• Radiation Oncology Journal
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• v.36 no.1
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• pp.1-10
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• 2018

Intensity-modulated radiation therapy (IMRT) has been considered the most successful development in radiation oncology since the introduction of computed tomography into treatment planning that enabled three-dimensional conformal radiotherapy in 1980s. More than three decades have passed since the concept of inverse planning was first introduced in 1982, and IMRT has become the most important and common modality in radiation therapy. This review will present developments in inverse IMRT treatment planning and IMRT delivery using multileaf collimators, along with the associated key concepts. Other relevant issues and future perspectives are also presented.

• Journal of the Korean Society of Radiology
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• v.9 no.6
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• pp.343-348
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• 2015

The purpose of this study is a comparison of forward planning(FP) and inverse planning(IP) of a radiosurgery procedure. 10 patients of acoustic schwannoma MR image were used for treatment plan. FP-1,2 and IP were established under the same condition. FP and IP were compared by number of shot, conformity index(CI), paddic conformity index(PCI), gradiant index(GI) and treatment time. On average the treatment plan produced by IP tool provided an improved or similar CI, PCI, GI and reduced treatment time as compared to the FP (CI;FP-1:0.85, FP-2:0.86, IP:0.94, PCI;FP-1:0.79, FP-2:0.81, IP:0.78, GI;FP-1:2.94, FP-2:2.94, IP:3.01). The inverse planning system provides a clinically useful plan while reducing the planning time and treatment time.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2448-2450
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• 2005

A robotic external fixation system for the surgery of bone deformity correction was developed to simulate the execution process of mal-unioned femur by the adjustment of the joints of the fixation system. An inverse kinematics analysis algorithm was developed to calculate the necessary rotations and translations at each joint of the robotic system. The computer graphic model was developed for validation of the analysis result and visualization of the surgical process. For given rotational and angular deformity case, the surgical execution process using the robotic system was well matched with the pre-operative planning. The final residual rotational deformities were within $1.0^{\circ}{\sim}1.6^{\circ}$ after surgical correction process. The presented robotic system with computer-aided planning can be useful for knowledge-based fracture treatment and bone deformity correction under external fixation.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.633-640
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• 2023

With the recent development of static and dynamic modulated brachytherapy methods in brachytherapy, which use radiation shielding to modulate the dose distribution to deliver the dose, the amount of parameters and data required for dose calculation in inverse treatment planning and treatment plan optimization algorithms suitable for new directional beam intensity modulated brachytherapy is increasing. Although intensity-modulated brachytherapy enables accurate dose delivery of radiation, the increased amount of parameters and data increases the elapsed time required for dose calculation. In this study, a GPU-based CUDA-accelerated dose calculation algorithm was constructed to reduce the increase in dose calculation elapsed time. The acceleration of the calculation process was achieved by parallelizing the calculation of the system matrix of the volume of interest and the dose calculation. The developed algorithms were all performed in the same computing environment with an Intel (3.7 GHz, 6-core) CPU and a single NVIDIA GTX 1080ti graphics card, and the dose calculation time was evaluated by measuring only the dose calculation time, excluding the additional time required for loading data from disk and preprocessing operations. The results showed that the accelerated algorithm reduced the dose calculation time by about 30 times compared to the CPU-only calculation. The accelerated dose calculation algorithm can be expected to speed up treatment planning when new treatment plans need to be created to account for daily variations in applicator movement, such as in adaptive radiotherapy, or when dose calculation needs to account for changing parameters, such as in dynamically modulated brachytherapy.

• The Journal of Korean Society for Radiation Therapy
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• v.15 no.1
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• pp.41-52
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• 2003

I. Purpose The dose distribution in normal tissues and target lesions is very important in the treatment planning. To make the uniform dose distribution in target lesions, many methods has been used. Especially in the head and neck, the dose inhomogeneity at the skin surface should be corrected. Conventional methods have a limitation in delivering the enough doses to the planning target volume (PTV) with minimized dose to the parotid gland and spinal cord. In this study, we investigated the feasibility and the practical QA methods of the forward IMRT. II. Material and Methods The treatment plan of the forward IMRT with the partial block technique using the dynamic multi-leaf collimator (dMLC) for the patients with the nasopharyngeal cancer was verified using the dose volume histogram (DVH). The films and pinpoint chamber were used for the accurate dose verification. III. Results As a result of verifying the DVH for the 2-D treatment plan with the forward IMRT, the dose to the both parotid gland and spinal cord were reduced. So the forward IMRT could save the normal tissues and optimize the treatment. Forward IMRT can use the 3-D treatment planning system and easily assure the quality, so it is easily accessible comparing with inverse IMRT IV. Conclusion The forward IMRT could make the uniform dose in the PTV while maintaining under the tolerance dose in the normal tissues comparing with the 2-D treatment.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.183-185
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• 2002

Heavy ion and proton therapy necessitate range weeks, which are time consuming. Three types of variable compensator, membrane type liquid variable compensator, are proposed by some of the authors to overcome the difficulties, by those arbitrarily thickness distribution of compensator obtained from treatment planning is created at the site of treatment. None of the ideas, however, is yet realized. In this research, we are trying to construct prototype membrane-type liquid variable compensator. This variable compensator partitions air and liquid with elasticity membrane and changes the surface of the elasticity membrane with the thread. The air and oil move through holes to and from the out of beam side of two boxes in which they are contained. The boxes are made of Plexiglas(PMMA), the thread which is made of nylon, the elasticity film which is made from latex for the moment.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.83-85
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• 2002

Yonsei Cancer Center introduced an IMRT System at the beginning of February, 2002. The system consists of CORVUS(NOMOS) inverse planning machine, LANTIS(SIEMENS), PRIMEVIEW and PRIMART Linac(SIEMENS). The optimization of CORVUS planning system with PRIMART is an important work to get an efficient treatment plan. So, we studied two Finite Size Pencil Beams, 1.0 x 1.0 cm$^2$ and 0.5 x 1.0 cm$^2$, and four leaf transmission sets, 5%, 10%, 20%, 33%. We compared the dose distribution of target volume and delivery efficiency of the plan results.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.207-216
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• 2014

Purpose : We present a method to reduce this gap and complete the treatment plan, to be made by the re-optimization is performed in the same conditions as the initial treatment plan different from Monaco treatment planning system. Materials and Methods : The optimization is carried in two steps when performing the inverse calculation for volumetric modulated radiation therapy or intensity modulated radiation therapy in Monaco treatment planning system. This study was the first plan with a complete optimization in two steps by performing all of the treatment plan, without changing the optimized condition from Step 1 to Step 2, a typical sequential optimization performed. At this time, the experiment was carried out with a pencil beam and Monte Carlo algorithm is applied In step 2. We compared initial plan and re-optimized plan with the same optimized conditions. And then evaluated the planning dose by measurement. When performing a re-optimization for the initial treatment plan, the second plan applied the step optimization. Results : When the common optimization again carried out in the same conditions in the initial treatment plan was completed, the result is not the same. From a comparison of the treatment planning system, similar to the dose-volume the histogram showed a similar trend, but exhibit different values that do not satisfy the conditions best optimized dose, dose homogeneity and dose limits. Also showed more than 20% different in comparison dosimetry. If different dose algorithms, this measure is not the same out. Conclusion : The process of performing a number of trial and error, and you get to the ultimate goal of treatment planning optimization process. If carried out to optimize the completion of the initial trust only the treatment plan, we could be made of another treatment plan. The similar treatment plan could not satisfy to optimization results. When you perform re-optimization process, you will need to apply the step optimized conditions, making sure the dose distribution through the optimization process.

• Progress in Medical Physics
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• v.24 no.3
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• pp.154-161
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• 2013

This study assessed compared photon and proton treatment techniques, such as intensity modulated radiation therapy (IMRT), uniform scanning proton therapy (USPT), and intensity modulated proton therapy (IMPT), for a total of 10 prostate cancers. All treatment plans delivered 70 Gy to 95% of the planned target volume in 28 fractions. IMRT plans had 7 fields for the step and shoot technique, while USPT and IMPT plans employed two equally weighted, parallel-opposed lateral fields to deliver the prescribed dose to the planned target. Inverse planning was then incorporated to optimize IMPT. The homogeneity index (HI) and conformity index (CI) for the target and the normal tissue complication probability (NTCP) for organ at risk (OAR) were calculated. Although the mean HI and CI for target were not significantly different for each treatment techniques, the NTCP of the rectum was 2.233, 3.326, and 1.707 for IMRT, USPT, and IMPT, respectively. The NTCP of the bladder was 0.008, 0.003, and 0.002 respectively. The NTCP values at the rectum and bladder were significantly lower using IMPT. Our study shows that using proton therapy, particularly IMPT, to treat prostate cancer could be beneficial compared to 7-field IMRT with similar target coverage. Given these results, radiotherapy using protons, particularly optimized IMPT, is a worthwhile treatment option for prostate cancer.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1552-1562
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• 2023

Soybean (Glycine max) is an important ingredient of cuisines worldwide. While there is a wealth of evidence that soybean could be a good source of macronutrients and phytochemicals with healthpromoting effects, concerns regarding adverse effects have been raised. In this work, we reviewed the current clinical evidence focusing on the benefits and risks of soybean ingredients. In breast, prostate, colorectal, ovarian, and lung cancer, epidemiological studies showed an inverse association between soybean food intake and cancer risks. Soybean intake was inversely correlated with risks of type 2 diabetes mellitus (T2DM), and soy isoflavones ameliorated osteoporosis and hot flashes. Notably, soybean was one of the dietary protein sources that may reduce the risk of breast cancer and T2DM. However, soybean had adverse effects on certain types of drug treatment and caused allergies. In sum, this work provides useful considerations for planning clinical soybean research and selecting dietary protein sources for human health.