A Prospective Study of Intensity-modified Radiation Therapy in Comparison with Conventional 3D-RT for BR Pancreatic Cancer Patients with Arterial Involvement

Background/Aim: Intensity-modulated radiation therapy (IMRT) is a form of radiation therapy that allows accurate irradiation with reduced damage to surrounding tissues. Here, we analyzed borderline-resectable pancreatic cancer (BRPC) with arterial abutment (BR-A) patients with IMRT as neoadjuvant therapy and performed comparisons with patients with conventional RT to clarify the advantages of IMRT as a neoadjuvant therapy. Patients and Methods: Thirty BR-A patients treated at our hospital between January 2012 and December 2015 were divided into two groups: 12 patients underwent conventional 3D-RT before resection (RT group); and 18 patients underwent IMRT before resection (IMRT group). We analyzed safety, tumor resection rate, histological classification of the tumor and overall survival. Results: The R0 rate was 84% for the IMRT group and 83% for the RT group. Local therapeutic effects as assessed by Evans classification showed a higher local control rate in the IMRT group (Grade: 1, 0%; 2a, 25%; 2b, 41.6%; 3, 17%; 4, 8%) than in the RT group (Grade: 1, 17%; 2a, 50%; 2b, 17%; 3, 17%; 4, 0%). The cumulative dose of S1 treatment as adjuvant therapy was much smaller in the RT group (18.3%) compared to that in the IMRT group (57.1%, p=0.047), and with better subsequent overall survival rate (MST 32 months vs. 13.8 months, p=0.0273). Conclusion: The IMRT group showed a better control rate than the RT group. The neoadjuvant IMRT has advantages of higher completion rate of adjuvant chemotherapy with better nutritional status and better subsequent overall survival rate (OS).

http://ift.tt/2BydmLI