Figo IIIB squamous cell carcinoma of the cervix: an analysis of prognostic factors emphasizing the balance between external beam and intracavitary radiation therapy

Explainable artificial intelligence analysis of brachytherapy boost receipt in cervical cancer during the COVID-19 era

PURPOSE

Brachytherapy is a critical component of the standard-of-care curative radiotherapy regimen for women with locally advanced cervical cancer (LACC). However, existing literature suggests that many patients will not receive the brachytherapy boost. We used machine learning (ML) and explainable artificial intelligence to characterize this disparity.

MATERIALS AND METHODS

Patients with LACC diagnosed from 2004 to 2020 who received definitive radiation were identified in the National Cancer Database. Five ML models were trained to predict if a patient received a brachytherapy boost. The best-performing model was explained using SHapley Additive exPlanation (SHAP) values. To identify trends that may be attributable to the coronavirus disease 2019 (COVID-19) pandemic, the previous analysis was repeated and limited to 2019 to 2020.

RESULTS

A total of 37,564 patients with LACC were identified; 5799 were diagnosed from 2019 to 2020 (COVID cohort). Of these patients, 59.3% received a brachytherapy boost, with 76.4% of patients diagnosed in 2019 to 2020 receiving a boost. The random forest model achieved the best performance for both the overall and COVID cohorts. In the overall cohort, the most important predictive features were the year of diagnosis, stage, age, and insurance status. In the COVID cohort, the most important predictive features were FIGO stage, age, insurance status, and hospital type. Of the 26 patients who tested positive for COVID-19 during their course of radiotherapy, 19 (73.1%) received a brachytherapy boost.

CONCLUSIONS

A gradual increase in brachytherapy boost utilization has been noted, which did not seem to be significantly impacted by the onset of the COVID-19 pandemic. ML could be considered to identify patient populations where brachytherapy is underutilized, which can provide actionable feedback for improving access.

Percutaneous interstitial brachytherapy ablation for targeting oligometastatic gynecologic cancers

INTRODUCTION

Treatment of recurrent oligometastatic gynecologic malignancy may involve targeted surgery, thermal ablation, or CT-guided high-dose-rate interstitial brachytherapy ablation (CT-HDR-IBTA). The purpose of this study was to describe the safety and efficacy of CT-HDR-IBTA for oligometastatic gynecologic malignancies.

METHODS

With institutional review board approval (IRB) approval and compliance with the Health Insurance Portability and Accountability Act of 1996 (HIPAA) compliance, we searched our database to assemble a single-arm study cohort of all patients with oligometastatic gynecologic cancers who underwent CT-HDR-IBTA from 2012-2022 with follow-up. The electronic record was reviewed to determine relevant clinicopathological variables including patient demographics, prior treatments, clinical course, local control, and local and distant recurrence with follow-up imaging.

RESULTS

The study cohort comprised 37 lesions in 34 patients treated with CT-HDR-IBTA for recurrent oligometastatic uterine (n = 17), cervix (n = 1), or ovarian cancer (n = 16) with an average lesion size of 2.5 cm with an average patient age of 61.4 years. Each lesion was treated with an average radiation dose of 23.8 Gy in 1.8 fractions and a median follow-up time of 24.0 months. The primary efficacy of CT HDR ITBA was 73% with a median progression-free survival of 8.0 months (95% CI 3.6-12.8 months) and with 58% of patients still alive at 43 months with median overall survival not reached. The rate of Grade 1 adverse events was 22% without any Grade 2, 3 or 4 events.

CONCLUSIONS

CT HDR IBTA was safe and effective for treating oligometastatic gynecologic cancers in a heavily pretreated cohort.

A Dosimetric Correlation Between Radiation Dose to Bone and Reduction of Hemoglobin Levels After Radiation Therapy for Prostate Cancer

PURPOSE

The aim of this work was to investigate the correlation between dose to pelvic bone marrow and anemia when treating prostate cancer (PC) with definitive radiation.

METHODS AND MATERIALS

Patients were selected from a prospective institutional database of patients with PC treated between 2008 and 2021. Pelvic bone (L3/L4 interface through ischial tuberosities) was contoured, and the dose to this structure was calculated. Doses were converted to 2-Gy equivalent doses using an α/β of 10. Exploratory analysis suggested dichotomizing into low-volume exposures of ≤1000 cc (LVE) and high-volume exposures of >1000 cc (HVE). Nonparametric kernel regressions were performed evaluating the effects of time, dose, and androgen deprivation therapy use on hemoglobin (Hgb) values. Reoptimization of plans was performed to evaluate the feasibility of adjusting significant dose levels.

RESULTS

A total of 203 patients were included in the final analysis. Median baseline Hgb was 14.9 g/dL (interquartile range, 14.1-15.6). Patients with bone marrow HVE ≥15 Gy were found to have significantly lower predicted Hgb levels compared with those with LVE at day 90: 12.8 g/dL (95% CI, 12.4-13.3) versus 14.5 g/dL (95% CI, 14.0-14.9), respectively (P < .05). When normalizing starting Hgb levels, HVE patients still had significantly lower predicted Hgb levels than LVE at day 90: 86.1% (95% CI, 83.2%-89.7%) versus 96.2% (95% CI, 92.4%-100%), respectively. Reoptimizing 20 plans with high volume of bone marrow receiving 15 Gy resulted in a mean reduction from 1422 cc to 997 cc without compromise of other organs at risk or target coverage.

CONCLUSIONS

Patients with >1000 cc of bone marrow receiving ≥15 Gy had significantly lower predicted Hgb levels than those with ≤1000 cc. Reoptimization of plans demonstrated that this dose constraint is achievable without impairing plan quality. This dose constraint can be considered to limit acute marrow toxicity in patients with PC.

Locally advanced cervical cancer: how the improvement in techniques in external beam radiotherapy and brachytherapy impacts on survival outcomes and long-term toxicities

BACKGROUND

Platinum-based chemoradiotherapy and brachytherapy are the standard treatment for locally advanced cervical cancer. Reported long-term outcomes for treated with both IMRT and 3D-Image-guided-adaptive brachytherapy are lacking.

METHODS

This retrospective study included 165 patients with FIGO Stage IB-IVB cervical cancer, treated with chemoradiotherapy in combination with brachytherapy. External beam radiotherapy was delivered as IMRT/VMAT/TOMO helical or 3DCRT. The intracavitary brachytherapy treatment (ICBT) was performed using two different planning system (with or without optimization).

RESULTS

Among the patient subgroups, comprising those who received IMRT/VMAT/Tomo helical and 3DCRT, as well as those who underwent ICBT planning optimization and those who did not, homogeneity was observed in terms of age, performance status, T stage, N status, TNM stage, and histology. With a median follow-up time of 60.5 months, the 5-year overall survival (OS) in the 3DCRT and IMRT groups was 74.9% and 92.8%, respectively (p = 0.033). The 5-year OS in the ICBT planning optimization group was 93.7%, compared to 75% in the non-optimization group (p = 0.014). Regarding late radiation toxicities, patients in the IMRT group had a lower incidence of chronic rectal toxicity compared to those in the 3DCRT group (6.5% vs. 34.1%, p = 0.001). The group with ICBT planning optimization had a lower incidence of late urinary toxicities (10.4%) compared to the non-optimized ICBT planning group (18.2%, p = 0.012). Similarly, the ICBT planning optimization group had a lower incidence of late rectal toxicity (6.5% with 80% grade 1 and 20% grade 2) compared to the non-optimized ICBT planning group (34.1%, p = 0.001).

CONCLUSION

In this series, the group of patients receiving optimized ICBT had an advantage in terms of OS and CSS suggesting that the use of new Treatment Planning Systems associated with 3D imaging, improves the long-term survival. Additionally, a significant reduction in late rectal and urinary toxicity has been observed.

Rationality of FIGO 2018 IIIC restaging of cervical cancer according to local tumor size: A cohort study

INTRODUCTION

FIGO 2018 IIIC remains controversial for the heterogeneity of its prognoses. To ensure a better management of cervical cancer patients in Stage IIIC, a revision of the FIGO IIIC version classification is required according to local tumor size.

MATERIAL AND METHODS

We retrospectively enrolled cervical cancer patients of FIGO 2018 Stages I-IIIC who had undergone radical surgery or chemoradiotherapy. Based on the tumor factors from the Tumor Node Metastasis staging system, IIIC cases were divided into IIIC-T1, IIIC-T2a, IIIC-T2b, and IIIC-(T3a+T3b). Oncologcial outcomes of all stages were compared.

RESULTS

A total of 63 926 cervical cancer cases were identified, among which 9452 fulfilled the inclusion criteria and were included in this study. Kaplan-Meier pairwise analysis showed that: the oncology outcomes of I and IIA were significantly better than of IIB, IIIA+IIIB, and IIIC; the oncology outcome of IIIC-(T1-T2b) was significantly better than of IIIA+IIIB and IIIC-(T3a+T3b); no significant difference was noted between IIB and IIIC-(T1-T2b), or IIIC-(T3a+T3b) and IIIA+IIIB. Multivariate analysis indicated that, compared with IIIC-T1, Stages T2a, T2b, IIIA+IIIB and IIIC-(T3a+T3b) were associated with a higher risk of death and recurrence/death. There was no significant difference in the risk of death or recurrence/death between patients with IIIC-(T1-T2b) and IIB. Also, compared with IIB, IIIC-(T3a+T3b) was associated with a higher risk of death and recurrence/death. No significant differences in the risk of death and recurrence/death were noted between IIIC-(T3a+T3b) and IIIA+IIIB.

CONCLUSIONS

In terms of oncology outcomes of the study, FIGO 2018 Stage IIIC of cervical cancer is unreasonable. Stages IIIC-T1, T2a, and T2b may be integrated as IIC, and it might be unnecessary for T3a/T3b cases to be subdivided by lymph node status.

ESGO/ESTRO quality indicators for radiation therapy of cervical cancer

BACKGROUND

The European Society of Gynaecological Oncology (ESGO) has previously defined and established a list of quality indicators for the surgical treatment of cervical cancer. As a continuation of this effort to improve overall quality of care for cervical cancer patients across all aspects, ESGO and the European SocieTy for Radiotherapy and Oncology (ESTRO) initiated the development of quality indicators for radiation therapy of cervical cancer.

OBJECTIVE

To develop a list of quality indicators for radiation therapy of cervical cancer that can be used to audit and improve clinical practice by giving to practitioners and administrators a quantitative basis to improve care and organizational processes, notably for recognition of the increased complexity of modern external radiotherapy and brachytherapy techniques.

METHODS

Quality indicators were based on scientific evidence and/or expert consensus. The development process included a systematic literature search for identification of potential quality indicators and documentation of scientific evidence, consensus meetings of a group of international experts, an internal validation process, and external review by a large international panel of clinicians (n = 99).

RESULTS

Using a structured format, each quality indicator has a description specifying what the indicator is measuring. Measurability specifications are detailed to define how the quality indicators will be measured in practice. Targets were also defined for specifying the level which each unit or center should be aiming to achieve. Nineteen structural, process, and outcome indicators were defined. Quality indicators 1-6 are general requirements related to pretreatment workup, time to treatment, upfront radiation therapy, and overall management, including active participation in clinical research and the decision making process within a structured multidisciplinary team. Quality indicators 7-17 are related to treatment indicators. Quality indicators 18 and 19 are related to patient outcomes.

DISCUSSION

This set of quality indicators is a major instrument to standardize the quality of radiation therapy in cervical cancer. A scoring system combining surgical and radiotherapeutic quality indicators will be developed within an envisaged future ESGO accreditation process for the overall management of cervical cancer, in an effort to support institutional and governmental quality assurance programs.

ESGO/ESTRO quality indicators for radiation therapy of cervical cancer

BACKGROUND

The European Society of Gynaecological Oncology (ESGO) has previously defined and established a list of quality indicators for the surgical treatment of cervical cancer. As a continuation of this effort to improve overall quality of care for cervical cancer patients across all aspects, ESGO and the European SocieTy for Radiotherapy and Oncology (ESTRO) initiated the development of quality indicators for radiation therapy of cervical cancer.

OBJECTIVE

To develop a list of quality indicators for radiation therapy of cervical cancer that can be used to audit and improve clinical practice by giving to practitioners and administrators a quantitative basis to improve care and organizational processes, notably for recognition of the increased complexity of modern external radiotherapy and brachytherapy techniques.

METHODS

Quality indicators were based on scientific evidence and/or expert consensus. The development process included a systematic literature search for identification of potential quality indicators and documentation of scientific evidence, consensus meetings of a group of international experts, an internal validation process, and external review by a large international panel of clinicians (n=99).

RESULTS

Using a structured format, each quality indicator has a description specifying what the indicator is measuring. Measurability specifications are detailed to define how the quality indicators will be measured in practice. Targets were also defined for specifying the level which each unit or center should be aiming to achieve. Nineteen structural, process, and outcome indicators were defined. Quality indicators 1-6 are general requirements related to pretreatment workup, time to treatment, upfront radiation therapy, and overall management, including active participation in clinical research and the decision making process within a structured multidisciplinary team. Quality indicators 7-17 are related to treatment indicators. Quality indicators 18 and 19 are related to patient outcomes.

DISCUSSION

This set of quality indicators is a major instrument to standardize the quality of radiation therapy in cervical cancer. A scoring system combining surgical and radiotherapeutic quality indicators will be developed within an envisaged future ESGO accreditation process for the overall management of cervical cancer, in an effort to support institutional and governmental quality assurance programs.

Parametrial involvement and decreased survival of women with FIGO stage IIIC1 cervical cancer

OBJECTIVE

To evaluate the effect of parametrial status on FIGO stage IIIC1 cervical cancer.

METHODS

A retrospective study was conducted from June 1, 2009, to December 31, 2018.Patients with stage IIIC1 cervical cancer were included and stratified into two groups based on the status of parametrial involvement. Patients with IIIA or IIIB were selected as control. The primary outcomes are overall survival (OS) and progression-free survival (PFS).

RESULTS

Of 586 patients included, 377 patients were stage IIIC1 (group A) and 209 patients were stage IIIA/IIIB (group B). Compared control, stage IIIC1 was not associated with worse 5-year OS or PFS. Of the stage IIIC1 patients, 58.1% without parametrial involvement (group A1) and 41.9% with parametrial involvement (group A2). Patients of group A1 showed a better prognosis than group A2 both in 5-year rates of OS (79.09% vs. 59.43%, p<0.001) and PFS (73.27% vs. 56.95%, p=0.0002). However, patients of group A1 showed a better prognosis than group B both in OS and PFS. Also, patients of group A2 showed a comparable prognosis to group B both in OS and PFS.

CONCLUSION

Reclassification of stage IIIC1 cervical cancer without parametrial into a new stage is more appropriate and improves discriminatory ability.

Comparing dosimetry of locally advanced cervical cancer patients treated with 3 versus 4 fractions of MRI-guided brachytherapy

PURPOSE

To demonstrate the feasibility of treating cervical cancer patients with MRI-guided brachytherapy (MRgBT) using 24 Gy in 3 fractions (F) versus a standard, more resource-intensive regimen of 28 Gy in 4F, and its ability to meet EMBRACE II planning aims.

METHODS AND MATERIALS

A retrospective review of 224 patients with FIGO Stage IB-IVA cervical cancer treated with 28 Gy/4F (n = 91) and 24 Gy/3F (n = 133) MRgBT between 2016-2021 was conducted. Multivariable linear regression models were fitted to compare dosimetric parameters between the two groups, adjusting for CTV_HR and T stage.

RESULTS

Most patients had squamous cell carcinoma, T2b disease, and were treated with intracavitary applicator plus interstitial needles (96%). The 28 Gy/4F group had higher CTV_HR (median 28 vs. 26 cm³, p = 0.04), CTV_IR D_98% (mean 65.5 vs. 64.5 Gy, p = 0.03), rectum D_2cm3 (mean 61.7 vs. 59.2 Gy, p = 0.04) and bladder D_2cm3 (81.3 vs. 77.9 Gy, p = 0.03). There were no significant differences in the proportion of patients meeting the EMBRACE II OAR dose constraints and planning aims, except fewer patients treated with 28 Gy/4F met rectum D_2cm3 < 65 Gy (73 vs. 85%, p = 0.027) and ICRU rectovaginal point < 65 Gy (65 vs. 84%, p = 0.005).

CONCLUSIONS

Cervical cancer patients treated with 24 Gy/3F MRgBT had comparable target doses and lower OAR doses compared to those treated with 28 Gy/4F. A less-resource intense fractionation schedule of 24 Gy/3F is an alternative to 28 Gy/4F in cervix MRgBT.

Advances in immunotherapy for cervical cancer

Cervical cancer still represents a major public health problem, being the fourth most common cancer in incidence and mortality in women worldwide. These figures are unacceptable since cervical cancer, an human papillomavirus-related malignancy, is a largely preventable disease by means of well-established screening and vaccination programs. Patients with recurrent, persistent, or metastatic disease unsuitable for curative therapeutic approaches represent a dismal prognosis population. Until recently, these patients were only candidates for cisplatin-based chemotherapy plus bevacizumab. However, the introduction of immune checkpoint inhibitors has revolutionized the treatment landscape of this disease achieving historical overall survival improvements in both the post-platinum and frontline settings. Interestingly, the clinical development of immunotherapy in cervical cancer is currently advancing to earlier stages of the disease, as the locally advanced setting, whose standard of care has not changed in the last decades with still modest outcomes. As more innovative immunotherapy approaches are in clinical early development in advanced cervical cancer, promising efficacy data are emerging that may shape the future of this disease. This review summarizes the main treatment advances carried out in the field of immunotherapy throughout the past years.

The Kelowna template for combined intracavitary and interstitial brachytherapy for gynecologic malignancies: Design, application, treatment planning, dosimetric and treatment outcomes

PURPOSE

We report the feasibility, experience, and early outcomes of the combined intracavitary and interstitial dedicated applicator using the Kelowna GYN template (Varian, Palo Alto, CA).

METHODS AND MATERIALS

The Kelowna GYN template is CT compatible and used for the treatment of gynecologic cancers. In cases with patients that have an intact uterus, a modified applicator system using the Kelowna GYN template and a 3D printed adapter piece allows for compatibility with an intrautaerine tandem.

RESULTS

We reviewed the treatment course of 23 patients comprising of 86 fractions of HDR treatment. Median D90 for cervical tumors (n = 7) was 82.4 Gy (range 77.7-92.6); for postoperative cervical tumors (n = 2) was 73.9 Gy (range 72.0-5.8); for vaginal tumors (n = 4) was 85.8 Gy (range 79.8-88.1); for recurrent endometrial (n = 10) was 86.9 Gy (range 74.8-103.2). Median EQD2 D2cc for bladder was 72.4 Gy (range 47.7-99.4), for rectum was 61.2 Gy (range 52.4-80.6), and for sigmoid colon of 50.5 Gy (44.3-66.9). At a median follow-up of 12 months, 2 patients had a local recurrence. Two patients had distant recurrence: one with carcinomatosis at 6 months, and one with pulmonary metastases at 3 months. No patients had late grade three toxicities.

CONCLUSIONS

Our single institutional experience supports the use of the Kelowna template as a robust system as a combined IC-IS applicator resulting in versatile and reproducible implants for a variety of gynecologic malignancies.

Improved survival in cervical cancer patients receiving care at National Cancer Institute-designated cancer centers

Background

Locally advanced cervical cancer (CC) remains lethal in the United States. We investigate the effect of receiving care at an National Cancer Institute–designated cancer center (NCICC) on survival.

Methods

Data for women diagnosed with CC from 2004 to 2016 who received radiation treatment were extracted from the California Cancer Registry (n = 4250). Cox proportional hazards regression models assessed whether (1) receiving care at NCICCs was associated with risk of CC‐specific death, (2) this association remained after multivariable adjustment for age, race/ethnicity, and insurance status, and (3) this association was explained by receipt of guideline‐concordant treatment.

Results

Median age was 50 years (interquartile range [IQR] 41–61 years), with median follow‐up of 2.7 years (IQR 1.3–6.0 years). One‐third of patients were seen at an NCICC, and 29% died of CC. The hazard of CC‐specific death was reduced by 20% for those receiving care at NCICCs compared with patients receiving care elsewhere (HR = .80; 95% CI, 0.70–0.90). Adjustment for guideline‐concordant treatment and other covariates minimally attenuated the association to 0.83 (95% CI, 0.74–0.95), suggesting that the survival advantage associated with care at NCICCs may not be due to receipt of guideline‐concordant treatment.

Conclusions

This study demonstrates survival benefit for patients receiving care at NCICCs compared with those receiving care elsewhere that is not explained by differences in guideline‐concordant care. Structural, organizational, or provider characteristics and differences in patients receiving care at centers with and without NCI designation could explain observed associations. Further understanding of these factors will promote equality across oncology care facilities and survival equity for patients with CC.

This study demonstrates survival benefit for patients receiving care for cervical cancer at National Cancer Institute–designated cancer centers that is not explained by receipt of guideline‐concordant treatment. Further understanding of these factors will promote equality across oncology care facilities resulting in survival equity for patients with cervical cancer.

Review on Treatment Planning Systems for Cervix Brachytherapy (Interventional Radiotherapy): Some Desirable and Convenient Practical Aspects to Be Implemented from Radiation Oncologist and Medical Physics Perspectives

Intracavitary brachytherapy (BT, Interventional Radiotherapy, IRT), plays an essential role in the curative intent of locally advanced cervical cancer, for which the conventional approach involves external beam radiotherapy with concurrent chemotherapy followed by BT. This work aims to review the different methodologies used by commercially available treatment planning systems (TPSs) in exclusive magnetic resonance imaging-based (MRI) cervix BT with interstitial component treatments. Practical aspects and improvements to be implemented into the TPSs are discussed. This review is based on the clinical expertise of a group of radiation oncologists and medical physicists and on interactive demos provided by the software manufacturers. The TPS versions considered include all the new tools currently in development for future commercial releases. The specialists from the supplier companies were asked to propose solutions to some of the challenges often encountered in a clinical environment through a questionnaire. The results include not only such answers but also comments by the authors that, in their opinion, could help solve the challenges covered in these questions. This study summarizes the possibilities offered nowadays by commercial TPSs, highlighting the absence of some useful tools that would notably improve the planning of MR-based interstitial component cervix brachytherapy.

To evaluate the use of tandem and cylinder as an intracavitary brachytherapy device for carcinoma of the cervix with regard to local control and toxicities

Introduction

Brachytherapy always remains a keystone in the treatment of gynecological carcinoma for both definitive and adjuvant treatments. Due to the rapid fall-off nature of brachytherapy, the target gets a high dose with a low dose to the normal organs nearby and thereby increasing the tumor control probability.

Aims and Objectives

This study aims at the evaluation of local control and toxicities in the carcinoma of the cervix using tandem and cylinder as brachytherapy applicator.

Materials and Methods

The study was conducted between January 2014 and December 2018 in a tertiary care hospital. Thirty-one patients who fulfilled our set criterion of Clinical stage IB3-IVA, Performance status Eastern Cooperative Oncology Group 0-2 were selected. All patients were treated initially with external beam radiotherapy and later by high dose rate intracavitary brachytherapy after completion of external beam radiation therapy (EBRT). A dose of 18-21 Gy was delivered to the residual disease in three sessions with a 1-week interval between each session. The dose was optimized in such a way that the organs at risk (OAR), namely bladder and rectum received doses within their tolerance levels. The patients were continuously monitored using Common Terminology Criteria for Adverse Events version 5.0 for both acute and late toxicities and by imaging for local control. Statistical analysis using SPSS Version 20.0 (SPSS Inc., Chicago, Illinois, USA) was used to evaluate the results. Continuous variables were expressed as mean ± standard deviation, and categorical variables were summarized as frequencies and percentages.

Results

Out of the 31 patients, 5 (16.1%) experienced radiation-induced Grade 1 skin changes which were due to EBRT, 1 (3.2%) had Grade 1 G. I. T toxicity, 1 (3.2%) had Grade 1 radiation-induced vaginal mucositis after brachytherapy. At 6-8-week follow-up, all the patients showed no evidence of disease on radiological imaging. At 3 months of follow-up, 1 (3.2%) patient had radiation-induced proctitis of Grades 2 and 3 (9.7%) had radiation-induced cystitis of Grades 1 and 1 (3.2%) had Grade 2 cystitis. At 6 months of follow-up, 1 (3.2%) had Grade 1, 1 (3.2%) had Grade 2, and 1 (3.2%) had Grade 3 radiation-induced proctitis. At 3 months of follow-up, 29 (93.5%) patients had no evidence of disease, while 2 (6.5%) were having residual disease on imaging. At 6 months of follow-up, all the patients were disease-free. At 12 months of follow-up, 26 (83.9%) patients were disease-free, 1 (3.2%) had local recurrence, 2 (6.5%) had distant metastasis, and 2 (6.5%) had expired. At 24 months of follow-up, 26 patients were disease-free. Acute and late toxicities were similar to those used in the treatment of carcinoma cervix by standard brachytherapy applicators. Local control was achieved in 83.87% of cases. Two-year survival was 93.5%.

Conclusion

We observed that the tandem and cylinder applicator is an acceptable applicator to be used for intracavitary brachytherapy. It is safe and simple besides this; the toxicities and local control are similar to the other standard applicators used in brachytherapy in carcinoma cervix. However, the required dose prescription to point A was not possible in all the patients due to limitations of OARs. Furthermore, long-term follow-up is needed to see the patterns of failure, recurrence-free survival, overall survival, and long-term toxicities in the treated patients.

Prognostic value of the 2018 FIGO staging system for cervical cancer

OBJECTIVE

To compare the prognostic performance of the FIGO 2009 and FIGO 2018 staging systems for cervical cancer (CC) in regards to risk stratification, survival and treatment outcome.

METHODS

A total of 4461 CC patients diagnosed in Denmark during 2005-2018 were identified through the Danish Gynaecological Cancer Database and restaged from the 2009 FIGO to the 2018 FIGO staging system. 5-year survival estimates were made for each group. Also, association between lymphovascular space invasion (LVSI) and lymph node metastasis (LNM) was assesed for tumors with a horizontal spread >7 mm and depth of invasion ≤5 mm.

RESULTS

Overall, stage migration was observed in 41.4% of our cases due to the introduction of stage IIIC (20.1%), refined tumor size criteria within stage I (76.2%), and use of radiological findings to define stage IV (3.7%). 5-year overall survival increased for all stages except IA2, IIA2, IIIA and IIIB. Restaging of 2009 IB1 to 2018 FIGO resulted in significant stage allocations. Furthermore, an association between LVSI and LNM was observed in squamous cell carcinomas with a depth of invasion of 3-5 mm and a horizontal spread >7 mm (p = 0.03).

CONCLUSION

The 2018 FIGO staging system provided improved discriminatory ability for stage I and IV. Grouping all patients with positive pelvic or paraortal lymph nodes to stage IIIC led to pronounced heterogenous survival rates within these stages. Lymph node assessment was proven imperative in FIGO 2018 IA2 squamous cell carcinomas with a depth of invasion of 3-5 mm, a horizontal spread >7 mm and LVSI.

Image-guided brachytherapy in cervical cancer including fractionation

Image-guided brachytherapy in cervical cancer has been developed to be a feasible and very efficient component of the treatment of locally advanced cervical cancer in addition to concurrent chemoradiation treatment. This technique allows effective dose coverage of the target while sparing the organs at risk through adjustment of the implants (intracavitary and interstitial needles) and multi-pararametric three-dimensional treatment planning. Emerging evidence from prospective studies shows a high rate of local control throughout all stages, superior to two-dimensional brachytherapy, with limited toxicity for each organ site. This is associated with a high rate of pelvic control and overall survival. Based on clinical evidence, there is a dose–effect relationship for both disease and morbidity endpoints from which clear dose constraints for the target and organs at risk were derived. This review gives an overview of the major milestones that occurred in the development of image-guided adaptive brachytherapy in the last two decades, including outcome data and a summary of the hard and soft dose constraints recommended for targets and organs at risk.

Active small bowel sparing in intracavitary brachytherapy for cervical cancer

OBJECTIVE

To propose and evaluate an active method for sparing the small bowel in the treatment field of cervical cancer brachytherapy by prone position procedure.

METHODS

The prone position procedure consists of five steps: making bladder empty, prone-positioning a patient on belly board, making the small bowel move to abdomen, filling the bladder with Foley catheter and finally turning the patient into the supine position. The proposed method was applied for the treatment of seven cervical cancer patients. Its effectiveness was evaluated and a correlation between the patient characteristics and the volumetric dose reduction of small bowel was also investigated. Brachytherapy treatment plans were built before and after the proposed method, and their dose-volume histograms were compared for targets and organs-at-risk. In this comparison, all plans were normalized to satisfy the same D90% for high-risk clinical target volume.

RESULTS

For the enrolled patients, the average dose of small bowel was significantly reduced from 75.2 ± 4.9 Gy before to 60.2 ± 4.0 Gy after the prone position procedure, while minor dosimetric changes were observed in rectum, sigmoid and bladder. The linear correlation to body mass index, thickness and width of abdominopelvic cavity and bladder volume were 76.2, 69.7, 28.8 and -36.3%, respectively.

CONCLUSIONS

The application of prone position procedure could effectively lower the volumetric dose of the small bowel. The dose reduction in the small bowel had a strong correlation with the patient's obesity and abdominal thickness. This means the patients for whom the proposed method would be beneficial can be judiciously selected for safe brachytherapy.

Better late than never: Brachytherapy is more important than timing in treatment of locally advanced cervical cancer

PURPOSE

To evaluate the utilization of brachytherapy and duration of treatment on overall survival for locally advanced cervical cancer.

METHODS

The National Cancer Database (NCDB) was queried to identify stage II-IVA cervical cancer patients diagnosed in the United States between 2004 and 2015 who were treated with definitive chemoradiation therapy. We defined standard of care (SOC) treatment as receiving external beam radiation therapy (EBRT) and concurrent chemotherapy, brachytherapy (BT), and completing treatment within 8 weeks, and compared SOC treatment to non-SOC. The primary outcome was overall survival (OS). We also evaluated the effect of sociodemographic and clinical variables on receiving SOC.

RESULTS

We identified 10,172 women with locally advanced cervical cancer primarily treated with chemotherapy and concurrent EBRT of which 6047 (59.4%) patients received brachytherapy, and only 2978 (29.3%) completed treatment within 8 weeks (SOC). Receipt of SOC was associated with significantly improved overall survival (median OS 131.0 mos vs 95.5 mos, 78.1 mos, 49.2 mos; p < 0.0001). Furthemore, in patients whose treatment extended beyond 8 weeks, brachytherapy was still associated with an improved survival (median OS 95.5 vs 49.2 mos, p < 0.0001). More advanced stage, Non-Hispanic Black race, lower income, lack of insurance or government insurance, less education, and rural residence were associated with decreased likelihood of receiving SOC.

CONCLUSIONS

Completing standard of care concurrent chemoradiation therapy and brachytherapy in the recommended 8 weeks was associated with a superior overall survival. Patients who received brachytherapy boost show superior survival to patients receiving EBRT alone, regardless of treatment duration. Disparities in care for vulnerable populations highlight the challenges and importance of care coordination for patients with cervical cancer.

Socioeconomic and Racial Determinants of Brachytherapy Utilization for Cervical Cancer: Concerns for Widening Disparities

PURPOSE

Cervical cancer (CC) disproportionately affects minorities who have higher incidence and mortality rates. Standard of care for locally advanced CC involves a multimodality approach including brachytherapy (BT), which independently improves oncologic outcomes. Here, we examine the impact of insurance status and race on BT utilization with the SEER database.

MATERIALS AND METHODS

In total, 7,266 patients with stage I-IV CC diagnosed from 2007 to 2015 were included. BT utilization, overall survival (OS), and disease-specific survival (DSS) were compared.

RESULTS

Overall, 3,832 (52.7%) received combined external beam radiation therapy (EBRT) + BT, whereas 3,434 (47.3%) received EBRT alone. On multivariate logistic regression analysis, increasing age (OR, 0.98; 95% CI, 0.98 to 0.99; P < .001); Medicaid (OR, 0.80; 95% CI, 0.72 to 0.88; P < .001), uninsured (OR, 0.67; 95% CI, 0.56 to 0.80; P < .001), and unknown versus private insurance (OR, 0.61; 95% CI, 0.43 to 0.86; P < .001); Black (OR, 0.68; 95% CI, 0.60 to 0.77; P < .001) and unknown versus White race (OR, 0.30; 95% CI, 0.13 to 0.77; P = .047); and American Joint Committee on Cancer stage II (OR, 1.07; 95% CI, 0.93 to 1.24; P = .36), stage III (OR, 0.82; 95% CI, 0.71 to 0.94; P = .006), stage IV (OR, 0.30; 95% CI, 0.23 to 0.40; P < .001), and unknown stage versus stage I (OR, 0.36; 95% CI, 0.28 to 0.45; P < .001) were associated with decreased BT utilization. When comparing racial survival differences, the 5-year OS was 44.2% versus 50.9% (P < .0001) and the 5-year DSS was 55.6% versus 60.5% (P < .0001) for Black and White patients, respectively. Importantly, the racial survival disparities resolved when examining patients who received combined EBRT + BT, with the 5-year OS of 57.3% versus58.5% (P = .24) and the 5-year DSS of 66.3% versus 66.6% (P = .53) for Black and White patients, respectively.

CONCLUSION

This work demonstrates notable inequities in BT utilization for CC that particularly affects patients of lower insurance status and Black race, which translates into inferior oncologic outcomes. Importantly, the use of BT was able to overcome racial survival differences, thus highlighting its essential value.

Evaluation of tumor response three months after concomitant chemoradiotherapy with high dose rate brachytherapy as a definitive treatment modality for locally advanced cervical cancer

OBJECTIVE

Radiotherapy remains an essential part of the management of locally advanced cervical cancer. Post-treatment surveillance allows for tumor response assessment and early detection of progressive prosecutions or local recurrences that may benefit from salvage treatment. The objective of this work is to assess the effectiveness of this therapeutic modality.

MATERIALS METHODS

This is a retrospective study of 69 patients treated with concomitant radiation chemotherapy followed by high dose rate intracavitary brachytherapy. The tumor response was assessed by gynecologic physical examination at three months after the end of treatment.

RESULTS

Median age of patients is 54.9 years (33-78 years). The most common histological type is squamous cell carcinoma (89.9%). The average dose received during external radiotherapy is 52.2Gy (46-60Gy). The average dose received during brachytherapy is 27.5Gy (18-28Gy). Three months after completion of treatment, 95.6% of patients had complete tumor remission, and only 4.4% had a tumor residue of 1cm.

CONCLUSION

Radiation chemotherapy with brachytherapy allows for improved short-term local control in cervical cancer.

The Case for Brachytherapy: Why It Deserves a Renaissance

The recent global events related to the coronavirus disease of 2019 pandemic have significantly changed the medical landscape and led to a shift in oncologic treatment perspectives. There is a renewed focus on preserving treatment outcomes while maintaining medical accessibility and decreasing medical resource utilization. Brachytherapy, which is a vital part of the treatment course of many cancers (particularly prostate and gynecologic cancers), has the ability to deliver hypofractionated radiation and thus shorten treatment time. Studies in the early 2000s demonstrated a decline in brachytherapy usage despite data showing equivalent or even superior treatment outcomes for brachytherapy in disease sites, such as the prostate and cervix. However, newer data suggest that this trend may be reversing. The renewed call for shorter radiation courses based on data showing equivalent outcomes will likely establish hypofractionated radiation as the standard of care across multiple disease sites. With shifting reimbursement, brachytherapy represents the pinnacle in hypofractionated, conformal radiation therapy, and with extensive long-term data in support of the treatment modality brachytherapy is primed for a renaissance.

Uterine Cervical Carcinoma: Evaluation Using Non-Gaussian Diffusion Kurtosis Imaging and Its Correlation With Histopathological Findings

OBJECTIVE

The aim of the study was to assess non-Gaussian diffusion kurtosis imaging (DKI)'s usefulness as a noninvasive method to evaluate tumor invasion depth, histological grade, and lymph node metastasis in cervical carcinoma (CC) patients.

METHODS

Twenty-two consecutive patients with histologically confirmed CC were examined by 1.5-T MRI and non-Gaussian DKI with 4 b values of 0, 500, 1000, and 2000 s/mm2. Kurtosis (K), diffusivity (D), and apparent diffusion coefficient (ADC) maps were compared with histopathological findings.

RESULTS

Kurtosis maps revealed the fibrous stroma as a distinct high K zone (1.442 ± 0.373) that was significantly different from values of the cervical mucosa, outer stroma, and parametrium (0.648 ± 0.083, 0.715 ± 0.113, and 0.504 ± 0.060, respectively, P < 0.0001). Kurtosis (1.189 ± 0.228) and D (0.961 ± 0.198 × 10-3 mm2/s) values of all CCs were significantly different from those of all uterine cervical wall layers. Kurtosis and D values were significantly correlated with histological grades of CCs (r = 0.934, P < 0.0001, and r = -0.925, P < 0.0001, respectively), whereas no significant differences were found in ADC values between grades 2 and 3 CCs (P = 0.787). Metastatic and nonmetastatic lymph nodes showed significantly different K (P < 0.0001) and D (P < 0.0001) values; however, their ADC values did not show significant differences (P = 0.437). For differentiating grade 3 CCs from grade 1 or 2 CCs, the areas under the curve for K (0.991, P = 0.0375) and D (0.982, P = 0.0337) values were significantly higher than those for ADC values (0.759). For differentiating metastatic and nonmetastatic lymph nodes, the areas under the curve for K (0.974, P = 0.0028) and D (0.968, P = 0.0018) values were significantly higher than those for ADC (0.596).

CONCLUSIONS

Non-Gaussian DKI may be clinically useful for noninvasive evaluation of tumor invasion depth, histological grade, and lymph node metastasis in CC patients.

Magnetic resonance imaging-based validation of the 2018 FIGO staging system in patients treated with definitive radiotherapy for locally advanced cervix cancer

OBJECTIVE

To validate the revised 2018 International Federation of Gynecologic and Obstetrics (FIGO) staging system in patients who underwent diagnostic magnetic resonance imaging (MRI) and radiotherapy (RT) for locally advanced cervix cancer.

METHODS

We analyzed 677 patients who were diagnosed with pelvic MRI and treated with definitive (chemo-)RT for locally advanced cervix cancer (stage IB2/IIA2-IVA or N+) between 1992 and 2018. Patients were classified according to 2009 and 2018 FIGO staging, and survival outcomes were compared. We developed a nomogram to improve prediction of progression-free survival (PFS).

RESULTS

Pelvic and paraaortic lymph nodes were positive in 331 (48.9%) and 78 (11.5%) patients, respectively. At a median follow-up of 77.9 months, the 5-year PFS was 83.5%, 65.2%, 71.0%, 60.6%, 37.6% and 38.9% for IB, IIA, IIB, IIIA, IIIB and IVA according to FIGO 2009 and 88.9%, 60.0%, 73.8%, 66.7%, 36.3%, 68.9%, 43.6%, and 38.9% for IB, IIA, IIB, IIIA, IIIB, IIIC1, IIIC2, and IVA according to FIGO 2018, respectively. Survival of stage IIIC cervix cancer depended on the local extent of the tumor: the 5-year PFS of T1, T2, and T3 stages were 80.3%, 73.9%, and 45.5% for IIIC1 and 100%, 44.9%, and 23.4% for IIIC2. Histology, tumor size, node metastasis, FIGO 2009, and treatment modality were independent prognostic factors in the Cox regression analysis, and the nomogram incorporating these factors outperformed FIGO 2009 and FIGO 2018 (AUC 0.718 vs. 0.616 vs. 0.594).

CONCLUSIONS

FIGO 2018 revision was associated with heterogenous outcomes among stage III cervix cancer patients. Our nomogram can assist the FIGO system in predicting PFS after definitive RT.

Prognostic Nomograms Predicting Survival in Patients With Locally Advanced Cervical Squamous Cell Carcinoma: The First Nomogram Compared With Revised FIGO 2018 Staging System

Objectives

To develop nomograms to assess prognostic factors for 5-year overall survival (OS) and 5-year progression-free survival (PFS) in locally advanced cervical squamous cell carcinoma (LACSC).

Methods

Overall, 618 patients with LACSC were included in this retrospective analysis. Nomograms for 5-year OS and PFS were developed based on Cox proportional hazards regression models. Concordance index (C-index) and calibration curves were used to define the predictive and discriminatory capacity of the nomogram. A comparison between the nomogram and the International Federation of Gynecology and Obstetrics (FIGO) staging system was conducted using time-dependent receiver operating characteristic (tROC) and area under the curve (tAUC).

Results

Multivariate analysis identified several prognostic factors for OS including squamous cell carcinoma antigen (SCC-Ag), body mass index (BMI), tumor size, pelvic wall involvement, and para-aortic lymph node metastasis (PALNM). Prognostic factors for PFS included BMI, hemoglobin (HGB), tumor size, pelvic wall involvement, pelvic lymph node metastasis (PLNM) and PALNM. Following bootstrap correction, the C-index of OS and PFS was 0.713 and 0.686, respectively. These nomograms showed superior performance compared with the FIGO 2009 and 2018 staging schema.

Conclusions

Nomograms were developed to identify prognostic factors for 5-year OS and PFS in patients with LACSC. These nomograms showed good prognostication and are more comprehensive in predicting survival outcomes than existing staging criteria.

Simulation-based learning for enhanced gynecologic brachytherapy training among radiation oncology residents

PURPOSE

Brachytherapy is an irreplaceable component of gynecologic cancer treatment. Resident training has declined, and procedural exposure is variable. We evaluated whether simulation-based gynecologic brachytherapy training among radiation oncology residents could improve knowledge, confidence, and interest.

METHODS AND MATERIALS

Before a brachytherapy workshop, radiation oncology residents without prior gynecologic brachytherapy experience completed a survey on brachytherapy knowledge, procedural confidence, plan evaluation, and quality/safety. Residents then participated in a gynecologic brachytherapy workshop. Lectures covered brachytherapy imaging and physics principles/quality assurance, followed by hands-on and individualized feedback regarding applicator selection and placement, target segmentation, and physics quality assurance. Afterward, preworkshop questions were recollected. Descriptive statistics and Fisher's exact tests were used for data analysis.

RESULTS

After the workshop, resident responses regarding the learning environment and baseline knowledge questions improved overall. There was a 30% improvement in favorable responses to the learning environment statement "My residency has a formal process/curriculum to teach brachytherapy" and for baseline knowledge the greatest improvement was seen for "I am familiar with the anatomy and placement of the applicators in relation to the anatomy". "Lack of didactic or procedural training exposure" was identified as the main reason for declining brachytherapy use. Initially, 1/8 residents correctly completed the knowledge questions, and after the workshop, 6/7 (p < 0.001) residents correctly completed the questions.

CONCLUSIONS

Domain-specific knowledge, procedural confidence, and brachytherapy interest improved after a gynecologic brachytherapy workshop. Integrated didactic and simulation-based brachytherapy training may serve as a valuable learning tool to augment resident knowledge, introduce practical skills, and spark resident interest in brachytherapy.

Prognostic Significance of Tumor Regression Rate during Concurrent Chemoradiotherapy in Locally Advanced Cervix Cancer: Analysis by Radiation Phase and Histologic Type

This study aimed to evaluate the prognostic significance of tumor regression rate according to radiation phase and histologic subtype in patients with locally advanced cervical cancer (LACC) treated with chemoradiation. We retrospectively reviewed the medical records of 398 patients with FIGO stage IIB-IVA cervical cancer treated with concurrent chemoradiotherapy (CCRT) between 2001 and 2019. Tumor response was assessed using serial magnetic resonance imaging (MRI) at three time points: pre-treatment, post-external beam radiotherapy (EBRT), and post-intracavitary radiotherapy (ICR). Tumor regression pattern according to histologic subtype and radiation phase (EBRT and ICR) was evaluated. Overall survival (OS) and progression-free survival (PFS) were the primary outcomes. Of 398 patients, 44 patients had adenocarcinoma/adenosquamous carcinoma (AC/ASC) and 354 patients had squamous cell carcinoma (SCC). AC/ASC was associated with significantly worse PFS and OS than SCC (p < 0.001). AC/ASC had a relatively poorer regression rate in response to EBRT than SCC (p < 0.001), whereas there was no significant difference in overall tumor regression rate after completion of RT (EBRT and ICR) between the two histologic subtypes. Multivariable analysis demonstrated AC/ASC histology to be an independent prognostic factor of decreased PFS and OS. Moreover, tumor regression rate after completion of EBRT (post-EBRT tumor regression rate (EBRT_regression ≤ 26%) and proportion of tumor regression during EBRT to overall tumor regression (EBRT_proportion ≤ 40%) were independent predictors of poor survival in patients with LACC. Tumor regression pattern of LACC in response to CCRT differs according to histologic subtype. AC/ASC histology and poor tumor response to EBRT are independent prognostic factors for worse survival in patients with LACC. Further studies are needed to develop a CCRT protocol that is specialized for patients with AC/ASC.

Bibliometric analysis of the 100 most cited articles on cervical cancer radiotherapy

PURPOSE

To identify the 100 most cited research articles on cervical cancer radiotherapy.

METHODS

The Web of Science and Scopus databases were searched to identify the 100 most cited articles on cervical cancer radiotherapy as of September 29, 2019. Articles were ranked based on the total citations received from 2 databases. One hundred articles about radiotherapy for cervical cancer were identified. The following important information was extracted: author, journal, year and month of publication, country or region, and radiotherapy technologies.

RESULTS

The 100 most cited articles on cervical cancer radiotherapy were published between 1964 and 2016, and the total citations from 2 databases ranged from 3478 to 211, including a total of 49,262 citations as of September 29, 2019. The index of citations per year ranged from 170.4 to 13.1. These articles were from 16 countries or regions, with most publications being from the United States (n = 38), followed by Austria (n = 15), Canada (n = 8), France (n = 8) and the United Kingdom (n = 7). The International Journal of Radiation Oncology, Biology, Physics produced the most articles (n = 42), followed by Radiotherapy and Oncology (n = 13), Cancer (n = 8) and Journal of Clinical Oncology (n = 7). These articles were categorized as original studies (n = 86), recommendations (n = 5), guidelines (n = 5) and reviews (n = 4). Of the 100 most cited articles, intracavitary brachytherapy (n = 50) and 3-dimensional conformal radiotherapy (n = 34) were the most commonly used treatment techniques.

CONCLUSION

To the best of our knowledge, this is the first report and analysis of the most cited articles on cervical cancer radiotherapy. This bibliographic study presents the history of technological development in external radiation therapy and brachytherapy. Brachytherapy is an indispensable part of radiotherapy for cervical cancer. The International Journal of Radiation Oncology Biology Physics is the journal with the most publications related to cervical cancer radiotherapy.

Diffusion-Tensor Imaging of Uterine Cervical Carcinoma: Correlation With Histopathologic Findings

The authors investigated the usefulness of diffusion-tensor imaging (DTI) for evaluating tumor invasion depth, histologic grade, and lymph node metastasis in patients with cervical carcinoma (CC). Fifteen consecutive patients with histologically confirmed CC underwent 1.5-T magnetic resonance imaging and DTI. The CCs were clearly depicted as hypointense areas on all DTI maps. Fractional anisotropy, mean diffusivity, and axial diffusivity showed significantly inverse correlations with CC histologic grades and were significantly different between metastatic and nonmetastatic lymph nodes.

Texture Analysis of Apparent Diffusion Coefficient Maps in Cervical Carcinoma: Correlation with Histopathologic Findings and Prognosis

Purpose

To determine the feasibility of texture analysis of apparent diffusion coefficient (ADC) maps and to assess the performance of texture analysis and ADC to predict histologic grade, parametrial invasion, lymph node metastasis, International Federation of Gynecology and Obstetrics (FIGO) stage, recurrence, and recurrence-free survival (RFS) in patients with cervical carcinoma.

Materials and Methods

This retrospective study included 58 patients with cervical carcinoma who were examined with a 1.5-T MRI system and diffusion-weighted imaging with b values of 0 and 1000 sec/mm². Software with volumes of interest on ADC maps was used to extract 45 texture features, including higher-order texture features. Receiver operating characteristic (ROC) analysis was performed to compare the diagnostic performance of ADC map random forest models and of ADC values. Dunnett test, Spearman rank correlation coefficient, Kaplan-Meier analyses, log-rank test, and Cox proportional hazards regression analyses were also used for statistical analyses.

Results

The ADC map random forest models showed a significantly larger area under the ROC curve (AUC) than the AUC of ADC values for predicting high-grade cervical carcinoma (P = .0036), but not for parametrial invasion, lymph node metastasis, stages III-IV, and recurrence (P = .0602, .3176, .0924, and .5633, respectively). The random forest models predicted that the mean RFS rates were significantly shorter for high-grade cervical carcinomas, parametrial invasion, lymph node metastasis, stages III-IV, and recurrence (P = .0405, < .0001, .0344, .0001, and .0015, respectively); the random forest models for parametrial invasion and stages III-IV were more useful than ADC values (P = .0018) for predicting RFS.

Conclusion

The ADC map random forest models were more useful for noninvasively evaluating histologic grade, parametrial invasion, lymph node metastasis, FIGO stage, and recurrence and for predicting RFS in patients with cervical carcinoma than were ADC values.Keywords: Comparative Studies, Genital/Reproductive, MR-Diffusion Weighted Imaging, MR-Imaging, Neoplasms-Primary, Pathology, Pelvis, Tissue Characterization, UterusSupplemental material is available for this article.© RSNA, 2020See also the commentary by Reinhold and Nougaret in this issue.

Inter-observer and intra-observer variability in reporting vaginal dose points for cervical cancer in high-dose-rate brachytherapy

Purpose

The ICRU 89 recommends reporting a set of vaginal dose points for cervical cancer treatments in order to quantify the goodness of implant. This vaginal dose reporting method for combined external beam radiotherapy and brachytherapy has been adopted by the EMBRACE II study protocol. Large variations in dose between patients and centers have been reported. The aim of this study was to determine possible discrepancies with consensus observers from the same institution. Therefore, the inter- and intra-observer variability were analyzed.

Material and methods

For five patients, five experienced observers reported dose at the proposed vaginal points twice. The effect of inter- and intra-observer variations on total dose was analyzed by estimating biologically equivalent dose EQD₂ (α/β = 3 Gy). Coefficient of variation (CV) was used to provide a measure of data dispersion as a proportion to the mean.

Results

The maximum inter-observer deviation among all patients and all points ranged from 0.5 Gy to 24.1 Gy in EQD₂. The higher inter-observer discrepancies were found at points at 3 o’clock and at 6 o’clock, with respect to ovoids. In case of the maximum intra-observer deviation, it ranged from 0.5 Gy to 14.2 Gy, with higher deviation points at 12 o’clock and 9 o’clock, with respect to ovoids.

Conclusions

There is a need to ensure consistency in vaginal points reporting. The impact of the dosimetric inter- and intra-observer variability should also be considered when dealing with dose tolerances and limits due to the potential dose gradient.

Disparities Among Cervical Cancer Patients Receiving Brachytherapy

OBJECTIVE

To evaluate the effects of race and insurance status on the use of brachytherapy for treatment of cervical cancer.

METHODS

This is a retrospective cohort study of the National Cancer Database. We identified 25,223 patients diagnosed with stage IB2 through IVA cervical cancer who received radiation therapy during their primary treatment from 2004 to 2015. A univariate analysis was used to assess covariate association with brachytherapy. A multivariable regression model was used to evaluate the effect of race and insurance status on rates of brachytherapy treatment. The Cox proportional hazards model and the multiplicative hazard model were used to evaluate overall survival. P<.05 indicated a statistically significant difference for comparisons of primary and secondary outcomes.

RESULTS

Non-Hispanic black patients received brachytherapy at a significantly lower rate than non-Hispanic white patients (odds ratio [OR] 0.93; 95% CI 0.86-0.99; P=.036); Hispanic (OR 0.93; 95% CI 0.85-1.02; P=.115) and Asian (OR 1.13; 95% CI 0.99-1.29; P=.074) patients received brachytherapy at similar rates. Compared with patients with private insurance, those who were uninsured (OR 0.72; 95% CI 0.65-0.79; P<.001), had Medicaid (OR 0.83; 95% CI 0.77-0.89; P<.001) or Medicare insurance (OR 0.85; 95% CI 0.78-0.92; P<.001) were less likely to receive brachytherapy. Brachytherapy was not found to be a mediator of race and insurance-related disparities in overall survival.

CONCLUSION

Racial and insurance disparities exist for those who receive brachytherapy, with many patients not receiving the standard of care, but overall survival was not affected.

Intensity modulated radiation therapy boost in locally-advanced cervical cancer in the absence of brachytherapy

OBJECTIVE

Standard treatment in locally-advanced cervical cancer is external beam radiotherapy concomitant with platinum-based chemotherapy, followed by brachytherapy. The goal of our study was to determine whether an intensity modulated radiation therapy (IMRT) boost is feasible in patients unfit for brachytherapy.

METHODS

We retrospectively analyzed data of 25 patients unfit for brachytherapy with median age 55 years (range, 30-82) with locally-advanced/metastatic cervical cancer who underwent external beam radiotherapy to pelvis ±para-aortic lymph nodes and sequential IMRT boost between July 2014 and December 2017. Total dose of 45-50.4 Gy in 25-28 fractions (1.8 Gy/fraction) was administered to the cervix, uterus, parametria, ovaries, vaginal tissues (based on vaginal extension), involved lymph nodes, or relevant draining lymph-nodal groups. Para-aortic nodes were included if involved at radiological staging or if common iliac nodes were positive. The IMRT boost included all residual tumor after external beam radiotherapy identified on MRI. The Kaplan-Meier method was used to calculate 2 years' overall survival, 2 years' progression-free survival, and 2 years' local control. Overall survival- and progression-free survival were calculated considering the starting of radiotherapy or neo-adjuvant chemotherapy if prescribed, while local control was calculated from the end of radiotherapy.

RESULTS

Median radiation dose to pelvis ±para-aortic lymph nodes was 50.4 Gy (45-50.4), boost treatment was homogeneously performed to a total dose of 25 Gy in five fractions every other day.After a median follow-up of 26 months (range, 4-77), tumor persistence at cervix at 6 months from the end of radiotherapy or local recurrence occurred in five women (20%), eight (32%) experienced a further distant progression (two of them had also tumor persistence). Two-year local control and overall survival rates for all stages were 78% and 67%, respectively. According to Common Terminology Criteria for Adverse Events v.4 scoring criteria, 10 patients experienced gastrointestinal and/or genitourinary grade G1-2 acute toxicity. G2 rectal late toxicity requiring laser-coagulation was registered in two patients, there were no gastrointestinal and/or genitourinary acute or late toxicities≥G3.

CONCLUSION

The combination of external beam radiotherapy and brachytherapy remains the standard of care, however our preliminary data show the feasibility of IMRT boost in terms of toxicity with promising results in terms of local control and overall survival.

Prognostic Performance of the 2018 International Federation of Gynecology and Obstetrics Cervical Cancer Staging Guidelines

OBJECTIVE

To examine the prognostic performance of the revised 2018 International Federation of Gynecology and Obstetrics (FIGO) cervical cancer staging schema.

METHODS

We used the National Cancer Database to identify women with cervical cancer diagnosed from 2004 to 2015. Using clinical and pathologic data, each patient's stage was classified using three staging schemas: American Joint Committee on Cancer 7th edition, FIGO 2009 and FIGO 2018. The FIGO 2018 revised staging classifies stage IB tumors into three substages based on tumor size (IB1-IB3) and classifies patients with positive lymph nodes (pathologically or clinically detected) as stage IIIC1 (positive pelvic nodes) or IIIC2 (positive para-aortic nodes). Five-year survival rates were estimated for each stage grouping. We sought to determine whether the 2018 FIGO staging system was able to offer improved 5-year survival rate differentiation compared with older staging schemas.

RESULTS

A total of 62,212 women were identified. The classification of stage IB tumors into three substages improved discriminatory ability. Five-year survival in the FIGO 2018 schema was 91.6% (95% CI 90.4-92.6%) for stage IB1 tumors, 83.3% (95% CI 81.8-84.8%) for stage IB2 neoplasms, and 76.1% (95% CI 74.3-77.8%) for IB3 lesions. In contrast, for women with stage III tumors, higher FIGO staging was not consistently associated with worse 5-year survival rates: stage IIIA (40.7%, 95 CI 37.1-44.3%), stage IIIB (41.4%; 95% CI 39.9-42.9%), stage IIIC1 (positive pelvic nodes) was 60.8% (95% CI 58.7-62.8%) and stage IIIC2 37.5% (95% CI 33.3-41.7%).

CONCLUSION

The FIGO 2018 staging schema provides improved discriminatory ability for women with stage IB tumors; however, classification of all women with positive lymph nodes into a single stage results in a very heterogeneous group of patients with highly variable survival rates.

COVID-19, Brachytherapy, and Gynecologic Cancers: a Moroccan Experience

The treatment of gynecological cancers is the main activity of brachytherapy units. However, during COVID-19 pandemic, precautions should be done in order to reduce the spread of the virus while maintaining all chances to recovery for all patients (Radiother Oncol 148, 227-228, 2020). Despite the extent of the pandemic in our country, limited data are available to establish recommendations with a sufficient level of evidence (Radiother Oncol 148, 227-228, 2020). More recently, the American Brachytherapy Society published some clarifications in this regard and international expert consensus recommendations of radiation therapy for gynecologic malignancies during the COVID-19 pandemic were published (https://www.americanbrachytherapy.org/about-abs/abs-news/abs-statement-on-coronavirus/, Gynecol Oncol 15, 2020). In this commentary, we sought to share the procedures adopted for the management of gynecological cancer patients during COVID-19 pandemic in our brachytherapy unit.

Long-term effectiveness and safety of image-based, transperineal combined intracavitary and interstitial brachytherapy in treatment of locally advanced cervical cancer

PURPOSE

The aim of the study was to evaluate the impact of image-based combined intracavitary-interstitial brachytherapy (IC-ISBT) using a transperineal template in locally advanced cervical cancer treatment.

METHODS AND MATERIALS

A total of 94 patients of cervical cancer stage IIB-IVA underwent image-based transperineal interstitial brachytherapy without tandem (ISBT) or with tandem (IC-ISBT) between June 2008 and June 2018 at our institution. After pelvic chemoradiation, 42 patients underwent ISBT and 52 IC-ISBT. Dosimetric data, clinical response, and toxicity records of these patients were reviewed.

RESULTS

Clinical stage distribution was as follows: IIB: 22.4% (21), IIIA: 10.6% (10), IIIB: 56.4% (53), and IVA: 10.6% (10). Mean high-risk clinical target volume was 75.72 cc, and mean cumulative equivalent of 2 Gy per fraction for high-risk clinical target volume was 81 Gy. The median followup was 35.5 months. Overall 3- and 5-year local control, disease-free survival (DFS), and overall survival (OS) were 84% and 84%, 69.1% and 62.9%, and 80.9% and 71.5%, respectively. Local control (90.4% vs. 76.2%; p = 0.048) and DFS (78.8% vs. 57.1%; p = 0.04) were significantly better in the patients of IC-ISBT arm. IC-ISBT (hazard ratio: 0.763; 95% confidence interval 0.217, 1.38; p = 0.046) and D90 dose >85 Gy (hazard ratio: 0.957; 95% confidence interval 0.927, 1.07; p = 0.037) were predictors of better DFS on univariate analysis. Overall survival was not affected significantly by any of the factors. Grade 3 and 4 late complications were recorded in 3.2% (3) of patients and were similar in both arms (p = 0.86). However, the mean rectum 2 cc dose was significantly lower in the IC-ISBT arm (p = 0.038).

CONCLUSIONS

Combined IC-ISBT is a safe and effective approach to treat ICBT unsuitable cases. It integrates the benefits of ICBT to the adaptability of ISBT around various targets and should be practiced whenever feasible to provide superior outcomes in locally advanced cervical cancer.

Results from chemoradiotherapy for squamous cell cervical cancer with or without intracavitary brachytherapy

Purpose

The aim of this study is to compare the outcomes of intracavitary high-dose-rate brachytherapy (BT-IC) boost and external beam radiotherapy (EBRT) boost in patients treated with concomitant chemoradiotherapy for squamous cell carcinoma of the cervix.

Material and methods

It is a retrospective review of 92 patients with stage IB1-IVA cervical cancer treated with concomitant chemoradiotherapy between 2008 and 2013. All patients received pelvic 3D conformal EBRT (range, 45-50.4 Gy) concomitant with weekly cisplatin (40 mg/m²), and a BT-IC boost (37 patients: 4 fractions of 6 Gy prescribed to a point A) to the tumor or a 3D conformal EBRT boost (55 patients: 16.2 Gy), if the former was not technically feasible.

Results

The 5-year overall survival and recurrence-free survival rates for both groups were 68% and 55%, respectively. The 5-year overall survival and recurrence-free survival were better and statistically significant in the BT-IC group with 82% and 79%, respectively, as compared to the EBRT group with 58% and 38%, respectively. In multivariate analysis controlling for maximum tumor dimension, lymph node status, and FIGO stage, EBRT boost was associated with a statistical significant increase in the risk of recurrence (HR: 3.56; 95% CI: 1.27-10.02; p = 0.016) and a trend towards an increase in the risk of death (HR: 3.14; 95% CI: 0.97-10.17; p = 0.056). Lymph node status was also significantly associated with a greater risk of recurrence.

Conclusions

BT-IC boost was associated with a lower recurrence rate and better overall survival and recurrence-free survival. EBRT boost patients had a three-fold increase in the risk of recurrence. Brachytherapy is essential in the treatment of cervical cancer and improved alternatives are needed for patients who are not candidates for standard brachytherapy applicators.

Interstitial High-Dose-Rate Gynecologic Brachytherapy: Clinical Workflow Experience From Three Academic Institutions

An interstitial brachytherapy approach for gynecologic cancers is typically considered for patients with lesions exceeding 5 mm within tissue or that are not easily accessible for intracavitary applications. Recommendations for treating gynecologic malignancies with this approach are available through the American Brachytherapy Society, but vary based on available resources, staffing, and logistics. The intent of this manuscript is to share the collective experience of 3 academic centers that routinely perform interstitial gynecologic brachytherapy. Discussion points include indications for interstitial implants, procedural preparations, applicator selection, anesthetic options, imaging, treatment planning objectives, clinical workflows, timelines, safety, and potential challenges. Interstitial brachytherapy is a complex, high-skill procedure requiring routine practice to optimize patient safety and treatment efficacy. Clinics planning to implement this approach into their brachytherapy practice may benefit from considering the discussion points shared in this manuscript.

Impact of CT-based brachytherapy in elderly patients with cervical cancer

PURPOSE

Three-dimensional image-guided brachytherapy (3D-IGBT) has become the standard therapy for patients with cervical cancer. However, in this population, the impact of 3D-IGBT in elderly individuals remains unknown. This study assessed the efficacy of 3D-IGBT for elderly patients with cervical cancer.

METHODS AND MATERIALS

We performed a retrospective chart review of 105 consecutive patients with cervical squamous cell carcinoma aged ≥70 years who received radiotherapy alone between January 2001 and September 2014. All patients were treated with external beam radiotherapy and high-dose-rate intracavitary brachytherapy. We assessed the treatment outcomes in all patients. We then compared outcomes between two groups: patients treated by changing the Point A dose at brachytherapy (Group A, n = 71) and those treated with 3D-IGBT at least twice (Group B, n = 34).

RESULTS

The median followup period was 59 (range, 6-203) months; the median age was 77 years. The 5-year local control and cause-specific survival rates were 89% and 78%, respectively. The 5-year cumulative rates of late toxicities of the rectum and bladder of Grade ≥3 were 2.0% and 4.2%, respectively. No statistically significant differences were observed in the local control and cause-specific survival rates, or in the incidence of rectal toxicities between groups. The 3-year cumulative rates of urinary toxicity of Grade ≥1 were 20.4% and 6.9% in Group A and Group B, respectively (p = 0.035).

CONCLUSION

In elderly patients with cervical cancer, 3D-IGBT could be performed safely and effectively and contributed to decreasing urinary toxicity incidence rates.

Treatment of locally advanced cervical cancer in a patient with a bicornuate uterus with MRI-guided intracavitary/interstitial brachytherapy

Purpose

Definitive treatment for locally advanced cervical cancer (LACC) includes external beam radiation therapy (EBRT) with concurrent cisplatin and brachytherapy. Image-guided intracavitary brachytherapy utilizes CT and/or MRI for target and organ at risk delineation and has been shown to improve local control rates and decrease toxicity. Hybrid intracavitary/interstitial applicators can be used to improve tumor coverage in certain cases. We describe the use of combined intracavitary/interstitial brachytherapy to treat a cervical cancer patient with a bicornuate uterus.

Case presentation

A 30-year-old female with bicornuate uterus and FIGO IB2 adenocarcinoma of the cervix was treated with 45 Gy of EBRT to the pelvis with concurrent weekly cisplatin. An examination after EBRT demonstrated a persistent bulky tumor covering most of the cervix. Brachytherapy was delivered via a combined intracavitary/interstitial approach, using a tandem and ring applicator and an interstitial needle. The placement of the tandem was alternated between uterine cornua with each fraction, and the interstitial needle was placed on the side opposite the tandem. CT and MRI were obtained with each fraction. The patient completed the treatment without complications. Three-month restaging PET-CT showed significant interval improvement in the cervix, with a complete clinical response on physical examination. The patient is without evidence of disease 18 months after the treatment.

Conclusions

We found that the use of the hybrid applicator allowed for adequate target coverage in a patient with unusual anatomy. The patient tolerated treatment well and demonstrated favorable response on follow-up exam and imaging. The long-term curative result needs to be further evaluated.

Racial disparities in brachytherapy administration and survival in women with locally advanced cervical cancer

OBJECTIVE

Black women have the highest incidence and mortality from cervical cancer in the United States. This study evaluated whether racial disparities in the receipt of brachytherapy (BT) for locally advanced cervical cancer mediate survival differences by race using the National Cancer Database.

METHODS

A retrospective cohort study was performed using 16,116 women with stage IB2-IVA cervical cancer treated from 2004 to 2014. Women who did not receive external beam radiation therapy, those with unknown survival data or stage, and those status post hysterectomy or pelvic exenteration were excluded. Multivariate logistic regression was performed to evaluate factors associated with BT use. Using a propensity score adjusted model with inverse probability treatment weighting, adjusted hazard ratios for overall survival were calculated, including an interaction term between BT and race.

RESULTS

Of 16,116 patients, 19.2% were black and 55.8% received BT. Black women were significantly less likely to receive BT (AOR 0.87, 95% confidence interval [CI] 0.79-0.96, p = 0.007) and had worse all-cause mortality (median survival 3.9 years [95% CI 3.6-4.6] versus 5.2 years [95% CI 4.9-5.5] for non-black women, p < 0.001). In the adjusted model, black patients had an increased risk of death compared to non-black patients (AHR 1.14, 95% CI 1.05-1.24; p = 0.002) among women who did not receive BT. However, there was no difference in survival by race when both groups received BT (AHR 1.04, 95% CI 0.95-1.13, p = 0.42; p-interaction = 0.005).

CONCLUSIONS

Black women with locally advanced cervical cancer are less likely to receive brachytherapy, which mediates survival differences by race. Improving access to brachytherapy may improve overall survival.

[Brachytherapy: When needs overtake care offer]

Brachytherapy has the unique characteristic of being able to deliver high doses to a very localized volume, and remains one of the radiotherapy techniques that has an unparalleled therapeutic index. However, its use has been declining in the past years. Globally, only 55 to 88 % of patients with locally advanced cervical cancer benefit from utero-vaginal brachytherapy, despite the fact that it is proven to enhance both progression-free and overall survival. A decline in the use of low dose rate brachytherapy has likewise been described in the treatment of low-risk and favorable intermediate-risk prostate cancers. Several factors could explain this. First, the radiation oncologists who have the proficiency to perform brachytherapy seems to be inadequate, as it is a technique that requires training and expertise for optimal applications. In many cancer care centers, the caseload is insufficient to provide this experience. Second, the increasing use of technically advanced external beam radiation therapy, such as intensity modulated radiation therapy, offers an easier substitute with more lucrative benefits, resulting in decreased utilization of brachytherapy. However, when brachytherapy is not delivered, a poorer survival rate is reported in locally advanced cervical cancer, and is suggested in intermediate and high-risk prostate cancer. The increasing level of evidence of treatment with brachytherapy necessitates an improvement in its accessibility by having more radiation oncologists as well as cancer centers equipped to perform the procedure.

Stereotactic Body Radiation Therapy, Intensity-Modulated Radiation Therapy, and Brachytherapy Boost Modalities in Invasive Cervical Cancer: A Study of the National Cancer Data Base

BACKGROUND AND PURPOSE

Our objective was to determine whether stereotactic body radiotherapy (SBRT), intensity-modulated radiation therapy (IMRT), and brachytherapy boost techniques have comparable overall survival in treating cervical cancer when adjusted for known prognostic factors.

MATERIALS AND METHODS

We used the National Cancer Database to study women with invasive cervical cancer who were treated with radiation between 2004 and 2013. A logistic regression model was built to identify factors associated with the receipt of SBRT and IMRT. Outcomes were compared using Kaplan-Meier and propensity score matching.

RESULTS

Of all 15,905 patients, 14,394 (90.5%) received brachytherapy, 42 (0.8%) received SBRT, and 1468 (9.2%) received IMRT. After propensity score matching, there was no significant difference in overall survival (OS) for patients who received SBRT boost versus brachytherapy boost (hazard ratio = 1.477, 95% confidence interval = 0.746-2.926, P = 0.263) but a significant OS detriment in patients who received IMRT boost versus brachytherapy boost (hazard ratio = 1.455, 95% confidence interval = 1.300-1.628, P < 0.001).

CONCLUSIONS

In a propensity-matched analysis, those who received SBRT boost had equal OS when compared with brachytherapy, but those who received IMRT boost had worse OS when compared with brachytherapy.

Brachytherapy: A critical component of primary radiation therapy for cervical cancer: From the Society of Gynecologic Oncology (SGO) and the American Brachytherapy Society (ABS)

Brachytherapy is well-established as an integral component in the standard of care for treatment of patients receiving primary radiotherapy for cervical cancer. A decline in brachytherapy has been associated with negative impacts on survival in the era of modern EBRT techniques. Conformal external beam therapies such intensity modulated radiation therapy (IMRT) or stereotactic body radiation therapy (SBRT) should not be used as alternatives to brachytherapy in patients undergoing primary curative-intent radiation therapy for cervical cancer. Computed tomography or magnetic resonance image-guided adaptive brachytherapy is evolving as the preferred brachytherapy method. With careful care coordination EBRT and brachytherapy can be successfully delivered at different treatment centers without compromising treatment time and outcome in areas where access to brachytherapy maybe limited.