Consensus and contouring atlas for the delineation of clinical target volume in pre-/post-operative image-guided intensity modulated radiotherapy for rectal cancer

Objective To establish a Chinese experts’ consensus for the delineation of clinical target volume (CTV) of pre-/post-operative radiotherapy for rectal cancer in the era of three dimensional conformal radiotherapy, and compile a high-resolution contouring atlas. Methods The consensus and contouring atlas for the delineation of CTV of pre-/post-operative radiotherapy for rectal cancer were drafted by referring to international guidelines and treatment experience of domestic radiation centers. The details of draft were discussed and voted on the annual conference of Professional Committee of Radiotherapy for Colorectal Cancer of Chinese Medical Doctor Association. The final consensus was summarized by the steering committee. Results Based on the strength of the evidence and the consistency of experts’ consensus, the grading recommendations for positioning technology, pre-/post-operative radiotherapy target definition, definition of organs at risk (OAR), radiotherapy dose and fraction were delivered. In addition, the atlas of CTV was demonstrated on high-resolution on CT scan images. Conclusions To establish a Chinese experts’ consensus for radiotherapy of rectal cancer, standardize the radiotherapy process and reduce the variance in the delineation of CTV among different hospitals and radiologists. Key words: Rectal neoplasm/radiotherapy; Target volume delineation; Three-dimensional radiotherapy technology