TY - JOUR
T1 - Estimation of the risk of secondary malignancies following intraoral electron radiotherapy for tongue cancer patients
AU - Jeong, Seonghoon
AU - Yoon, Myonggeun
AU - Chung, Weon Kuu
AU - Chung, Mijoo
AU - Kim, Dong Wook
N1 - Funding Information:
This work was supported by the General Researcher Program (NRF-2015R1D1A1A 09056828), the Nuclear Safety Research Program (Grant No. 1603016) through the Korea Foundation Of Nuclear Safety (KOFONS), granted financial resource from the Nuclear Safety and Security Commission (NSSC), and Radiation Technology Development Program (2013M2A2A4027117) of the Republic of Korea.
Publisher Copyright:
© 2016 Cambridge University Press.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - Purpose: To measure dosimetric characteristics for linear accelerator-based electron beams, which are applied through locally manufactured acrylic tubes for intraoral radiotherapy and to calculate the secondary cancer risk for organs at risk. Materials and methods: Six different acrylic tubes were exposed to a 6-MeV electron beam; they had tips with three angles (0°, 15° and 30°) and two diameters (2·5 and 3·0 cm). Gafchromic EBT2 film was horizontally and vertically inserted in a solid water phantom to measure the dose profiles and percentage depth doses (PDDs). The measured data from radio-photoluminescence glass dosimeters placed on the neck and both eyes were used to estimate the lifetime attributable risk of secondary cancer resulting from intraoral radiotherapy for tongue cancer. Results: A total of 12 dose profiles were obtained from six different acrylic applicators at 0·5 and 1·28 cm depths. Circular shapes were obtained from 0° applicators, and oval shapes were obtained from 15° and 30° applicators. Absorbed doses at a 0·5 cm depth were higher than those at a 1·28 cm depth. PDD shapes for the six acrylic applicators were similar to those of a normal 6 MeV electron beam. Larger-diameter applicators showed higher PDD than smaller-diameter applicators with the same tip angle. According to our secondary cancer risk estimation, if 100,000 patients received intraoral radiotherapy at 30 years and lived until 80 years, 122 female and 22 male patients would develop secondary thyroid cancer, while 13 female and 18 male patients would develop secondary ocular melanoma or retinoblastoma. Conclusions: Dosimetric characteristics for linear accelerator-based intraoperative radiotherapy treatment beam were confirmed. In addition, we found that 0·1% of tongue cancer patients would get secondary malignancies for both eyes and thyroid from this treatment.
AB - Purpose: To measure dosimetric characteristics for linear accelerator-based electron beams, which are applied through locally manufactured acrylic tubes for intraoral radiotherapy and to calculate the secondary cancer risk for organs at risk. Materials and methods: Six different acrylic tubes were exposed to a 6-MeV electron beam; they had tips with three angles (0°, 15° and 30°) and two diameters (2·5 and 3·0 cm). Gafchromic EBT2 film was horizontally and vertically inserted in a solid water phantom to measure the dose profiles and percentage depth doses (PDDs). The measured data from radio-photoluminescence glass dosimeters placed on the neck and both eyes were used to estimate the lifetime attributable risk of secondary cancer resulting from intraoral radiotherapy for tongue cancer. Results: A total of 12 dose profiles were obtained from six different acrylic applicators at 0·5 and 1·28 cm depths. Circular shapes were obtained from 0° applicators, and oval shapes were obtained from 15° and 30° applicators. Absorbed doses at a 0·5 cm depth were higher than those at a 1·28 cm depth. PDD shapes for the six acrylic applicators were similar to those of a normal 6 MeV electron beam. Larger-diameter applicators showed higher PDD than smaller-diameter applicators with the same tip angle. According to our secondary cancer risk estimation, if 100,000 patients received intraoral radiotherapy at 30 years and lived until 80 years, 122 female and 22 male patients would develop secondary thyroid cancer, while 13 female and 18 male patients would develop secondary ocular melanoma or retinoblastoma. Conclusions: Dosimetric characteristics for linear accelerator-based intraoperative radiotherapy treatment beam were confirmed. In addition, we found that 0·1% of tongue cancer patients would get secondary malignancies for both eyes and thyroid from this treatment.
KW - dose
KW - electron radiotherapy
KW - intraoral cone radiotherapy
KW - radio-photoluminescence glass dosimeter
KW - secondary cancer risk
UR - http://www.scopus.com/inward/record.url?scp=84997335664&partnerID=8YFLogxK
U2 - 10.1017/S1460396916000480
DO - 10.1017/S1460396916000480
M3 - Article
AN - SCOPUS:84997335664
VL - 16
SP - 46
EP - 52
JO - Journal of Radiotherapy in Practice
JF - Journal of Radiotherapy in Practice
SN - 1460-3969
IS - 1
ER -