Outcomes with image-based interstitial brachytherapy for vaginal cancer

TRImodal DEfinitive invasive vagiNal carcinoma Treatment (TRIDENT protocol): how a standardized approach may change prognostic outcomes

OBJECTIVE

Vaginal carcinoma is a rare malignancy accounting for 1-2% of all gynecological cancers. Surgery has a limited role, while definitive radiotherapy-chemotherapy followed by interventional radiotherapy is considered a valid alternative. The aim of the TRIDENT (TRImodal DEfinitive invasive vagiNal carcinoma Treatment) pilot study was to report the results of a modern standardized trimodal protocol treatment consisting of image guided definitive radiotherapy-chemotherapy followed by image guided interventional radiotherapy in terms of safety and efficacy.

METHODS

Between January 2019 and December 2021, we analyzed 21 consecutive patients with primary vaginal cancer who had received radiotherapy-chemotherapy followed by interventional radiotherapy. The primary study endpoint was local control, and secondary endpoints were metastasis free survival, overall survival, and rate and severity of acute and late toxicities.

RESULTS

14 patients had FIGO (International Federation of Gynecology and Obstetrics) stage II, five patients had stage III, and two had stage IVB disease. Median total external beam radiotherapy dose for the tumor was 45 Gy. Median total dose on positive nodes was 60 Gy. Median total dose for interventional radiotherapy was 28 Gy over four high dose rate fractions to achieve between 85 and 95 Gy equivalent dose, in 2 Gy fractions (EQD2)α/β10, to the high risk clinical target volume, and 60 Gy EQD2α/β10 to the intermediate risk clinical target volume. All patients received weekly platinum based chemotherapy. Median follow-up was 20 months (range 10-56 months). Two year actuarial local control, metastasis free survival, and overall survival rate were 79.4%, 90.5%, and 79.4%, respectively. In terms of acute toxicity, there were no grade 4 events and only one acute grade (G) 3 toxicity (skin). Only vaginal stenosis (G3) was documented 12 months after therapy due to late toxicity.

CONCLUSIONS

In this study, definitive radiotherapy-chemotherapy followed by interventional radiotherapy was a safe and effective treatment modality for primary vaginal cancer.

Image-guided Interstitial Brachytherapy in the Treatment of Primary and Recurrent Vulvovaginal Gynaecological Malignancies

AIMS

To evaluate the use, outcomes and toxicities of high dose rate brachytherapy (HDRB) to the vulvovaginal region in previously irradiated and radiotherapy-naïve patients for primary or recurrent gynaecological malignancies.

MATERIALS AND METHODS

From January 2010 to December 2020, 94 women with a median age of 64 years (range 31-88 years) were treated with interstitial HDRB for vulvovaginal disease. Treatment details, including cumulative radiotherapy doses, were recorded together with reported toxicity, using Common Terminology Criteria for Adverse Events (CTCAE) grading. Dosimetric parameters, including D90, V100 and V150 together with treatment response at 3 months, overall survival, relapse-free survival and long-term toxicity data, were collated from referring centres.

RESULTS

The median follow-up was 78 months (range 2-301). Primary sites of disease included vagina (37), endometrium (29), vulva (16), ovary (7) and cervix (5). Eighty-six (91.5%) patients were treated with curative intent, eight (8.5%) were palliative treatments. Fifty patients received HDRB for recurrent disease, 39 patients for primary disease and five as part of adjuvant treatment. The anatomical site of disease treated with HDRB ranged from vagina (76), vulva (14) and peri-urethral sites (four). The 2- and 5-year local relapse-free survival rates were 76% and 72%, respectively; 15 patients experienced local failure only, whereas six patients had local and nodal/distant failure. The median time to local recurrence was 8 months (range 2-88 months). The 2- and 5-year overall survival rates for all patients were 67% and 47%, respectively; the median overall survival was 59 months. Seventy-nine (84%) patients had a complete response measured with imaging at 3 months. Grade 3 toxicity was reported in 14 patients (14.8%).

CONCLUSION

This retrospective series suggests the use of interstitial brachytherapy for vulvovaginal gynaecological malignancy to be an effective and safe treatment option. Good local control was achieved with a tolerable toxicity profile; it is a valuable treatment modality.

ESTRO/ESGO/SIOPe guidelines for the management of patients with vaginal cancer

Primary vaginal malignancies are rare, comprising only 2% of all female genital tract malignancies in adults and 4.5% in children. As part of its mission to improve the quality of care for women with gynecological cancers across Europe, the European Society of Gynaecological Oncology (ESGO) jointly with the European Society for Radiotherapy & Oncology (ESTRO) and the European Society of Pediatric Oncology (SIOPe) developed evidence-based guidelines in order to improve the management of patients with vaginal cancer within a multidisciplinary setting. ESTRO/ESGO/SIOPe nominated practicing clinicians who are involved in the management of vaginal cancer patients and have demonstrated leadership through their expertise in clinical care and research, their national and international engagement and profile as well as dedication to the topics addressed to serve on the expert panel (13 experts across Europe comprising the international development group). To ensure that the statements were evidence based, the current literature was reviewed and critically appraised. In the case of absence of any clear scientific evidence, judgment was based on the professional experience and consensus of the international development group. Prior to publication, the guidelines were reviewed by 112 independent international practitionners in cancer care delivery and patient representatives and their comments and input were incorporated and addressed accordingly. These guidelines cover comprehensively the diagnostic pathways as well as the surgical, radiotherapeutical and systemic management and follow-up of adult patients (including those with rare histological subtypes) and pediatric patients (vaginal rhabdomyosarcoma and germ cell tumours) with vaginal tumours.

ESTRO/ESGO/SIOPe Guidelines for the management of patients with vaginal cancer

Primary vaginal malignancies are rare, comprising only 2% of all female genital tract malignancies in adults and 4.5% in children. As part of its mission to improve the quality of care for women with gynecological cancers across Europe, the European Society of Gynaecological Oncology (ESGO) jointly with the European Society for Radiotherapy & Oncology (ESTRO) and the European Society of Pediatric Oncology (SIOPe) developed evidence-based guidelines in order to improve the management of patients with vaginal cancer within a multidisciplinary setting.ESTRO/ESGO/SIOPe nominated practicing clinicians who are involved in the management of vaginal cancer patients and have demonstrated leadership through their expertise in clinical care and research, their national and international engagement and profile as well as dedication to the topics addressed to serve on the expert panel (13 experts across Europe comprising the international development group). To ensure that the statements were evidence based, the current literature was reviewed and critically appraised.In the case of absence of any clear scientific evidence, judgment was based on the professional experience and consensus of the international development group. Prior to publication, the guidelines were reviewed by 112 independent international practitionners in cancer care delivery and patient representatives and their comments and input were incorporated and addressed accordingly.These guidelines cover comprehensively the diagnostic pathways as well as the surgical, radiotherapeutical and systemic management and follow-up of adult patients (including those with rare histological subtypes) and pediatric patients (vaginal rhabdomyosarcoma and germ cell tumours) with vaginal tumours.

Recommendations of the Spanish brachytherapy group of the Spanish Society of Radiation Oncology and the Spanish Society of Medical Physics for interstitial high-dose-rate brachytherapy for gynaecologic malignancies

The present document includes consensus-based recommendations from the Brachytherapy Group (GEB) of the Spanish Society of Radiation Oncology (SEOR) and the Spanish Society of Medical Physics (SEFM) for interstitial high-dose-rate (HDR) brachytherapy (BT) for gynaecologic malignancies. A nine-item survey-which included questions on experience with interstitial BT; indications and technique; applicator type; magnetic resonance imaging (MRI)-based planning; dose; fractionation schedule; and treatment planning-was sent to all radiation oncology departments (n = 174) in Spain in 2021. Responses were received from 36 centres (50% of all centres [n = 72] with a BT unit). The consensus-based recommendations presented here are based on a review of the available literature, professional experience among the group of experts, and in-person discussions held during the annual meeting of these two societies. We describe the results of the survey and the following: indications; contraindications; patient selection; description of applicators; role of imaging in planning; contouring; dose prescription; dosimetric reconstruction; optimisation; and dose indications for cancers of the cervix, vagina, and vulva. The various clinical scenarios in which interstitial BT is used in the treatment of gynaecological tumours are described in detail, including cervix intracavitary/interstitial hybrid HDR-BT; cervix perineal templates/freehand implants; primary vaginal malignancies/vaginal recurrences; and vulvar interstitial implants.

Outcomes of 3D MRI based HDR brachytherapy with hybrid multichannel vaginal cylinder applicator and freehand needles for treatment of vaginal disease

Freehand needles can be used with multichannel vaginal cylinders (MCVC) to cover vaginal cancer >7 mm thick or with supra-vaginal extension. We report our institutional outcomes using this novel hybrid technique. Patients with vaginal malignancies treated with HDR BT using MCVC plus freehand needles from 2014-2021 at our institution were identified. Clinical characteristics, details of brachytherapy, initial response, and overall local control (LC) outcomes were recorded. LC was analyzed via Kaplan-Meier method. 34 patients were identified with median follow-up 1.9 years. 19 patients had primary endometrial cancer with vaginal recurrence/disease, and remaining had primary vaginal cancer or other primaries. 7 patients had recurrence after previous RT course. 25 patients received EBRT with median dose 45 Gy in 25 fractions, and rest received BT alone. Median HR-CTV D90 for patients treated with EBRT plus BT was 77.4 Gy. 30 patients had complete local response to BT on initial examination and/or follow-up imaging. 1 and 2-year LC rates in patients without prior RT treated with EBRT + BT were 94.1% and 94.1%, respectively. 1 and 2-year LC rates for those without prior RT were 88.1% and 76.4%, respectively. 1 and 2-year LC rates for those with prior RT were 68.6% and 34.3%, respectively. 1 patient had vaginal laceration requiring surgical repair, and 1 patient developed small bowel obstruction 1 month after BT, with no additional acute grade 3+ toxicities identified. Our approach with MCVC plus freehand needles with MRI-based planning was feasible and safe, with excellent initial local response and low rate of serious toxicities.

Development and validation of models for predicting the overall survival and cancer-specific survival of patients with primary vaginal cancer: A population-based retrospective cohort study

Background

No models have been developed to predict the survival probability for women with primary vaginal cancer (VC) due to VC’s extreme rareness. We aimed to develop and validate models to predict the overall survival (OS) and cancer-specific survival (CSS) of VC patients.

Methods

A population-based multicenter retrospective cohort study was carried out using the 2004–2018 Surveillance, Epidemiology, and End Results Program database in the United States. The final multivariate Cox model was identified using the Brier score and Harrell’s C concordance statistic (C-statistic). The decision curve, calibration plot, and area under the time-dependent receiver operating characteristic curve (AUC) were used to evaluate model prediction performance. Multiple imputation followed by bootstrap was performed. Bootstrap validation covered the entire statistic procedure from model selection to baseline survival and coefficient calculation. Nomograms predicting OS and CSS were generated.

Results

Of the 2,417 eligible patients, 1,692 and 725 were randomly allocated to the training and validation cohorts. The median age (Interquartile range) was 66 (56–78) and 65 (55–76) for the two cohorts, respectively. Our models had larger net benefits in predicting the survival of VC patients than the American Joint Committee on Cancer stage, presenting great discrimination ability and excellent agreement between the expected and observed events. The performance metrics of our models were calculated in three cohorts: the training cohort, complete cases of the validation cohort, and the imputed validation cohort. For the OS model in the three cohorts, the C-statistics were 0.761, 0.752, and 0.743. The slopes of the calibration plots were 1.017, 1.005, and 0.959. The 3- and 5-year AUCs were 0.795 and 0.810, 0.768 and 0.771, and 0.770 and 0.767, respectively. For the CSS model in the three cohorts, the C-statistics were 0.775, 0.758, and 0.755. The slopes were 1.021, 0.939, and 0.977. And the 3- and 5-year AUCs were 0.797 and 0.793, 0.786 and 0.788, and 0.757 and 0.757, respectively.

Conclusion

We were the first to develop and validate exemplary survival prediction models for VC patients and generate corresponding nomograms that allow for individualized survival prediction and could assist clinicians in performing risk-adapted follow-up and treatment.

Updates in the treatment of vaginal cancer

Vaginal cancer is a rare cancer. A lot of the data used in the treatment of this cancer are extrapolated from cervical cancer data. Radiation therapy plays a significant role in the treatment of vaginal cancer. The advances in radiation therapy in both external beam and brachytherapy have improved local control, survival, and toxicity. Brachytherapy plays an important role in treating vaginal cancer, but treatment should be individualized to each tumor. Imaging, particularly magnetic resonance imaging, plays an essential role in the management of patients with vaginal cancer, from diagnosis to staging to treatment management to surveillance.

Role of radiotherapy in the treatment of primary vaginal cancer: Recommendations of the French society for radiation oncology

Primary vaginal cancers are rare tumours, for which external beam radiotherapy and brachytherapy are major treatment tools. Given the complexity of brachytherapy techniques, the treatment should be performed in specialised centres. We present the recommendations of the French society for radiation oncology on the indications and techniques for external beam radiotherapy and brachytherapy for primary vaginal cancer.

Clinical results of image-guided interstitial brachytherapy with or without external beam radiotherapy for postsurgical vaginal recurrence of cervical and endometrial cancers

Purpose

This study aimed to evaluate the clinical outcome and efficacy of image-guided interstitial brachytherapy (ISBT) for postsurgical vaginal recurrence of cervical and endometrial cancers.

Materials and methods

The study included 11 patients who received CT-based image-guided high-dose-rate ISBT with or without external beam radiotherapy (EBRT). Local control, progression-free survival, and treatment-related toxicities were evaluated retrospectively.

Results

Of the 11 patients, 4 underwent ISBT with EBRT and the other 7 ISBT alone; two of the latter patients received previous pelvic radiotherapy. After a median follow-up of 43.9 months (range 3.9–92.7 months), the 2-year local control rate was 100%. The median equivalent doses in 2 Gy fractions received by at least 90% of the clinical target volume for ISBT with versus without EBRT were 82.2 Gy (range 60.4–84.2 Gy) versus 69.0 Gy (range 50.8–98.2 Gy). The 2-year progression-free survival rates after ISBT with versus without EBRT were 75% versus 80%, and the difference was not significant (p = 0.74). Grade 3 late toxicities occurred in two patients.

Conclusion

Our radiotherapy strategy using image-guided ISBT, either with or without EBRT, for postsurgical vaginal recurrence showed effective treatment outcomes.

ACR Appropriateness Criteria® Staging and Follow-up of Primary Vaginal Cancer

Primary vaginal cancer is rare, comprising 1% to 2% of gynecologic malignancies and 20% of all malignancies involving the vagina. More frequently, the vagina is involved secondarily by direct invasion from malignancies originating in adjacent organs or by metastases from other pelvic or extrapelvic primary malignancies. Data on the use of imaging in vaginal cancer are sparse. Insights are derived from the study of imaging in cervical cancer and have reasonable generalizability to vaginal cancer due to similar tumor biology. Given the trend toward definitive chemoradiation for both cancers in all but early stage lesions, principles of postchemoradiation tumor response evaluation are largely analogous. Accordingly, many of the recommendations outlined here are informed by principles translated from the literature on cervical cancer. For pretreatment assessment of local tumor burden and in the case of recurrent vaginal cancer, MRI is the preferred imaging modality. PET/CT has demonstrated utility for the detection of nodal metastatic and unexpected distant metastatic disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Computed Tomography-Based Interstitial Brachytherapy for Recurrent Cervical Carcinoma in the Vaginal Apex

AIMS

To determine the factors influencing the outcomes of patients with recurrences post-hysterectomy for cervical cancers treated with external beam radiotherapy (EBRT) and interstitial brachytherapy.

MATERIALS AND METHODS

This prospective study accrued 90 patients between October 2008 and May 2014. All patients had had a prior hysterectomy and were diagnosed with recurrent vaginal apex cancers with squamous cell carcinomas. All underwent EBRT of 50 Gy (2 Gy/fraction) using tomotherapy-based image-guided intensity-modulated radiotherapy with concurrent chemotherapy of weekly cisplatin (40 mg/m²) followed by high dose rate interstitial brachytherapy boost of 20 Gy (4 Gy/fraction twice a day). Local relapse, disease-free and overall survival were determined.

RESULTS

At a median follow-up of 74 months (4-123 months), 10/90 (11%) patients had local failure as the first site of relapse and 12/90 (13.3%) had first distant relapse. Only one patient had synchronous local and distant relapse. The 7-year local relapse-free, disease-free and overall survival were 87.6, 68.3 and 68.3%, respectively. Grade 2 and 3 rectal toxicity were seen in 5.6 and 3.1% of patients, respectively. Among these, two (2.2%) patients underwent temporary diversion colostomy due to vaginal sigmoid and rectovaginal fistula. Grade 2 and 3 bladder toxicity were seen in 5.6 and 1.1% of patients, respectively. In summary, the lateral disease extent (P = 0.048) and the presence of nodal disease at diagnosis (P = 0.08) had a statistically significant or borderline impact on local relapse without any impact on disease-free survival. Tumour size in itself did not affect overall survival.

CONCLUSION

With the integration of EBRT and interstitial brachytherapy, most vaginal apex recurrences can be salvaged. An excellent local control and survival is achievable using intensity-modulated radiotherapy with image guidance and concurrent chemotherapy followed by high dose rate interstitial brachytherapy.

Clinical outcomes of distal vaginal and vulvar cancer treated with image-guided brachytherapy

Purpose

To evaluate treatment outcomes with image-guided brachytherapy (IGBT) for distal vaginal and vulvar cancers.

Material and methods

Women treated for distal vaginal or vulvar malignancies utilizing IGBT were retrospectively reviewed, and acute and late toxicities were retrospectively graded. Descriptive statistical analysis was performed.

Results

Eighteen patients were included, out of which, twelve patients (66.7%) were with primary disease of the distal vagina and vulva, most commonly squamous cell carcinoma of the vulva (n = 8, 66.7%), and six with recurrent disease, most commonly recurrent endometrial carcinoma (n = 5, 83.3%). All patients received external beam radiation (EBRT) to a median dose of 45 Gy in 25 fractions, followed by IGBT (range of 15 to 27.5 Gy in 3 to 5 fractions). Mean follow-up was 20.6 months. Mean dose to high-risk clinical target volume (HR-CTV) D₉₀ was 72.4 Gy. Mean D_2cc for the rectum, bladder, and urethra were 50 Gy, 50.6 Gy, and 62.9 Gy, respectively. Five patients (27.8%) recurred. Three patients (16.7%) had local recurrence, 1 patient (5.6%) had distant recurrence only, and 1 patient (5.6%) had simultaneous regional and distant recurrence. Grade 3 acute toxicities included 1 (5.6%) vaginal stenosis, 6 (33.3%) dermatitis/mucositis, 2 (11.1%) vaginal pain, and 1 (5.6%) vaginal/vulvar infection. Grade 3 late toxicities comprised 3 (17.7%) cases of vaginal pain and 1 (5.9%) skin/vaginal necrosis. There were no grade 4 or higher toxicities.

Conclusions

Definitive radiation therapy in the form of EBRT and IGBT provides meaningful loco-regional control in women with distal vaginal and vulvar cancers, with mainly skin and vaginal toxicity.

Image-Guided Adaptive Brachytherapy (IGABT) for Primary Vaginal Cancer: Results of the International Multicenter RetroEMBRAVE Cohort Study

PURPOSE

This study assessed outcomes following the nowadays standing treatment for primary vaginal cancer with radio(chemo)therapy and image-guided adaptive brachytherapy (IGABT) in a multicenter patient cohort.

METHODS

Patients treated with computer tomography (CT)-MRI-assisted-based IGABT were included. Retrospective data collection included patient, tumor and treatment characteristics. Late morbidity was assessed by using the CTCAE 3.0 scale.

RESULTS

Five European centers included 148 consecutive patients, with a median age of 63 years. At a median follow-up of 29 months (IQR 25-57), two- and five-year local control were 86% and 83%; disease-free survival (DFS) was 73% and 66%, and overall survival (OS) was 79% and 68%, respectively. Crude incidences of ≥ grade-three urogenital, gastro-intestinal and vaginal morbidity was 8%, 3% and 8%, respectively. Lymph node metastasis was an independent prognostic factor for disease-free survival (DFS). Univariate analysis showed improved local control in patients with T2-T4 tumors if >80 Gy EQD2α/β10 was delivered to the clinical target volume (CTV) at the time of brachytherapy.

CONCLUSIONS

In this large retrospective multicenter study, IGABT for primary vaginal cancer resulted in a high local control with acceptable morbidity. These results compared favorably with two-dimensional (2D) radiograph-based brachytherapy and illustrate that IGABT plays an important role in the treatment of vaginal cancer.

Preliminary results of modified interstitial MIAMI brachytherapy applicator for treatment of upper and apical vaginal tumors

Purpose

Intracavitary vaginal brachytherapy (VBT) cylinders are limited in treating upper/apical vaginal disease due to the distance between the target and radiation source positions. Interstitial brachytherapy devices directly expose the vaginal mucosa to radiation sources, increasing morbidity. To target apical disease while limiting excessive treatment to the vaginal mucosa and organs at risk, we modified the commercially available multichannel MIAMI applicator, allowing the direct extension of needles into the apex with the protection of cylinder.

Material and methods

The device has one central plastic core with six peripheral channels. The modified device permits titanium needles to surpass the apical surface into vaginal tissue. A retrospective analysis on thirteen patients treated with this device was conducted. Patient demographics, gross tumor volume (GTV)/clinical target volume (CTV), initial diagnosis and management, toxicity data, and EQD₂ data for the bladder and rectum were obtained.

Results

There were ten patients with vaginal recurrences and three with primary vaginal/cervical cancers. Mean dosage of VBT treatment was 25.5 Gy in 3-5 fractions. Mean dosage of external beam radiation therapy (EBRT) treatment was 44 Gy. Common acute toxicities included diarrhea, fatigue, cystitis, and nausea. Common chronic toxicities were pelvic pain, vaginal stenosis, and skin telangiectasia. Mean EQD₂ dose for bladder and rectum were 72.3 Gy and 62.3 Gy, respectively. Ten patients had no evidence of relapse, two suffered from distant metastases, and one patient with stage IIIA cervical adenocarcinoma had loco-regional recurrence seventeen months after radiation treatment.

Conclusions

Our data suggests that the custom applicator is associated with robust dosimetric coverage, good loco-regional control, acceptable toxicity, and reduced tissue trauma. This device allows treatment of apically located vaginal tumors without significant damage to the vaginal vault and organs at risk. Additionally, it provides the flexibility to treat multiple patients with variable vaginal diameters and sizes/depths of apical tumors using a single device.

Radiotherapy and Its Intersections with Surgery in the Management of Localized Gynecological Malignancies: A Comprehensive Overview for Clinicians

Surgery, including minimally invasive surgery, and radiotherapy are key modalities in the treatment of gynecological malignancies. The aim of this review is to offer the multidisciplinary care team a comprehensive summary of the intersections of surgery and radiotherapy in the local treatment of gynecological malignancies. Recent advances in radiotherapy are highlighted. Relevant publications were identified through a review of the published literature. Ovarian, endometrial, cervical, vaginal, and vulvar cancer were included in the search. Current guidelines are summarized. The role of radiotherapy in adjuvant as well as definitive treatment of these entities is synthesized and put into context with surgery, focusing on survival and quality of life. Although these outcomes have improved recently, further research must be focused on the number of life years lost, and the potential morbidity encountered by patients.

Radiotherapy Plus Chemotherapy Is Associated With Improved Survival Compared to Radiotherapy Alone in Patients With Primary Vaginal Carcinoma: A Retrospective SEER Study

Background

The efficacy of radiotherapy plus chemotherapy (RTCT) versus radiotherapy alone (RT) in the treatment of primary vaginal carcinoma has been controversial. We aimed to evaluate the up-to-date efficacy of RTCT on primary vaginal carcinoma in a real-world cohort.

Methods

We performed a retrospective analysis in patients with primary vaginal carcinoma retrieved from the Surveillance, Epidemiology, and End Results Program database from 2004 to 2016. Kaplan-Meier survival curves were plotted and compared by the log-rank test. Inverse probability weighting (IPW)-adjusted multivariate Cox proportional hazards and Fine-Gray competing-risk model was applied.

Results

Of the 1,813 qualified patients with primary vaginal carcinoma from 2004 to 2016, 1,137 underwent RTCT and 676 underwent RT. The median survival time was 34 months for the RT group and 63 months for the RTCT group. RTCT was significantly associated with improved overall survival (unadjusted HR = 0.71, 95% CI 0.62-0.82, p < 0.001; adjusted HR = 0.73, 95% CI 0.63-0.84, p < 0.001) and cancer-specific survival (unadjusted sHR = 0.81, 95% CI 0.69-0.95, p = 0.012; adjusted sHR = 0.81, 95% CI 0.69-0.96, p = 0.016). Age, histological type, tumor size, surgery, and FIGO stage were all independent prognostic factors for survival (p < 0.05 for all). Subgroup analysis demonstrated that RTCT was significantly associated with better survival in most subgroups, except for those with adenocarcinoma, tumor size <2 cm, or FIGO stage I. Moreover, sensitivity analysis did not alter the beneficial effects of RTCT.

Conclusion

RTCT is significantly correlated with prolonged survival in patients with primary vaginal carcinoma. RTCT should be applied to most patients with primary vaginal carcinoma instead of RT alone, except for those with adenocarcinoma, tumor size <2 cm, or FIGO stage I.

3D image-guided interstitial brachytherapy for primary vaginal cancer: A multi-institutional experience

PURPOSE/OBJECTIVES

High dose rate (HDR) interstitial brachytherapy (ISBT) boost is integral for definitive radiation treatment of primary vaginal cancer. Technological advances with CT or MRI guidance provide improved precision and ability to treat more extensively invasive tumors over historical techniques, but reported experience is limited. We sought to provide updated outcome and toxicity data for women with primary vaginal cancer undergoing treatment with a modern ISBT technique.

MATERIAL/METHODS

Databases of primary vaginal carcinoma patients treated at two Canadian academic cancer institutions were combined including patient, tumor and treatment characteristics, and survival outcomes and toxicity data. Descriptive statistics, survival estimates based on the Kaplan-Meier method, and univariable/multivariable Cox proportional hazards regression analyses are reported.

RESULTS

Between 2002 and 2017, 67 women with primary vaginal cancer were treated with 3D HDR ISBT. FIGO stage distribution was I (22.4%), II (50.8%), III (17.9%), IVa (9.0%). All patients received external beam radiotherapy and HDR ISBT of 500-750 cGy per fraction over 2-4 fractions. Median follow-up was 2.68 years (95% confidence interval: 2.04-6.04). Cumulative rate of grade 3-4 genitourinary/gastrointestinal toxicity was 10.4%. Four patients developed vaginal fistula. Progression-free survival at 2 and 3 years was 73.5% and 66.4% for all patients, 78.3% and 75.0% for stage I-II and 61.6% and 46.2% for stage III-IVa, respectively (log-rank p = 0.252).

CONCLUSIONS

Use of 3D image-guided HDR ISBT boost was safe and resulted in improved survival outcomes compared to historical rates in this series of primary vaginal cancer patients. Prospective study is warranted to better define clinical and dosimetric predictors of local control.

The impact of brachytherapy boost and radiotherapy treatment duration on survival in patients with vaginal cancer treated with definitive chemoradiation

PURPOSE

Vaginal cancer is a rare tumor that is optimally treated with a combination of chemotherapy (CHT) and radiation therapy. Because of the rarity of this cancer, the benefit of a brachytherapy boost (BT) and the relevance of radiotherapy time to treatment completion (TTC) are unclear.

METHODS

Patients diagnosed between 2004 and 2015 with non-metastatic vaginal cancer treated with definitive CHT and external beam radiotherapy with or without BT but with no surgery were identified in the National Cancer Database. Overall survival (OS) was assessed with Kaplan-Meier curves, and differences between groups were compared with the log-rank test. A Cox model was constructed to evaluate survival after controlling for confounders. A Cox model using a penalized spline function was constructed to evaluate how the length of radiation therapy correlated with OS among patients receiving BT.

RESULTS

A total of 1094 patients who met the inclusion criteria were identified. The utilization of BT was associated with improved 5-year OS (62.9% vs. 49.3%, p = 0.0126) on propensity score-weighted analyses. TTC of 63 days or less was associated with improved 5-year OS (67.8% vs. 54.5%, p = 0.0031) in patients who underwent BT. Other factors associated with improved OS in patients who received CHT, external beam radiotherapy, and BT were younger age, absent comorbidity score, and negative lymph nodes.

CONCLUSIONS

A brachytherapy boost and shorter TTC were associated with a survival benefit in a cohort of patients with non-metastatic vaginal cancer treated with definitive chemoradiotherapy.

Survival benefit of vaginectomy compared to local tumor excision in women with FIGO stage I and II primary vaginal carcinoma: a SEER study

PURPOSE

The effectiveness of vaginectomy compared to that of local tumor excision (LTE) for the International Federation of Gynecology and Obstetrics (FIGO) stage I and II vaginal carcinoma is unclear. We aimed to clarify if the effectiveness of vaginectomy is comparable to that of LTE in the real world.

METHODS

We retrospectively evaluated data of patients with primary vaginal carcinoma registered in the Surveillance, Epidemiology, and End Results Program (SEER) database from 2004 to 2016. The multivariate Cox proportional hazards models and Fine-Gray competing risk models were used to estimate the overall survival (OS) and disease-specific survival (DSS) after propensity score matching.

RESULTS

Of the 533 patients with FIGO stage I and II primary vaginal carcinoma, 243 and 290 patients were treated with vaginectomy and LTE, respectively. Vaginectomy was significantly associated with improved OS [unadjusted hazard ratio (HR) = 0.70, 95% confidence interval (CI) 0.53-0.95, P = 0.020; adjusted HR = 0.63, 95% CI 0.46-0.87, P = 0.005] and DSS [unadjusted subdistribution HR (sHR) = 0.75, 95% CI 0.52-1.07, P = 0.115; adjusted sHR = 0.65, 95% CI 0.44-0.97, P = 0.036]. Age, marital status, histology type, FIGO stage, chemotherapy, and lymph node metastases were significant prognostic factors of survival. Moreover, radiotherapy did not influence the effectiveness of vaginectomy. Subgroup and sensitivity analysis confirmed the consistent beneficial effectiveness of vaginectomy.

CONCLUSION

Compared with LTE, vaginectomy results in significantly prolonged survival in patients with FIGO stage I and II primary vaginal carcinoma. Thus, it can be the preferred treatment for FIGO I and II vaginal cancer regardless of radiotherapy status.

Radiation therapy for gynecologic malignancies during the COVID-19 pandemic: International expert consensus recommendations

OBJECTIVE

To develop expert consensus recommendations regarding radiation therapy for gynecologic malignancies during the COVID-19 pandemic.

METHODS

An international committee of ten experts in gynecologic radiation oncology convened to provide consensus recommendations for patients with gynecologic malignancies referred for radiation therapy. Treatment priority groups were established. A review of the relevant literature was performed and different clinical scenarios were categorized into three priority groups. For each stage and clinical scenario in cervical, endometrial, vulvar, vaginal and ovarian cancer, specific recommendations regarding dose, technique, and timing were provided by the panel.

RESULTS

Expert review and discussion generated consensus recommendations to guide radiation oncologists treating gynecologic malignancies during the COVID-19 pandemic. Priority scales for cervical, endometrial, vulvar, vaginal, and ovarian cancers are presented. Both radical and palliative treatments are discussed. Management of COVID-19 positive patients is considered. Hypofractionated radiation therapy should be used when feasible and recommendations regarding radiation dose, timing, and technique have been provided for external beam and brachytherapy treatments. Concurrent chemotherapy may be limited in some countries, and consideration of radiation alone is recommended.

CONCLUSIONS

The expert consensus recommendations provide guidance for delivering radiation therapy during the COVID-19 pandemic. Specific recommendations have been provided for common clinical scenarios encountered in gynecologic radiation oncology with a focus on strategies to reduce patient and staff exposure to COVID-19.

Definitive radiotherapy with image-guided adaptive brachytherapy for primary vaginal cancer

Primary vaginal cancer is a rare cancer and clinical evidence to support recommendations on its optimal management is insufficient. Because primary vaginal cancer resembles cervical cancer in many aspects, treatment strategies are mainly adopted from evidence in locally advanced cervical cancer. To date, the organ-sparing treatment of choice is definitive radiotherapy, consisting of external beam radiotherapy and brachytherapy, combined with concurrent chemotherapy. Brachytherapy is an important component of the treatment and its steep dose gradient enables the delivery of high doses of radiation to the primary tumour, while simultaneously sparing the surrounding organs at risk. The introduction of volumetric CT or MRI image-guided adaptive brachytherapy in cervical cancer has led to better pelvic control and survival, with decreased morbidity, than brachytherapy based on x-ray radiographs. MRI-based image-guided adaptive brachytherapy with superior soft-tissue contrast has also been adopted sporadically for primary vaginal cancer. This therapy has had promising results and is considered to be the state-of-the-art treatment for primary vaginal cancer in standard practice.

Recommendations from gynaecological (GYN) GEC-ESTRO working group - ACROP: Target concept for image guided adaptive brachytherapy in primary vaginal cancer

BACKGROUND AND AIM

External beam radiotherapy (EBRT) combined with brachytherapy has an essential role in the curative treatment of primary vaginal cancer. EBRT is associated with significant tumour shrinkage, making primary vaginal cancer suitable for image guided adaptive brachytherapy (IGABT). The aim of these recommendations is to introduce an adaptive target volume concept for IGABT of primary vaginal cancer.

METHODS

In December 2013, a task group was initiated within GYN GEC-ESTRO with the purpose to introduce an IGABT target concept for primary vaginal cancer. All participants have broad experience in IGABT and vaginal cancer brachytherapy. The target concept was elaborated as consensus agreement based on an iterative process including target delineation and dose planning comparison, retrospective analysis of clinical data and expert opinions.

RESULTS

Gynaecological examination and MR imaging are the modalities of choice for local tumour assessment. A specific template for standardised documentation with clinical drawings for vaginal cancer was developed. The adaptive target volume concept comprises different response-related target volumes. For EBRT these are related to the primary tumour and the lymph nodes, while for IGABT these are related to the primary tumour and are consisting of the residual gross tumour volume (GTV-T_res) and the high-, and intermediate risk clinical target volumes (CTV-T_HR, CTV-T_IR).

CONCLUSION

This target concept for IGABT of primary vaginal cancer defines adaptive target volumes for volumetric dose prescription and should improve comparability of different radiotherapy schedules of this rare disease. A prospective evaluation of the target volume concept within a multicentre study is planned.

MRI- and PET-Guided Interstitial Brachytherapy for Postsurgical Vaginal Recurrences of Cervical Cancer: Results of Phase II Study

PURPOSE

This phase II study evaluated the utility of magnetic resonance imaging (MRI) and positron emission tomography for planning radiation and brachytherapy in patients with postsurgical recurrence of cervical cancer.

METHODS AND MATERIALS

The study (NCT01391065) recruited patients with residual or recurrent disease after hysterectomy. Patients underwent baseline T2 weighted (T2W) MRI, ¹⁸F-flouro-deoxyglucose (¹⁸F-FDG), ¹⁸F-flouro thymidine (¹⁸F-FLT) and ¹⁸F-flouromisonidazole (¹⁸F-F Miso) positron emission tomography (PET) and received external radiation (50 Gy/25 fractions for 5 weeks) and weekly cisplatin (40 mg/m²). MRI was performed at brachytherapy and used for delineation of clinical target volume (CTV). Patients with parametrial disease at baseline received interstitial brachytherapy (16-20 Gy/4-5 fractions) and those with vaginal disease received intracavitary brachytherapy (12-14 Gy/2-4 fractions). Kaplan-Meier analysis was performed to evaluate locoregional relapse, disease free survival, and overall survival. Common Toxicity Criteria for adverse event reporting (CTCAE) v4.1 was used for toxicity scoring and European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questtionaire Core 30 (QLQC-30) and Cx 24 for quality-of-life reporting.

RESULTS

Between January 2011 and February 2016, 60 patients were included, of which 50 received study treatment. The mean gross tumor volume on T2 W MR was 20 (IQR 3.6-90) cc. The metabolic tumor volume was 15 (interquartile range [IQR] 2.1-56.1) cc. The median FLT volume was 10 (IQR 0-48) cc. A total of 8 patients had ^18-F F Miso uptake. The median CTV at brachytherapy was 38 (12-85) cc. The median CTVD90 and D 98 was 71 (53-74) and 74 (53-74) Gy. At a median follow-up of 60 (5-93) months, the 5-year local control, disease free survival, and overall survival were 84%, 73%, and 74.5%, respectively. Grade III and IV proctitis and cystitis were observed in 4% and 2% of patients. On multivariate analysis baseline tumor volume, on T2 W MR impacted disease free (91% vs 65%, P = .03) and overall survival (96% vs 77%, P = .06).

CONCLUSIONS

Image-guided assisted radiation and brachytherapy are associated with good to excellent local control and survival in patients with vaginal recurrences of cervical cancer.

A Clinical Evaluation of American Brachytherapy Society Consensus Guideline for Bulky Vaginal Mass in Gynecological Cancer

Objectives

American Brachytherapy Society (ABS)-recommended interstitial brachytherapy (IBT) should be considered for bulky vaginal tumor thicker than 5 mm. The aim of this study was to evaluate the ABS consensus guideline for patients with severe vaginal invasion based on our long-term follow-up results.

Methods/Materials

The study included 7 patients with vaginal cancer and 14 patients with cervical cancer invading to the lower vagina. Based on prebrachytherapy magnetic resonance imaging findings, patients received intracavitary brachytherapy (ICT) for vaginal tumors 5 mm or less or IBT for vaginal tumors less than 5 mm. Nine patients received ICT and the remaining 12 patients received IBT. For dosimetric comparison, an experimental recalculation as the virtual IBT for patients actually treated by ICT, and vice versa, was performed.

Results

The 5-year local control rate for all tumors was 89.4%. No differences in local control between ICT- and IBT-treated groups were observed (P = 0.21). One patient experienced a grade 3 rectal complication. There were no significant differences in the CTV D90 and rectum D2cc between the 2 groups (P = 0.13 and 0.39, respectively). In the dosimetric study of ICT-treated patients, neither the actual ICT plans nor the experimental IBT plans exceeded the limited dose for organs at risk, which were recommended in the guideline published from the ABS. In the IBT-treated patients, D2cc for bladder and rectum of the experimental ICT plans was significantly higher than for the actual IBT plans (P < 0.001 and <0.001, respectively), and 11 experimental ICT plans (92%) exceeded the limited dose for bladder and/or rectum D2cc.

Conclusions

Tumor control and toxicity after selected brachytherapy according to vaginal tumor thickness were satisfactory; IBT instead of ICT is recommended for patients with vaginal tumor thickness greater than 5 mm to maintain bladder and/or rectum D2cc.

A machine-learning-based prediction model of fistula formation after interstitial brachytherapy for locally advanced gynecological malignancies

PURPOSE

External beam radiotherapy combined with interstitial brachytherapy is commonly used to treat patients with bulky, advanced gynecologic cancer. However, the high radiation dose needed to control the tumor may result in fistula development. There is a clinical need to identify patients at high risk for fistula formation such that treatment may be managed to prevent this toxic side effect. This work aims to develop a fistula prediction model framework using machine learning based on patient, tumor, and treatment features.

METHODS AND MATERIALS

This retrospective study included 35 patients treated at our institution using interstitial brachytherapy for various gynecological malignancies. Five patients developed rectovaginal fistula and two developed both rectovaginal and vesicovaginal fistula. For each patient, 31 clinical features of multiple data types were collected to develop a fistula prediction framework. A nonlinear support vector machine was used to build the prediction model. Sequential backward feature selection and sequential floating backward feature selection methods were used to determine optimal feature sets. To overcome data imbalance issues, the synthetic minority oversampling technique was used to generate synthetic fistula cases for model training.

RESULTS

Seven mixed data features were selected by both sequential backward selection and sequential floating backward selection methods. Our prediction model using these features achieved a high prediction accuracy, that is, 0.904 area under the curve, 97.1% sensitivity, and 88.5% specificity.

CONCLUSIONS

A machine-learning-based prediction model of fistula formation has been developed for patients with advanced gynecological malignancies treated using interstitial brachytherapy. This model may be clinically impactful pending refinement and validation in a larger series.

Risk factors for fistula formation after interstitial brachytherapy for locally advanced gynecological cancers involving vagina

Purpose

To determine risk factors for fistula formation after interstitial brachytherapy (ISBT) in patients with advanced gynecologic cancers.

Material and methods

We performed an Institutional Review Board (IRB) approved retrospective review of 44 patients treated with transperineal template-based ISBT from 2011 to 2017 at a major metropolitan county and university health system. All patients were treated with image-guided high-dose-rate ISBT. Statistical analysis was performed using the χ² test to identify factors correlated with fistula formation. Survival and tumor control outcomes were calculated using Kaplan Meier analyses.

Results

Patients had a mean age of 53 years (range, 28-81 years), a mean external beam dose of 43.1 Gy (range, 42.5-51.3 Gy), and a mean brachytherapy dose of 22.8 Gy (range, 21.3-30 Gy). Two of 44 patients had fistulas that could be definitively attributed to therapy for a fistula rate of 4.5%. Six additional patients (13.6%) developed fistula after treatment with associated recurrent disease but were included in the causality analysis. We analyzed patient tumor and treatment factors, and on univariate analyses we found that age ≥ 60 years, Hispanic ethnicity, bladder involvement, rectal D2 cc ≥ 70 Gy, and whether patients had post-radiation biopsies were predictors for fistula formation. The 1-year overall survival (OS), progression-free survival (PFS), and local control (LC) were 85%, 58.5%, and 76.9%, respectively, with a mean follow-up time 23 months (range, 4.0-68.8 months).

Conclusions

We identified factors that predict fistula formation in patients with advanced gynecologic tumors treated with ISBT. These factors can be used to stratify patients into a high-risk group, with potential for modification of brachytherapy planning to reduce their risk of fistula formation.

Image-based multichannel vaginal cylinder brachytherapy for the definitive treatment of gynecologic malignancies in the vagina

PURPOSE

Brachytherapy is integral to vaginal cancer treatment and is typically delivered using an intracavitary single-channel vaginal cylinder (SCVC) or an interstitial brachytherapy (ISBT) applicator. Multi-channel vaginal cylinder (MCVC) applicators allow for improved organ-at-risk (OAR) sparing compared to SCVC while maintaining target coverage. We present clinical outcomes of patients treated with image-based high dose-rate (HDR) brachytherapy using a MCVC.

METHODS AND MATERIALS

Sixty patients with vaginal cancer (27% primary vaginal and 73% recurrence from other primaries) were treated with combination external beam radiotherapy (EBRT) and image-based HDR brachytherapy utilizing a MCVC if residual disease thickness was 7 mm or less after EBRT. All pts received 3D image-based BT to a total equivalent dose of 70-80 Gy.

RESULTS

The median high-risk clinical target volume was 24.4 cm³ (interquartile range [IQR], 14.1), with a median dose to 90% of 77.2 Gy (IQR, 2.8). After a median follow-up of 45 months (range, 11-78), the 4-year local-regional control, distant control, DFS, and OS rates were 92.6%, 76.1%, 64.0%, and 67.2%, respectively. The 4-year LRC rates were similar between the primary vaginal (92%) and recurrent (93%) groups (p = 0.290). Pts with lymph node positive disease had a lower rate of distant control at 4 years (22.7% vs. 89.0%, p < 0.001). There were no Grade 3 or higher acute complications. The 4-year rate of late Grade 3 or higher toxicity was 2.7%.

CONCLUSIONS

Clinical outcomes of pts with primary and recurrent vaginal cancer treated definitively in a systematic manner with combination EBRT with image-guided HDR BT utilizing a MCVC applicator demonstrate high rates of local control and low rates of severe morbidity. The MCVC technique allows interstitial implantation to be avoided in select pts with ≤7 mm residual disease thickness following EBRT while maintaining excellent clinical outcomes with extended 4-year follow-up in this rare malignancy.

Differences in urethral dosimetry between CT and MR imaging in multichannel vaginal cylinder brachytherapy

PURPOSE

In image-based brachytherapy (IBBT), the dosimetry of small structures may be particularly sensitive to changes in contouring between imaging modalities. We therefore sought to characterize differences in urethral dosimetry in vaginal brachytherapy based on contouring on MRI vs. CT.

METHODS AND MATERIALS

We retrospectively identified our most recent 15 patients treated with intracavitary brachytherapy for distal vaginal malignancies. On T2-weighted MRI, both the lumen and urethral wall were contoured. On CT, the urethral lumen alone was contoured, as the wall is indistinguishable from surrounding tissue. High-dose-rate (HDR) IBBT plans were generated for all patients.

RESULTS

Mean urethral volume was higher on MRI than CT at 3.7 cc vs. 1.1 cc (p < 0.0005). As a result, there were statistically significant increases on MRI in D_0.1cc and D_0.5cc, as well as EQD2 D_0.1cc and EQD2 D_0.5cc when applied to a full course of treatment (45 Gy EBRT + 25 Gy IBBT).

CONCLUSIONS

We have quantified the expected differences in urethral volume and dosimetry when contoured on MRI vs. CT. Inclusion of the urethral wall on MRI, with its average thickness of 2.2 mm, likely more accurately reflects the true organ at risk and results in an increase in reported dose compared to CT.