3T MR-Guided Brachytherapy for Gynecologic Malignancies

TL;DR

This paper presents a novel 3T MRI-guided brachytherapy methodology for gynecologic cancers, enhancing tumor targeting and normal tissue sparing through advanced imaging and planning techniques, tested in 18 cases.

Contribution

It introduces a specialized MR-guided brachytherapy approach with new imaging sequences and planning software for improved gynecologic cancer treatment.

Findings

Effective tumor coverage with reduced normal tissue radiation.

Successful application in 18 clinical cases.

Development of advanced image analysis and planning tools.

Abstract

Gynecologic malignancies are a leading cause of death in women worldwide. Standard treatment for many primary and recurrent gynecologic cancer cases includes a combination of external beam radiation, followed by brachytherapy. Magnetic Resonance Imaging (MRI) is benefitial in diagnostic evaluation, in mapping the tumor location to tailor radiation dose, and in monitoring the tumor response to treatment. Initial studies of MR-guidance in gynecologic brachtherapy demonstrate the ability to optimize tumor coverage and reduce radiation dose to normal tissues, resulting in improved outcomes for patients. In this article we describe a methodology to aid applicator placement and treatment planning for 3 Tesla (3T) MR-guided brachytherapy that was developed specifically for gynecologic cancers. This has been used in 18 cases to date in the Advanced Multimodality Image Guided Operating suite at Brigham and Women's Hospital. It is comprised of state of the art methods for MR imaging, image analysis, and treatment planning. An MR sequence using 3D-balanced steady state free precession in a 3T MR scan was identified as the best sequence for catheter identification with ballooning artifact at the tip. 3D treatment planning was performed using MR images. Item in development include a software module designed to support virtual needle trajectory planning that includes probabilistic bias correction, graph based segmentation, and image registration algorithms. The results demonstrate that 3T MR has a role in gynecologic brachytherapy. These novel developments improve targeted treatment to the tumor while sparing the normal tissues.