Volume 37, Issue 8 p. 4445-4455
Radiation therapy physics

Measurement and verification of positron emitter nuclei generated at each treatment site by target nuclear fragment reactions in proton therapy

Aya Miyatake

Aya Miyatake

Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan

Electronic mail: [email protected]

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Teiji Nishio

Teiji Nishio

Particle Therapy Division, Research Center for Innovative Oncology, National Cancer Center, Kashiwa, 6-5-1 Kashiwano-ha, Kashiwa-shi, Chiba 277-8577, Japan and Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

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Takashi Ogino

Takashi Ogino

Particle Therapy Division, Research Center for Innovative Oncology, National Cancer Center, Kashiwa, 6-5-1 Kashiwano-ha, Kashiwa-shi, Chiba 277-8577, Japan

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Nagahiro Saijo

Nagahiro Saijo

National Cancer Center, Kashiwa, 6-5-1 Kashiwano-ha, Kashiwa-shi, Chiba 277-8577, Japan

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Hiroyasu Esumi

Hiroyasu Esumi

National Cancer Center, Kashiwa, 6-5-1 Kashiwano-ha, Kashiwa-shi, Chiba 277-8577, Japan

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Mitsuru Uesaka

Mitsuru Uesaka

Nuclear Professional School, School of Engineering, University of Tokyo, 22-2 Shirane-shirakata, Tokai, Naka, Ibaraki 319-1188, Japan

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First published: 29 July 2010
Citations: 23

0094-2405/2010/37(8)/4445/11/$30.00

Abstract

Purpose:

The purpose of this study is to verify the characteristics of the positron emitter nuclei generated at each treatment site by proton irradiation.

Methods:

Proton therapy using a beam on-line PET system mounted on a rotating gantry port (BOLPs-RGp), which the authors developed, is provided at the National Cancer Center Kashiwa, Japan. BOLPs-RGp is a monitoring system that can confirm the activity distribution of the proton irradiated volume by detection of a pair of annihilation gamma rays coincidentally from positron emitter nuclei generated by the target nuclear fragment reactions between irradiated proton nuclei and nuclei in the human body. Activity is measured from a start of proton irradiation to a period of 200 s after the end of the irradiation. The characteristics of the positron emitter nuclei generated in a patient's body were verified by the measurement of the activity distribution at each treatment site using BOLPs-RGp.

Results:

The decay curves for measured activity were able to be approximated using two or three half-life values regardless of the treatment site. The activity of half-life value of about 2 min was important for a confirmation of the proton irradiated volume.

Conclusions:

In each proton treatment site, verification of the characteristics of the generated positron emitter nuclei was performed by using BOLPs-RGp. For the monitoring of the proton irradiated volume, the detection ofurn:x-wiley:00942405:media:mp2559:mp2559-math-0001 generated in a human body was important.