Abstract
Contemporary lymphoma radiation target volumes that rely on post-systemic therapy imaging do not have standardised nomenclature. A forum of radiation oncology lymphoma leaders from the National Clinical Trials Network groups (NRG Oncology, Children's Oncology Group, SWOG Cancer Research Network, Alliance for Clinical Trials in Oncology, Eastern Cooperative Oncology Group-American College of Radiology Imaging Network Cancer Research Group, and the Canadian Cancer Trials Group) was convened and established standardised nomenclature for these volumes in the autumn of 2024. Involved-site radiotherapy includes the full cranial-caudal extent of prechemotherapy disease and takes into account axial anatomical changes only. Residual site radiotherapy targets only the postchemotherapy CT-anatomical mass. PET-directed radiotherapy exclusively targets PET-positive disease and includes three types: PET-directed involved site radiotherapy using the superior-inferior aspect of prechemotherapy involved disease sites that remain PET-avid on post-treatment imaging; PET-directed residual site radiotherapy using only the postchemotherapy CT-anatomical residual mass that contains the PET-avid lesion on post-treatment imaging, without excluding sites that had complete metabolic response; and PET-directed residual PET radiotherapy using only the PET-avid focus, irrespective of the corresponding adjacent non-PET-avid CT-anatomical disease surrounding it.
Overview
- The study aims to establish standardized nomenclature for contemporary lymphoma radiation target volumes that rely on post-systemic therapy imaging. The study involves a forum of radiation oncology lymphoma leaders from various National Clinical Trials Network groups. The study focuses on involved-site radiotherapy, residual site radiotherapy, and PET-directed radiotherapy. The study aims to provide a clear and consistent nomenclature for these volumes to improve communication and collaboration among radiation oncologists and researchers.
Comparative Analysis & Findings
- The study establishes standardized nomenclature for involved-site radiotherapy, residual site radiotherapy, and PET-directed radiotherapy. Involved-site radiotherapy targets the full cranial-caudal extent of prechemotherapy disease and takes into account axial anatomical changes only. Residual site radiotherapy targets only the postchemotherapy CT-anatomical mass. PET-directed radiotherapy exclusively targets PET-positive disease and includes three types: PET-directed involved site radiotherapy using the superior-inferior aspect of prechemotherapy involved disease sites that remain PET-avid on post-treatment imaging; PET-directed residual site radiotherapy using only the postchemotherapy CT-anatomical residual mass that contains the PET-avid lesion on post-treatment imaging, without excluding sites that had complete metabolic response; and PET-directed residual PET radiotherapy using only the PET-avid focus, irrespective of the corresponding adjacent non-PET-avid CT-anatomical disease surrounding it.
Implications and Future Directions
- The study's findings provide a standardized nomenclature for involved-site radiotherapy, residual site radiotherapy, and PET-directed radiotherapy, which can improve communication and collaboration among radiation oncologists and researchers. The study's findings can also facilitate the development of clinical guidelines and quality improvement initiatives. Future research should focus on the implementation and evaluation of the standardized nomenclature in clinical practice and the development of new imaging technologies that can enhance the accuracy and effectiveness of radiation targeting.