The value of MRI enhanced scan sequence in the radiotherapy target volume delineation in lung cancer with obstructive pneumonia/atelectasis / 中华放射肿瘤学杂志

ABSTRACT

Objective:To explore the feasibility and advantages of different MRI sequences in delineating target volumes in lung cancer with obstructive pneumonia or atelectasis (OC).Methods:Fourteen patients with OC underwent CT localization and MRI scan. CT, T 1WI, fat suppression T 2WI, LAVA, LAVA+ C images were collected respectively. CT and MRI images were fused in the treatment planning system, and GTV-p was target delineated on CT and MRI respectively. Results:CT showed tumor and OC boundaries in 2 patients, fat suppression T 2WI showed tumor and OC boundaries in 10 patients, LAVA showed tumor and OC boundaries in 12 patients, and LAVA+ C showed tumor and OC boundaries in 10 patients. Fat suppression T 2WI, LAVA, and LAVA+ C sequences showed similar resolving ability ( P>0.05). The GTV of T 2WI, LAVA, and LAVA+ C sequences decreased significantly compared with ST-GTV ( P<0.05), and T 2WI_GTV and LAVA_GTV were similar ( P>0.05). The GTV value of LAVA+ C was the smallest among all sequences. Conclusions:The application of MRI fat compression T 2WI, LAVA, and LAVA+ C sequences to the radiotherapy target volume delineation in lung cancer patients with OC improved the accuracy, among which the boundary resolution of LAVA was better than that of fat compression T 2WI, and LAVA+ C showed the best effect on tiny blood vessels.