MR-guided SBRT boost for patients with locally advanced or recurrent gynecological cancers ineligible for brachytherapy: feasibility and early clinical experience

Indrawati Hadi,Lukas Nierer,Michael Reiner,Claus Belka,Rieke Von Bestenbostel,Raphael Bodensohn,Maximilian Niyazi,Stephan Schönecker,Stefanie Corradini,Chukwuka Eze,Paul Rogowski,Guillaume Landry

doi:10.1186/s13014-022-01981-z

Indrawati Hadi, Lukas Nierer + Show 10 more

Open Access

https://doi.org/10.1186/s13014-022-01981-z

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Abstract

Background and purposeChemoradiotherapy (CRT) followed by a brachytherapy (BT) boost is the standard of care for patients with locally advanced or recurrent gynecological cancer (LARGC). However, not every patient is suitable for BT. Therefore, we investigated the feasibility of an MR-guided SBRT boost (MRg-SBRT boost) following CRT of the pelvis.Material and methodsTen patients with LARGC were analyzed retrospectively. The patients were not suitable for BT due to extensive infiltration of the pelvic wall (10%), other adjacent organs (30%), or both (50%), or ineligibility for anesthesia (10%). Online-adaptive treatment planning was performed to control for interfractional anatomical changes. Treatment parameters and toxicity were evaluated to assess the feasibility of MRg-SBRT boost.ResultsMRg-SBRT boost was delivered to a median total dose of 21.0 Gy in 4 fractions. The median optimized PTV (PTVopt) size was 43.5ccm. The median cumulative dose of 73.6Gy10 was delivered to PTVopt. The cumulative median D2ccm of the rectum was 63.7 Gy; bladder 72.2 Gy; sigmoid 65.8 Gy; bowel 59.9 Gy (EQD23). The median overall treatment time/fraction was 77 min, including the adaptive workflow in 100% of fractions. The median duration of the entire treatment was 50 days. After a median follow-up of 9 months, we observed no CTCAE ≥ °II toxicities.ConclusionThese early results report the feasibility of an MRg-SBRT boost approach in patients with LARGC, who were not candidates for BT. When classical BT-OAR constraints are followed, the therapy was well tolerated. Long-term follow-up is needed to validate the results.

Highlights

Background and purposeChemoradiotherapy (CRT) followed by a brachytherapy (BT) boost is the standard of care for patients with locally advanced or recurrent gynecological cancer (LARGC)
After a median follow-up of 9 months, we observed no Common Terminology Criteria for Adverse Events (CTCAE) ≥ °II toxicities. These early results report the feasibility of an MRg-stereotactic body radiotherapy (SBRT) boost approach in patients with LARGC, who were not candidates for BT
External beam radiotherapy (EBRT) with concurrent chemotherapy followed by a brachytherapy (BT) boost is the standard of care for most patients with locally advanced gynecological cancer [1]

Summary

Introduction

Chemoradiotherapy (CRT) followed by a brachytherapy (BT) boost is the standard of care for patients with locally advanced or recurrent gynecological cancer (LARGC). External beam radiotherapy (EBRT) with concurrent chemotherapy followed by a brachytherapy (BT) boost is the standard of care for most patients with locally advanced gynecological cancer [1]. Hadi et al Radiation Oncology (2022) 17:8 the management of patients with non-metastasized recurrent gynecological cancer remains a challenge. Even though the utilization of a sequential BT boost improves the outcomes in patients with locally advanced or recurrent gynecological cancer (LARGC) [2,3,4], not every patient is suitable for a BT boost due to the extent or localization of the tumor, bone infiltration, infiltration of the pelvic wall or adjacent organs, or in multimorbid patients, who cannot undergo anesthesia. As it is important to deliver high doses to the high-risk clinical target volume (HR-CTV) while sparing critical organs at risk (OAR), the use of high precision radiotherapy becomes indispensable

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