Designing a ridge filter based on a mouse foot skin reaction to spread out Bragg-peaks for carbon-ion radiotherapy. Issue 2 (May 2015)

• Record Type: Journal Article
• Authors: Uzawa, Akiko; Ando, Koichi; Kase, Yuki; Hirayama, Ryoichi; Matsumoto, Yoshitaka; Matsufuji, Naruhiro; Koike, Sachiko; Kobashi, Gen
• Is Part Of: Radiotherapy and oncology. Volume 115:Issue 2(2015:May)
• Page Start: 279
• Page End: 283
• Publication Date: 2015-05
• Subjects: Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2015.04.007
• Languages: English
• ISSNs: 0167-8140

Abstract

<abstract xml:lang="en" abstract-type="author" id="ab005"> <title id="st005">Abstract</title> <sec> <title id="st010">Background and purpose</title> <p id="sp0005">Carbon-ion radiotherapy uses spread-out Bragg peaks (SOBP) to produce uniform biological effects within a target volume. The relative biological effectiveness is determined by the in vitro cell kill after a single dose is employed to design the SOBP. A question remains as to whether biological effects for in vivo tissues after fractionated doses are also uniform within the SOBP.</p> </sec> <sec> <title id="st015">Material and methods</title> <p id="sp0010">Mouse foot skin was irradiated with fractionated doses of carbon ions at various linear energy transfer (LET) values. A new ridge filter was designed based on alpha and beta values for each LET to cause moderate skin reaction, and was studied concerning its uniformity.</p> </sec> <sec> <title id="st020">Results</title> <p id="sp0015">The reciprocal total doses of intermediate-LET carbon ions and of reference gamma rays linearly increased with an increase of a dose per fraction in Fe-plots. As the single total dose of higher LET run off linearity, data obtained from 2 to 6 fractions were used to design a new ridge filter. The physical dose distribution of the new ridge filter was almost identical to, and indistinguishable from, the ridge filter designed based on the in vitro cell kill.</p> </sec> <sec> <title id="st025">Conclusions</title> <p id="sp0020">The LET dependence of alpha is a principle of the biological factor to be used for designing spread-out Bragg peaks of carbon-ion radiotherapy.</p> </sec> </abstract>