Radiation Therapy Oncology Group Consensus Panel Guidelines for the Delineation of the Clinical Target Volume in the Postoperative Treatment of Pancreatic Head Cancer

Abstract

Purpose To develop contouring guidelines to be used in the Radiation Therapy Oncology Group protocol 0848, a Phase III randomized trial evaluating the benefit of adjuvant chemoradiation in patients with resected head of pancreas cancer. Methods and Materials A consensus committee of six radiation oncologists with expertise in gastrointestinal radiotherapy developed stepwise contouring guidelines and an atlas for the delineation of the clinical target volume (CTV) in the postoperative treatment of pancreas cancer, based on identifiable regions of interest and margin expansions. Areas at risk for subclinical disease to be included in the CTV were defined, including nodal regions, anastomoses, and the preoperative primary tumor location. Regions of interest that could be reproducibly contoured on postoperative imaging after a pancreaticoduodenectomy were identified. Standardized expansion margins to encompass areas at risk were developed after multiple iterations to determine the optimal margin expansions. Results New contouring recommendations based on CT anatomy were established. Written guidelines for the delineation of the postoperative CTV and normal tissues, as well as a Web-based atlas, were developed. Conclusions The postoperative abdomen has been a difficult area for effective radiotherapy. These new guidelines will help physicians create fields that better encompass areas at risk and minimize dose to normal tissues.

Upper abdominal normal organ contouring guidelines and atlas: A Radiation Therapy Oncology Group consensus

“…Only recently, normal tissue contouring atlases for radiation planning (eg, lung, pelvis, postoperative pancreas) have been published. 2–4 …”

Comparison of conventional and 3-dimensional computed tomography against histopathologic examination in determining pancreatic adenocarcinoma tumor size: Implications for radiation therapy planning

“…In conventionally fractionated RT, gross tumor volume (GTV) on CT is expanded to cover non-visualized disease (clinical target volume, CTV) and then further enlarged to accommodate breathing and set-up error (planning target volume, PTV). Presently, limited data exist to define optimal margin size, although guidelines have been suggested by expert committees for CTV [2] and PTV [3]. …”

Patterns of radiotherapy practice for pancreatic cancer: Results of the Gastrointestinal Radiation Oncology Study Group multi-institutional survey

“…In fact, the clinical target volume contouring proposal in preoperative/definitive and postoperative PC settings was suggested (11,12). Moreover, AIRO-GI groups published a handy, pocket-sized manual that summarizes the main gastrointestinal guidelines [(13) available on line at www.…”

“…Evidence suggests gemcitabine-oxaliplatin followed by gemcitabine alone were the most employed nCT schedules, administered mostly by 3-4 scheduled cycles (range, [1][2][3][4][5][6][7][8][9][10][11][12] prior to RT (15). The drug most used for radiosensitizing was gemcitabine (63.4%), followed by 5-fluorouracil/capecitabine (26.8%).…”

“…The schedules most frequently used were gemcitabine-oxaliplatin (45%), gemcitabine alone (32.5%) or 5-fluorouracil-irinotecan-oxaliplatin (i.e., folfirinox) (12.5%) mostly with 3 or 4 cycles prior to RT (range, [1][2][3][4][5][6][7][8][9][10][11][12].…”