| Effect of topogram-tube angle combination on CT radiation do… This study assessed the ability of various
types of topograms, when used with an automatic tube current modulation (ATCM) technique,
to reduce radiation dose from computed tomography (CT) scans. Three types of
topograms were used with the ATCM technique: (i) anteroposterior (AP) topograms alone, (ii)
AP topograms followed by lateral topograms, and (iii) lateral topograms followed by AP topograms.
Various regions (chest, abdomen and whole-body) of a humanoid phantom were scanned at several
tube voltages (80, 100 and 120 kVp) with the selected topograms. Although the CT dose depended on
the order of topograms, the CT dose with respect to patient positioning depended on the
number of topograms performed. The magnitude of the difference in CT dose between number and
order of topograms was greater for the scans of the abdomen than the chest. These results
suggest that, for the Siemens SOMATOM Definition AS CT scanner, choosing the right combination
of CT scan conditions with the ATCM technique can minimize radiation dose to a patient.
J. Shim and M. Yoon
Department of Bio-Convergence Engineering, Korea University,
145, Anam-ro, Seongbuk-gu, Seoul, Republic of Korea
Department of Diagnostic Radiology, Severance Hospital,
50-1, Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea
Journal of Instrumentation |
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| Development of Beam Monitoring System for Proton Pencil Beam… We aimed to develop a beam monitoring system based on a fiber-optic radiation sensor (FORS),
which can be used in real time in a beam control room, to monitor a beam in proton therapy, where
patients are treated using a pencil beam scanning (PBS) mode, by measuring the beam spot width
(BSW) and beam spot position (BSP) of the PBS. We developed two-dimensional detector arrays to
monitor the PBS beam in the beam control room. We measured the BSW for five energies of the PBS
beam and compared the measurements with those of Lynx and EBT3 film. In order to confirm the
BSP, we compared the BSP values of the PBS calculated from radiation treatment planning (RTP),
to five BSP values measured using FORS at 224.2 MeV. When comparing BSW values obtained
using developed monitoring system to the measurements obtained using commercial EBT3 film, the
average difference in BSW value of the PBS beam was 0.1 ± 0.1 mm. In the comparison of BSW
values with the measurements obtained using Lynx, the average difference was 0.2 ± 0.1 mm. When
comparing BSP measurements to the values calculated from RTP, the average difference was 0.4 ±
0.2 mm. The study results confirmed that the developed FORS-based beam monitoring system can
monitor a PBS beam in real time in a beam control room, where proton beam is controlled for the
patient.
Jaeman Son,∗ Jihye Koo, Sunyoung Moon and Myonggeun Yoon
Department of Bio-convergence Engineering, Korea University, Seoul 10408, Korea
Jonghwi Jeong,∗ Sun-Young Kim, Youngkyung Lim, Se Byeong Lee and Dongho Shin
Proton Therapy Center, National Cancer Center, Goyang 02841, Korea
Meyoung Kim
Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, Korea
Dongwook Kim
Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Seoul 05278, Korea
Journal of the Korean Physical Society, Vol. 71, No. 7, October 2017, pp. 438∼443 |
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| Development of Optical Fiber Based Measurement System for th… This study describes the development of a beam monitoring system for the verification of entrance dose map in pencil beam scanning (PBS) proton therapy based on fiber optic radiation sensors (FORS) and the validation of this system through a feasibility study. The beam monitoring system consisted of 128 optical fibers optically coupled to photo-multiplier tubes. The performance of the beam monitoring system based on FORS was verified by comparing 2D dose maps of square-shaped fields of various sizes, which were obtained using conventional dosimeters such as MatriXX and EBT3 film, with those measured using FORS. The resulting full-width at half maximum and penumbra were compared for PBS proton beams, with a 2% difference between each value, indicating that measurements using the conventional dosimetric tool corresponded to measurements based on FORS. For irregularly-shaped fields, a comparison based on the gamma index between 2D dose maps obtained using MatriXX and EBT3 film and the 2D dose map measured by the FORS showed passing rates of 96.9 1.3% and 96.2 1.9%, respectively, confirming that FORS-based measurements for PBS proton therapy agreed well with those measured using the conventional dosimetric tools. These results demonstrate that the developed beam monitoring system based on FORS is good candidate for monitoring the entrance dose map in PBS proton therapy.
Jaeman Son 1, Se Byeong Lee 2, Youngkyung Lim 2, Sung Yong Park 3, Kwanho Cho 2, Myonggeun Yoon 1,* and Dongho Shin 2,*
1 Department of Bio-convergence Engineering, Korea University, Seoul 02841, Korea; jaeman0410@naver.com
2 Proton Therapy Center, National Cancer Center, Goyang 10408, Korea; sblee@ncc.re.kr (S.B.L.);
yklim@ncc.re.kr (Y.L.); kwancho@ncc.re.kr (K.C.)
3 Department of Medical Physics, Chinan Biomedical Technology Inc., Zhubei 30268, Taiwan;
sungyong.park63@gmail.com
Sensors 2018, 18, 227. |
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| Study on the Dose Uncertainties in the Lung during Passive P…A moving phantom is manufactured for mimicking lung model to study the dose uncertainty from CT number-stopping power conversion and dose calculation in the soft tissue, light lung tissue and bone regions during passive proton irradiation with compensator smearing value. The phantom is scanned with a CT system, and a proton beam irradiation plan is carried out with the use of a treatment planning system (Eclipse). In the case of the moving phantom, a RPM system is used for respiratory gating. The uncertainties in the dose distribution between the measured data and the planned data are investigated by a gamma analysis with 3%-3 mm acceptance criteria. To investigate smearing effect, three smearing values (0.3 cm, 0.7 cm, 1.2 cm) are used to for fixed and moving phantom system. For both fixed and moving phantom, uncertainties in the light lung tissue are severe than those in soft tissue region in which the dose uncertainties are within clinically tolerable ranges. As the smearing value increases, the uncertainty in the proton dose distribution decreases.
Seung Hoon Yoo
Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Science, Seoul 01812, Korea
Jae Man Son and Myonggeun Yoon
Department of Department of Bio-Convergence Engineering, Korea University, Seoul 02841, Korea
Sung Yong Park
McLaren Proton Therapy Center, McLaren Cancer Institute, Flint, Michigan 48532, USA
Dongho Shin
Proton Therapy Center, National Cancer Center, Goyang 10408, Korea
Byung Jun Min
Department of Radiation Oncology, Kangbuk Samsung Hospital,
Sungkyunkwan University School of Medicine, Seoul 03181, Korea
Journal of the Korean Physical Society, Vol. 72, No. 11, June 2018, pp. 1369∼1378 |
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| Toward a novel dosimetry system using acrylic disk radiation…Purpose: Fabricate an acrylic disk radiation sensor (ADRS) and characterize the photoluminescence
signal generated from the optical device as basis for the development and evaluation of a new
dosimetry system for pencil beam proton therapy.
Methods: Based on the characteristics of the proposed optical dosimetry sensor, we established the
relation between the photoluminescence output and the applied dose using an ionization chamber.
Then, we obtained the relative integral depth dose profiles using the photoluminescence signal generated
by pencil beam irradiation at energies of 99.9 and 162.1 MeV, and compared the results with the
curve measured using a Bragg peak ionization chamber.
Results: The relation between the photoluminescence output and applied dose was linear. In addition,
the ADRS was dose independent for beam currents up to 6 Gy/min, and the calibration factor
for energy was close to 1. Hence, the energy dependence on the optical device can be disregarded.
The integral depth dose profiles obtained for the ADRS suitable agreed with the curve measured in
the Bragg peak ionization chamber without requiring correction.
Conclusions: These results suggest that the ADRS is suitable for dosimetry measurements in pencil
beam scanning, and it will be employed as a low-cost and versatile dosimetry sensor in upcoming
developments.
Shinhaeng Cho
Proton Therapy Center, National Cancer Center, Goyang, Korea
Nuri Lee
Department of Radiation and Oncology, National Medical Center, Seoul, South Korea
Sanghyeon Song
Department of Radiation and Oncology, Soon Chun Hyang University Hospital, Seoul, South Korea
Jaeman Son
Department of Radiation and Oncology, Seoul National University Hospital, Seoul, South Korea
Haksoo Kim, Jong Hwi Jeong, Se Byeong Lee, and Youngkyung Lim
Proton Therapy Center, National Cancer Center, Goyang, Korea
Sunyoung Moon and Myonggeun Yoon
Department of Bio-Convergence Engineering, Korea University, Seoul, Korea
Dongho Shina)
Proton Therapy Center, National Cancer Center, Goyang, Korea
Med. Phys. 45(11), November 2018
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| Quantitative study of fast non-local means-based denoising f…In chest radiography, a solitary pulmonary nodule, which may be a precursor of lung cancer, is a frequently detected finding. However, as the image quality is deteriorated owing to the increase in the noise, lung cancer screening studies revealed that the likelihood of finding a nodule is lower than those of other modalities. This study quantitatively evaluates three widely used filters (median, Wiener, and total variation) and a newly proposed filter (fast non-local means (FNLM)), which reduce image noise. Images of a phantom with lung nodules, obtained from a patient using the 3D printing technology, were acquired at the chest anterior–posterior, lateral, and posterior– anterior positions. To evaluate their denoising performance, normalized noise power spectrum, contrast to noise ratio and coefficient of variation were used. In the quantitative evaluation
of the overall image, the proposed FNLM filter exhibited the best image performance. In the quantitative evaluation of the nodule image, the FNLM filter, which exhibits outstanding denoising performance and time efficiency, can be employed. Therefore, with the use of the FNLM filter in chest radiography, the detection probability of a nodule, which can be a precursor of lung
cancer, is increased, and the cancer can be prevented even with a lower dose.
Jina Shim, Myonggeun Yoon, Youngjin Lee
a Department of Bio-Convergence Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, Republic of Korea
b Department of Diagnostic Radiology, Severance Hospital, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea
c Department of Radiological Science, Gachon University, 191, Hambakmoero, Yeonsu-gu, Incheon, Republic of Korea
Optik - International Journal for Light and Electron Optics 179(2019) |
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| Effectiveness of a Fractionated Therapy Scheme in Tumor Trea… This study aimed to evaluate the biological effectiveness of cancer therapy with tumor treating fields using a fractionated
treatment scheme that was originally designed for radiotherapy. Discontinuous fractional tumor treating fields of an intensity of
0.9 to 1.2 V/cm and a frequency of 150 KHz were applied to U373 cancer cells and IEC6 normal cells for 3 days, with durations of 3, 6, 12, or 24 h/d. As the treatment duration of the tumor treating fields increased from 3 to 24 h/d, the relative tumor cell (U373) number (% of control) reduced in proportion to the treatment duration. Compared to a 25% cell number reduction (75% of
control) for the group of 6 h/d treatment at 1.2 V/cm, only 5% (70% of control) and 8% (67% of control) of additional reductions
were observed for the group of 12 and 24 h/d treatment, respectively. This experimental result indicates that the dependence on
treatment duration in tumor cell inhibition was weakened distinctly at treatment duration over 6 h/d. For normal cells (IEC6), the
relative cell number corresponding to the treatment time of the tumor treating fields at 1.2 V/cm of electric field strength was not
decreased much for the treatment times of 3, 6, and 12 h/d, revealing 93.3%, 90.0%, and 89.3% relative cell numbers, respectively, but it suddenly decreased to *73% for the 24 h/d treatment. Our results showed that the effects of tumor treating fields on tumor cells were higher than on normal cells for treatment duration of 3 to 12 h/d, but the difference became minimal for treatment duration of 24 h/d. The fractionated scheme, using tumor treating fields, reduced the treatment time while maintaining efficacy, suggesting that this method may be clinically applicable for cancer treatment.
Yunhui Jo, BS1,2, Jiwon Sung, PhD1, Hyesun Jeong, MS3,
Sunghoi Hong, PhD3, Youn Kyoung Jeong, PhD4, Eun Ho Kim, PhD2, and
Myonggeun Yoon, PhD1
Technology in Cancer Research & Treatment
Volume 18: 1-10 The Author(s) 2019
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| Tumor-treating fields induce autophagy by blocking the Akt2/… Tumor-treating fields (TTFs) — a type of electromagnetic field-based therapy using low-intensity electrical fields — has
recently been characterized as a potential anticancer therapy for glioblastoma multiforme (GBM). However, the molecular
mechanisms involved remain poorly understood. Our results show that the activation of autophagy contributes to the TTFinduced anti-GBM activity in vitro or in vivo and GBM patient stem cells or primary in vivo culture systems. TTF-treatment
upregulated several autophagy-related genes (~2-fold) and induced cytomorphological changes. TTF-induced autophagy in
GBM was associated with decreased Akt2 expression, not Akt1 or Akt3, via the mTOR/p70S6K pathway. An Affymetrix
GeneChip miRNA 4.0 Array analysis revealed that TTFs altered the expression of many microRNAs (miRNAs). TTFinduced
autophagy upregulated miR-29b, which subsequently suppressed the Akt signaling pathway. A luciferase reporter assay confirmed that TTFs induced miR-29b to target Akt2, negatively affecting Akt2 expression thereby triggering autophagy. TTF-induced autophagy suppressed tumor growth in GBM mouse models subjected to TTFs as determined by positron emission tomography and computed tomography (PET-CT). GBM patient stem cells and a primary in vivo culture system with high Akt2 levels also showed TTF-induced inhibition. Taken together, our results identified autophagy as a critical cell death pathway triggered by TTFs in GBM and indicate that TTF is a potential treatment option for GBM.
Eun Ho Kim, Yunhui Jo1,2 , Sei Sai3 , Mung-Jin Park1 , Jeong-Yub Kim1, Jin Su Kim4, Yeon-Joo Lee 1,
Jae-Min Cho1, Seo-Young Kwak5, Jeong-Hwa Baek1, Youn Kyoung Jeong6, Jie-Young Song 1,
Myonggeun Yoon2, Sang-Gu Hwang1
Oncogene (2019) 38:6630–6646
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| Feasibility study of a plastic scintillating plate-based tre…Purpose: The purpose of this study was to describe a plastic scintillating plate-based gantryattachable
dosimetry system for pencil beam scanning proton therapy to monitor entrance proton beam
fluence, and to evaluate the dosimetric characteristics of this system and its feasibility for clinical use.
Methods: The dosimetry system, consisting of a plastic scintillating plate and a CMOS camera, was
attached to a dedicated scanning nozzle and scintillation during proton beam irradiation was
recorded. Dose distribution was calculated from the accumulated recorded frames. The dosimetric
characteristics (energy dependency, dose linearity, dose rate dependency, and reproducibility) of the
gantry-attachable dosimetry system for use with therapeutic proton beams were measured, and the
feasibility of this system during clinical use was evaluated by determining selected quality assurance
items at our institution.
Results: The scintillating plate shortened the range of the proton beam by the water-equivalent thickness
of the plate and broadened the spatial profile of the single proton spot by 11% at 70 MeV. The
developed system functioned independently of the beam energy (<1.3%) and showed dose linearity,
and also functioned independently of the dose rate. The feasibility of the system for clinical use was
evaluated by comparing the measured quality assurance dose distribution to that of the treatment
planning system. The gamma passing rate with a criterion of 3%/3 mm was 97.58%.
Conclusions: This study evaluated the dosimetric characteristics of a plastic scintillating plate-based
dosimetry system for use with scanning proton beams. The ability to account for the interference of
the dosimetry system on the therapeutic beam enabled offline monitoring of the entrance beam fluence
of the pencil beam scanning proton therapy independent of the treatment system with high resolution
and in a cost-effective manner.
Seonghoon Jeong
Department of Bio-Convergence Engineering, Korea University, Seoul, Republic of Korea
Kwangzoo Chung, Sung Hwan Ahn, and Boram Lee
Department of Radiation Oncology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of
Korea
Jaehyeon Seo and Myonggeun Yoon
Department of Bio-Convergence Engineering, Korea University, Seoul, Republic of Korea
Med. Phys. 47 (2), February 2020.
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| Development of a Daily-Treatment Beam-Monitoring System Base…
This
study describes the development of a simple method to assess inter-fractional
deviations of delivered proton beams in treatment rooms. To monitor the
treatment beam, we measured the field-by-field beam fluences by attaching the
EBT3 film to the snout, followed by a simple constancy check based on
comparisons between the reference beam fluences (acquired during the
pre-treatment quality assurance process) and the test beam fluences (acquired
during treatment). The feasibility of the proposed treatment beam-monitoring
system was confirmed by evaluating 12 treatment fields for each of six patients
(brain, liver, prostate, lung, cranial and spinal area, and head and neck). The
constancy of the treatment beams was verified by using a gamma index analysis to
compare three measurements per field with the reference beam fluence. On the
basis of the 3%/3 mm criterion, the average gamma-index passing rates for all
measurements were over 99.6%. These results suggest that the constancy of
fractional proton beams delivered to patients in treatment rooms can be
verified with EBT3 film-based proton-beam monitoring system that can be easily
attached to the treatment nozzle and is cost effective.
Seonghoon Jeong
Proton Therapy Center, National Cancer
Center, Goyang Korea
Myonggeun Yoon∗
Department of Bio-convergence Engineering,
Korea University, Seoul, Korea
Kwangzoo Chung† Department of Radiation Oncology, Samsung Medical
Center, School of Medicine, Sungkyunkwan University, Seoul, Korea
Journal of the Korean Physical
Society, Vol. 76, No. 8, April 2020, pp. 769∼773 |
| |
| Tumor treating fields (TTF) treatment enhances radiation-ind…Purpose:Tumor
treating fields (TTF) therapy is a noninvasive method that uses alternating
electric fields to treat various types of cancer. This study demonstrates the
combined effect of TTF and radiotherapy (RT) in vitro on pancreatic cancer,
which is known to be difficult to treat.
Materials and methods: In CFPAC-I and HPAF-II pancreatic cancer cell lines, the
combined in vitro effect of TTF and RT was evaluated by measuring cell counts,
markers of apoptosis, and clonogenic
cell survival. The
synergy effects were verified using
the Valeriote and Carpentier equations.
Results: TTF and RT
inhibited cancer cell growth more effectively than did mono therapy with TTF or
RT. The combined treatment also enhanced apoptosis more than mono therapy, as
shown by as says for cleaved poly (ADP-ribose) polymerase (PARP) and annexin V.
In addition, on the survival curve, this treatment method has been shown to work
synergistically.
Conclusion:These results suggest that combined treatment with
TTF and RT may be a good alter-native treatment for patients with pancreatic
cancer
Yunhui Jo
Department of Bio-convergence
Engineering, Korea University, Seoul, Korea
Geon Oh, Yongha Gi, Heehun Sung, Myonggeun
Yoon
Department of Bio-medical Engineering,
Korea University,Seoul, Korea
Eun Bin Joo, Suk Lee
Department of Radiation Oncology,
College of Medicine, Korea University, Seoul, Korea
INTERNATIONAL
JOURNAL OF RADIATION BIOLOGY2020, VOL. 96, NO. 12, 1528–1533 |
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| Biophysical Model Including a Potentially Lethal Damage Repa…The
amount of potentially lethal damage repair (PLDR) is a significant factor in
the process of modeling the survival curves of cells irradiated with
fractionated carbon beams. Because the amount of PLDR generally depends on the
features of the cells and the linear energy transfer (LET), the amount of PLDR
of cells irradiated with fractionated carbon beams shows distinct differences
from that of cells irradiated with X-rays. This study considered a new
parameter dependent on the correlation between the PLDR trait (T) of the cells
over a time interval (Δ) at the fractionated carbon beam irradiation. The survival
curves of the cells irradiated with fractionated carbon beams n times were
predicted using the ζ and the Ψ values from the delay assay. This study aims to
overcome the barriers of traditional methods by developing a new survival curve
model with new parameters based on an analysis of the PLDR traits of cells over
time interval in fractionated carbon beam irradiation and to suggest a model
that produces results significantly closer to the experimental data.
Eunae Choi and Myonggeun Yoon∗
Department of Bio-convergence Engineering,
Korea University, Seoul 02841, Korea
Masao Suzuki and Naruhiro Matsufuji
National Institutes for Quantum and
Radiological Science and Technology, Chiba 263-8555, Japan
Wonguyn Jung
Korea Institute of Radiological and Medical
Science, Seoul 01812, Korea
Journal
of the Korean Physical Society, Vol. 77, No. 2, July 2020, pp. 161∼167 |
| |
| Evaluating direct and indirect effects of low-energy electro…Monte
Carlo simulations can classify DNA damage into different types and predict the
amount of energy deposited. Geant4-DNA was used to predict simple and complex
DNA damage induced by irradiation of low-energy electrons at 0.1–50 keV. The
number of molecules generated at different energy levels of radiation was
analyzed after observing the gradual changes in the level of water radiolysis.
ADNA model was used to categorize direct damage according to the location of
strand breaks at the atomic level. The parameters of energy threshold (minimum
amount of energy needed to break DNA strands) and 10 base pairs (maximum
distance that separates two strand breaks) were set. All instances of water
radiolysis including the main OH radical occurred most frequently at 1 keV
followed by at 1.5 and 0.5 keV. Direct strand breaks most commonly occurred at
0.5 keV followed by at 0.3 keV. Finally, most of strand breaks occurred
more frequently at 0.5 keV than at 0.3 keV. The computational measure-ment
results for indirect and direct effects of irradiation depend on the type of
simulation code and the DNA model used. Values used in Geant4 (physics list,
chemical interaction time and energy threshold)may also influence the results.
Eunae Choi and Myong Geun Yoon
Department
of Bio Convergence Engineering, Korea University, Seongbuk-gu, Republic of
Korea
Kwon
Su Chon
Catholic University of Daegu, Gyeongsan, Republic
of Korea
RADIATION
EFFECTS & DEFECTS IN SOLIDS2020, VOL. 175, NOS. 11–12, 1042–1051 |
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| Feasibility Study of Beam Angle Optimization for Proton Trea…This
study describes a method that uses a genetic algorithm to select optimal beam
angles in proton therapy and evaluates the effectiveness of the proposed
algorithm in actual patients. In the use of the genetic algorithm to select the
optimal angle, a gene represents the angle of each field and a chromosome
represents the combination of beam angles. The fitness of the genetic
algorithm, which represents the suitability of the chromosome to the solution,
was quantified by using the dose distribution. The weighting factors of the
organs used for fitness were obtained from clinical data through logistic
regression, reflecting the dose characteristics of actual patients. Genetic
operations, such as selection, crossover, mutation, and replacement, were used
to modify the population and were repeated until an evaluation based on fitness
reached the termination criterion. The proposed genetic algorithm was tested by
assessing its ability to select optimal beam angles in three patients with
liver cancer. The optimal results for fitness, planning target volume (PTV),
normal liver, and skin in the population were compared with the clinical
treatment plans, a process that took an average of 36.8 minutes. The
dose-volume histograms (DVHs) and the fitness of the genetic algorithm plans
did not differ significantly from the actual treatment plans. These findings
indicate that the proposed genetic algorithm can automatically generate proton
treatment plans with the same quality as actual clinical treatment plans.
Jaehyeon Seo, Yunhui Jo, Sunyoung Moon and
Myonggeun Yoon∗
Department of Bio-convergence Engineering,
Korea University, Seoul 02841, Korea
Sung Hwan Ahn, Boram Lee and Kwangzoo
Chung†
Department of Radiation Oncology, Samsung
Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
Seonghoon Jeong Department of Proton Therapy Center, National
Cancer Center, Goyang 10408, Korea
Journal
of the Korean Physical Society, Vol. 77, No. 4, August 2020, pp. 312∼316 |
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| Clinical application of a gantry-attachable plastic scintill…Purpose: The entrance beam fluence of therapeutic proton scanning
beams can be monitored using a gantry-attachable plastic scintillating plate
(GAPSP). This study evaluated the clinical application of the GAPSP using
amethod that measures intensity modulated proton therapy (IMPT) beams for
patient treatment.
Methods: IMPT beams for the treatment of nine patients, at sites
that included the spine, head and neck, pelvis, and lung, were measured using
the GAPSP, composed of an EJ-212 plastic scintillator and a CMOS camera. All energy
layers distinguished by the GAPSP were accumulated to determine the dose
distribution of the treatment field. The evaluated fields were compared with
reference dose maps verified by quality assurance.
Results: Comparison of dose distributions of evaluation treatment
fields with reference dose distributions showed that the 3%/1 mm average gamma
passing rate was 96.4%, independent of the treatment site, energy range and
field size. When dose distributions were evaluated using the same criteria for
each energy layer, the average gamma passing rate was 91.7%.
Conclusions: The GAPSP is a suitable, low-cost
method for monitoring pencil beam scanning proton therapy, especially for
non-spot scanning or additional collimation. The GAPSP can also estimate the
treatment beam by the energy layer, a feature not common to other proton
dosimetry tool.
Seonghoon Jeong
Proton Therapy
Center, National Cancer Center, Goyang, Republic of Korea
Myonggeun Yoon⁎ , Jaehyeon Seo
Department of
Bio-Convergence Engineering, Korea University, Seoul, Republic of Korea
Kwangzoo Chung,⁎ , Sung Hwan Ahn , Boram Lee, Department of Radiation
Oncology, Samsung Medical Center, Seoul, Republic of Korea
Physica
Medica 77(2020)181-186 |
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