Reduction of parotid damage by Continuous Hyperfractionated Accelerated Radiotherapy

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 09671917
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 病態科学系歯学(含放射線系歯学)
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: YOSHINO Norio Tokyo Med. & Dent Univ. Dentistry. Assistant Professo, 歯学部, 助手 (70220704)
• Co-Investigator(Kenkyū-buntansha): OHBAYASHI Naoto Tokyo Med. & Dent Univ. Dentistry. Assistant professo, 歯学部, 助手 (40176988) ; KURABAYASHI Toru Tokyo Med. & Dent Univ. Dentistry. Lecturer, 歯学部, 講師 (60178093)
• Project Period (FY): 1997 – 1999
• Keywords: CHART / MTC / radiation damage / parotid gland

Research Abstract

The parotid damage with Continuous Hyperfractionated Accelerated Radiotherapy (CHART) was examined by the model experiment system. To detect the parotid damage, Magnetization Transfer Contrast (MTC) was made an image with MRI device. To evaluate the damage of the parotid gland, X rays were irradiated to the rat parotid gland with 5Gy to 30Gy. We measured the serum and the urine amylase activity of the damaged parotid origin, and in the parotid at the time of the remaining total amylase passing.
As for pulse sequence used to detect MTC, it has been understood that gradient echo or FISP is useful. It was clarified to the maximum value appearance of the urine amylase activity that time was different by the difference of the absorbed dose of the parotid. It is suggested that the mechanism of the appearance of the cell death by the irradiation of the parotid acinar cell is different depending on the dose.