Standard Chemoradiation and Conventional Brachytherapy for Locally Advanced Cervical Cancer: Is It Still Applicable in the Era of Magnetic Resonance-Based Brachytherapy?

The prognostic effect of tumor volume, reduction ratio, and cumulative doses on external beam radiotherapy with central-shielding method and image-guided adaptive brachytherapy for cervical cancer

Objective

To evaluate the prognostic effect of tumor volume at diagnosis, tumor reduction ratio during external beam radiotherapy (EBRT) with central-shielding method, and cumulative minimal dose to 90% of the high-risk clinical target volume (CTVHR D90) on combined EBRT and image-guided adaptive brachytherapy (IGABT) for cervical cancer.

Methods

Consecutive patients who underwent definitive radiotherapy or concurrent chemoradiotherapy for cervical cancer at Gunma University Hospital between January 2010 and December 2019 were retrospectively reviewed. Tumor volume at diagnosis and reduction ratio were calculated using magnetic resonance imaging at diagnosis and before the first IGABT session. The cumulative dose of EBRT and IGABT was calculated as an equivalent dose in 2 Gy fractions (EQD2). Optimal cutoff values were determined according to a receiver operating characteristic curve. Treatment outcomes were evaluated using the Kaplan-Meier method and compared using the log-rank test and Cox proportional hazards regression.

Results

A total of 254 patients were included in the analysis. The median follow-up for all patients was 57 (2-134) months. The 5-year overall survival (OS) was 81.9%, progression-free survival (PFS) was 71.3%, and local control (LC) was 94.5%. The patients were divided into four groups according to tumor volume at diagnosis and reduction ratio. The group with tumor volume at diagnosis ≥ 34.1 cm3 and reduction ratio < 68.8% showed significantly worse OS, PFS, and LC than the other three groups (All p < 0.05). In this group, the patients with a cumulative CTVHR D90 < 69.6 GyEQD2 showed significantly worse PFS and LC (p = 0.042 and p = 0.027, respectively). In the multivariate analysis of OS, adenocarcinoma/adenosquamous carcinoma, International Federation of Gynecology and Obstetrics 2009 stage III/IV, and a reduction ratio of < 68.8% were independent significant poor prognostic factors (p = 0.045, p = 0.009 and p = 0.001, respectively). In the univariate analysis of LC, a reduction ratio of < 68.8% was the only poor prognostic factor (p = 0.041).

Conclusion

The patients with large and poorly responding tumors had significantly worse prognoses in terms of OS, PFS, and LC, suggesting that dose escalation should be considered for such tumors.

Transitioning India to advanced image based adaptive brachytherapy: a national impact analysis of upgrading National Cancer Grid cervix cancer guidelines

Background

High-dose-rate image guided brachytherapy (IGBT) for cervical cancer leads to improved local control and reduced toxicity and is a critical component of treatment. However, transition to IGBT requires capacity upscaling. An institutional activity mapping and national impact analysis of such a transition were undertaken to understand feasibility.

Methods

Between September 2020 and March 2021, activity mapping was conducted in a high-volume centre that triaged cervical cancer patients for brachytherapy into four workflows; A: two-dimensional (2D) X-Ray point A-based intracavitary brachytherapy, B: CT point A-based intracavitary brachytherapy, C: MRI/CT-volume based intracavitary brachytherapy, D: MRI/CT volume-based intracavitary +/- interstitial brachytherapy. Clinical process time mapping was performed, and case scenarios for transition were modelled at the institutional and national levels based on available incidence and infrastructure levels. Treatment capacity changes were calculated, and potential strategies for workflow reorganisation were proposed.

Findings

Eighty-four patients were included in the study. The total time taken for the workflows A, B, C, and D were 176 min (57-208), 224 min (74-260), 267 min (101-302), and 348 min (232-383), respectively. The transition from workflow A to D through sequential steps led to 35%, 49%, and 64% loss of treatment capacity in the index institution. Solutions such as 10-hour or 12-hour overlapping shifts increased treatment capacity by 25% and 50% and performing single implants and delivering multiple fractions increased capacity by 100%. Twenty-three Indian states and Union Territories are predicted to be able to transition to advanced workflows. For four Indian states, it may be detrimental considering the current infrastructure level, and eight Indian states lacked brachytherapy access. Further financial investment is required in the latter 12 states for transition to advanced workflows.

Interpretation

Our study demonstrates that unplanned transition to IGBT can lead to treatment capacity loss and increase in waiting lists to access treatment. The proposed solutions of workflow reorganisation, using strategies such as single brachytherapy applicator implant and delivering multiple treatment fractions can improve access to treatment for women with cervix cancer in resource-strained and high patient-volume settings. We recommend state-wise solutions for the upscale from conventional 2D workflows to IGBT, subject to the availability of skilled personnel, infrastructure and training. Financial investments may be needed in some states to achieve this goal.

Funding

International Atomic Energy Agency (IAEA) supported the salary of VH through project E33042 that focussed on implementation strategies of image guided brachytherapy.

Concurrent chemoradiation and brachytherapy alone or in combination with nelfinavir in locally advanced cervical cancer (NELCER): study protocol for a phase III trial

INTRODUCTION

In locally advanced cervical cancer, nodal, local and distant relapse continue to be significant patterns of relapse. Therefore, strategies to improve the efficacy of chemoradiation are desirable such as biological pathway modifiers and immunomodulating agents. This trial will investigate the impact of nelfinavir, a protease inhibitor that targets the protein kinase B (AKT) pathway on disease-free survival (DFS).

METHODS AND ANALYSIS

Radiosensitising effect of nelfinavir in locally advanced carcinoma of cervix is a single-centre, open-label, parallel-group, 1:1 randomised phase-III study. Patients aged over 18 years with a diagnosis of carcinoma cervix stage III are eligible for the study. After consenting, patients will undergo randomisation to chemoradiation and brachytherapy arm or nelfinavir with chemoradiation and brachytherapy arm. The primary aim of the study is to compare the difference in 3-year DFS between the two arms. Secondary aims are locoregional control, overall survival, toxicity and quality of life between the two arms. Pharmacokinetics of nelfinavir and its impact on tumour AKT, programmed cell death ligand 1, cluster of differentiation 4, cluster of differentiation 8 and natural killer 1.1 expression will be investigated. The overall sample size of 348 with 1 planned interim analysis achieves 80% power at a 0.05 significance level to detect a HR of 0.66 when the proportion surviving in the control arm is 0.65. The planned study duration is 8 years.

ETHICS AND DISSEMINATION

The trial is approved by the Institutional Ethics Committee-I of Tata Memorial Hospital, Mumbai (reference number: IEC/0317/1543/001) and will be monitored by the data safety monitoring committee. The study results will be disseminated via peer-reviewed scientific journals, and conference presentations. Study participants will be accrued after obtaining written informed consent from them. The confidentiality and privacy of study participants will be maintained.

TRIAL REGISTRATION NUMBER

The trial is registered with Clinical Trials Registry-India (CTRI/2017/08/009265) and ClinicalTrials.gov (NCT03256916).

Point-Based Brachytherapy in Cervical Cancer With Limited Residual Disease: A Low- and Middle-Income Country Experience in the Era of Magnetic Resonance-Guided Adaptive Brachytherapy

PURPOSE

To evaluate the clinical outcomes in patients with cervical cancer with limited residual disease at brachytherapy (BT) treated with point-based dose prescription.

METHODS

Patients with locally advanced squamous cell carcinoma of the cervix treated with computed tomography (CT)-based intracavitary BT were considered for analysis. Patients with good response to external beam radiotherapy and limited residual disease suitable for intracavitary BT alone were included. Postapplication CT scans were performed before each fraction and individual plans were made for each session. The dose per fraction was 9Gy high dose rate, prescribed to point-A. Two sessions were planned, 1 week apart. The organs at risk were contoured, and cumulative dose-volume histograms were computed. Local control, pelvic control, disease-free survival, and overall survival were evaluated and late toxicities were documented.

RESULTS

Four hundred ninety patients were included. Overall, 79.8% had International Federation of Gynecology and Obstetrics (FIGO) stage IB2 to IIB disease and 20.2% had stage III to IVA disease. Median dose at point A (EQD2_10Gy) was 74.4 Gy (interquartile range [IQR] 72.3-74.5 Gy) and median D_2cc (EQD2_3Gy) for bladder, rectum, and sigmoid were 82.5 Gy (IQR, 65.5-90.8 Gy), 66.5 Gy (IQR, 60.7-75.7 Gy), and 54.1 Gy (IQR, 50.5-77.3 Gy), respectively. At a median follow-up of 62 (IQR, 33-87) months, the 5-year local and pelvic control rates were 90.1% and 88.3%, respectively. The 5-year disease-free survival was 80% and overall survival was 88%. Rates of grade 3-4 bladder and rectosigmoid toxicities were 6.93% and 4.08%, respectively.

CONCLUSION

In patients with limited residual disease at BT, point-based dose prescription with CT planning results in good local control and acceptable toxicity. In a resource-constrained setting, patients may be triaged to receive point-based BT or magnetic resonance imaging–guided adaptive BT depending on the extent of residual disease.

Point-based brachytherapy can be utilized in cervical cancer with limited residual disease after external RT

Contribution of Tata Memorial Centre, India, to cervical cancer care: Journey of two decades

Cervical cancer continues to be a major public health concern in India and other low- and middle-income countries. Tata Memorial Centre, India, has been at the forefront in providing treatment, developing best practice guidelines for low-cost efficacious interventions, conducting practice-changing randomized trials and engaging in regional and international collaborations for education and research in cervical cancer. This review summarizes how cervical cancer research and clinical care has evolved over the past two decades at the Tata Memorial Centre, right from testing low-cost public health screening of cervical cancers to the incorporation of the latest technological advancements and providing high-quality evidence for therapeutic management of cervical cancer. The various ongoing strategies for improving survival, toxicity reduction, translational research studies, educational activities and teaching programmes initiated by the Tata Memorial Centre at both national and international levels are discussed.

Development and clinical validation of Knowledge-based planning for Volumetric Modulated Arc Therapy of cervical cancer including pelvic and para aortic fields

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A knowledge-based planning model was configured for VMAT of cervical cancer.

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Knowledge-based plans were comparable, and for some OARs, outperformed clinical plans.

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Improved organ sparing was observed, when individual patient geometry was considered.

Background and Purpose

Knowledge-based planning (KBP) is based on a model to estimate dose-volume histograms, configured using a library of historical treatment plans to efficiently create high quality plans. The aim was to report configuration and validation of KBP for Volumetric Modulated Arc Therapy of cervical cancer.

Materials and methods

A KBP model was configured from the institutional database (n = 125), including lymph node positive (n = 60) and negative (n = 65) patients. KBP Predicted plans were compared with Clinical Plans (CP) and Re-plans (Predicted plan as a base-plan) to validate the model. Model quality was quantified using coefficient of determination R2, mean square error (MSE), standard two-tailed paired t-test and Wilcoxon signed rank test.

Results

Estimation capability of the model was good for the bowel bag (MSE = 0.001, R2 = 0.84), modest for the bladder (MSE = 0.008) and poor for the rectum (MSE = 0.02 R2 = 0.78). KBP resulted in comparable target coverage, superior organ sparing as compared to CP. Re-plans outperformed CP for the bladder, V30 (66 ± 11% vs 74 ± 11%, p < .001), V40 (48 ± 14% vs 52 ± 14%, p < .001), however sparing was modest for the bowel bag V30 (413 ± 191cm³ vs 445 ± 208cm³, p = .037) V40 (199 ± 105cm³ vs 218 ± 127cm³, p = .031). All plans were comparable for rectum, while KBP resulted in significant sparing for spinal cord, kidneys and femoral heads.

Conclusion

KBP yielded comparable and for some organs superior performance compared to CP resulting in conformal and homogeneous target coverage. Improved organ sparing was observed when individual patient geometry was considered.

Patterns of cervical cancer brachytherapy in India: results of an online survey supported by the Indian Brachytherapy Society

PURPOSE

Cervical cancer is the most common gynecological cancer in India. Uniform protocol-based treatment is important for achieving optimal outcomes. We undertook a survey to investigate patterns of care with special regard to patterns of care in cervical cancer brachytherapy in India.

MATERIAL AND METHODS

A 17-question online survey was sent to radiation oncologists across India. Respondents were required to have a minimum of 1-year experience. One response per center was accepted and deemed as representative.

RESULTS

Out of 116 centers, 59 responses were generated. Two-thirds (66.1%) were from academic centers and the majority (96.6%) used high-dose-rate (HDR) brachytherapy. The centers treated an average of 255 patients per year (median 161 patients, IQR 76-355). The majority were locally advanced cancers (FIGO 2009 stage II-IV 87.5%). External beam radiotherapy (EBRT) schedules were fairly consistent, administering doses of 45-50 Gy over 5 weeks. Brachytherapy was performed towards EBRT completion by 37/59 (62%) and 43/59 (74.3%) centers used a schedule of 7 Gy × 4 fractions (HDR). Brachytherapy was commonly performed under anesthesia (spinal/general: 44% each) with ultrasound (USG) guidance (29%). Computed tomography (CT) imaging (65%) and orthogonal X-rays (35%) represented the most common imaging for planning, while point A prescription (66%) or GEC-ESTRO based parameters (35%) with manual/geometric methods represented the most common methodology for dose volume prescription and optimization. Overall treatment time (OTT) reported was within 49-56 days in 50%. Complex implants (IC + IS) were performed for more than 30% of cases by 3 centers.

CONCLUSIONS

Our survey suggested a fairly uniform treatment paradigm for cervical cancer brachytherapy, with a progressive shift from 2D to 3D image-based parameters for planning, with persistence of point A based prescription. Further efforts are needed to augment and ease this transition.

Global Collaborations for Cervical Cancer: Can the East-West Alliance Facilitate Treatment for all?

Despite the advances in the primary prevention of cervical cancer, there is an absolute increase in the incidence of cervical cancer as a result of an increase in world population. A vast majority of patients in low and low-middle income countries continue to present at a locally advanced stage, necessitating treatment with chemoradiation and brachytherapy. There is a dearth of equipment and trained professionals for the treatment of cervical cancer, especially in low and low-middle income countries. There is an urgent need to improve treatment availability and develop better treatments. Worldwide trends, however, reveal a low number of therapeutic and innovative research trials in cervical cancer. The present article elucidates the existing challenges and provides solutions to improve outcomes. The proposed strategies hinge on strengthening collaborations for global advocacy.