Proton beam therapy in Japan: current and future status

Abstract

The number of patients treated by proton beam therapy in Japan since 2000 has increased; in 2016, 11 proton facilities were available to treat patients. Notably, proton beam therapy is very useful for pediatric cancer; since the pediatric radiation dose to normal tissues should be reduced as much as possible because of the effect of radiation on growth, intellectual development, endocrine organ function and secondary cancer development. Hepatocellular carcinoma is common in Asia, and most of the studies of proton beam therapy for liver cancer have been reported by Japanese investigators. Proton beam therapy is also a standard treatment for nasal and paranasal lesions and lesions at the base of the skull, because the radiation dose to critical organs such as the eyes, optic nerves and central nervous system can be reduced with proton beam therapy. For prostate cancer, comparative studies that address adverse effects, safety, patient quality of life and socioeconomic issues should be performed to determine the appropriate use of proton beam therapy for prostate cancer. Regarding new proton beam therapy applications, experience with proton beam therapy combined with chemotherapy is limited, although favorable outcomes have been recently reported for locally advanced lung cancer, esophageal cancer and pancreatic cancer. Therefore, 'chemoproton' therapy appears to be a very attractive field for further clinical investigations. In conclusion, there are cost issues and considerations regarding national insurance for the use of proton beam therapy in Japan. Further studies and discussions are needed to address the use of proton beam therapy for several types of cancers, and for maintaining the quality of life of patients while retaining a high cure rate.

The evolution of proton beam therapy: Current and future status (Review)

“…PBT is also considered a standard treatment for nasal and paranasal lesions, as well as lesions at the base of the skull, as the radiation dose to critical organs, such as the eyes, optic nerves and central nervous system, may be reduced with PBT (14).…”

Stent-graft placement for treatment of massive hemobilia caused by porto-biliary fistula

“…[7][8][9] Although PBT is a promising modality for the management of various malignancies because of the possibility of radiation dose reduction to critical organs, acute and late toxicities due to normal tissue damage have been reported. [5][6][7] The incidence of cholangitis and common bile duct stenosis (two late complications) previously reported for PBT in advanced cholangiocarcinoma was 21.4% (6/28) and 3.6% (1/28), respectively. 7 In our case, we observed the stricture and distal localized saccular dilatation of the hilar bile duct.…”

“…Appropriate application of PBT can lead to fewer adverse effects and higher therapeutic efficacy compared with conventional radiation therapy that uses X-ray beams. 5 Despite this, there are reports of some adverse reactions including severe complications due to normal tissue damage. 6,7 We report a case of massive hemobilia with porto-biliary fistula due to PBT, which was successfully treated by endovascular treatment via a percutaneous transhepatic approach.…”

Transient increases in serum α fetoprotein and protein induced by vitamin K antagonist II levels following proton therapy does not necessarily indicate progression of hepatocellular carcinoma

“…However, although 5-year survival rates after curative treatments like hepatectomy, radiofrequency ablation (RFA), and liver transplantation are as high as 50-70%, only 20-40% patients were able to receive these therapies due to their comorbidities and/or tolerability, in addition to late diagnosis (2,3). Recently, proton therapy (PT) has offered promising results to overcome these limitations (4,5). To test whether PT is non-inferior to hepatectomy for resectable HCC, a non-randomized controlled study of PT vs. hepatectomy for resectable HCC started in June 2017 (Japan Clinical Oncology Group, JCOG1315C, SPRING study).…”