Image‐Guided Adaptive Brachytherapy for Cervical Cancer Using Magnetic Resonance Imaging: Overview and Experience

Abstract

Image-guided adaptive brachytherapy (IGABT) using magnetic resonance imaging (MRI) has been accepted as a novel treatment technique for cervical cancer. During the development of MRI-based IGABT, a very important concept called "High-risk clinical target volume (HR-CTV)" was introduced. However, computed tomography (CT)-based IGABT is the most common modality in Japan.MRI-based IGABT was initiated in September 2014 at Kobe University Hospital and 50 patients were treated through March 2016. Although a total HR-CTV D90 ranging from 80 to 85 Gy equivalent dose in 2 Gy fractions in combination with 45 Gy of external beam radiotherapy (EBRT) and 7 Gy×4 fractions of IGABT is the most standard treatment aim in European institutions, our aim for a total HR-CTV D90 was a 70-80 Gy because of the use of the central shielding technique for the protection of organs at risk in the late phase of EBRT.The mean total HR-CTV D90 for our 50 patients was 77 Gy. Although our aim was achieved, it was relatively low because Japanese radiotherapy protocols for cervical cancer still differ from those in European institutions. Therefore, a new treatment protocol, which is closer to the global standard, should be established.

Current Status and Future Directions of Image-Guided Adaptive Brachytherapy for Locally Advanced Cervical Cancer

“…Currently, there are no ongoing prospective studies in the United States or Europe examining the utility of TRUS for cervical cancer brachytherapy planning, since MRI is commonly used in these countries. Certain centers within Japan and India (such as Kobe University Hospital and Tata Memorial Hospital) routinely utilize TRUS in their workflow and have published their experiences [55,56], which could serve as frameworks to standardize the use of TRUS for brachytherapy application and planning in other countries.…”