• Progress in Medical Physics
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• v.21 no.3
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• pp.291-297
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• 2010

This study examined the dosimetric influence of implanted gold markers in proton therapy and the effects of their positions in the spread-out Bragg peak (SOBP) proton beam. The implanted cylindrical gold markers were 3 mm long and 1.2 mm in diameter. The dosimetric influence of the gold markers was determined with markers at various locations in a proton-beam field. Spatial dose distributions were measured using a three-dimensional moving water phantom and a stereotactic diode detector with an effective diameter of 0.5 mm. Also, a film dosimetry was performed using Gafchromic External Beam Treatment (EBT) film. The GEANT4 simulation toolkit was used for Monte-Carlo simulations to confirm the measurements and to construct the dose-volume histogram with implanting markers. Motion data were obtained from the portal images of 10 patients to investigate the effect of organ motions on the dosimetric influence of markers in the presence of a rectal balloon. The underdosed volume due to a single gold marker, in which the dose was less than 95% of a prescribed amount, was 0.15 cc. The underdosed volume due to the presence of a gold marker is much smaller than the target volume. However, the underdosed volume is inside the gross tumor volume and is not smeared out due to translational prostate motions. The positions of gold markers and the conditions of the proton-beam field give different impacts on the dose distribution of a target with implanted gold markers, and should be considered in all clinical proton-based therapies.

• Radiation Oncology Journal
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• v.26 no.2
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• pp.113-117
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• 2008

Purpose: To evaluate the long term results(local control, survival, failure, and complications) after radiation therapy for skin cancer in elderly patients. Material and Methods: The study spanned from January 1990 to October 2002. Fifteen elderly patients with skin cancer were treated by radiotherapy at the Keimyung University Dongsan Medical Center. The age distribution of the patients surveyed was 72 to 95 years, with a median age of 78.8 years. The pathologic classification of the 15 patients included squamous cell carcinoma(10 patients), basal cell carcinoma(3 patients), verrucous carcinoma(1 patient) and skin adnexal origin carcinoma(1 patient). The most common tumor location was the head(13 patients). The mean tumor diameter was 4.9 cm(range 2 to 9 cm). The radiation dose was delivered via an electron beam of 6 to 15 MeV. The dose range was adjusted to the tumor diameter and depth of tumor invasion. The total radiation dose ranged from $50{\sim}80$ Gy(mean: 66 Gy) with a 2 Gy fractional dose prescribed to the 80% isodose line once a day and 5 times a week. One patient with lymph node metastasis was treated with six MV photon beams boosted with electron beams. The length of the follow-up periods ranged from 10 to 120 months with a median follow-up period of 48 months. Results: The local control rates were 100%(15/15). In addition, the five year disease free survival rate(5YDFS) was 80% and twelve patients(80%) had no recurrence and skin cancer recurrence occurred in 3 patients(20%). Three patients have lived an average of 90 months($68{\sim}120$ months) without recurrence or metastasis. A total of 9 patients who died as a result of other causes had a mean survival time of 55.8 months after radiation therapy. No severe acute or chronic complications were observed after radiation therapy. Only minor complications including radiation dermatitis was treated with supportive care. Conclusion: The results suggest that radiation therapy is an effective and safe treatment method for the treatment of skin cancer in elderly patients who achieved a good survival rate and few minor complications.

• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.83-92
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• 2022

Purpose: To evaluate usefulness of Tomotherapy and Halcyon VMAT treatment in radiation therapy for bi-breast cancer Materials and Methods: For 10 patients with bi-breast cancer, volumetric modulated arc therapy(VMAT) treatment plan was established using helical Tomotherapy(Accuray. USA) with field width of 5.0-cm and pitch of 0.287, and Halcyon(Varian Medical System, Palo Alto, CA, Version 3.0 USA) of 6arc and 8arc. Prescribed dose was 42.4 Gy/16, and V _40.3Gy of Planning Target Volume(PTV) was 90%. The quality of plan was evaluated by comparing the dose to tumor and normal organs, and the efficiency was evaluated by comparing total MU and beam on time. Results: About three treatment plans(Tomotherapy, Halcyon 6Arc VMAT, Halcyon 8Arc VMAT) , the mean homogeneity index(H.I) of PTV were 1.07, 1.10, 1.11, and the mean conformity index(C.I) of PTV were 1.21, 1.16, 1.17, respectively. The average value of the dose assessment item for a normal organ is V _5Gy(%) of both lung was 36.3, 31.2, 29.7, and V _15Gy(%) were 18.6, 15.5, 14.6, respectively. The mean heart dose(Gy) were 4.17, 2.69, 2.51. Total MU were (7498.6, 2494.2, 2471.5), and beam on time(sec) were 462.5, 195.4, 198.0. Conclusion: Halcyon VMAT showed similar quality of treatment plan compared to helical Tomotherapy, while also protecting normal organs. In addition, the efficiency of radiotherapy increased due to a decrease in Beam On Time and MU.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.2
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• pp.43-49
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• 2019

Purpose: This study examined changes in the position of the heat and lungs depending on the patient's breathing method during left breast cancer radiotherapy and used treatment plans to compare the resulting radiation dose. Materials and methods: The participants consisted of 10 patients with left breast cancer. A CT simulator(SIMENS SOMATOM AS, Germany) was used to obtain images when using three different breathing methods: free breathing(FB), deep inspiration breath hold(DIBH with Abches, DIBH), inspiration breath hold(IBH with CPAP, CPAP). A Ray Station(5.0.2.35, Sweden) was used for treatment planning, the treatment method was volumetric modulated arc therapy (VMAT) with one partial arc of the same angle, and the prescribed dose to the planning target volume (PTV) was a total dose of 50Gy(2Gy/day). In treatment plan analysis, the 95% dose (D95) to the PTV, the conformity index(CI), and the homogeneity index (HI) were compared. The lungs, heart, and left anterior descending artery (LAD) were selected as the organs at risk(OARs). Results: The mean volume of the ipsilateral lung for FB, DIBH, and CPAP was 1245.58±301.31㎤, 1790.09±362.43 ㎤, 1775.44±476.71 ㎤. The mean D95 for the PTV was 46.67±1.89Gy, 46.85±1.72Gy, 46.97±23.4Gy, and the mean CI and HI were 0.95±0.02, 0.96±0.02, 0.95±0.02 and 0.91±0.01, 0.90±0.01, 0.92±0.02. The V20 of Whole Lung was 10.74±4.50%, 8.29±3.14%, 9.12±3.29% and The V20 of the ipsilateral lung was 20.45±8.65%, 17.18±7.04%, 18.85±7.85%, the Dmean of the heart was 7.82±1.27Gy, 6.10±1.27Gy, 5.67±1.56Gy, and the Dmax of the LAD was 20.41±7.56Gy, 14.88±3.57Gy, 14.96±2.81Gy. The distance from the thoracic wall to the LAD was measured to be 11.33±4.70mm, 22.40±6.01mm, 20.14±6.23mm. Conclusion: During left breast cancer radiotherapy, the lung volume was 46.24% larger for DIBH than for FB, and 43.11% larger for CPAP than FB. The larger lung volume increases the distance between the thoracic wall and the heart. In this way, the LAD, which is one of the nearby OARs, can be more effectively protected while still satisfying the treatment plan. The lung volume was largest for DIBH, and the distance between the LAD and thoracic wall was also the greatest. However, when performing treatment with DIBH, the intra-fraction error cannot be ignored. Moreover, communication between the patient and the radiotherapist is also an important factor in DIBH treatment. When communication is problematic, or if the patient has difficulty holding their breath, we believe that CPAP could be used as an alternative to DIBH. In order to verify the clinical efficacy of CPAP, it will be necessary to perform long-term follow-up of a greater number of patients.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.71-82
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• 2011

Purpose: To evaluate the biochemical control rate and the rate of side effects after performing permanent brachytherapy of localized prostate cancer. Materials and Methods: 67 patients with localized prostate cancer were treated with brachytherapy between April 2007 and December 2008. Of these, 43 patients who were followed up and did not receive external radiotherapy were evaluated for the change in prostate specific antigen (PSA) level and the occurrence of side effects. In total, 18 patients were classified as low risk, 19 patients as intermediate risk, and 6 patients as high risk. The prescription dose was 145 Gy. Results: A PSA increase greater than 2 ng/mL occurred in 2 patients (4.7%). Radiation Therapy Oncology Group (RTOG) grade 1 and 2 acute urologic complications (UC) occurred in 40 and 3 patients, respectively. Further, 5 patients had RTOG grade 1 acute rectal complication (RC). The numbers of RTOG grade 1, 2, and 3 chronic UC were 1, 4, and 1, respectively. The numbers of RTOG grade 1, 2, and 4 chronic RC were 5, 10, and 3, respectively. The statistically significant risk factors (RF) of acute RC were the minimal dose in the most irradiated 0.1 cc volume ($D_{0.1cc}$, p=0.041) and absolute volume receiving 150% of the prescribed dose ($V_{150cc}$, p=0.038) in the entire rectum (ER). The percentage ($V_{100%}$, p=0.019) and absolute volume ($V_{100cc}$, p=0.047) in the involved rectum (IR) were also statistically significant. The RF of chronic RC were $V_{100%}$ (p=0.011) in the ER and the $D_{0.1cc}$ (p=0.049), $V_{100cc}$ (p=0.023) in the IR. The number of used seeds were related with acute UC (p=0.028). Conclusion: Permanent brachytherpy of localized prostate cancer showed a favorable short term biochemical control rate. As such, selective intermediate and high risk patients can be managed with permanent brachytherapy. The effort to reduce rectal complication is also necessary.

• Radiation Oncology Journal
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• v.27 no.1
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• pp.35-41
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• 2009

Purpose: This study was designed to determine the optimum radiotherapy technique for internal mammary node (IMN) irradiation after breast-conserving surgery. Materials and Methods: We selected ten cases of early stage partial mastectomy for plan comparison. Five of the patients were treated to the right-side breast and the rest of the patients were treated to the left-side breast. For each case, four different treatment plans were made to irradiate the entire breast, IMNs and supraclavicular lymph nodes (SCLs). The four planning techniques include a standard tangential field (STF), wide tangential field (WTF), partially wide tangential field (PWT) and a photon-electron mixed field (PEM). We prescribed a dose of 50.4 Gy to the SCL field at a 3 cm depth and isocenter of the breast field. Results: The dose distribution showed clear characteristics depending on the technique used. All of the techniques covered the breast tissue well. IMN coverage was also good, except for the STF, which was not intended to cover IMNs. For the cases of the left-side breasts, the volume of the heart that received more than 30 Gy was larger (in order) for the WTF, PWT, PEM and STF. For radiation pneumonitis normal tissue complication probability (NTCP), the PWT showed the best results followed by the STF. Conclusion: Despite the variety of patient body shapes, the PWT technique showed the best results for coverage of IMNs and for reducing the lung and heart dose.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.277-282
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• 2010

The study is to verify non-uniform dose distribution in Field-In-Field (FIF) technique using two-dimensional ionization chamber (MatriXX, Wellhofer Dosimetrie, Germany) for breast tangential irradiation. The MatriXX and an inverse planning system (Eclipse, ver 6.5, Varian, Palo Alto, USA) were used. Hybrid plans were made from the original twenty patients plans. To verify the non-uniform dose distribution in FIF technique, each portal prescribed doses (90 cGy) was delivered to the MatriXX. The measured doses on the MatriXX were compared to the planned doses. The quantitative analyses were done with a commercial analyzing tool (OmniPro IMRT, ver. 1.4, Wellhofer Dosimetrie, Germany). The delivered doses at the normalization points were different to average 1.6% between the calculated and the measured. In analysis of line profiles, there were some differences of 1.3-5.5% (Avg: 2.4%), 0.9-3.9% (Avg: 2.5%) in longitudinal and transverse planes respectively. For the gamma index (criteria: 3 mm, 3%) analyses, there were shown that 90.23-99.69% (avg: 95.11%, std: 2.81) for acceptable range ($\gamma$-index $\geq$ 1) through the twenty patients cases. In conclusion, through our study, we have confirmed the availability of the FIF technique by comparing the calculated with the measured using MatriXX. In the future, various clinical applications of the FIF techniques would be good trials for better treatment results.

• Herbal Formula Science
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• v.25 no.1
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• pp.11-28
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• 2017

Objectives : The contents of aconitine in aconiti radix lateralis preparata, purified hot water extract of Aconiti Radix lateralis preparata, and purified hot water extract of Sambutang-P that contains Aconiti Radix lateralis preparata was analyzed to compare toxicity. Toxicity of Sambutang-P that contains Aconiti Radix lateralis preparata was assessed with a single oral toxicity test on 6-week-old male and female Sprague-Dawley rats. Methods : 1. The contents of aconitine in Aconiti Radix lateralis preparata, purified hot water extract of Aconiti Radix lateralis preparata, and purified hot water extract of Sambutang-P that contains Aconiti Radix lateralis preparata was analyzed using the purity test according to the "Korean Herbal Pharmacopoeia". 2. 2,000mg/kg was injected for the single oral toxicity test of purified hot water extract of Sambutang-P that contains Aconiti Radix lateralis preparata, and the test was done for a test group (injection) and a control group, each with 5 male and 5 female rats. For 14 days after injection, rats were observed for general symptoms and changes in weight. Afterwards, blood biochemical test, autopsy, and histophathological exam of the liver was conducted. Results : 1. The contents of aconitine was 0.0785% for Aconiti Radix lateralis preparata, 0.1510% for purified hot water extract of Aconiti Radix lateralis preparata, and 0.1248% for purified hot water extract of Sambutang-P that contains Aconiti Radix lateralis preparata. 2. There was no death of either male or female rats in both the control group and the test group (injection of 2,000mg/kg). 3. No unusual symptom was observed in both the control group and the test group (injection of 2,000mg/kg). 4. No significant change in weight was observed for both male and female rats in the test group (2,000mg/kg). 5. The histopathological exam of ALT, AST, ALP, GGT and LDH showed no significant changes for both male and female rats in the test group (2,000mg/kg). 6. According to the autopsy results, no visible abnormality of organs or tissues was found in both the control group and the test group (2,000mg/kg). 7. According to the histopathological exam of the liver, the effect of the injected material was not observed for either male or female rats in the test group (2,000mg/kg). Conclusions : The contents of aconitine in Aconiti Radix lateralis preparata was lower for decoction of Sambutang-P with ginseng radix alba than for decoction of only Aconiti Radix lateralis preparata. This suggests that ginseng radix alba can dilute toxicity of Aconiti Radix lateralis preparata. As for a single oral toxicity test of Sambutang-P that contains Aconiti Radix lateralis preparata, no abnormal reaction was observed even when the injection amount far exceeded a toxic dose or a lethal dose. Thus, it is deemed that using Sambutang-P at a clinically prescribed dose would not lead to hepatoxicity.

• Radiation Oncology Journal
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• v.23 no.4
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• pp.236-242
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• 2005

Purpose: To evaluate the role of surgical clips and scars in determining electron boost field for early stage breast cancer undergoing conserving surgery and postoperative radiotherapy and to provide an optimal method in drawing the boost field. Materials and Methods: Twenty patients who had $4{\sim}7$ surgical clips in the excision cavity were selected for this study. The depth informations were obtained to determine electron energy by measuring the distance from the skin to chest wall (SCD) and to the clip implanted in the most posterior area of tumor bed. Three different electron fields were outlined on a simulation film. The radiological tumor bed was determined by connecting all the clips implanted during surgery Clinical field (CF) was drawn by adding 3 cm margin around surgical scar. Surgical field (SF) was drawn by adding 2 cm margin around surgical clips and an Ideal field (IF) was outlined by adding 2 cm margin around both scar and clips. These fields were digitized into our planning system to measure the area of each separate field. The areas of the three different electron boost fields were compared. Finally, surgical clips were contoured on axial CT images and dose volume histogram was plotted to investigate 3-dimensional coverage of the clips. Results : The average depth difference between SCD and the maximal clip location was $0.7{\pm}0.55cm$. Greater difference of 5 mm or more was seen in 12 patients. The average shift between the borders of scar and clips were 1.7 1.2, 1.2, and 0.9 cm in superior, inferior, medial, and lateral directions, respectively. The area of the CF was larger than SF and IF in 6y20 patients. In 15/20 patients, the area difference between SF and if was less than 5%. One to three clips were seen outside the CF in 15/20 patients. In addition, dosimetrically inadequate coverage of clips (less than 80% of prescribed dose) were observed in 17/20 patients when CF was used as the boost field. Conclusion: The electron field determined from clinical scar underestimates the tumor bed in superior-inferior direction significantly and thereby underdosing the tissue at risk. The electron field obtained from surgical clips alone dose not cover the entire scar properly As a consequence, our technique, which combines the surgical clips and clinical scars in determining electron boost field, was proved to be effective in minimizing the geographical miss as well as normal tissue complications.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.303-312
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• 2017

The central goal of Gamma Knife radiosurgery(GKRS) is to maximize the conformity of the prescription isodose surface, and to minimize the radiation effect of the normal tissue surrounding the target volume. There are the various kinds of indices related with the quality of treatment plans such as conformity index, coverage, selectivity, beam-on time, gradient index(GI), and conformity/gradient index(CGI). As the best treatment plan evaluation tool, we must check by all means conformity index, GI, and CGI among them. Specially, GI and CGI related with complication of healthy normal tissue is more indispensible than conformity index. Then author calculated and statistically analysed CGI, the newly defined conformity/gradient index as well as GI being applied widely using the treatment planning system Leksell GammaPlan(LGP) and the verification method Variable Ellipsoid Modeling Technique(VEMT). In the study 10 patients with intracranial lesion treated by GKRS were included. Author computed the indices from LGP and VEMT requiring only four parameters: the prescribed isodose volume, the volume with dose > 30%, the target volume, and the volume of half the prescription isodose. All data were analyzed by paired t-test, which is statistical method used to compare two different measurement techniques. No statistical significance in GI at 10 cases was observed between LGP and VEMT. Differences in GI ranged from -0.14 to 0.01. The newly defined gradient index calculated by two methods LGP and VEMT was not statistically significant either. Author did not find out the statistical difference for the prescribed isodose volume between LGP and VEMT. CGI as the evaluation index for determining the best treatment plan is not significant statistically also. Differences in CGI ranged from -4 to 3. Similarly newly defined Conformity/Gradient index for GKRS was also estimated as the metric for the evaluation of the treatment plans through statistical analysis. Statistical analyses demonstrated that VEMT was in excellent agreement with LGP when considering GI, new gradient index, CGI, and new CGI for evaluating the best plans of GKRS. Due to the application of the fast and easy evaluation tool through LGP and VEMT author hopes CGI and newly defined CGI as well as gradient indices will be widely used.