The purpose of this study is to verify the accuracy of the dose delivered to the patient during
intensity-modulated radiation therapy (IMRT) by using in-vivo dosimetry and to avoid accidental
exposure to healthy tissues and organs close to tumors. The in-vivo dose was reconstructed by
back projection of the transit dose with a simple approximation that considered only the percent
depth dose and inverse square law. While the average gamma index for comparisons of dose distributions
between the calculated dose map and the film measurement was less than the one for
96.3% of all pixels with the homogeneous phantom, the passing rate was reduced to 92.8% with the
inhomogeneous phantom, suggesting that the reduction was apparently due to the inaccuracy of the
reconstruction algorithm for inhomogeneity. The proposed method of calculating the dose inside
a phantom was of comparable or better accuracy than the treatment planning system, suggesting
that it can be used to verify the accuracy of the dose delivered to the patient during treatment.

 

 

Ui-Jung Hwang and Mi Hee Song
Department of Radiation Oncology, National Medical Center, Seoul, Korea
Tae Seong Baek and Eun Ji Chung
Department of Radiation Oncology, National Health Insurance Corporation Ilsan Hospital, Ilsan, Korea
Myonggeun Yoon?
Department of Bio-convergence Engineering, Korea University, Seoul 136-703, Korea

 

Journal of the Korean Physical Society, Vol. 66, No. 4, February 2015, pp. 694∼699

 

This study describes the development and evaluation of a new dosimetric system for proton therapy
using an array of fiber-optic Cerenkov radiation sensors (AFCRS). The AFCRS was superior to a conventional,
multi-layer ion chamber (MLIC) system in real-time data acquisition and cost effectiveness.

 

 

 

 

Jaeman Son a,b, Meyoung Kim c, Dongho Shin a,?, Uijung Hwang d, Sebyeong Lee a, Youngkyung Lim a,
Jeonghoon Park a, Sung yong Park e, Kwanho Cho a, Daeyong Kim a, Kyoung Won Jang f,
Myonggeun Yoon b,?
a Proton Therapy Center, National Cancer Center, Goyang; b Department of Bio-Convergence Engineering, Korea University, Seoul, Republic of Korea; c Research Center,
Dongnam Institute of Radiological & Medical Sciences, Busan, Republic of Korea; d Radiation Oncology, National Medical Center, Seoul; e Great Lakes Cancer Institute, McLaren
Regional Medical Center, Flint, USA; and f Department of Medical Engineering, Konkuk University, Chungju, Republic of Korea

 

Son J et al. Development of a novel proton dosimetry system using an array of fiber-optic Cerenkov radiation sensors.
Radiother Oncol (2015)

Background: We measured and assessed ways to reduce the secondary neutron dose from a system for proton
eye treatment.
Methods: Proton beams of 60.30 MeV were delivered through an eye-treatment snout in passive scattering mode.
Allyl diglycol carbonate (CR-39) etch detectors were used to measure the neutron dose in the external field at 0.00,
1.64, and 6.00 cm depths in a water phantom. Secondary neutron doses were measured and compared between
those with and without a high-hydrogen?boron-containing block. In addition, the neutron energy and vertices
distribution were obtained by using a Geant4 Monte Carlo simulation.
Results: The ratio of the maximum neutron dose equivalent to the proton absorbed dose (H(10)/D) at 2.00 cm
from the beam field edge was 8.79 ± 1.28 mSv/Gy. The ratio of the neutron dose equivalent to the proton
absorbed dose with and without a high hydrogen-boron containing block was 0.63 ± 0.06 to 1.15 ± 0.13 mSv/Gy at
2.00 cm from the edge of the field at depths of 0.00, 1.64, and 6.00 cm.
Conclusions: We found that the out-of-field secondary neutron dose in proton eye treatment with an eye snout is
relatively small, and it can be further reduced by installing a borated neutron absorbing material.

 

 

 

Dong Wook Kim1, Weon Kuu Chung1, Jungwook Shin2, Young Kyung Lim3, Dongho Shin3*, Se Byeong Lee3,
Myongguen Yoon4, Sung-Yong Park5, Dong Oh Shin6 and Jung Keun Cho7

1Department of Radiation Oncology, Kyung Hee University Hospital at
Gandong, Seoul, Korea. 2Radiation Oncology, University of California, San
Francisco, USA. 3Proton Therapy Center, National Cancer Center, Ilsan, Korea.
4Department of Radiological Science, Korea University, Seoul, Korea. 5Proton
Therapy Center, McLaren Cancer Institute, Flint, MI, USA. 6Department of
Radiation Oncology, Kyung Hee University Medical Center, Seoul, Korea.
7Department of Radiological Science, Jeonju University, Jeonju, Korea.

 

Kim et al. Radiation Oncology 2013, 8:182