Impact of digital positron emission tomography/computed tomography on the delineation of clinical target volume in advanced lung cancer.

The present study investigated the differences between digital [18F]-Fluorodeoxyglucose (FDG) positron emission tomography [PET]/computed tomography [CT] (dPET/CT) and conventional PET/CT (cPET/CT) in delineating the clinical target volume (CTV) in patients with advanced lung cancer in the involved field radiation therapy (IFRT) era. Patients with advanced lung cancer were scanned using two dual-imaging protocols (dPET/CT and cPET/CT). Two virtual delineations contoured with reference to dPET/CT and cPET/CT images were created for each patient by five radiation oncologists. Changes in the delineation of target volumes in each patient were examined. A total of 10 patients [male/female, 9/1; median age, 65 years (range, 58-80 years)] were enrolled between April 2020 and September 2020. Significant changes in the delineation of CTVs were uncommon between dPET/CT and cPET/CT. A notable increase in CTVn was observed in 10% of the patients (1/10; P<0.05; Smirnov-Grubbs analysis). In this patient, a node that was not assessed as lymph node metastasis when cPET/CT was used was assessed as lymph node metastasis when dPET/CT was used and was included in the CTVn by all five radiation oncologists. In patients with advanced lung cancer, notable changes in CTV delineations are uncommon, regardless of whether dPET/CT or cPET/CT is used. However, in some cases, CTVn delineation with reference to dPET/CT may improve the treatment outcomes of IFRT for advanced lung cancer.
Competing Interests: TKo received an honorarium from MSD, Ono, Kyowa Hakko Kirin, AstraZeneca, Boehringer Ingelheim, Chugai, TAIHO, Eli Lilly, Bristol Myers Squibb, Pfizer, Merck Biopharma, Nippon Kayaku, Novartis, Bayer, Sawai, and AMGEN; consulting fee from Chugai, AstraZeneca, Ono, Pfizer, Daiichi-Sankyo, Bayer, and Abbvie; and received research funding from MSD, Kyowa Hakko Kirin, AstraZeneca, Eli Lilly, Pfizer, Chugai, TAIHO, Ono, Bristol-Myers, Merck Biopharma, Daiichi-Sankyo, AbbVie, AMGEN, Sanofi, Eisai, LabCorp Development, IQVIA Services, Gilead Sciences, Pfizer, and Bayer. All other authors declare that they have no competing interests.
(Copyright: © Makita et al.)