Simulation study of dosimetric effect in proton beam therapy using concomitant boost technique for unresectable pancreatic cancers
- 78 Downloads
The purpose of this study is to investigate the dose distribution of proton beam therapy (PBT) using a concomitant boost technique for unresectable pancreatic cancers.
Materials and methods
This simulation study involved 36 patients with unresectable pancreatic cancer. The irradiation dose was set as 67.5 gray equivalent (GyE) with 25 fractions using concomitant boost technique. The irradiation dose was set as 50 GyE to cover the whole target and another posterior beam of 17.5 GyE was added to ensure that 10% isodose line was not delivered to the gastrointestinal (GI) tract. Dose distribution of the gross tumor volume and GI tract was examined.
V55GyE, 60GyE, 65GyE were 80.8, 66.5, and 42.4%, respectively, and mean dose was 64.1 GyE in all patients. The distance from the GI tract showed significant difference in dose distribution (P = 0.002 in V55GyE, 0.0009 in V60GyE, 0.003 in V65GyE, and 0.02 in mean dose, respectively). Location, tumor diameter, or lymph nodes metastasis did not show any difference.
We found that irradiated dose is closely related to the distance from the GI tract. Clinically, this protocol is expected to have outstanding effects on local control of tumors compared to conventional PBT.
KeywordsPancreatic cancer Proton beam therapy Concomitant boost technique Gross tumor volume
This study was partially supported by Grants-in-Aid for Scientific Research in Japan (no. 17H04256). We really appreciate Thomas D. Mayers, Medical English Communications Center, University of Tsukuba, for grammatical revision of the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
The institutional review board approved.
- 1.Hori M, Matsuda T, Shibata A, Katanoda K, Sobue T, Nishimoto H, et al. Cancer incidence and incidence rates in Japan in 2009: a study of 32 population-based cancer registries for the monitoring of cancer incidence in Japan (MCIJ) project. Jpn J Clin Oncol. 2015;45:884–91.CrossRefPubMedGoogle Scholar
- 15.Hong TS, Ryan DP, Blaszkowsky LS, Mamon HJ, Kwak EL, Mino-Kenudson M, et al. Phase I study of preoperative short-course chemoradiation with proton beam therapy and capecitabine for resectable pancreatic ductal adenocarcinoma of the head. Int J Radiat Oncol Biol Phys. 2011;79:151–7.CrossRefPubMedGoogle Scholar
- 21.Group EBCC, Group ER, Bijker N, Meijnen P, Peterse JL, Bogaerts J, et al. Breast-conserving treatment with or without radiotherapy in ductal carcinoma-in situ: ten-year results of European Organisation for Research and Treatment of Cancer randomized phase III trial 10853—a study by the EORTC Breast Cancer Cooperative Group and EORTC Radiotherapy Group. J Clin Oncol. 2006;24:3381–7.CrossRefGoogle Scholar