Transition from LDR to HDR brachytherapy for cervical cancer: Evaluation of tumor control, survival, and toxicity

High-Dose-Rate Brachytherapy in Cervical and Endometrial Cancer Patients: A Retrospective Study From a Tertiary Cancer Center in the UAE

Purpose This study evaluates the therapeutic outcomes and practical application of high-dose-rate (HDR) brachytherapy in managing cervical and endometrial cancers at a tertiary hospital in the UAE, focusing on treatment efficacy, safety, and patient-reported outcomes. Methods A retrospective analysis was conducted on 368 female patients treated between January 2008 and January 2022. Data included demographic information, cancer type, histopathology, treatment details, and survival outcomes. Statistical analyses were performed using descriptive and inferential statistics. Results The cohort comprised 275 cervical cancer patients (74.73%) and 93 endometrial cancer patients (25.27%). The majority were non-nationals (79.62%). The mean age was 57 years. Squamous cell carcinoma was the most common histopathological type (63.59%). HDR brachytherapy was administered to 290 patients (79.89%). The 12-month survival probability was significantly higher in the HDR-Brachy group (75%, 95% CI: 60% to 85%) compared to the noHDR-Brachy group (50%, 95% CI: 35% to 65%), with a hazard ratio of 0.953 (p=0.0035). At the last review, 86.68% of patients were alive, and disease progression was observed in 37.88% of patients. Conclusion HDR brachytherapy significantly improves survival outcomes in cervical and endometrial cancer patients. Continued efforts to enhance access and standardize brachytherapy protocols are essential to optimize treatment efficacy and patient outcomes in similar healthcare settings.

Morbidity following image-guided brachytherapy for cervical cancer: Patient and treatment related factors

PURPOSE

This retrospective study aims to assess factors associated with the occurrence of toxicity after brachytherapy (BT), as boost after external beam radiotherapy (EBRT) for treatment of invasive cervix carcinoma.

METHODS AND MATERIALS

All consecutive patients diagnosed with cervical carcinoma, and treated with concurrent radiochemotherapy from August 2017 to January 2020 were retrospectively included. An isodose conformation index (ICI) was developed to assess the percentage of the prescription isodose contained within the intermediate risk clinical target volume (IR-CTV).

RESULTS

Eighty-one patients with invasive cervix carcinoma from stage IB to stage IVa were included. Thirty-two (40%) and 49 (60%) patients were treated with Pulsed Dose Rate (PDR) and High Dose Rate (HDR) BT, respectively. Median follow-up was 19.6 months (5.6-41.2). The main factors associated with development of gastrointestinal toxicity were: the median volume of the prescription isodose (67.9cm[3] [37.6-92.9] vs. 49.1cm[3] [34.5-53.5], p = 0.05), the value of ICI (59% [51%-83%] vs. 86% [65%-96%], p = 0.01), the median equivalent dose delivered to the sigmoid (D2cc= 58.4 GyEQD2 [53.9-61.1] vs. 55.2 GyEQD2 [52.8-57.5], p = 0.06) and the median equivalent dose delivered to the IR-CTV (D90= 63.9 GyEQD2 [60.6-66.4] vs. 61.2 GyEQD2 [59.4-64.5], p = 0.03). The proportion of patients who received EBRT lymph node boost was higher in patients who developed urinary toxicity than in patients who did not (57.1% vs. 28.6%, p = 0.08). Anticoagulant (p = 0.02) and antiaggregant therapy (p = 0.01) were associated with occurrence of both urinary and gastrointestinal toxicity.

CONCLUSIONS

Our study confirms the predictive value of irradiated volume in the occurrence of gastrointestinal toxicity, as well as the need for a better conformation to the target volume. Precautions should be considered in patients with vascular comorbidities.

Adverse events of after-loading high dose rate brachytherapy reported to the United States Food and Drug Administration (FDA)

PURPOSE

To provide an assessment of safety regarding high-dose-rate after-loading brachytherapy (HDR-BT) based on adverse events reported to the OpenFDA, an open access database maintained by the United States Food and Drug Administration (FDA).

METHODS

OpenFDA was queried for HDR-BT events between 1993 and 2019. A brachytherapist categorized adverse events (AEs) based on disease site, applicator, manufacturer, event type, dosimetry impact, and outcomes. Important findings are summarized.

RESULTS

372 AEs were reported between 1993 and 2019, with a downwards trend after 2014. Nearly half of AEs (48.9%) were caused by a device malfunction, and 27.4% resulted in patient injury. Breast (49.2%) and Gyn (23.7%) were the most common disease sites of AEs. Applicator breaks cause the majority of AEs (64.2%) and breast balloon implants were the most common applicator to malfunction (38.7%). User error contributed to only 16.7% of events. 11.0% of events required repair of the afterloader. There were no reported staff injuries or patient deaths from an AE, however 24.7% of patients received resultant incorrect radiation dose, 16.4% required additional procedures to rectify the AE, and 3.0% resulted in unintended radiation to staff.

CONCLUSION

The OpenFDA database has shown a decreasing trend in AEs since 2014 for HDR-BT. Most AEs are not caused by user error and do not cause patient injury or incorrect radiation dose. Investigation into methods to prevent failures and improve applicators such as the breast balloon could improve safety. These results support the continued use of HDR-BT as a safe treatment modality for cancer.

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.

Effects of 3D image-guided brachytherapy compared to 2D conventional brachytherapy on clinical outcomes in patients with cervical cancer: A systematic review and meta-analyses

PURPOSE

To assess the effects of three-dimensional image-guided brachytherapy (3D BT) compared to bi-dimensional BT (2D BT) on clinical outcomes in patients with cervical cancer.

METHODS AND MATERIALS

We searched PubMed/MEDLINE, EMBASE, Scopus, CENTRAL, Web of Science, and LILACS for studies assessing the effects of 3D BT versus 2D BT on clinical outcomes. Two reviewers independently screened retrieved citations, extracted data and assessed risk of bias from eligible studies. Hazard ratios (HR) were calculated from Kaplan-Meier curves considering the number of events, their timing and the followup of censored patients. We conducted meta-analyses of HR using the inverse-variance random-effects method. Risk Difference (RD) for toxicities were pooled using the Mantel-Haenszel random-effects method. We used the GRADE system to rate the certainty of evidence.

RESULTS

Twenty observational studies involving 4287 patients were included. The meta-analyses assessing the effect of 3D BT versus 2D BT on overall survival resulted in a HR of 0.78 (95%CI 0.62-0.98), HR of 0.75 (95%CI 0.62-0.90) for pelvic disease-free survival, HR of 0.93 (95%CI 0.81-1.06) for metastatic disease-free survival, and HR of 0.77 (95%CI 0.59-0.99) for local control. Grade 3-4 global and gastrointestinal toxicities were, respectively, 9% lower (95%CI 6% to 11%) and 5% lower (95%CI 2% to 8%) in patients receiving 3D BT versus 2D BT. Certainty of evidence was very low for all assessed outcomes.

CONCLUSIONS

Our study may suggest a benefit of 3D BT over conventional 2D BT on important clinical outcomes.

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.

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.

High dose-rate tandem and ovoid brachytherapy in cervical cancer: dosimetric predictors of adverse events

Background

Brachytherapy (BT) is a vital component of the curative treatment of locally advanced cervical cancer. The American Brachytherapy Society has published guidelines for high dose rate (HDR) BT with recommended dose limits. However, recent reports suggest lower doses may be needed to avoid toxicity. The purpose of this study is to investigate incidence and predictive factors influencing gastrointestinal (GI) and genitourinary (GU) toxicity following HDR intracavitary brachytherapy for locally advanced cervical cancer.

Methods

We retrospectively evaluated a cohort of patients with locally advanced cervical cancer who received CT-based HDR BT. Cumulative doses were calculated using the linear-quadratic model. Statistical analyses were used to investigate clinical and dosimetric predictors of GI and GU toxicity following HDR brachytherapy according to CTCAE v4.0 grading criteria.

Results

Fifty-six women with FIGO IB1 – IVA cervical cancer were included. The overall rate of any GU adverse event (Grade 1+) was 23.3% (n = 13) and severe adverse events (Grade 3+) was 7.1% (n = 4). Of those, the bladder equivalent dose in 2- Gray (Gy) fractions (EQD₂) D_2cc was ≥80 for three of the four patients. The overall rate of any GI adverse event was 26.8% (n = 15) and the rate of severe adverse events was 14.3% (n = 8). Of those, six of the eight patients had a rectal EQD₂ D_2cc ≥ 65 Gy and seven patients had a sigmoid D2cc ≥ 65 Gy. Amongst clinically meaningful factors for development of adverse events (i.e. diabetes, smoking status, ovoid size, and treatment duration), there were no statistically significant prognostic factors identified.

Conclusions

Severe adverse events are observed even with adherence to current ABS guidelines. In the era of recent multi-institutional study results, our data also supports more stringent dosimetric goals. We suggest cumulative D2cc dose limits of: less than 80 Gy for the bladder and less than 65 Gy for the rectum and sigmoid.