Dosimetric analysis of upper gastrointestinal ulcer after carbon-ion radiotherapy for pancreatic cancer

作者：Shinoto Makoto^*; Shioyama Yoshiyuki; Matsunobu Akira; Okamoto Kei; Suefuji Hiroaki; Toyama Shingo; Honda Hiroshi; Kudo Sho

来源：Radiotherapy and Oncology, 2016, 120(1): 140-144.

DOI：10.1016/j.radonc.2016.04.040

• Pancreatic cancer
• Carbon-ion radiotherapy
• Dose volume histogram
• Gastrointestinal ulcer

Purpose: The aim of this study was to clarify the incidence, clinical risk factors, and dose-volume relationship of upper gastrointestinal (GI) ulcer after carbon-ion radiotherapy (C-ion RT) for pancreatic cancer.
Materials and methods: Fifty-eight pancreatic cancer patients were treated with C-ion RT from April 2014 to December 2015. The total dose was 55.2 Gy (RBE) in 12 fractions. D-2cm3 of GI tracts were restricted under 46 Gy (RBE); RBE-weighted absorbed dose. The association between dosimetric parameters (V10-50, D-max, D-1cm3, D-2cm3) and GI ulcer was examined using Spearman's correlation. The incidence of GI ulcer was compared between the two groups divided by the cutoff value.
Results: Twelve patients (21%) experienced gastric ulcer including only one (2%) grade 3 ulcer. There was no grade 4/5 toxicity or duodenal ulcer. V10-30 was significantly associated with gastric ulcer. The 1-year estimated risk of gastric ulcer for the determined cutoff values were 51% vs. 10% (V-10, >= 102 cm(3) or less), 42% vs. 9% (V-20, >= 24 cm(3) or less), 34% vs. 4% (V-30, >= 6 cm(3) or less).
Conclusions: The incidence of GI ulcer after C-ion RT was very low with the dose constraint of D-2cm3 <46 Gy (RBE). To further minimize the risk of GI ulcer, V10-30 should also be reduced.

• 出版日期2016-7