Efficacy of Magnetic Resonance IVIM Imaging in Guiding Target Delineation and Dose Escalation of Concurrent Radiochemotherapy on Locally Advanced NSCLC

Objective To clarify the efficacy and safety of magnetic resonance IVIM imaging in guiding target delineation and dose escalation of concurrent radiochemotherapy on locally advanced NSCLC.

Methods From September 2014 to March 2018, 60 patients with inoperable locally advanced NSCLC were randomly divided into the experimental group and the control group. In the experimental group, 4DCT combined with IVIM imaging was used to guide the delineation of the target area of SIB-IMRT and dose escalation during radiotherapy. In the control group, 4DCT simulation was used to delineate the target area of SIB-IMRT. The clinical efficacy and safety between the two groups were compared, and the correlation between IVIM parameters and chemoradiotherapy efficacy was analyzed.

Results Compared with the control group, the overall response rate was higher (86.7% vs. 60%, P=0.020) and the incidence of grade 3/4 radiation pneumonia was lower (20% vs. 46.7%, P=0.028) in the experimental group. The change of D value during treatment was related to the overall response rate of patients (P < 0.05). The more the D value increased, the longer PFS of patients was(P=0.006).

Conclusion IVIM imaging guide could significantly increase the overall response rate of locally advanced NSCLC to concurrent chemoradiotherapy and reduce the incidence of grade 3/4 radiation pneumonia. The change of IVIM imaging parameter D value during radiotherapy is expected to be a predictor of chemoradiotherapy efficacy.