (PTV) was defined as the prostate gland with a 10 mm margins around the clinical target volume (CTV), except for the posterior margin (prostate gland - the anterior part of rectum wall), where a 5 mm margin was applied. The clinical target volume (CTV) was defined as prostate gland. For each patient the following organs at risk (OAR) were outlined: rectum, bladder, and right femoral head. The following three-field and four-field plans were made: 3 field techniques with beam angles orientations 0 degree, 120 degrees, 240 degrees and 0 degree, 90 degrees, 270 degrees, and 4 field technique (0 degree, 90 degrees, 180 degrees, 270 degrees). Two versions of treatment plans were also made including different range of applied energy of photons (6 MV or 20 MV) for the therapeutic machine - Clinac 2300 CD. Beam portals were conformal by shaped by a multileaf collimator (MLC). The daily fractionation dose 1.8 Gy and the total dose 73.8 Gy were applied in each case. One hundred and twenty treatment plans were made and compared according to the following parameters: the mean total dose (MTD) in the target, the tumor control probability (TCP), the mean total dose (MTD) in the OAR (rectum, bladder, and right femoral head), the normal tissue complication probabilities (NTCP), and the volume of OARs which received arbitrary chosen fraction (%) of the total prescribed dose (73.8 Gy=100%). ANOVA statistical methods to verify the significance of differences between the treatment plans were used. There were no significant differences in the distribution of MTD and TCP in the PTV for the evaluated treatment plans. There were no significant differences in the MTD, NTCP, V80, and V90 distribution in bladder. The distribution of MTD, NTCP, and V80 for rectum indicated that lower parameters were achieved in the case of the three-field technique with the orientation of beams 0 degree, 90 degrees, 270 degrees. The distribution of MTD, NTCP, and V70 in right femoral head for each treatment plan was below the tolerance dose. The study has shown that the three-field technique (an anterior and two opposing lateral fields with the portals orientation 0 degree, 90 degrees, 270 degrees) and applied energy photons 20 MV, provides the best rectal protection. All evaluated plans according to the dose distribution in the target (PTV) have not indicated any significant differences. None of the techniques has shown any significant advantages in sparing bladder. The risk of morbidity in the femoral heads for all the applied techniques, in a dose up to 73.8 Gy was not a therapeutic problem. However, the three-field technique with beams orientation 0 degree, 120 degrees, 240 degrees gave the best sparing effect for femoral heads.
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Affiliation(s)
- P Milecki
- Department of Radiotherapy, Greatpoland Cancer Center, Poznan, 61-866 Poland.
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24
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Zoroofi RA, Sato Y, Sasama T, Nishii T, Sugano N, Yonenobu K, Yoshikawa H, Ochi T, Tamura S. Automated segmentation of acetabulum and femoral head from 3-D CT images. ACTA ACUST UNITED AC 2003; 7:329-43. [PMID: 15000359 DOI: 10.1109/titb.2003.813791] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This paper describes several new methods and software for automatic segmentation of the pelvis and the femur, based on clinically obtained multislice computed tomography (CT) data. The hip joint is composed of the acetabulum, cavity of the pelvic bone, and the femoral head. In vivo CT data sets of 60 actual patients were used in the study. The 120 (60 x 2) hip joints in the data sets were divided into four groups according to several key features for segmentation. Conventional techniques for classification of bony tissues were first employed to distinguish the pelvis and the femur from other CT tissue images in the hip joint. Automatic techniques were developed to extract the boundary between the acetabulum and the femoral head. An automatic method was built up to manage the segmentation task according to image intensity of bone tissues, size, center, shape of the femoral heads, and other characters. The processing scheme consisted of the following five steps: 1) preprocessing, including resampling 3-D CT data by a modified Sinc interpolation to create isotropic volume and to avoid Gibbs ringing, and smoothing the resulting images by a 3-D Gaussian filter; 2) detecting bone tissues from CT images by conventional techniques including histogram-based thresholding and binary morphological operations; 3) estimating initial boundary of the femoral head and the joint space between the acetabulum and the femoral head by a new approach utilizing the constraints of the greater trochanter and the shapes of the femoral head; 4) enhancing the joint space by a Hessian filter; and 5) refining the rough boundary obtained in step 3) by a moving disk technique and the filtered images obtained in step 4). The above method was implemented in a Microsoft Windows software package and the resulting software is freely available on the Internet. The feasibility of this method was tested on the data sets of 60 clinical cases (5000 CT images).
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Affiliation(s)
- Reza A Zoroofi
- Department of Electrical and Computer Engineering, Faculty of Engineering, University of Tehran, 14395-515 Tehran, Iran.
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25
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Abstract
The potential shortage of allograft bone has led to the need to investigate other sources of bone for allografts. Some allograft bone donated from primary total hip arthroplasty recipients must be discarded or treated to become usable as a result of bacterial contamination. Femoral head allografts were contaminated with Staphylococcus aureus and Bacillus subtilis. A domestic microwave oven was used. The contaminated bone was exposed to microwave irradiation for different time periods. The samples were then cultured to attempt to grow the two bacterial species. The contaminated bone samples failed to grow any organisms after 2 min of exposure to microwave irradiation. This study shows that sterilization of femoral head allografts contaminated with S. aureus and B. subtilis can be achieved with microwave irradiation in a domestic microwave oven. This method of sterilization of bone allografts is cheap, easily used, and an effective way to process contaminated bone.
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Affiliation(s)
- Robert A Dunsmuir
- Department of Orthopaedics, Southern General Hospital, Glasgow, United Kingdom.
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26
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Abstract
The current philosophy of dose escalation in the treatment of prostate cancer has forced the treatment planner to re-evaluate his/her planning approach. Precise and accurate delivery of dose to the prostate while maintaining the required dose limits to the normal critical structures, such as the rectum, has become increasingly difficult in light of these escalated doses. Conformal treatment techniques allow the treatment planner to precisely shape each individual treatment field so that desired volume coverage and normal tissue sparing can be achieved. In addition to these beam-shaping advantages, adjustment of an individual beam's weighting also helps to create the desired distribution and tissue sparing. Rotational therapy "simulates" treatment with multiple beams and angles, similar to the thought process behind conformal treatment technique. With rotational therapy, however, the treatment planner's inability to provide adequate beam shaping and weighting adjustment has placed limits on its value as a viable planning option. The introduction of computer-controlled treatment machines, which allow dynamic adjustment of the field shape with the rotation of the beam, makes it possible to re-evaluate rotational therapy as a potential option. Similarly, the treatment planner's ability to change field weighting can be accomplished by the application of dynamic dose rate control, allowing a rotational beam to deliver a weighting similar to that possible with conformal fixed-field techniques. Dose-volume histogram data will be used to evaluate doses delivered to the prostate, rectum, and bladder using rotational therapy with dynamic field shape and dynamic dose rate control as a treatment planning option. The dose delivery and normal tissue-sparing potential of this technique compared to coplanar and noncoplanar conformal fixed-field techniques will also be presented.
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Affiliation(s)
- Matt Tobler
- Department of Radiation Oncology, University of Utah Health Science Center, Salt Lake City, UT 84132, USA.
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27
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Abstract
Merkel cell carcinoma is an extremely rare malignant tumor which derives from the neuroendocrine cell system with features of epithelial differentiation. It belongs to the APUD-system (amine and precursor uptake and decarboxylation) and is characterized by highly aggressive spread with a predisposition for local recurrence and local regional and distant metastases. Metastatic spread to the hip has not been described in the literature before. We report on a 76-year old male patient with metastases of the left femoral head and greater trochanter 3 1/2 years after excision of a Merkel cell carcinoma of the left thigh with consecutive radical lymph node dissection of the left inguinal area and radiation therapy. Although microscopic,immunohistological and ultrastructural characteristics of the carcinoma have been well defined, there are no established treatment guidelines and prognostic factors that may predict the behaviour of the tumor due to the limited number of cases. Elective lymph node dissection decreases the rate of local recurrence but is not associated with improved overall survival. At the time of establishing the diagnosis, about half of the patients has positive lymph nodes with a 3-year-survival rate of 60%.
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Affiliation(s)
- I Gockel
- Klinik für Unfall-, Hand-, und Wiederherstellungschirurgie, HSK, Dr.-Horst-Schmidt-Kliniken GmbH,Wiesbaden.
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Das S, Cullip T, Tracton G, Chang S, Marks L, Anscher M, Rosenman J. Beam orientation selection for intensity-modulated radiation therapy based on target equivalent uniform dose maximization. Int J Radiat Oncol Biol Phys 2003; 55:215-24. [PMID: 12504056 DOI: 10.1016/s0360-3016(02)03817-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To develop an automated beam-orientation selection procedure for intensity-modulated radiotherapy (IMRT), and to determine if a small number of beams picked by this automated procedure can yield results comparable to a large number of manually placed orientations. METHODS AND MATERIALS The automated beam selection procedure maximizes an unconstrained objective function composed of target equivalent uniform dose (EUD) and critical structure dose-volume histogram (DVH) constraints. Beam orientations are selected from a large feasible set of directions through a series of alternating fluence optimization and orientation alteration steps, until convergence to a stable orientation set. The fluence optimization step adjusts fluences to maximize the objective function. The orientation alteration step substitutes beams in the orientation set currently under consideration with beams of the parent set in the immediate angular vicinity; the altered orientation set is deemed current if it produces a higher objective function value in the fluence optimization step. RESULTS AND CONCLUSIONS It is demonstrated, for prostate IMRT planning, that a modest number of appropriately selected beam orientations (3 or 5) can provide dose distributions as satisfactory as those produced by a large number of unselected equispaced orientations. Such selected beam orientations can reduce overall treatment time, thus making IMRT more clinically practical.
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Affiliation(s)
- Shiva Das
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA.
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29
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Bolch WE, Patton PW, Rajon DA, Shah AP, Jokisch DW, Inglis BA. Considerations of marrow cellularity in 3-dimensional dosimetric models of the trabecular skeleton. J Nucl Med 2002; 43:97-108. [PMID: 11801712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
UNLABELLED Dose assessment to active bone marrow is a critical feature of radionuclide therapy treatment planning. Skeletal dosimetry models currently used to assign radionuclide S values for clinical marrow dose assessment are based on bone and marrow cavity chord-length distributions. Accordingly, these models cannot explicitly consider energy loss to inactive marrow (adipose tissue) during particle transport across the trabecular marrow space (TMS). One method to account for this energy loss is to uniformly scale the resulting TMS absorbed fractions by reference values of site-specific marrow cellularity. In doing so, however, the resulting absorbed fractions for self-irradiation of the trabecular active marrow (TAM) do not converge to unity at low electron source energies. This study attempts to address this issue by using nuclear magnetic resonance microscopy images of trabecular bone to define 3-dimensional (3D) dosimetric models in which explicit spatial distributions of adipose tissue are introduced. METHODS Cadaveric sources of trabecular bone were taken from both the femoral heads and humeral epiphyses of a 51-y-old male subject. The bone sites were sectioned and subsequently imaged at a proton resonance frequency of 200 MHz (4.7 T) using a 3D spin-echo pulse sequence. After image segmentation, voxel clusters of adipocytes were inserted interior to the marrow cavities of the binary images, which were then coupled to the EGS4 radiation transport code for simulation of active marrow electron sources. RESULTS Absorbed fractions for self-irradiation of the TAM were tabulated for both skeletal sites. Substantial variations in the absorbed fraction to active marrow are seen with changes in marrow cellularity, particularly in the energy range of 100-500 keV. These variations are seen to be more dramatic in the humeral epiphysis (larger marrow volume fraction) than in the femoral head. CONCLUSION Results from electron transport in 3D models of the trabecular skeleton indicate that current methods to account for marrow cellularity in chord-based models are incomplete. At 10 keV, for example, the Eckerman and Stabin model underestimates the self-absorbed fraction to active marrow by 75%. At 1 MeV, the model of Bouchet et al. overestimates this same value by 40%. In the energy range of 20-200 keV, neither model accurately predicts energy loss to the active bone marrow. Thus, it is proposed that future extensions of skeletal dosimetry models use 3D transport techniques in which explicit delineation of active and inactive marrow is feasible.
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Affiliation(s)
- Wesley E Bolch
- Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, Florida 32611-8300, USA.
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Kordelle J, Richolt JA, Millis M, Jolesz FA, Kikinis R. Development of the acetabulum in patients with slipped capital femoral epiphysis: a three-dimensional analysis based on computed tomography. J Pediatr Orthop 2001; 21:174-8. [PMID: 11242245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Orientation and shape of the acetabulum were determined by the use of three-dimensional reconstruction of computed tomography (CT) data sets in 22 patients with a total of 30 slipped capital femoral epiphyses. We developed an interactive three-dimensional software program to measure the anteversion and inclination of the acetabulum without projectional and pelvis-tilting errors. Furthermore, we determined the height, width, depth, volume, and surface of the acetabulum as parameters describing the acetabular shape. Comparison of the affected side with the contralateral unaffected hip showed no significant differences for acetabular orientation and shape. The relationship between the degree of the slip and the acetabular orientation was calculated. No correlation was found. Based on the results of this study, we conclude that the slipping of the capital femoral epiphysis has no influence on acetabular development.
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Affiliation(s)
- J Kordelle
- Department of Radiology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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Khoo VS, Bedford JL, Webb S, Dearnaley DP. Evaluation of the optimal co-planar field arrangement for use in the boost phase of dose escalated conformal radiotherapy for localized prostate cancer. Br J Radiol 2001; 74:177-82. [PMID: 11718391 DOI: 10.1259/bjr.74.878.740177] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The aim of this study was to determine the optimal co-planar beam arrangement from a variety of three-field (3F), four-field (4F) and six-field (6F) plans for the boost phase of a dose escalated conformal radiotherapy schedule. Three selected plans (3F 0 degrees, 90 degrees, 270 degrees plan, 4F 45 degrees, 90 degrees, 270 degrees, 315 degrees plan and 6F 40 degrees, 90 degrees, 115 degrees, 245 degrees, 270 degrees, 320 degrees plan) were compared with reference plans (3F 0 degrees, 120 degrees, 240 degrees plan, 4F 0 degrees, 90 degrees, 180 degrees, 270 degrees plan, 6F 55 degrees, 90 degrees, 125 degrees, 235 degrees, 270 degrees, 305 degrees plan and 6F 50 degrees, 90 degrees, 130 degrees, 230 degrees, 270 degrees, 310 degrees plan) in 10 patients. Doses of 64 Gy and 74 Gy were prescribed to the isocentre using 6 MV photons. The boost planning target volume comprised the prostate gland alone without a margin. Plans were compared by means of rectal volumes irradiated to >50% (V50), >80% (V80) and >90% (V90) of the prescribed dose. Irradiated volumes were also measured for the bladder (V90) and the femoral heads (V70). All optimal 3F, 4F and 6F plans gave lower irradiated rectal V80 and V90 levels than their corresponding reference plan. The 3F (0 degrees, 90 degrees, 270 degrees) plan consistently provided lower irradiated rectal levels at V50 to V90, with acceptable bladder and femoral head doses compared with the other plans in the study. When the 6F (50 degrees, 90 degrees, 130 degrees, 230 degrees, 270 degrees, 310 degrees) plan used at our institution for the boost phase was compared with the 3F (0 degrees, 90 degrees, 270 degrees) plan, the rectal V50 was reduced from 20.8+/-5.2%, to 12.6+/-5.1%, the rectal V80 was reduced from 8.7+/-2.9% to 6.5+/-3.1% and the rectal V90 was reduced from 5.5+/-2.1% to 3.9+/-2.0% (all p<0.001). The bladder V90 and the femoral heads V70 levels were equivalent. For the boost phase when escalating the dose from 64 Gy to 74 Gy, the co-planar plan that allowed optimal rectal sparing was a 3F beam arrangement using gantry angles of 0 degrees, 90 degrees and 270 degrees. This 3F plan provided improved rectal sparing compared with the 6F (50 degrees, 90 degrees, 130 degrees, 230 degrees, 270 degrees, 310 degrees) beam arrangement currently used at our institution, with equivalent and acceptable bladder and femoral head doses.
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Affiliation(s)
- V S Khoo
- The Academic Unit of Radiotherapy & Oncology, The Institute of Cancer Research and The Royal Marsden NHS Trust, Sutton, Surrey, UK
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Abstract
BACKGROUND AND PURPOSE A series of coplanar three-field configurations for two different clinical treatment volumes, prostate only (PO) and prostate plus seminal vesicles (PSV) were studied to determine the optimal three-field plan arrangement for prostate radiotherapy. MATERIALS AND METHODS A variety of conformal three-field 6 MV plans prescribed to both 64 and 74 Gy were created for PO and PSV volumes in each of ten patients. For description, the orientation of each sequential beam was named in a clockwise fashion. Plans included series with arrangements of 0 degrees, 60-150 degrees, 210-300 degrees; 0 degrees, 90 degrees, 225-255 degrees; 90 degrees, 210-240 degrees, 300-330 degrees and a four-field (4F) box plan for comparison. Six-hundred and eighty plans were compared using the rectal volume irradiated to greater than 50% (V(50)), 80% (V(80)), and 90% (V(90)) of the prescribed dose, normal tissue complications (NTCP) for rectum, bladder, and femoral heads (FH), and tumour control probabilities (TCP). FH tolerance was set at 52 Gy to 10% volume. RESULTS In comparing the 34 different three-field configurations for each of the PO and PSV groups, the greatest rectal sparing was achieved by a three-field plan with gantry angles of 0 degrees, 90 degrees, 270 degrees (PO: rectal V(80)=22.8+/-5.5% (1S.D.), V(90)=18.4+/-5.7%, and PSV: rectal V(80)=41.9+/-5.8%, V(90)=35.5+/-5.9%). This also improved on the 4F-box plan (PO: rectal V(80)=26.0+/-5.8%, V(90)=21.4+/-5.2%, P<0.001; and PSV: rectal V(80)=47.3+/-5.5%, V(90)=41.6+/-5.1%, P<0.001). The worst rectal sparing was seen with the 0 degrees, 120 degrees, 240 degrees plan (PO: rectal V(80)=35.2+/-8.0%, V(90)=30.3+/-7.1%, P<0.001; and PSV: rectal V(80)=65.7+/-9.0%, V(90)=58.8+/-8.8%, P<0.001). In the PO group, the increase in predicted rectal NTCP with dose escalation from 64 to 74 Gy was 3.3% using the 0 degrees, 90 degrees, 270 degrees plan, 4.7% with the 4F-box plan, and 6.9% with the 0 degrees, 120 degrees, 240 degrees plan. In the PSV group, dose escalation increased the predicted rectal NTCP by 7.9, 10.1 and 15.7% for the 0 degrees, 90 degrees, 270 degrees plan, 4F-box plan, and 0 degrees, 120 degrees, 240 degrees plan, respectively. CONCLUSIONS For both PO and PSV volumes, the three-field plan which afforded the greatest rectal sparing with acceptable bladder and femoral head doses was the 0 degrees, 90 degrees, 270 degrees plan. This plan also improved on the 4F-box. The increase in predicted rectal NTCP when escalating dose from 64 to 74 Gy was smaller using this plan compared to either the three-field 0 degrees, 120 degrees, 240 degrees plan or the 4F-box plan.
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Affiliation(s)
- V S Khoo
- The Academic Unit of Radiotherapy and Oncology, The Institute of Cancer Research and The Royal Marsden NHS Trust, Downs Road, Sutton, Surrey, UK
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Fiorino C, Broggi S, Corletto D, Cattaneo GM, Calandrino R. Conformal irradiation of concave-shaped PTVs in the treatment of prostate cancer by simple 1D intensity-modulated beams. Radiother Oncol 2000; 55:49-58. [PMID: 10788688 DOI: 10.1016/s0167-8140(00)00140-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND In the case of concave-shaped PTVs including prostate (P) and seminal vesicles (SV), intensity-modulated radiation therapy (IMRT) should improve the therapeutic ratio of the treatment of prostate cancer. PURPOSE Comparing IMRT by simple 1D modulations with conventional 3D conformal therapy (i.e. non-IMRT) in the treatment of concave-shaped PTVs including P+SV. MATERIALS AND METHODS For five patients having a concave-shaped PTV (P+SV) previously treated at our Institute with conformal radiotherapy, conventional 3- and 4-fields conformal plans were compared with IMRT plans in terms of biological indices. IMRT plans were generated by using five equi-spaced beams with a partial shielding of the rectum obtainable with our single-absorber modulation technique (Fiorino C, Lev A, Fusca M, Cattaneo GM, Rudello F, Calandrino R. Dynamic beam modulation by using a single dynamic absorber. Phys. Med. Biol. 1995;40:221-240). The modulation was one-dimensional and the shape of the beams was at single minimum in correspondence with the 'core' of the rectum; the beam intensity in the minimum was set equal to 20 or 40% of the open beam intensity. All plans were simulated on the CADPLAN TPS using a pencil-beam based algorithm (with 18 MV X-rays). Tumour control probability (TCP) and normal tissue complication probabilities (NTCPs) (for rectum, bladder and femoral head) were calculated for all situations when varying the isocentre dose from 60 to 90 Gy. Dose distributions were corrected taking dose fractionation into account through the linear-quadratic model; for the TCP/NTCP estimations the Webb-Nahum and the Lyman-Kutcher models were respectively applied. Three different scores were considered: (a) increase of TCP while keeping rectum NTCP equal to 5% (TCP(5%)); (b) increase of the uncomplicated tumour control probability (P+); (c) increase of the biological-based scoring function (S+), developed by Mohan et al. (Mohan R, Mageras GS, Baldwin B, Clinically relevant optimization of 3D conformal treatments. Med. Phys. 1992;19:933-944). The impact of the uncertainty in the knowledge of the parameters of the biological models was investigated for TCP(5%). RESULTS (a) The average gain in TCP(5%) when considering IMRT against non-IMRT conformal plans was 7.3% (range 5.0-13.5%); (b) the average increase of P+ was 3.4% (range: 1. 0-8.5%); and (c) the average increase of S+ was 5.4% (range 2.9-12. 4%). The largest gain was found for one patient (patient 5) showing a significantly larger overlapping between PTV and rectum. CONCLUSIONS Simple 1D-IMRT may clearly improve the therapeutic ratio in the treatment of concave-shaped PTVs including P and SV. In the range of clinically suitable values, the impact of the uncertainty of the parameters n and sigma(alpha) does not significantly alter the main results concerning the gain in TCP(5%). The reported gain in terms of P+ and S+ should be considered with great caution because of the intrinsic uncertainties of the model's parameters and, for bladder, because the 'true' DVH (considering variations of the shape and dimension due to variable filling) may be very different from the DVH calculated on a single CT scan. Further investigations should consider inversely-optimised 1D and 2D-IMRT plan in order to compare them in terms of cost-benefit.
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Affiliation(s)
- C Fiorino
- Servizio di Fisica Sanitaria, H. San Raffaele, Via Olgettina 60, 20132, Milano, Italy
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Oh CE, Antes K, Darby M, Song S, Starkschall G. Comparison of 2D conventional, 3D conformal, and intensity-modulated treatment planning techniques for patients with prostate cancer with regard to target-dose homogeneity and dose to critical, uninvolved structures. Med Dosim 2000; 24:255-63. [PMID: 10643734 DOI: 10.1016/s0958-3947(99)00030-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The purpose of this study was to compare 2-dimensional (2D), 3-dimensional (3D) and intensity-modulated radiation therapy (IMRT) techniques for external-beam radiation treatment for prostate cancer. Dose homogeneity within the target volume and doses to critical, uninvolved anatomic structures were evaluated. Computed tomography (CT) scans of 3 patients with localized prostate cancer (T2NOM0) were acquired and transferred to the treatment planning systems. The target volume and uninvolved structures were contoured on axial CT slices throughout the volume of interest. A comparison of the 3 treatment techniques was performed using isodose distributions, dose statistics, and dose-volume histograms. Dose homogeneity was found to be most uniform with the 2D technique; however, the 2D technique delivers unnecessary radiation doses to the rectum and bladder. The dose conformity observed with IMRT is increased compared with that observed with the 3D technique, as is the sparing of critical uninvolved structures; however, dose homogeneity appears to be worse with IMRT than with the 3D technique. Overall, of the 3 techniques, IMRT offers the most conformity in delivery of tumoricidal doses to the prostate while sparing dose to critical, uninvolved structures. Association of Medical Dosimetrists.
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Affiliation(s)
- C E Oh
- Department of Medical Physics, University of Texas Southwestern Moncrief Cancer Center, Fort Worth, USA
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Abstract
The purpose of this paper is to compare the femoral head dose distribution of 6-MV x-rays vs. 10-MV x-rays when treating prostate patients using a 4-field initial box technique with a Michigan technique boost. First, tissue maximum ratio (TMR) calculations were utilized to project the expected dose contributions to the femoral heads from each energy based upon the average male pelvis. Then, plans for both the 6- and 10-MV energies were developed for 5 prostate patients using the ADAC Pinnacle3 (Milpitas, CA) treatment planning computer. Average doses and dose gradients were determined by examination of isodose curves. The dose contributions to the femoral heads were analyzed and compared with the tolerance dose (TD) 5/5 for this region. No significant dose differences existed between the 6- and 10-MV photon energies. This conclusion was supported by examination of point doses at depths of 3, 6, 12, and 15 cm for each energy.
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Affiliation(s)
- J R Tanner
- Medical College of Georgia Dosimetry Program, Augusta, USA
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Abstract
BACKGROUND AND PURPOSE Conformal radiotherapy of the prostate is an increasingly common technique, but the optimal choice of beam configuration remains unclear. This study systematically compares a number of coplanar treatment plans for four-field irradiation of two different clinical treatment volumes: prostate only (PO) and the prostate plus seminal vesicles (PSV). MATERIALS AND METHODS A variety of four-field coplanar treatment plans were created for PO and PSV volumes in each of ten patients. Plans included a four-field 'box' plan, a symmetric plan having bilateral anterior and posterior oblique fields, a plan with anterior oblique and lateral fields, a series of asymmetric plans, and a three-field plan having anterior and bilateral fields for comparison. Doses of 64 and 74 Gy were prescribed to the isocentre. Plans were compared using the volume of rectum irradiated to greater than 50% (V50), 80% (V80) and 90% (V90) of the prescribed dose. Tumour control probabilities (TCP) and normal tissue complication probabilities (NTCP) for the rectum, bladder and femoral heads were also evaluated. Femoral head dose was limited such that less than 10% of each femoral head received 70% of the prescribed dose. RESULTS For the PO group, the optimal plan consisted of anterior oblique and lateral fields (Rectal V80 = 23.8+/-5.0% (1 SD)), while the box technique (V80 = 26.0+/-5.8%) was less advantageous in terms of rectal sparing (P = 0.001). Similar results were obtained for the PSV group (Rectal V80 = 43.9+/-5.0% and 47.3+/-5.5% for the two plan types, respectively, P = 0.001). The three-field plan was comparable to the optimal four-field plan but gave higher superficial body dose. With dose escalation from 64 to 74 Gy, the mean TCP for the optimal plan rose from 52.0+/-2.8% to 74.1+/-2.0%. Meanwhile, rectal NTCP for the optimal plan rose by 3.5% (PO) or 8.4% (PSV), compared to 4.7% (PO) or 10.1% (PSV) for the box plan. CONCLUSIONS For PO volumes, a plan with gantry angles of 35 degrees, 90 degrees, 270 degrees and 325 degrees offers a high level of rectal sparing and acceptable dose to the femoral heads for all patients, while for PSV volumes, the corresponding plan has gantry angles of 20 degrees, 90 degrees , 270 degrees and 340 degrees. Using these plans, the gain in TCP resulting from dose escalation can be achieved with a smaller increase in anticipated rectal NTCP.
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Affiliation(s)
- J L Bedford
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Trust, Sutton, Surrey, UK
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Koswig S, Dinges S, Buchali A, Böhmer D, Salk J, Rosenthal P, Harder C, Schlenger L, Budach V. [Comparison of different 3-dimensional irradiation techniques in local radiotherapy of prostatic carcinoma]. Strahlenther Onkol 1999; 175:10-6. [PMID: 9951512 DOI: 10.1007/bf02743455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
PURPOSE Four different three-dimensional planning techniques for localized radiotherapy of prostate cancer were compared with regard to dose homogeneity within the target volume and dose to organs at risk, dependent upon tumor stage. PATIENTS AND METHODS Six patients with stage T1, 7 patients with stage T2 and 4 patients with stage T3 were included in this study. Four different 3D treatment plans (rotation, 4-field, 5-field and 6-field technique) were calculated for each patient. Dose was calculated with the reference point at the isocenter (100%). The planning target volume was encompassed within the 95% isodose surface. All the techniques used different shaped portal for each beam. Dose volume histograms were created and compared for the planning target volume and the organs at risk (33%, 50%, 66% volume level) in all techniques. RESULTS The 4 different three-dimensional planning techniques revealed no differences concerning dose homogeneity within the planning target volume. The dose volume distribution at organs at risk show differences between the calculated techniques. In our study the best protection for bladder and rectum in stage T1 and T2 was achieved by the 6-field technique. A significant difference was achieved between 6-field and 4-field technique only in the 50% volume of the bladder (p = 0.034), between the 6-field and rotation technique (all volume levels) and between 5-field and rotation technique (all volume levels). In stage T1, T2 6-field and 4-field technique in 50% (p = 0.033) and 66% (p = 0.011) of the rectum volume. In stage T3 a significant difference was not observed between the 4 techniques. The best protection of head of the femur was achieved by the rotation technique. CONCLUSION In the localized radiotherapy of prostate cancer in stage T1 or T2 the best protection for bladder and rectum was achieved by a 3D-planned conformal 6-field technique. If the seminal vesicles have been included in the target volume and in the case of large planning target volume other techniques should be taken for a better protection for organs at risk e. g. a 3D-planned 4-field technique box technique.
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Affiliation(s)
- S Koswig
- Klinik für Strahlentherapie, Charité, Humboldt-Universität Berlin
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Fiorino C, Reni M, Cattaneo GM, Bolognesi A, Calandrino R. Comparing 3-, 4- and 6-fields techniques for conformal irradiation of prostate and seminal vesicles using dose-volume histograms. Radiother Oncol 1997; 44:251-7. [PMID: 9380824 DOI: 10.1016/s0167-8140(97)00066-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE Comparing some isocentric coplanar techniques for conformal irradiation of prostate and seminal vesicles. MATERIALS AND METHODS Five conformal techniques have been considered: (A) a 3-fields technique with an antero-posterior (AP) field and two lateral (LAT-LAT) 30 degrees wedged fields; (B) a 3-fields technique with an AP field and two oblique posterior (OBL) 15 degrees wedged fields with relative weights of 0.8, 1 and 1, respectively; (C) a 4-fields technique (AP-PA and LAT-LAT); (D) a 6-fields technique (LAT-LAT and four OBL at gantry angles 45 degrees, 135 degrees, 235 degrees and 315 degrees) with all the fields having the same weight; (E) the same 6-fields technique with lateral fields double-weighted with respect to the oblique fields. The conformal plans have been simulated on 12 consecutive patients (stages B and C) by using our 3D treatment planning system (Cadplan 2.7). The contours of the rectum, the bladder and the left femoral head were outlined together with the clinical target volume (CTV) which included the prostate and the seminal vesicles. A margin of 10 mm was added to define the planning target volume (PTV) through automatic volume expansion. Then a 7 mm margin between the PTV and block edges was added to take the beam penumbra into account. Dose distributions were normalised to the isocentre and the reference dose was considered to be 95% of the isocentre dose. Dose-volume histograms and dose statistics of the rectum, the bladder and the left femoral head were collected for all plans. For the rectum and the bladder the mean dose (Dm) and the fraction of volume receiving a dose higher than the reference dose (V95) were compared. For the femoral head, the mean dose together with the fraction of volume receiving a dose higher than 50% (V50) were compared. RESULTS Differences among the techniques have been found for all three considered organs at risk. When considering the rectum, technique A is better than the others both when considering Dm and V95 (P = 0.002), while technique D is the worst when considering Dm (P < 0.002) and is also worse than techniques A, E (P = 0.002) and C (P = 0.003) when considering V95. Technique E is the best when considering the bladder mean dose (P = 0.002 against A and D, P < 0.01 against B and C) and technique C is the worst (P < 0.012). No relevant differences were found for the bladder V95. In the femoral heads, techniques A and E are worse than B, C and D (P < 0.003) when considering Dm and V50. Moreover, techniques B and D are better than C (P < 0.004) when considering V50. CONCLUSIONS There is no technique that is absolutely better than the others. Technique A gives the best sparing of the rectum; the bladder is better spared with technique E. These results are reached with a worse sparing of the femoral heads which should be carefully taken into account.
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Affiliation(s)
- C Fiorino
- Servizio di Fisica Sanitaria, H. San Raffaele, Milan, Italy
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Abstract
Historically, four perpendicular treatment fields or bilateral arcs have been used in the treatment of prostate cancer. "New techniques" including four conformal fields, seven conformal fields, 120 degrees bilateral conformal coplanar, and non-coplanar arc'ed beam arrangements, are replacing the "older" approaches. These techniques result in a reduction in doses to adjacent critical structures while covering the clinical target volume (CTV). This study, analyzes the impact of random or systematic isocenter displacement errors (IDE) associated with the delivery of radiotherapy, using the best of these "newer techniques". Dose Volume Histograms (DVH) were used to evaluate the dose to the prostate and surrounding normal tissues with 0.3 cm, 0.5 cm and 0.8 cm IDE. It was determined that IDE associated with fixed coplanar treatment techniques could reduced the prescribed dose to the prostate by 0-8%, the coplanar are technique reduced the prescribed prostate dose by 3-10%, and the noncoplanar conformal arc technique could lower the prescribed prostate dose by 0-5%. Predictably, 0.3 cm IDE found in the posterior and inferior direction increase the dose to the rectum by 5-12% and lowered the dose to the bladder by 4-8%. Errors in the superior and anterior direction increased the dose to the bladder by 4-8% and decreased the dose to the rectum by 8-10%. Errors in the right to left direction slightly increased the dose to the ipsilateral femoral head. Doses to the rectum and bladder associated with 0.5 cm and 0.8 cm IDE are significantly larger. The frequency and magnitude of IDE must be accounted for before higher doses can be delivered safety. Recognizing the impact of IDE on our ability to deliver the prescribed dose to the planning target volumes (PTV) could incorporate the impact of IDE during the planning process.
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Affiliation(s)
- B Pickett
- Department of Radiation Oncology, University of California, San Francisco UCSF/Mt. Zion Cancer Center, USA
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Neal AJ, Oldham M, Dearnaley DP. Comparison of treatment techniques for conformal radiotherapy of the prostate using dose-volume histograms and normal tissue complication probabilities. Radiother Oncol 1995; 37:29-34. [PMID: 8539454 DOI: 10.1016/0167-8140(95)01619-r] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The aim of this study was to evaluate the relative merits of the coplanar field arrangements most frequently used for conformal radiotherapy of the prostate using dose-volume histograms and normal tissue complication probabilities (NTCPs). Twelve patients with early prostate cancer underwent a planning CT scan of the pelvis. Isocentric plans for each patient were devised using three, four, six and eight conformal fields and beam-weights optimised using fast simulated annealing to give a dose homogeneity across the planning target volume of +/- 5% or better while minimising irradiation of the relevant organs at risk. The plans were then evaluated using dose-volume histograms of the organs at risk (bladder, rectum and both femoral heads) and the Lyman model of normal tissue complication probability for the rectum. Analysis of dose-volume histogram data averaged over the 12 patients indicates an advantage for six (p = 0.002) and eight (p = 0.0001) fields with respect to the percentage volume of the femoral heads receiving > 50% of the prescribed dose compared with three fields. There was a similar advantage for six (p = 0.0007) and eight (p = 0.0001) fields compared with four fields. Ranking of the treatment techniques indicates that the four-field technique is the worst with respect to femoral head irradiation but the best with respect to reducing rectal irradiation. A higher dose can be prescribed to the isocentre with the four-field technique for a 5% rectal NTCP. The six-field technique led to sparing of the bladder when the different treatment techniques were ranked using bladder dose-volume histogram data. We conclude that none of the techniques studied consistently proved to be superior when applied to this sample of patients with prostate cancer with respect to sparing all the organs at risk. The absolute differences between techniques are small and would be very difficult to detect with respect to clinically relevant endpoints.
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Affiliation(s)
- A J Neal
- Academic Radiotherapy Unit, Institute of Cancer Research and Royal Marsden NHS Trust, Sutton, UK
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Pickett B, Roach M, Horine P, Verhey L, Phillips TL. Optimization of the oblique angles in the treatment of prostate cancer during six-field conformal radiotherapy. Med Dosim 1994; 19:237-54. [PMID: 7893358 DOI: 10.1016/s0958-3947(16)30032-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Historically, four perpendicular treatment fields or bilateral arcs have been used in the treatment of prostate cancer. As new techniques challenge the four-field box technique for their superiority of tumor coverage and adjacent critical structure sparing, oblique beam angles (in addition to right and left laterals) have been introduced as an alternative to anterior (AP) and posterior (PA) beams. Among the most popular of these alternative approaches is a six-field technique. Traditionally 45 degrees angles have been used with this technique. In this study, opposed coplanar oblique beams angled 20, 25, 30, 35, 40, and 45 degrees off the lateral beam position, were compared for their ability to minimize adjacent critical structure doses, while maintaining maximum clinical target volume (CTV) coverage. This analysis compared rectum, bladder, and femoral head dose volume histograms (DVH) for each of these varying oblique gantry angles. As the angle of the posterior oblique beams became more horizontal, it is more difficult to encompass the apex of the prostate in the 95% isodose value. On inferior CT slices near the apex of the prostate, the density of the pelvic bones in the path of the posterior oblique fields causes the beam to be slightly attenuated, thereby underdosing the CTV. The oblique angles most affected by this bone heterogeneity are beams angled from 20 to 30 degrees off the lateral beam position. As the angles approach the vertical direction, rectal and bladder doses increase, while femoral head doses decrease. Oblique gantry angles approaching the horizontal direction result in a decrease in rectal and bladder doses, while femoral head doses increase. Of the oblique angles studied, 35 degrees off the lateral position provides lower rectum and bladder doses than 30, 40, and 45 degrees; lower femoral head doses than 20, 25, and 30 degrees, and the maximum CTV coverage on all CT slices studied.
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Affiliation(s)
- B Pickett
- University of California, San Francisco 94143
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42
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Delaere O, Orloff S, Autrique JC, Nyssen-Behets C, Dambrain R, Dhem A. Long-term sequelae of pelvis irradiation: histological and microradiographical study of a femoral head. Clin Rheumatol 1991; 10:206-10. [PMID: 1914423 DOI: 10.1007/bf02207666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Despite the lack of radiological signs, a femoral head showed histological and microradiographical features of osteonecrosis, 54 years after massive irradiation of the right hip. Intertrabecular spaces were invaded by connectivo-vascular tissue with focal accumulation of mast cells, and several resorption foci were filled with mononucleated cells. Moreover, all the microradiographs showed peculiar hypercalcified lines, sometimes containing empty osteocytic lacunae, the origin of which is difficult to precise. This study suggests that massive irradiation of weight-bearing epiphyses may be responsible for particularly long-term hypovascularity, osteonecrosis and disturbed bone remodeling.
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Affiliation(s)
- O Delaere
- Human Anatomy Research Unit, Catholic University of Louvain, Brussels, Belgium
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43
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Abstract
A model is presented to predict adult stature in children treated successfully for cancer outside the CNS. The model is based on radiation dose in Gray adjusted for location of therapy and attained stature (GALA); ideal adult stature (IAS), assuming the patient had not developed cancer, calculated by the Roche-Wainer-Thissen (RWT) method (which uses patient stature and weight before developing cancer, and parent stature data); a femur correction if both the acetabula or heads of both femurs were irradiated (FEMUR); and sex. The model was constructed using data from 49 patients with a mean time from completion of therapy to follow-up of 8.9 years (range, 3.3 to 15.4 years). Thirteen patients received no radiotherapy. All model coefficients were highly significant (P less than .001), and the model appears to be an excellent predictor of adult stature, with a multiple correlation coefficient of 0.84 (R2 = .74) between corrected adult stature (CAS) based on the most recent follow-up stature available for the patient projected to final adult stature, compared with the model's predicted adult stature (MPAS), based only on initial data at presentation and subsequent radiation treatment. Patients who did not receive radiotherapy did not have loss of stature, ie, there was no significant difference between IAS and CAS, (P less than .71; n = 13), but patients who received radiotherapy had shorter statures than would be expected from the healthy population model (P less than .0004; n = 36). The magnitude of the loss in stature appears to be well explained by the dose and location of radiation, the stature already achieved at the time of radiotherapy, along with IAS, FEMUR, and sex. We believe this model will help clinicians to predict the growth effects of radiotherapy in children with cancer not involving the CNS.
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Affiliation(s)
- J H Silber
- Department of Pediatrics, Children's Hospital, Philadelphia, PA 19104
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Silverman CL, Thomas PR, McAlister WH, Walker S, Whiteside LA. Slipped femoral capital epiphyses in irradiated children: dose, volume and age relationships. Int J Radiat Oncol Biol Phys 1981; 7:1357-63. [PMID: 7319860 DOI: 10.1016/0360-3016(81)90031-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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45
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de Sèze S, Mazabraud A. [Parcelled necrosis of the femur head]. Rev Rhum Mal Osteoartic 1971; 38:1-15. [PMID: 5549165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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47
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Vertova F, Fava G. [Clinical, biological and dosimetric problems in "radiotherapeutic hips" due to HIGH ENERGY RADIOTHERAPY]. Radiol Med 1968; 54:1271-84. [PMID: 4980662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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48
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Fries G. [Orthopedic treatment possibilities in radiation necrosis of the hip]. Geburtshilfe Frauenheilkd 1968; 28:40-50. [PMID: 5668620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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49
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HIRAYAMA P. [Osteoradionecrosis of the coxa end of the femur after irradiation of genital cancer]. Z Orthop Ihre Grenzgeb 1962; 96:286-90. [PMID: 13907645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
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