Feasibility of omitting the clinical target volume under PET-CT guidance in unresectable stage III non-small-cell lung cancer: A phase II clinical trial

• Published in: Radiotherapy and oncology 2023-04, Vol.181, p.109505-109505, Article 109505
• Main Authors: Cui, Tianxiang, Zhang, Anmei, Cui, Jianxiong, Chen, Lu, Chen, Guangpeng, Dai, Hongya, Qin, Xianli, Li, Guanghui, Sun, Jianguo
• Format: Article
• Language: English
• Subjects: Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Carcinoma, Non-Small-Cell Lung - diagnostic imaging; Carcinoma, Non-Small-Cell Lung - radiotherapy; Concurrent radiochemotherapy; CTV; Esophagitis; Feasibility Studies; Humans; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - drug therapy; Lung Neoplasms - radiotherapy; PET-CT; Positron Emission Tomography Computed Tomography - methods; Unresectable NSCLC
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2023.109505

•This study adopted the precise positioning method combining PET-CT and 4D-CT, and explored the feasibility of CTV-omitted under the guidance of precise positioning combined with PET-CT and 4D-CT.•The results showed that CTV-omitted can effectively reduce the incidence of radiation esophagitis and radiation pneumonitis in patients with stage III NSCLC without compromising survival. This clinical trial aims at investigate the feasibility of CTV-omitted, positron-emission tomography computed tomography (PET-CT) combined with intensity-modulated radiation therapy (IMRT) for unresectable stage III NSCLC. This was a single-center, phase II clinical trial initiated in July 2016. Patients with unresectable stage III NSCLC undergoing routine IMRT were randomly enrolled into the study group (CTV-omitted under PET-CT guidance) and the control group (CTV-delineated). Patients received platinum-based dual-drug concurrent chemoradio therapy. In the study group, the PGTV dose was 60 Gy given in 30 daily 2 Gy fractions; in the control group, the PCTV dose was 54 Gy given in 30 daily 1.8 Gy fractions, and the PGTV dose was 60 Gy given in 30 daily 2 Gy fractions. The primary endpoint was the incidence of radiation respiratory events or esophagitis with grade 3 or higher. The secondary endpoints included objective response rate (ORR), locate control rate, progression-free survival (PFS), failure pattern and overall survival (OS). A total of 90 patients were enrolled between July 2016 and March 2019. The incidence of radiation respiratory events or esophagitis with grade 3 or higher was 11.1 % in the study group, significantly lower than the rate of 28.9 % in the control group (P = 0.035), basically due to the reduced irradiated volumes of the lungs and esophagus in the study group. The median PFS was 9.0 months versus 10.0 months (P = 0.597), and the median OS 31.0 months versus 26.0 months (P = 0.489) in the study group and the control group, respectively. The failure pattern was not significantly different between the two groups (P = 0.826). Omitting the CTV under PET-CT guidance has high feasibility to reduce severe radiation associated toxicity in IMRT for unresectable stage III NSCLC, without compromising the efficacy.