Author:

Keywords:

Consensus guidelines, Rectal cancer, Clinical Target Volume delineation, Science & Technology, Life Sciences & Biomedicine, Oncology, Radiology, Nuclear Medicine & Medical Imaging, LOCAL RECURRENCE, RADIOTHERAPY, Consensus, Humans, Lymph Nodes, Organs at Risk, Practice Guidelines as Topic, Radiotherapy Planning, Computer-Assisted, Rectal Neoplasms, Tomography, X-Ray Computed, 0299 Other Physical Sciences, 1112 Oncology and Carcinogenesis, Oncology & Carcinogenesis, 3202 Clinical sciences, 3211 Oncology and carcinogenesis, 5105 Medical and biological physics

Abstract:

INTRODUCTION: The delineation of Clinical Target Volume (CTV) is a critical step in radiotherapy. Several guidelines suggest different subvolumes and anatomical boundaries in rectal cancer (RC), potentially leading to a misunderstanding in the CTV definition. International consensus guidelines (CG) are needed to improve uniformity in RC CTV delineation. MATERIAL AND METHODS: The 7 radiation oncologist experts defined a roadmap to produce RC CG. Step 1: revision of the published guidelines. Step 2: selection of RC cases with different clinical stages. Step 3: delineation of cases using Falcon following previously published guidelines. Step 4: meeting in person to discuss the initial delineation outcome, followed by a CTV proposal based on revised and if needed, adapted anatomical boundaries. Step 5: peer review of the agreed consensus. Step 6: peer review meeting to validate the final outcome. Step 7: completion of RC delineation atlases. RESULTS: A new ontology of structure sets was defined and the related table of anatomical boundaries was generated. The major modifications were about the lateral lymph nodes and the ischio-rectal fossa delineation. Seven RC cases were made available online as consultation atlases. CONCLUSION: The definition of international CG for RC delineation endorsed by international experts might support a future homogeneous comparison between clinical trial outcomes.