Declining brachytherapy utilization for cervical cancer patients - Have we reversed the trend?

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.

Updated Trends in Cervical Cancer Brachytherapy Utilization and Disparities in the United States From 2004 to 2020

PURPOSE

Lower brachytherapy utilization for cervical cancer patients is associated with decreased survival. This study examines more recent trends in brachytherapy utilization from 2004 to 2020 to assess any trend reversal after awareness increased regarding the importance of brachytherapy.

METHODS AND MATERIALS

This study analyzed data from the National Cancer Database of patients with Federation of Gynecology and Obstetrics (FIGO) IB to IVA cervical cancer treated with radiation therapy between 2004 and 2020. To compare brachytherapy utilization over time, 2- to 3-year categories were created to account for potential variation seen in individual years. A multivariate log binomial regression with robust variance was used to estimate the incidence rate ratio (IRR) of brachytherapy utilization in each year category in reference to the 2004-2006 category. Additionally, risk factors for brachytherapy utilization were identified.

RESULTS

Overall brachytherapy utilization for cervical cancer increased from 54.9% in 2004 to 75.7% in 2020. Compared with 2004 to 2006 when rates of utilization totaled 55.2%, brachytherapy utilization significantly increased to 63.4% in 2011 to 2014 (IRR, 1.15; 95% CI, 1.11-1.19), 66.0% in 2015 to 2017 (1.20 [1.16-1.23]), and 76.0% in 2018 to 2020 (1.38 [1.34-1.42]). Sociodemographic factors associated with lower brachytherapy utilization included Black race (0.94 [0.92-0.97]), Hispanic ethnicity (0.92 [0.90-0.95]), and age >59 years (age ≥60-69: 0.96 [0.94-0.98]; age ≥70-79: 0.89 [0.87-0.92]; age ≥80: 0.73 [0.69-0.77]). Positive predictors of brachytherapy utilization included having insurance (IRR, 1.11; 95% CI, 1.07-1.14).

CONCLUSIONS

In patients with FIGO IB-IVA cervical cancer treated with radiation therapy from 2004 to 2020, brachytherapy utilization has increased during the past decade. These results are encouraging given the known benefit to cause-specific survival and overall survival provided by brachytherapy treatment and indicate a reversal in the trend of declining brachytherapy noted previously. Concerns related to disparities by race, ethnicity, and insurance status require further interventions.

Can an in-person hands-on applicator-based teaching session improve trainee knowledge and comfort with complex gynecologic brachytherapy?

INTRODUCTION

With the emergence of imaged-based planning and hybrid applicators the complexity of gynecologic brachytherapy has dramatically increased. Despite the known advantages of brachytherapy, notable national declines in utilization of brachytherapy have been documented. Clearly improved education in the sphere of gynecologic brachytherapy is needed. We hypothesize that a hands-on applicator-based training session would improve trainee comfort with gynecologic brachytherapy.

METHODS AND MATERIALS

An in-person, applicator-based, hands-on training session was held with trainees from both radiation and gynecologic oncology programs. Trainees practiced assembling and handling applicators while receiving instruction on clinical scenarios in which various applicators are used in gynecologic cancer brachytherapy. Pre- and post-session, participants were administered an objective test of 10 pictorial-based case vignettes to quantify ability to select the correct applicator based on the interpretation of T2-weighted MR images. Participants additionally received a subjective survey to quantify comfort and experience with gynecologic brachytherapy using Likert-type question formatting.

RESULTS

A total of 14 trainees participated. Most common case volume experience was 0-10 intracavitary (57%), 0-10 hybrid (71%), and 0-10 interstitial (71%). Pre-session, the most common answer to comfort level was "not comfortable still learning" for all brachytherapy types, and most common answer to largest gap in knowledge was all facets of brachytherapy. Average case-based test score was 3.5/10 pre-session versus 5.3/10 post-session (p = 0.028). Post-session, all respondents reported improved comfort level with brachytherapy. Post-session, most common answer to largest gap in knowledge was applicator/patient selection, and applicator/patient selection was also the largest area of identified improvement. 100% of participants felt repeating the session in the future would be helpful.

CONCLUSIONS

Hands-on training with applicators improves both subjective and objective comfort with gynecologic brachytherapy. With 100% of participants requesting to implement this session into resident training, we suggest national opportunities might exist to expand educational processes and improve utilization of complex gynecologic brachytherapy in practice.

Challenges in the Sustainability of Brachytherapy Service in Contemporary Radiotherapy

Brachytherapy has a long history of delivering a highly conformal radiation dose to the target volume with sparing of adjacent normal tissue and has an irreplaceable role in certain cancers, such as cervical and prostate cancers. There have been futile attempts to replace brachytherapy with other radiation techniques. Despite that there are multifaceted challenges in preserving this dying art, from establishment, to a trained workforce, to maintenance of the equipment and source replacement costs. Here we focus on the challenges to access brachytherapy, the availability and distribution of care across the globe and appropriate training leading to proper implementation of the procedure. Brachytherapy holds a significant place in the treatment armamentarium of most common cancers, such as cervical, prostate, head and neck and skin cancers. However, there is an uneven distribution of brachytherapy facilities, not only across the globe, but also at a national level, with a larger proportion of facilities concentrated in certain regions, more so in low and low-middle income countries. The regions with the highest incidence of cervical cancer have the least access to brachytherapy facilities. Attempts to bridge the gap are essential and should be focused on uniform distribution and access to care, improving training of the workforce through specialised training programmes, reducing the cost of care, planning to reduce the recurring cost, generating evidence and research guidelines, renewing interest in brachytherapy through rebranding, use of social media and building an attainable long-term roadmap.

Safety and efficacy of single insertion accelerated MR-image guided brachytherapy following chemo-radiation in locally advanced cervix cancer: modifying our EMBRACE during the COVID pandemic

BACKGROUND

Utero-vaginal brachytherapy (BT) is an irreplaceable care component for the curative treatment of locally advanced cervix cancer (LACC). Magnetic Resonance Imaging (MRI)-image guided adaptive BT (IGABT) using the GYN-GEC-ESTRO EMBRACE guidelines is the international care standard. Usually following chemo-radiation therapy (CRT), IGABT has high proven utility in LACC but requires significant health system resources. Timely access was disrupted by the COVID-19 pandemic which challenged us to re-design our established IGABT care pathway.

METHODS

From April 2020 consecutive patients with LACC were enrolled after CRT in a single arm exploratory non-inferiority study of a modified IGABT (mIGABT) protocol. This delivered an iso-effective IGABT dose (39.3 Gy: EQD2: α/β10Gy concept) over a 24-h period during a single overnight hospitalisation.

RESULTS

Fourteen LACC patients received mIGABT from April 2020 to March 2022. Median age was 62.5 years (37-82 years). LACC histology was primary squamous (9/14) or adeno-carcinoma (5/14). International Federation of Gynaecology and Obstetrics (FIGO) 2018 stages ranged from IB1/2 (N = 3), IIA1/IIB (5), IIIB (2), IIIC1/2 (4) with mean ± standard deviation (SD) gross tumour volume-at-diagnosis (GTV_D) of 37.7 cc ± 71.6 cc. All patients achieved complete metabolic, clinical, and cytologic cancer response with CRT and IGABT. High-risk HPV was cleared by 6-months. Complete MRI-defined cancer response before mIGABT (GTV_Fx1) was seen in 77% of cases (10/13). Only two women developed metastatic disease and one died at 12-months; 13 patients were alive without cancer at mean 20.3 ± 7.2 months follow-up. Actuarial 2-year overall survival was 93%. Compared with our pre-COVID IGABT program, overall mIGABT cost-saving in this cohort was USD 22,866. Prescribed dose covered at least 90% (D90) of the entire cervix and any residual cancer at time of BT (HRCTV_D90: high-risk clinical target volume) with 3-fractions of 8.5 Gy delivered over 24-h (22.8 ± 1.7 h). Total treatment time including CRT was 38 days. The mIGABT schedule was well tolerated and the entire cohort met EMBRACE recommended (EQD2: α/β10Gy) combined HRCTV_D90 coverage of 87.5 ± 3.7 Gy. Similarly, organ-at-risk (OAR) median: interquartile range D2cc constraints (EQD2: α/β3Gy) were EMBRACE compliant: bladder (65.9 Gy: 58.4-72.5 Gy), rectum (59.1 Gy: 55.7-61.8 Gy), and sigmoid colon (54.6 Gy: 50.3-58.9 Gy). ICRU recto-vaginal point dose was significantly higher (75.7 Gy) in our only case of severe (G4) pelvic toxicity.

CONCLUSIONS

This study demonstrated the utility of mIGABT and VMAT CRT in a small cohort with LACC. Loco-regional control was achieved in all cases with minimal emergent toxicity. Single insertion mIGABT was logistically efficient, cost-saving, and patient-centric during the COVID-19 pandemic.

Underutilization of brachytherapy for cervical cancer in the United States

Brachytherapy is a critical component of the definitive management of cervical cancer and allows for the safe delivery of about half of the total effective radiation dose needed for optimal outcomes. Moreover, the dose distribution of brachytherapy is highly conformal, allowing for a therapeutic index currently unmatched by alternative techniques. However, a modern brachytherapy program requires special equipment, infrastructure, and procedural expertise. Unfortunately, multiple lines of evidence suggest that brachytherapy is currently underutilized in the United States. In this review, we examine the importance of brachytherapy, contemporary recommendations, and avenues for growth.

Brachytherapy training survey among radiation oncology residents in Europe

We aim to investigate the current state of brachytherapy (BT) training among the radiation oncology trainees in Europe.

MATERIAL AND METHODS

A 22-question online survey based on the one by the American Association of Radiation Oncology Residents (2017) with added queries pertinent to training in Europe was sent to 1450 residents in two iterations. These included site-specific training, volume of experience, barriers to training, institutional support, and preferences for further education. Responses to individual statements were given on a 1 to 5 Likert-type scale. The answers were reported by junior (≤3 years of training) and senior years of training (year of training 4/5/6 and junior staff). Descriptive statistics were used to describe frequencies.

RESULTS

Residents from 21 European countries participated, 445 (31%) responded. 205 (47%) were senior residents. 60% residents consider that performing BT independently at the end of residency is very or somewhat important. Confidence in joining a brachytherapy practice at the end of residency was high or somewhat high in 34% of senior residents. They reported as barriers to achieving independence in BT to be lack of appropriate didactic/procedural training from supervisors (47%) and decreased case load (31%). 68% reported their program lacks a formal BT curriculum and standardized training assessment.

CONCLUSIONS

Residents in Europe, feel independent BT practice is very or somewhat important, but do not feel confident they will achieve this goal. To address this gap, efforts are needed to develop and implement a formal and comprehensive BT curriculum with easy access to trained instructors.

Survival, treatment pattern, and treatment outcome in patients with cervical cancer metastatic to distant lymph nodes

Background

Cervical cancer with nodal involvement beyond the pelvis was considered as distant nodal metastasis in the previous International Federation of Gynecology and Obstetrics staging system. With the improvement of cancer-directed therapies, some of these patients can receive curative treatment. Classifying them as distant metastasis may result in underestimation of their prognosis as well as undertreatment. However, limited research has been conducted on the survival and treatment pattern in distant lymphatic metastatic cervical cancer.

Objective

To investigate the survival, treatment pattern, and treatment outcome of patients with cervical cancer metastasized to distant lymph nodes (DLN) beyond the pelvis.

Methods

Patients with stage III-IV cervical cancer from 1988 to 2016 were identified using the Surveillance, Epidemiology, and End Results program. The cancer cause-specific survival (CSS) was analyzed using the Kaplan-Meier method, log-rank test, multivariable Cox proportional hazard regression, subgroup analysis, and propensity score-matched analysis.

Results

Of 17783 patients with stage III-IV cervical cancer, patients with distant nodal disease beyond the pelvis (n=1883; included para-aortic lymph nodes metastasis) had superior survival compared to those with pelvic organ invasion or with distant organ(s) metastasis (5-year CSS, 32.3%, 26.3%, and 11.5%, respectively; adjusted P<0.001). The T stage significantly affected the survival of patients with positive DLN (5-year CSS for T1, T2, and T3: 47.3%, 37.0%, and 19.8%, respectively, adjusted P<0.01). For patients with positive DLN, combination radiotherapy (external beam radiotherapy [EBRT] with brachytherapy) prolonged CSS compared to EBRT alone (5-year CSS, 38.0% vs 21.7%; propensity score-adjusted HR, 0.60; 95% CI 0.51-0.72; P<0.001). Despite the superiority of combination radiotherapy, EBRT was the most frequently used treatment after 2004 (483/1214, 39.8%), while the utilization of combination radiotherapy declined from 37.8% (253/669) during 1988 through 2003 to 25.2% (306/1214) during 2004 through 2016.

Conclusion

Patients with cervical cancer metastasized to DLN have favorable survival compared to those with pelvic organ invasion or with distant organ(s) metastasis. Their prognosis is significantly affected by local tumor burden and local treatment. Adequate and aggressive local radiotherapy, such as image-guided brachytherapy, can be considered for these patients to achieve better outcomes.

Adopting Health Economic Research in Radiation Oncology: A Perspective From Low- or Middle-Income Countries

Establishing a new radiation therapy (RT) setup is resource-intensive as it involves substantial capital costs and the recruitment of a skilled workforce. It is essential to incorporate health economic analysis that estimates recurring and nonrecurring expenses on the basis of the national and local needs, infrastructure, and future projections. RT costing exercises can be especially relevant for low- or middle-income countries (LMICs) with more than 70% of the global cancer burden, with access to < 20% of the available resources. This review article summarizes the scope of RT costing exercises in LMICs, the hurdles in conducting them, and possible ways to circumvent them. The purpose of performing costing studies in RT lies in their utility to improve the efficiency of the investment while at the same time helping to address the issues of uniformity and equitable distribution of resources. This will help assess the net benefit from RT in terms of utility and outcome-linked parameters like Quality-Adjusted Life Years. There are numerous barriers to conducting economic evaluations in LMICs, including the lack of national costing values for equipment, data on manpower salary, cost for public and private setups, and indirect costs. The situation is further complicated because of the nonuniform pay structure, lack of an organizational framework, robust real-world data on outcomes, and nonavailability of country-specific reference utility values. Collaborative national efforts are required to collect all elements required to perform health technology assessments. Information from the national and hospital databases can be made available in the public domain to ease access and broader adoption of health economic end points in routine care. Although resource-intensive at the onset, costing studies and health economic assessments are essential for improving the coverage and quality of RT in LMICs.

Treatment of cervical cancer: overcoming challenges in access to brachytherapy

INTRODUCTION

Brachytherapy is an essential component of the cervical cancer treatment paradigm as it contributes to improved clinical outcomes and overall survival. Yet brachytherapy remains globally underutilized, with disparities in access at both national and international levels.

AREAS COVERED

The review explores current brachytherapy utilization practices and efforts being undertaken to address barriers to implementation in low-, middle-, and high-income countries, and how these efforts are projected to impact future brachytherapy access. The content presented is based on a review of published literature and the authors' collective clinical experiences.

EXPERT OPINION

There exists a tremendous opportunity to expand access to essential brachytherapy services for women with cervical cancer. Many national and international brachytherapy efforts exist; yet it remains imperative that such focused efforts continue to grow and provide further access to this critical treatment modality for women in need worldwide.

Current Management of Locally Advanced and Metastatic Cervical Cancer in the United States

Despite decreases in incidence in the twentieth century, cervical cancer continues to be a highly morbid disease in the United States. For those diagnosed with locally advanced disease, single-agent cisplatin-based chemotherapy concurrent with radiation remains the mainstay of treatment. For patients with metastatic, progressive, and recurrent disease, treatment typically consists of combination chemotherapy and incorporation of bevacizumab, and recent data show benefits with the addition of upfront immunotherapy in women whose cancer expresses programmed death ligand-1. The physical sequelae of locally advanced cervical cancer treatments stem largely from irradiation of the pelvis, and treatment of these is aimed at identifying reversible or treatable causes of symptoms and palliating those with irreversible causes. From a psychologic standpoint, patients with cervical cancer face the stigma of having a preventable cancer caused by a sexually transmitted infection and the ramifications of sexual dysfunction. Clinicians must invite honest dialogue to be able to address specific survivorship issues.

Evaluation of sociodemographic and baseline patient characteristic differences in cervical cancer patients treated with either external beam or brachytherapy boost

PURPOSE

Chemoradiation is considered the standard of care for locally advanced cervical cancer. While brachytherapy (BT) boost is associated with improved survival and less toxicity compared to external beam radiation therapy (EBRT) boost, it is unclear why many patients do not receive a BT boost. In this study, we compared sociodemographic and baseline patient characteristics between patients receiving EBRT boost versus BT boost.

METHODS

We analyzed patients in the National Cancer Database diagnosed between 2004 and 2016 with FIGO stage IIB-IVA cervical cancer treated with nonpalliative doses of chemoradiation. Logistic regression analysis was utilized to evaluate BT utilization over time and by other clinicopathological and sociodemographic factors.

RESULTS

Overall, 5764 patients were evaluated, of which 4937 (86%) underwent BT boost. Using multivariable logistic regression, higher FIGO stage was a significant predictor for utilization of EBRT versus BT boost, with odds ratio 2.92 (95% confidence interval [CI] 2.04-4.16; p < 0.001), 2.68 (95%CI 2.22-3.24; p < 0.001), and 4.51 (95%CI 3.05-6.67; p < 0.001) for IIIA, IIIB, and IVA, respectively, compared to IIB. Increased utilization of EBRT boost was also associated with community cancer facility types, lower income (based on zip code), earlier year of diagnosis, and higher comorbidity score.

CONCLUSIONS

In FIGO stage IIB-IVA cervical cancer patients treated with nonpalliative doses of chemoradiation, overall utilization of BT is 86%. Higher FIGO stage, community cancer facilities, lower income, earlier year of diagnosis, and higher comorbidity score were significant predictors of EBRT boost utilization. Future studies are needed to better understand reasons for this as higher FIGO stage patients are the mostly likely to benefit from a BT boost.

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.

Emerging technologies in brachytherapy

Brachytherapy is a mature treatment modality. The literature is abundant in terms of review articles and comprehensive books on the latest established as well as evolving clinical practices. The intent of this article is to part ways and look beyond the current state-of-the-art and review emerging technologies that are noteworthy and perhaps may drive the future innovations in the field. There are plenty of candidate topics that deserve a deeper look, of course, but with practical limits in this communicative platform, we explore four topics that perhaps is worthwhile to review in detail at this time. First, intensity modulated brachytherapy (IMBT) is reviewed. The IMBT takes advantage ofanisotropicradiation profile generated through intelligent high-density shielding designs incorporated onto sources and applicators such to achieve high quality plans. Second, emerging applications of 3D printing (i.e. additive manufacturing) in brachytherapy are reviewed. With the advent of 3D printing, interest in this technology in brachytherapy has been immense and translation swift due to their potential to tailor applicators and treatments customizable to each individual patient. This is followed by, in third, innovations in treatment planning concerning catheter placement and dwell times where new modelling approaches, solution algorithms, and technological advances are reviewed. And, fourth and lastly, applications of a new machine learning technique, called deep learning, which has the potential to improve and automate all aspects of brachytherapy workflow, are reviewed. We do not expect that all ideas and innovations reviewed in this article will ultimately reach clinic but, nonetheless, this review provides a decent glimpse of what is to come. It would be exciting to monitor as IMBT, 3D printing, novel optimization algorithms, and deep learning technologies evolve over time and translate into pilot testing and sensibly phased clinical trials, and ultimately make a difference for cancer patients. Today's fancy is tomorrow's reality. The future is bright for brachytherapy.

Brachytherapy utilization rate and effect on survival in cervical cancer patients in Korea

OBJECTIVE

External beam radiation therapy (EBRT) with concurrent chemotherapy followed by intracavitary brachytherapy is the standard treatment in locally advanced cervical cancer. This study examined the brachytherapy utilization rate and evaluated the effect of brachytherapy on survival in cervical cancer patients in Korea.

METHODS

In this study, data from the Korea Central Cancer Registry and Korean National Health Insurance Service and data on mortality from Statistics Korea were linked and used. Patients with other cancers, distant metastasis at diagnosis, or unknown stage or who underwent hysterectomy were excluded. A total of 12,721 cervical cancer patients were analyzed in this study.

RESULTS

The brachytherapy utilization rate (%) was calculated as the proportion of patients who received brachytherapy among those who received curative EBRT. The brachytherapy utilization rate decreased from 84% in 2005 to 78% in 2013 (p<0.001). Brachytherapy utilization rates varied by region, ranging from 72% to 100% except for in Jeju Island, where the rate was 56%. The brachytherapy utilization rate was lower in patients older than 80 years; patients with localized disease, non-squamous cell carcinoma, or Charlson comorbidity index 3 or more; patients diagnosed after 2010; patients from certain regions; patients receiving medical aid; and patients who underwent gynecologic procedures. Multivariable Cox regression analysis showed that brachytherapy when added to curative EBRT was independently associated with better cancer-specific survival (CSS) and overall survival (OS) than curative EBRT only.

CONCLUSION

The brachytherapy utilization rate decreased from 2005 to 2013 and varied by region in Korea. Brachytherapy use is independently associated with significantly higher CSS and OS 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.

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.

Early outcomes after definitive chemoradiation therapy with Vienna/Venezia hybrid high-dose rate brachytherapy applicators for cervical cancer: A single-institution experience

PURPOSE

The Vienna and Venezia (Elekta) are hybrid intracavitary/interstitial brachytherapy (BT) applicators for cervical cancers unsuitable for intracavitary BT alone to improve target coverage or reduce critical organ dose. There is limited outcome data with the use of these applicators outside published experience of the EMBRACE group. We report feasibility and early outcomes with the use of these hybrid applicators at our institution.

METHODS AND MATERIALS

Hybrid applicators were used to treat 61 patients with cervical cancer from November 2011 to December 2019. Indications for hybrid applicator use were involvement of the vagina in 10 patients (16%), residual central or parametrial disease in 46 patients (75%), and a narrow introitus in 5 patients (9%). Toxicities were graded using the CTCAE v4.0. Outcomes were assessed with the Kaplan-Meier method.

RESULTS

Median follow-up was 16 months (IQR 9-32 mos). Median HRCTV volume was 31.6 cm³ (IQR 25-48 cm³). Median HRCTV D90 was 86.1 Gy (IQR 84.3-88.0 Gy). In 54 patients with follow-up PET/CT at 3 months, complete initial imaging response locally was seen in 46 patients.Estimated 12-month Kaplan-Meier overall survival, locoregional control, distant control, and recurrence-free survival estimates were 86.9%, 80.6%, 73.8%, and 65.9%, respectively. The 12-month incidence of Grade 3+ GI/GU chronic toxicities was 5.7%, consisting of vesicovaginal fistula, rectovaginal fistula, and ureterovesical fistula.

CONCLUSIONS

Our single-institution data support the use of the hybrid applicators, as an alternative to traditional BT applicators when clinically warranted. Use of hybrid applicators is feasible with adequate coverage of disease in the vagina and parametrium.

A national surveillance study of the current status of reirradiation using brachytherapy in Japan

PURPOSE

This study aimed to explore the current status and pattern of practice for reirradiation using brachytherapy (ReRT-BT) through a survey in Japan.

MATERIALS AND METHODS

We distributed an e-mail-based questionnaire to 153 institutions equipped with high-dose-rate brachytherapy facilities.

RESULTS

We received responses from 76 institutions (49.7%). Forty-three of these institutions performed ReRT-BT and 42 institutions (55%) performed ReRT-BT during 2009-2018. However, 29 of the 42 institutions (69%) reported difficulty in obtaining ReRT-BT case information from their respective databases. Almost all the institutions encountered insufficient database system to extract details about the ReRT-BT cases. Responses from 33 institutions included the number of ReRT-BT cases; this increased from 90 in the period 2009-2013 (institution median = 0.5; 0-16) to 172 in the period 2014-2018 (institution median = 2; 0-26). Nine institutions had to perform ReRT-BT for more than one case per year. The major location for cancer treatment was the pelvis (94%), followed by the head and neck (5%) and others (1%). In six site-specific scenarios, barring uterine corpus cancer recurrence, more than 90% of radiation oncologists agreed to perform ReRT-BT, whereas other areas (head and neck, prostate, and rectal cancer) gained 16-37% agreement.

CONCLUSIONS

This decade saw an increase in the number of ReRT-BT cases in Japan and radiation oncologists' interest in ReRT-BT as a viable therapeutic option. However, scarce availability, immature education system, and insufficient database system are barriers to further consensus building.