Brachytherapy for cervix cancer: low-dose rate or high-dose rate brachytherapy - a meta-analysis of clinical trials

Redefining the role of pulsed-dose-rate brachytherapy in cervical cancer treatment using a preplanned approach

INTRODUCTION

This study aims to determine predictive factors for cervical cancer patients who would benefit more from high-dose-rate (HDR) or pulsed-dose-rate (PDR) brachytherapy.

METHODS

The sample included 50 patients treated with brachytherapy following external radiochemotherapy. PDR plans were compared to HDR preplans, with a focus on patients who may benefit from PDR using preplan metrics and clinical variables. The expected clinical effect was quantified using a tumor control probability model.

RESULTS

Results showed PDR plans with 60 pulses to be optimal for achieving target clinical goals for D90CTVHR. A CTVHR volume of >67.5cc and/or D90CTVHR dose on the HDR preplan of <31.1 Gy was the strongest indicator for patient selection who would gain >3% increase in TCP with PDR. The process showed 96% accuracy, 88% sensitivity, and 98% specificity. Only 16% of patients showed a relevant benefit from PDR over HDR, with a mean D90CTVHR of 7 Gy higher and a mean TCP at 3 years of 4.8% higher for PDR. The benefit of PDR is highly influenced by the choice of alpha/beta ratio and repair halftime.

CONCLUSION

A small subset of cervical cancer patients may gain from PDR over HDR. CTVHR volume and preplan D90CTVHR doses may be useful in selecting patients for PDR brachytherapy.

External Beam Radiotherapy Interdigitated with High Dose Rate(HDR) Intracavitary Brachytherapy versus External Beam Radiotherapy followed by Sequential HDR Intracavitary Brachytherapy for Locally Advanced Carcinoma Cervix-Randomized Control Study

BACKGROUND

In cervical cancer treatment, overall treatment time (OTT) is an important prognostic factor. This study compares the clinical outcomes when High-Dose-Rate Intracavitary-Brachytherapy(HDR-ICRT) is interdigitated with external beam radiotherapy(EBRT) versus sequential HDR-ICRT after EBRT in the treatment of locally advanced carcinoma cervix.

METHODS

Histologically confirmed carcinoma cervix patients [FIGO Stage IIB-IVA (except IIIC-2)] were included and randomized into two groups. The study group received EBRT 50Gy in 25 fractions with interdigitated HDR-ICRT 7Gy per fraction weekly for three fractions starting after completion of 3 weeks of EBRT or as soon as cervical os became negotiable thereafter. Patients in the control group received EBRT 50Gy in 25 fractions with sequential HDR-ICRT 7Gy per fraction weekly for three fractions starting one week after completion of EBRT. All patients were regularly followed up during and after radiotherapy for local toxicity and disease control.

RESULTS

This study enrolled 102 patients; 51 in each arm. Median OTT in study and control arm were 46 and 60 days, respectively. Median follow-up duration was 24 months (two years). Loco-regional control after two years of follow-up was 84.31 % and 72.54% of patients in study arm control arm respectively (p-value 0.148). Two (3.92%) patients from study arm and eight (15.68%) from control arm had residual disease. Two patients in study arm and one from control arm had local recurrence. Two patients from study arm three patients from control arm developed distant metastases. RTOG mucosal grade III acute mucosal toxicity in either arm. Cervical-os negotiability was limiting factor for interdigitated HDR-ICRT.

CONCLUSIONS

Interdigitated HDR-ICRT with EBRT may give local control with manageable toxicities as compared to sequential HDR-ICRT, with the advantage of significant reduction in OTT.
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Outcome analysis of HDR compared to PDR IGABT in locally advanced cervical cancer: a single-center cohort analysis

PURPOSE

This monocentric study aimed to assess the impact of technical advancement in brachytherapy (BT) on local control (LC) and cancer-specific survival (CSS) in locally advanced cervical cancer (LACC).

METHODS

Since 2010, 211 patients with LACC have been treated with 45/50.4 Gy or 60 Gy radiochemotherapy (RTCT) followed by image-guided adaptive brachytherapy (IGABT) at the authors' institution. In 2013, combined intracavitary and interstitial brachytherapy (BT IC/IS) was implemented and in 2018, pulsed-dose-rate BT (PDR-BT) was replaced by high-dose-rate BT (HDR-BT). LC, CSS, and morbidity according to the RTOG/EORTC scoring system were analyzed. Dose-volume parameters for the high-risk clinical target volume (HRCTV) and organs at risk (OAR) were reported.

RESULTS

While 27 (12.8%) patients died of LACC, complete local remission was achieved in 199 (94.3%). Local relapse decreases with a high D95 in the HRCTV (hazard ratio, HR = 0.85, p = 0.0024). D95 in the HRCTV is lower after 60 Gy even if interstitial BT is used. Mean D95 in the HRCTV is 78.2 Gy, 83.3 Gy, and 83.4 Gy with PDR-BT IC, PDR-BT IC/IS, and HDR-BT IC/IS, respectively, after 45/50.4 Gy. D2 cc of OARs is significantly reduced by using interstitial BT. The mean rectum and sigmoid D2 cc are about 61.5 Gy with PDR-BT IC/IS and significantly decreased with HDR-BT IC/IS. This translates into a low fistula incidence. A very low rate of severe gastrointestinal (3.4%) and genitourinary (2.3%) toxicity was observed with HDR-BT IC/IS.

CONCLUSION

This large monocentric study provides further evidence that implementation of BT IC/IS has an impact on D95 in the HRCTV, LC, and CSS. There are no differences between HDR and PDR in terms of efficacy, D95 in the HRCTV, and toxicity grade ≥ 3.

Low-Dose-Rate versus High-Dose-Rate intracavitary brachytherapy in cervical cancer - Final Results of a Phase III randomized trial

PURPOSE

Intracavitary brachytherapy using High-Dose-Rate (HDR) and Low-dose-rate (LDR) in cervical cancer has been utilized. We report the long-term final results of a large randomized trial in terms of toxicities and efficacy.

METHODS AND MATERIALS

Between 1996 to 2005, 816 patients were randomized to LDR (n = 441 patients) or HDR brachytherapy (n = 369 patients) stratified by FIGO Stage grouping. Patients with Stage I-II received external irradiation of 40 Gy in 20 fractions (with midline block (MLB)) followed by either 2 LDR Intracavitary applications of 30 Gy to point A (2-3 weeks apart) or 5 HDR Intracavitary applications of 7 Gy to point A once weekly. Patients with Stage III received 50 Gy in 25 fractions (with MLB after 40 Gy) followed by either one application of LDR 30 Gy to point A or three applications of HDR 7 Gy to point A once weekly.

RESULTS

With a median follow-up was 64 months (interquartile range [IQR]: 21 - 111), moderate to severe rectal and bladder complications were higher in LDR arm as compared to HDR arm (9.7% vs. 3.6%; p = 0.02) and (10.5% vs. 5.5%; p = 0.06) for Stage I-II. No difference in rectal or bladder complications for Stage III patients. Disease free and overall survivals were similar in both the arms for all stages.

CONCLUSIONS

HDR intracavitary brachytherapy with 7 Gy per fraction weekly is superior to LDR in terms of late rectal and bladder complications. Local control rates and survivals are similar irrespective of stages.

Outcomes of patients with cervical cancer treated with low- or high-dose rate brachytherapy after concurrent chemoradiation

OBJECTIVE

The majority of patients with cervical cancer in Ghana present with locally advanced disease. In October 2014, high-dose rate (HDR) brachytherapy was introduced at the National Center for Radiotherapy, Accra after years of using low-dose rate (LDR) brachytherapy. The aim of this study was to compare the treatment outcomes of patients treated with LDR versus HDR brachytherapy.

METHODS

Patients with cervical cancer treated from January 2008 to December 2017 were reviewed. Those with stage IB-IIIB who received chemoradiation plus brachytherapy were included in the study. Post-operative patients and those with stage IV were excluded. The study end points were local control, disease-free survival, and overall survival at 2 years. Endpoints were estimated using the Kaplan-Meier method. Comparisons between treatment groups were performed using the log-rank test and Cox proportional hazards model.

RESULTS

We included 284 LDR and 136 HDR brachytherapy patients. For stages IB, IIA, IIB, IIIA and IIIB disease, the 2-year local control for LDR versus HDR brachytherapy was 63% and 61% (p=0.35), 86% and 90% (p=0.68), 86% and 88% (p=0.83), 66% and 60% (p=0.56), and 77% and 40% (p=0.005), respectively. The 2-year disease-free survival for LDR versus HDR brachytherapy was 64% and 61% (p=0.50), 81% and 69% (p=0.18), 81% and 80% (p=0.54), 62% and 33% (p=0.82), and 71% and 30% (p=0.001) for stages IB, IIA, IIB, IIIA, and IIIB, respectively. The 2-year overall survival for LDR versus HDR brachytherapy was 94% and 93% (p=0.92), 98% and 68% (p=0.21), 89% and 88% (p=0.60), and 88% and 82% (p=0.34) for stages IB, IIA, IIB, and IIIB disease, respectively.

CONCLUSION

There was no difference between LDR and HDR brachytherapy in local control and disease-free survival for all stages of disease, except in stage IIIB. These findings highlight the need to refine this brachytherapy technique for this group of patients.

The Impact of High-Dose-Rate Brachytherapy: Measuring Clinical Outcomes in the Primary Treatment of Cervical Cancer

Purpose

Radical concurrent chemoradiotherapy with combined external beam radiotherapy (EBRT) and brachytherapy is used to treat locally advanced cervical cancer. Our institution has transitioned to high-dose-rate (HDR) intracavitary brachytherapy (ICBT) from low-dose-rate (LDR) brachytherapy in 2008, and a review was conducted on the effect of this change on patient outcomes.

Methods and Materials

A single-arm retrospective chart review was performed on locally advanced (Fédération Internationale de Gynécologie et d’Obstétrique stage IB-IVA) patients with cervical cancer treated with combined external beam radiation therapy and HDR-ICBT with curative intent between 2008 and 2014. Clinical outcomes were evaluated, and multivariate analysis was performed to identify prognostic factors.

Results

Of the 76 patients selected, median age was 47.9 years and median follow-up was 5.2 years. Thirteen patients (17.1%) developed locoregional recurrence and 23 patients (30.3%) patients developed distant recurrence. Five-year progression-free survival and overall survival were 63.7% and 69.3%, respectively. A significant survival difference was found between stages (P < .001). Multivariate analysis found nodal involvement was strongly associated with poorer survival (P = .007).

Conclusions

Our experience with the transition to HDR-ICBT as part of concurrent chemoradiotherapy in treatment of locally advanced cervical cancer resulted in acceptable long-term outcomes and toxicity to that of LDR brachytherapy. Potential further improvement of treatment outcomes for patients may be possible with image guided brachytherapy and the addition of effective systemic therapy.

High precision radiotherapy including intensity-modulated radiation therapy and pulsed-dose-rate brachytherapy for cervical cancer: a retrospective monoinstitutional study

Purpose

To analyse the survival outcomes and toxicity profile of patients treated with pulsed-dose-rate (PDR) brachytherapy (BT) after intensity-modulated radiation therapy (IMRT) for uterine cervical cancer in a single institution.

Material and methods

Between March 2011 and December 2014, 50 patients with histologically proven stages IB1-IVB cervical cancer were treated with IMRT followed by PDR-BT boost. Radiation treatment consisted of IMRT to pelvic with or without paraaortic lymph nodes to a total dose of 45-50.4 Gy. Weekly concomitant chemotherapy was administered to 45 patients. PDR-BT boost was delivered with a median dose of 30 Gy to the high-risk clinical target volume (HR-CTV) after a median time of 14 days since IMRT. Acute and late toxicity were evaluated by Radiation Therapy Oncology Group (RTOG) - European Organization for Research and Treatment of Cancer (EORTC) scoring criteria and Subjective Objective Management Analytic-Late Effects of Normal Tissues (SOMA-LENT) criteria.

Results

Two patients had tumour persistence at 6 months after the end of BT. After a median follow-up of 33 months, 6 distant metastases with or without regional relapse were observed. The 1- and 5-year progression-free survival was 83% (95% CI: 69-91%) and 76% (95% CI: 61-86%), whereas the 3- and 5-year overall survival was 91% (95% CI: 78-97%) and 76% (95% CI: 56-88%), respectively. Urinary and rectal toxicity higher than grade 2 was observed in 6.3% and 17% of patients, respectively. Five patients (10.6%) had grade 4 gastrointestinal toxicity requiring colostomy.

Conclusions

Our study confirms that the combination of IMRT and PDR-BT can be considered an effective treatment for cervical cancer, ensuring high local control, despite the high percentage of locally advanced disease.

Treatment Outcomes and Dose Rate Effects Following Gamma Knife Stereotactic Radiosurgery for Vestibular Schwannomas

BACKGROUND

Gamma Knife radiosurgery (GKRS; Elekta AB) remains a well-established treatment modality for vestibular schwannomas. Despite highly effective tumor control, further research is needed toward optimizing long-term functional outcomes. Whereas dose-rate effects may impact post-treatment toxicities given tissue dose-response relationships, potential effects remain largely unexplored.

OBJECTIVE

To evaluate treatment outcomes and potential dose-rate effects following definitive GKRS for vestibular schwannomas.

METHODS

We retrospectively reviewed 419 patients treated at our institution between 1998 and 2015, characterizing baseline demographics, pretreatment symptoms, and GKRS parameters. The cohort was divided into 2 dose-rate groups based on the median value (2.675 Gy/min). Outcomes included clinical tumor control, radiographic progression-free survival, serviceable hearing preservation, hearing loss, and facial nerve dysfunction (FND). Prognostic factors were assessed using Cox regression.

RESULTS

The study cohort included 227 patients with available follow-up. Following GKRS 2-yr and 4-yr clinical tumor control rates were 98% (95% CI: 95.6%-100%) and 96% (95% CI: 91.4%-99.6%), respectively. Among 177 patients with available radiographic follow-up, 2-yr and 4-yr radiographic progression-free survival rates were 97% (95% CI: 94.0%-100.0%) and 88% (95% CI: 81.2%-95.0%). The serviceable hearing preservation rate was 72.2% among patients with baseline Gardner-Robertson class I/II hearing and post-treatment audiological evaluations. Most patients experienced effective relief from prior headaches (94.7%), tinnitus (83.7%), balance issues (62.7%), FND (90.0%), and trigeminal nerve dysfunction (79.2%), but not hearing loss (1.0%). Whereas GKRS provided effective tumor control independently of dose rate, GKRS patients exposed to lower dose rates experienced significantly better freedom from post-treatment hearing loss and FND (P = .044).

CONCLUSION

Whereas GKRS provides excellent tumor control and effective symptomatic relief for vestibular schwannomas, dose-rate effects may impact post-treatment functional outcomes. Further research remains warranted.

Comparison of iso-effective and cost-effective high-dose-rate brachytherapy treatment schedules in cervical cancer - regional cancer center experience

Purpose

The study is to evaluate the difference between outcomes of two high-dose-rate fractionation schedules in the treatment of intracavitary brachytherapy (ICBT) of cervical cancer.

Material and methods

A retrospective analysis of 163 cervical cancer patients was completed. All patients received external beam radiotherapy (EBRT) to whole pelvis with concurrent weekly chemotherapy, followed by ICBT with either 7 Gy per fraction in three fractions (arm A) or 9 Gy per fraction in two fractions (arm B). Median follow-up was 19 months. The outcomes were compared in terms of 2-year actuarial local control, disease-free survival, overall survival, and late toxicity in the two treatment arms.

Results

The 2-year actuarial local control rates in arm A and arm B were 88.5% and 91.5%, respectively. The actuarial 2-year disease-free survival rates in arm A and arm B were 85.9% and 82.6%, respectively. The actuarial 2-year overall survival in arm A and arm B were 95.7% and 100%, respectively (p = 0.06). There were 12.7% and 15.2% local failures in arm A and arm B, respectively. Distant metastases were seen in 8.5% and 7.6% in arm A and arm B, respectively. The 2-year actuarial risk of developing late rectal toxicity in arm A and arm B were 5.6% and 5.4%, respectively. The 2-year actuarial risk of developing late bladder toxicity in arm A and arm B were 2.8% and 2.2%, respectively.

Conclusions

ICBT treatment with 9 Gy in two fractions offers equivocal local control rates and survival rates in cancer cervix cases with many advantages of short overall treatment time, improved patient compliance, cost effectiveness, and reduced exposure to aesthetic agents. The toxicities observed were few, low grade, and easily manageable.

Concurrent chemoradiation for cervical cancer: Comparison of LDR and HDR brachytherapy

PURPOSE

To compare clinical outcomes between low-dose-rate (LDR) brachytherapy and high-dose-rate (HDR) brachytherapy for cervical cancer patients.

METHODS AND MATERIALS

All consecutive newly diagnosed cervical cancer patients undergoing pretreatment 18-fluorodeoxyglucose positron emission tomography imaging and treated with curative-intent definitive chemoradiation from 1997 to 2016 at a U.S. academic center were included. Brachytherapy boost was LDR or HDR 2D treatment planning from 1997 to 2005 and HDR with MR-based 3D planning from 2005 to 2016. Local control (LC), cancer-specific survival (CSS), and late bowel/bladder complications were evaluated.

RESULTS

Tumor stages were International Federation of Gynecology and Obstetrics IB1-IIB (n = 457; 75%) and III-IVA (n = 152; 25%). Brachytherapy was LDR for 104 patients and HDR for 505 patients. Concurrent weekly cisplatin was administered to 536 patients (88%). With median followup of 9.4 years, there was no difference in LC (p = 0.24) or CSS (p = 0.50) between LDR and HDR brachytherapy. Cox multivariable regression showed that only International Federation of Gynecology and Obstetrics stage III-IVA (HR=2.4, p = 0.004) was associated with worse LC. A propensity-matched cohort (90 LDR vs. 90 HDR) was created, and the 5-year LC rates were 88% LDR and 82% HDR, p = 0.26; 5-year CSS rates were 66% LDR and 58% HDR, p = 0.19; 5-year grade ≥3 bowel/bladder toxicities were 23% LDR and 16% HDR, p = 0.44. For all patients, the 5-year late toxicity in stage III-IVA patients was higher with LDR 47% vs. HDR 15%, p = 0.03, with no difference in LC, 86% and 75%, respectively (p = 0.09).

CONCLUSIONS

There was no difference in LC with either LDR or HDR brachytherapy. The late complication rate was reduced with HDR and 3D-planned brachytherapy compared to LDR and 2D-planned brachytherapy.

Outcomes of Computed Tomography-Guided Image-Based Interstitial Brachytherapy for Cancer of the Cervix Using GEC-ESTRO Guidelines

Locally advanced cancer of the cervix is treated by concurrent chemoradiation followed by brachytherapy. Interstitial brachytherapy is used to treat large tumors with involvement of parametrium, post-hysterectomy, and narrow, conical vagina. The GYN GEC-ESTRO working group described target volume delineation and also 3D image-based planning using MRI and 3D dose-volume parameters for brachytherapy of carcinoma cervix. CT-based as compared to MR-based image-guided brachytherapy (IGBT) is much more feasible and practical because MR access is still difficult for most departments. This is a retrospective study done to assess the local control in cancer of the cervix, treated based on these guidelines and dose received by 2 cm3 of the rectum as defined by the GEC-ESTRO guidelines and its correlation with long-term toxicity. Sixty-three patients of cancer of the cervix received 45 Gy/25 fractions of external beam radiotherapy with concurrent weekly cisplatin followed by interstitial brachytherapy. A central tandem was inserted into the uterine cavity. The needles were inserted based on the concept of gross tumor volume (GTV), high-risk clinical target volume (HRCTV), and intermediate-risk CTV (IR CTV) as defined by the GYN GEC-ESTRO guidelines. All patients underwent CT-based planning. A dose of 6.5 Gy × 4 fractions was delivered in two sessions such that the HRCTV received a total dose of 26 Gy. Dose optimization was done to prevent 2 cm3 of rectum from receiving > 400 cGy (60% of prescribed dose) per fraction and 2 cm3 of bladder from receiving 500 cGy per fraction. At a median follow-up of 41.5 months (range 6-106 months), 74.6% (47/63) of the patients were alive, with no local, loco-regional, or distant metastasis. Loco-regional control rate was 88% (56/63). Eight percent (5/63) of the patients developed grade I proctitis which was managed conservatively. There was no grades II, III, or IV proctitis. There was no bladder or sigmoid toxicity. GEC-ESTRO guidelines can be modified for CT-based planning also with very minimal late toxicity without compromising local control.

MR Imaging in Gynecologic Brachytherapy

Magnetic resonance-based image-guided adaptive brachytherapy is gaining popularity in the United States in the setting of gynecologic malignancies. This technique improves local control, increases overall survival, and minimizes toxicity to the adjacent organs at risk. The purpose of this article is to familiarize radiologists with image-guided adaptive brachytherapy by describing its history, detailing MR imaging techniques, describing treatment considerations, and reviewing image interpretation.

Californium-252 neutron brachytherapy combined with external pelvic radiotherapy plus concurrent chemotherapy for cervical cancer: a retrospective clinical study

Background

Cervical cancer is the sixth most common cancer in Chinese women. A standard treatment modality for cervical cancer is the combination of surgery, chemotherapy, external-beam radiotherapy and intracavitary brachytherapy. The aim of this study was to retrospectively assess the long-term treatment outcomes of patients with cervical cancer who were treated with californium-252 neutron brachytherapy combined with external-beam radiotherapy plus concurrent chemotherapy.

Methods

We retrospectively analyzed the medical records of 150 patients with primary stages IB-IVB cervical cancer who received neutron brachytherapy combined with external-beam radiotherapy concurrently with cisplatin chemotherapy. All patients were followed up. Using an actuarial analysis, patient outcomes and treatment-related adverse effects were evaluated and compared.

Results

The median overall survival (OS) was 33.2 months. The 3-year progression-free survival rates for patients with stages I–II, III, and IV diseases were 81.0% (68/84), 65.0% (39/60), and 0% (0/6), respectively; the 3-year OS rates were 90.5% (76/84), 85.0% (51/60), and 16.7% (1/6), respectively. Vaginal bleeding was controlled within the median time of 4.0 days. One month after treatment, 97.3% of patients achieved short-term local control. The local recurrence rates for patients with stages I–II, III, and IV disease were 4.8% (4/84), 11.7% (7/60), and 33.3% (2/6), respectively, and the occurrence rates of distant metastasis were 16.7% (14/84), 25.0% (15/60), and 100.0% (6/6), respectively. Cancer stage, tumor size, and lymph node metastasis were identified as prognostic risk factors, but only lymph node metastasis was found to be an independent prognostic factor. The most common adverse effects during treatment were grades 1 and 2 irradiation-related proctitis and radiocystitis.

Conclusion

For patients with cervical cancer, neutron brachytherapy combined with external-beam radiotherapy plus concurrent chemotherapy produces a rapid response and greatly improves local control and long-term survival rates with tolerable adverse effects.

[Prognostic factors of disease-free survival in patients with uterine cervix tumor]

La radiochimiothérapie est le traitement de référence des tumeurs du col localement avancées, et plusieurs études ont montré l'importance des facteurs pronostiques sur le contrôle local de la tumeur et la survie des malades. L'objectif de cette étude est d'évaluer l'impact des facteurs pronostiques, en particulier de l'étalement sur la survie sans récidive des patientes suivies pour cancer du col utérin. Il s'agit d'une série rétrospective portant sur 177 femmes suivies en 2011 pour tumeur du col utérin de stade IB à III selon la classification de FIGO 2009 ayant bénéficié d'une radiothérapie à la dose de 46 Grays sur le pelvis et une surimpression sur les paramètres envahis associée à du cisplatine 40mg/m² par semaine suivie de curiethérapie réalisée selon le mode haut débit de dose (HDR) ou bas débit de dose (LDR). La moyenne d'âge était de 53ans, la médiane de l'étalement total était de 65 jours, 75% des patientes ont reçu 4 cures de chimiothérapie, et les patientes ont été suivies après le traitement pendant une durée médiane de 34 mois. La récidive locale et métastatique était de 33,3% chez les patientes ayant des adénopathies pelviennes, contre 16,3% chez celles qui en étaient indemnes (p= 0,031), elle était de 26,3% chez les patientes ayant un étalement supérieur à 65 jours contre 11% chez celles dont l'étalement en était inférieur (p= 0,01). La présence d'adénopathies pelviennes et l'étalement total de la radiothérapie apparaissaient respectivement comme les seuls facteurs pronostiques indépendant de survenue de récidive, p= 0,04 OR= 2,6 IC95% (1,05 6,3) et p= 0,01 OR= 2,9 IC95% (1,26 6,7). En analyse multivariée, la technique de curiethérapie p = 0,003 OR= 0,25 IC95% (0,1 0,6) et l'étalement total du traitement p= 0,0001 OR= 4,7 IC95% (2 10,8) apparaissaient comme les seuls facteurs pronostiques indépendant de survie sans récidive. L'étalement supérieur à 65 jours et la technique de curiethérapie LDR semblent être les facteurs de mauvais pronostic de survie sans récidive dans notre étude.

High-dose-rate vs. low-dose-rate intracavitary brachytherapy for carcinoma of the uterine cervix: Systematic review and meta-analysis

PURPOSE

We performed a meta-analysis to compare the treatment outcomes between high-dose-rate (HDR) and low-dose-rate (LDR) intracavitary brachytherapy (ICBT) for the treatment of cervical cancer.

METHODS AND MATERIALS

We searched the PubMed database for articles and the related referenced articles that compared HDR-ICBT and LDR-ICBT. A total of 15 published articles, 3 prospective randomized trials, and 12 retrospective studies performed between 1966 and December 2013 were selected using predefined inclusion and exclusion criteria for each study. The effect sizes were obtained from the odds ratios of the 5-year overall survival, 5-year disease-free survival (DFS), pelvic (locoregional) recurrence, and rectal and bladder complication rates in each study. The common effect sizes and 95% confidence intervals (CIs) were calculated using either the fixed or the random-effect model, according to the results of the homogeneity tests.

RESULTS

We analyzed the outcome data for 18,937 patients, including 10,807 patients in the HDR-ICBT treatment group and 8,130 patients in the LDR-ICBT group. The common effect sizes (95% CI) for the 5-year survival rate, 5-year DFS rate, and pelvic recurrence rate were 1.1350 (0.9231-1.3955), 1.0777 (0.4896-2.3720), and 0.9521 (0.7624-1.1890), respectively. The common effect sizes (95% CI) for moderate-to-severe complication rates of the rectum and the bladder were 0.7645 (0.5099-1.1463) and 0.9051 (0.6140-1.3342), respectively. There were no significant differences between HDR- and LDR-ICBT considering the 5-year survival, 5-year DFS, pelvic recurrence, and the rectal and bladder complication rates.

CONCLUSION

The treatment outcome after HDR-ICBT seems to be equivalent to that following LDR-ICBT in terms of survival, pelvic recurrence, and major complications.

Severe gastrointestinal complications in the era of image-guided high-dose-rate intracavitary brachytherapy for cervical cancer

PURPOSE

The purposes of this analysis are to report a modern series of severe gastrointestinal toxic effects after definitive chemoradiotherapy in the treatment of locally advanced cervical cancer at our institution and to review the existing literature on factors that contribute to toxic effects and preventive strategies and management.

METHODS

Our institution's cervical cancer cohort was evaluated for patients with late grade 3 to 4 gastrointestinal toxic effects who were retrospectively reviewed for clinical or dosimetric parameters that could have contributed to late toxic effects. A review of the published literature was performed to identify factors associated with late toxic effects, prophylactic agents, and corrective therapy.

FINDINGS

Five of 85 patients were identified as having late grade 3 to 4 gastrointestinal toxic effects with a median follow-up of 13.3 months. Two of 5 patients developed late grade 3 toxic effects, and 3 of 5 developed late grade 4 toxic effects. Three of the 5 patients reviewed ultimately required permanent colostomies. Cumulative median dose (in equivalent dose in 2-Gy fractions) of clinical target volume to the hottest 90% was 107.2 Gy, rectal dose to the hottest 2 cc (D2cc) was 81.7 Gy, sigmoid D2cc was 61.7 Gy, and bladder D2cc was 79.5 Gy. No patient had evidence of disease recurrence in the pelvis. One patient developed oligometastatic disease in the suprarenal gland and was successfully salvaged with adrenalectomy.

IMPLICATIONS

Despite its risk of toxic effects, intracavitary brachytherapy remains a critical component of the treatment of locally advanced cervical cancer. Even with modern radiotherapy planning and delivery techniques, extra attention is warranted to continue to strive for optimal outcomes.

Cervix cancer brachytherapy: high dose rate

Cervical cancer, although less common in industrialized countries, is the fourth most common cancer affecting women worldwide and the fourth leading cause of cancer death. In developing countries, these cancers are often discovered at a later stage in the form of locally advanced tumour with a poor prognosis. Depending on the stage of the disease, treatment is mainly based on a chemoradiotherapy followed by uterovaginal brachytherapy ending by a potential remaining tumour surgery or in principle for some teams. The role of irradiation is crucial to ensure a better local control. It has been shown that the more the delivered dose is important, the better the local results are. In order to preserve the maximum of organs at risk and to allow this dose escalation, brachytherapy (intracavitary and/or interstitial) has been progressively introduced. Its evolution and its progressive improvement have led to the development of high dose rate brachytherapy, the advantages of which are especially based on the possibility of outpatient treatment while maintaining the effectiveness of other brachytherapy forms (i.e., low dose rate or pulsed dose rate). Numerous innovations have also been completed in the field of imaging, leading to a progress in treatment planning systems by switching from two-dimensional form to a three-dimensional one. Image-guided brachytherapy allows more precise target volume delineation as well as an optimized dosimetry permitting a better coverage of target volumes.

Three-dimensional treatment planning for vaginal cuff brachytherapy: dosimetric effects on organs at risk according to patients position

PURPOSE

Aim of this study was to evaluate dose distribution within organs at risk (OARs) and planning target volume (PTV) based on three-dimensional treatment planning according to two different setup positions in endometrial carcinoma patients submitted to postoperative brachy-radiotherapy on vaginal vault.

METHODS AND MATERIALS

Patients with endometrial cancer necessitating of adjuvant brachytherapy on vaginal vault were enrolled. Pelvic computed tomography studies were prospectively obtained in two different setup positions: extend legs (A position) and gynecological (B position). Contoured OARs were bladder, rectum, and small bowel. The PTV was identified as applicator's surface with an isotropic 5-mm margin expansion. Radiation dose delivered in 1 cc (D1cc) and 2 cc (D2cc) of OAR were calculated.

RESULTS

Coverage of PTV and values of D1cc and D2cc obtained for bladder and small bowel were similar in the two positions. For rectum, both D1cc and D2cc had statistically significant lower values in A with respect to B position.

CONCLUSIONS

Both in A and B positions, radiation doses delivered do not exceed the dose constraints. However, A setup seems to significantly reduce doses to rectum while obtaining the same PTV coverage. The findings from our study provide evidence supporting the use of A position setup for delivering vaginal vault brachytherapy.

Treatment planning methods in high dose rate interstitial brachytherapy of carcinoma cervix: a dosimetric and radiobiological analysis

Treatment planning is a trial and error process that determines optimal dwell times, dose distribution, and loading pattern for high dose rate brachytherapy. Planning systems offer a number of dose calculation methods to either normalize or optimize the radiation dose. Each method has its own characteristics for achieving therapeutic dose to mitigate cancer growth without harming contiguous normal tissues. Our aim is to propose the best suited method for planning interstitial brachytherapy. 40 cervical cancer patients were randomly selected and 5 planning methods were iterated. Graphical optimization was compared with implant geometry and dose point normalization/optimization techniques using dosimetrical and radiobiological plan quality indices retrospectively. Mean tumor control probability was similar in all the methods with no statistical significance. Mean normal tissue complication probability for bladder and rectum is 0.3252 and 0.3126 (P = 0.0001), respectively, in graphical optimized plans compared to other methods. There was no significant correlation found between Conformity Index and tumor control probability when the plans were ranked according to Pearson product moment method (r = −0.120). Graphical optimization can result in maximum sparing of normal tissues.

Pulsed-dose-rate brachytherapy for uterine cervix carcinoma: 10 years of experience with 226 patients at a single institution

PURPOSE

To analyze the long-term results of pulsed-dose-rate (PDR) brachytherapy (BT) in cervical carcinoma patients treated at a single institution.

METHODS AND MATERIALS

All patients with histopathologically proven Stages IB-IVA cervical carcinoma, treated at our institution with PDR intracavitary BT between April 1996 and November 2007, were included in this retrospective analysis. All patients underwent primary pelvic radiotherapy (45 Gy) with concomitant chemotherapy from 1999 and PDR intracavitary BT (16 Gy to the clinical target volume), followed by hysterectomy in 124 patients.

RESULTS

Two hundred twenty-six patients received radiochemotherapy and BT. With a median followup of 81.7 months, the 5-year overall survival, disease-free survival, and local control (LC) were 67%, 65%, and 80%, respectively; seventy-seven relapses were observed including 38 local recurrences. Multivariate analysis showed earlier FIGO (International Federation of Gynecology and Obstetrics) stage and absence of nodal involvement to be associated with better overall and disease-free survivals. Use of three-dimensional image-guided BT planning and absence of nodal involvement were associated with better LC in the multivariate analysis. Late Grade ≥3 toxicity was experienced by 22 patients (9.7%), consisting of gastrointestinal toxicity for 6 patients, urinary tract for 10 patients, lymphatics for 3 patients, and vaginal toxicity for 3 patients.

CONCLUSIONS

This study demonstrates excellent LC rates with few late side effects with PDR BT for cervix carcinoma, similar to those reported in the literature with historical standard low-dose-rate BT.

Non isocentric film-based intracavitary brachytherapy planning in cervical cancer: a retrospective dosimetric analysis with CT planning

Purpose

To compare intracavitary brachytherapy dose estimation for organs at risk (bladder and rectum) based on semi-orthogonal reconstruction of radiographs on non-isocentric X-ray unit and Computed Tomography (CT) – based volumetric planning in cervical cancer.

Material and methods

Bladder and rectal points as per International Commission on Radiation Units and Measurements (ICRU) report 38, were retrospectively evaluated on 15 high dose rate intracavitary brachytherapy applications for cervical cancer cases. With the same source configuration as obtained during planning on radiographs performed on a non-isocentric X-ray unit, the mean doses to 2cc of most irradiated part of bladder and rectum were computed by CT planning and these estimates were compared with the doses at ICRU bladder and rectal points.

Results

The mean ICRU point dose for bladder was 3.08 Gy (1.9-5.9 Gy) and mean dose to 2 cc (D2cc) bladder was 6.91 Gy (2.9-12.2 Gy). ICRU rectal dose was 3.8 Gy (2.4-4.45 Gy) and was comparable with D2cc rectum dose 4.2 Gy (2.8-5.9 Gy). Comparison of mean total dose (ICRU point vs. D2cc) for each patient was found to be significantly different for bladder (p = 0.000), but not for rectum (p = 0.08).

Conclusions

On comparison of ICRU point based planning with volumetric planning on CT, it was found that bladder doses were underestimated by the film based method. However, the rectal doses were found to be similar to the D2cc doses. The results with non isocentric film based treatment planning were similar to the existing literature on orthogonal film based simulator planning.

ACR Appropriateness Criteria® definitive therapy for early-stage cervical cancer

OBJECTIVES

The definitive treatment of early-stage cervical cancer involves multidisciplinary decision making. This expert panel was convened to reach consensus on the selection of appropriate therapies based on patient and disease characteristics at presentation.

METHODS

The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or the treatment.

RESULTS

Three clinical variants were developed to represent common scenarios in the treatment of early-stage cervical cancer. Group members reached consensus on the appropriateness of therapeutic options. This process yielded numerical ratings and descriptive commentary.

CONCLUSIONS

This manuscript represents the consensus opinion of an expert panel based on a survey of all available medical literature. This manuscript may be used to inform the clinical decision making of physicians involved in the treatment of early-stage cervical cancer.

The effects of two HDR brachytherapy schedules in locally advanced cervical cancer treated with concurrent chemoradiation: a study from Chiang Mai, Thailand

Efficacy of different schedules of HDR brachytherapy in concurrent chemoradiotherapy was evaluated. The study compared the effectiveness of the two HDR brachytherapy schedules which have the same Biological Effective Dose (BED) in locally advanced cervical carcinoma that was treated with concurrent chemoradiotherapy. Included in the study were 377 randomly selected patients with advanced carcinoma of the cervix uteri who were treated during the period 2004-2006. Patients were divided into Group I: 7.2 Gy × 3 fractions and Group II: 6 Gy × 4 fractions. With a median follow-up time of 35 months, local control, disease-free survival and overall survival rates were 80.8%, 63.4%, 98.8% in group I and 86.7%, 63.8%, 97.3% in group II, respectively. There was no statistical significance in terms of local control, disease-free survival, overall survival and complication rates between the two treatment schedules which could be observed. Seven patients in group I developed acute grade 2-4 GI toxicities and two patients in group II. In GU toxicities, there were three patients in group I and three patients in group II who developed grade 2-4 toxicities. In late toxicity, no patient developed grade 3-4 GU toxicities in group I while two patients developed grade 3-4 GU toxicities in group II. In GI toxicities, there were five and six patients in group I and group II, respectively, who developed grade 3-4 severity. Both HDR schedules seem to be safe and effective for the treatment of locally advanced cervical cancer.

Preoperative high dose rate brachytherapy for clinical stage II endometrial carcinoma

Purpose

We sought to evaluate pathological response, tolerance, and outcome after preoperative (neoadjuvant) high dose rate brachytherapy in a small series of patients with clinical stage II endometrial carcinoma, and to evaluate a dose and fractionation protocol for this treatment.

Material and methods

Twelve women diagnosed with clinical stage II endometrial carcinoma from 1999-2010 were treated with preoperative radiation therapy. Their medical charts were retrospectively analyzed for HDR treatment regimen, pathological response, and longitudinal outcomes. Radiation doses were normalized to a biologically equivalent dose of 2 Gy per fraction (EQD2).

Results

Two patients had complete pathological response to neoadjuvant therapy; five more had only microscopic residual disease at the time of surgery. At a median follow up of 37 months (1-91 months), one patient has developed recurrence at the vaginal apex six months after completing initial therapy, while another developed a lung recurrence at 28 months. Two-year disease-free and cause-specific survivals were 88% and 100%, respectively.

Conclusions

Our small study shows that the HDR fractionation schedule, as done in our series for preoperative radiation therapy for clinical stage II endometrial cancer, is well tolerated and would be an option for patients treated with neoadjuvant radiation therapy.

Superoxide dismutase mimics: chemistry, pharmacology, and therapeutic potential

Oxidative stress has become widely viewed as an underlying condition in a number of diseases, such as ischemia-reperfusion disorders, central nervous system disorders, cardiovascular conditions, cancer, and diabetes. Thus, natural and synthetic antioxidants have been actively sought. Superoxide dismutase is a first line of defense against oxidative stress under physiological and pathological conditions. Therefore, the development of therapeutics aimed at mimicking superoxide dismutase was a natural maneuver. Metalloporphyrins, as well as Mn cyclic polyamines, Mn salen derivatives and nitroxides were all originally developed as SOD mimics. The same thermodynamic and electrostatic properties that make them potent SOD mimics may allow them to reduce other reactive species such as peroxynitrite, peroxynitrite-derived CO(3)(*-), peroxyl radical, and less efficiently H(2)O(2). By doing so SOD mimics can decrease both primary and secondary oxidative events, the latter arising from the inhibition of cellular transcriptional activity. To better judge the therapeutic potential and the advantage of one over the other type of compound, comparative studies of different classes of drugs in the same cellular and/or animal models are needed. We here provide a comprehensive overview of the chemical properties and some in vivo effects observed with various classes of compounds with a special emphasis on porphyrin-based compounds.

Comparison of conventional and CT-based planning for intracavitary brachytherapy for cervical cancer: target volume coverage and organs at risk doses

Background

To compare intracavitary brachytherapy (ICBT) planning methods for cervical cancer, based on either orthogonal radiographs (conventional plan) or CT sections (CT plan); the comparison focused on target volume coverage and dose volume analysis of organs at risk (OARs), by representing point doses defined by the International Commission on Radiation Units and Measurement (ICRU) and dose volume histograms (DVHs) from 3D planning.

Methods

We analyzed the dosimetric data for 62 conventional and CT-based ICBT plans. The gross tumor volume (GTV), clinical target volume (CTV) and organs at risk (OAR)s were contoured on the CT-plan. Point A and ICRU 38 rectal and bladder points were defined on reconstructed CT images.

Results

Patients were categorized on the basis of whether the >95% isodose line of the point-A prescription dose encompassed the CTV (group 1, n = 24) or not (group 2, n = 38). The mean GTV and CTV (8.1 cc and 20.6 cc) were smaller in group 1 than in group 2 (24.7 cc and 48.4 cc) (P <0.001). The mean percentage of GTV and CTV coverage with the 7 Gy isodose was 93.1% and 88.2% for all patients, and decreased with increasing tumor size and stage. The mean D2 and D5 rectum doses were 1.66 and 1.42 times higher than the corresponding ICRU point doses and the mean D2 and D5 bladder doses were 1.51 and 1.28 times higher. The differences between the ICRU dose and the D2 and D5 doses were significantly higher in group 2 than in group 1 for the bladder, but not for the rectum.

Conclusion

The CT-plan is superior to the conventional plan in target volume coverage and appropriate evaluation of OARs, as the conventional plan overestimates tumor doses and underestimates OAR doses.