• Radiation Oncology Journal
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• v.11 no.1
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• pp.29-34
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• 1993

Experiments have been carried out with C3H mouse fibrosarcoma (FSa II) to determine the effect of different sequence and time intervals between irradiation and administration of cis-diammihedichloroplatinum (cis-DDP) with gross tumors (6 mm in diameter), microscopic tumors (3 days after transplantation of $10^3$ cells) and cells in culture. The drug was administered either 24, 12, 8, 4, 2, 1, 0.5 hour before irradiation, immediately before irradiation, or 0.5, 1, 2, 4, 8, 12, 24 hours after irradiation. In case of in vivo studies, tumor growth delay was used as an end point. Clonogenic cell surviving fraction was used for in vitro studies. Tumor growth delay for gross tumor after 10 Gy radiation plus 10 mg/kg cis-DDP ranged from 6.3 to 10.66 days and the enhancement ratio ranged from 1.37 to 2.23. The most effective combination was when cis-DDP was given 4 hours before irradiation. Tumor growth delay for microscopic tumor after 5 Gy of radiation and 5 mg/kg of cis-DDP ranged from 3.55 to 11.98 days with enhancement ratio from 2.05 to 6.92. Microscopic tumors showed response significantly greater than additive in every time interval and the most effective treatments were when cis-DDP was given 2 and 1 hour before irradiation. In in vitro experiment, the surviving fraction after 6 Gy of radiation and 1 hour exposure to 4 ${\mu}M$ cis-DDP fluctuated as a function of time between treatments, but the difference between maximum and minimum surviving fractions was very small. According to the above results the sequence and time interval between irradiation and chemotherapy is very critical especially for the management of microscopic tumors as in the case of postoperative adjuvant treatment.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.225-231
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• 1998

Purpose : To determine whether TNF-$\alpha$ increases the antitumor effect of radiotherapy in murine syngeneic tumor system. Materials and Methods : Syngeneic murine tumors of MCa-K or MCa-4 (mammary carcinoma), OCa-I (ovarian carcinoma), or HCa-I(hepatocarcinoma were grown in hind legs of C3Hf/HeJ mice. When tumors were grown to 6 mm in mean diameter mice were treated with TNF-$\alpha$, radiation, or combination of the both. Gamma-radiation was given as a single dose of 30 Gy for HCa-I and 15 Gy for other tumors using Cobalt-60 teletherapy unit. A novel TNF-$\alpha$ mutein developed in Korea, was intraperitoneally administered daily at a dose of 10 ug per mouse for 7 days. In combination of radiation and TNF-$\alpha$, the drug was started 1 hour after radiation. Tumor growth delay assay was used to measure the tumor response to the treatment. Results : Among 4 tested tumors, TNF-$\alpha$ alone showed significant antitumor activity in MCa-K and OCa-I tumors, which showed absolute growth delay (AGD) of 5.0 days and 6.5 days, respectively. In combination with radiation, TNF-$\alpha$ showed significant delay of AGD (41.1 days) in OCA-I compared to AGDs of TNF-$\alpha$ alone and radiation, i.e., 6.5 days and 26.9 days, respectively(p<0.05). Enhancement factor was 1.29 in OCa-I, which showed supraadditive effect. TNF-$\alpha$ did not show significant delay of AGDs in the remaining 3 tumors compared to AGDs of TNF-$\alpha$ alone and radiation. Conclusions: TNF-$\alpha$ alone showed antitumor effects in MCa-K and OCa-I. In combination with radiation, TNF-$\alpha$ acted in supraadditive way in OCa-I only. The results of this study imply that the combination of TNF-$\alpha$ and radiation has different therapeutic potential depending on tumor model and further study is advocated.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.153-160
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• 2018

Purpose : We retrospectively analyzed doses of each radiation therapy technique used in the treatment for left breast cancer patients after partial mastectomy through dose results for normalorgans and tumor volume to use this as a clinical reference for radiation therapy of domestic left breast cancer patients. Materials and Methods : 40 patients who underwent partial mastectomy on left breast cancer were classified in 3 treatment methods. The treatment plan was evaluated by HI(homogeneity index), $D_{95%}$, and CI(conformity index), and the $V_{hot}$ for gross tumor volume and clinical target volume of each treatment method. In Cyberknife treatment, tumor volume was the same as high dose volume in the other techniques, so no consideration was given to clinical target volume. Treatment plan evaluation for normal organs were evaluated by mean dose on ipsilateral lung, heart, left anterior descending artery, opposite breast and lung, and non-target tissue. Result : Treatment with volumetric arc radiotherapy(VMAT) showed $95.84{\pm}0.75%$ of $D_{95%}$ on the clinical target volume, significantly higher than that of 3D-CRT. The $D_{95%}$ value of the total tumor volume was slightly higher than the other treatments. In Cyberknife treatment, the dose to the normal organs was significantly lower than other treatments. Overall, the maximum dose and mean dose to the heart were $26.2{\pm}6.12Gy$ and $1.88{\pm}0.2Gy$ in VMAT treatment and $20.25{\pm}9.35Gy$ and $1.04{\pm}0.19Gy$ in 3D-CRT therapy, respectively. Conclusion : In comparison on 3D-CRT and VMAT, most of the dosimetric parameters for the evaluation of the treatment plan showed similar values, so that there is no significant difference in treatment plan evaluation. It is possible to select the treatment method according to the patient's anatomical structure or possibility of breath control. Cyberknife treatment is very useful treatment for normal organs because of its accurate dose exposure to the tumor volume However, it has restrictions to treat the local area, to have relatively long treatment time and to involve invasive procedure.

• Progress in Medical Physics
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• v.26 no.2
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• pp.79-86
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• 2015

The purpose of this study is to evaluate efficacy and feasibility of adaptive radiotherapy according to tumor volume change (TVC) in early stage non-small cell lung cancer (NSCLC) using stereotactic body radiotherapy (SBRT). Twenty-two lesions previously treated with SBRT were selected. SBRT was usually performed with a total dose of 48 Gy or 60 Gy in four fractions with an interval of three to four days between treatments. For evaluation of TVC, gross tumor volume (GTV) was contoured on each cone-beam computed tomography (CBCT) image used for image guidance. Intensity modulated radiotherapy (IMRT) planning was performed in the first CBCT (CBCT1) using a baseline plan. For ART planning (ART), re-optimization was performed at $2^{nd}$, $3^{rd}$, and $4^{th}$ CBCTs (CBCT2, CBCT3, and CBCT4) using the same angle and constraint used for the baseline plan. The ART plan was compared with the non-ART plan, which generated copying of the baseline plan to other CBCTs. Average GTV volume was 10.7 cc. Average TVC was -1.5%, 7.3%, and -25.1% in CBCT2, CBCT3, and CBCT4 and the TVC after CBCT3 was significant (p<0.05). However, the nine lesions were increased GTV in CBCT2. In the ART plan, $V_{20\;Gy}$, $D_{1500\;cc}$, and $D_{1000\;cc}$ of lung were significantly decreased (p<0.05), and $V_{30\;Gy}$ and $V_{32\;Gy}$ of the chest wall were also decreased (p<0.05). While D min of planning target volume (PTV) decreased by 8.3% in the non-ART plan of CBCT2 compared with the baseline plan in lesions with increased tumor size (p=0.021), PTV coverage was not compromised in the ART plan. Based on this result, use of the ART plan may improve target coverage and OAR saving. Thus ART using CBCT should be considered in early stage NSCLC with SBRT.

• Radiation Oncology Journal
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• v.24 no.2
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• pp.149-155
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• 2006

Meningeal hemangiopericytoma (HPC) is an uncommon dura-based tumor and can recur not only locally but also distantly in the neural axis or extraneural sites. We report our experience of radiation therapy, one preoperative and one elective postoperative, In two patients with meningeal HPC and reviewed the role of radiation therapy. A 41-year-old man (Case 1) presented with a 3-month history of headache and right hemiparesis. The mass was nearly unresectable at the first and second operation and diagnosed as meningeal HPC. Preoperative radiation therapy was given with a total dose of 55.8 Gy/31 fractions to the large residual mass of left frontoparietal area. Follow-up computerized tomography (CT) showed marked regression of tumor after radiation therapy. The third operation was peformed to remove the residual tumor at 6 months after the radiation therapy and a $2{\times}2cm$ sized tumor was encountered. The mass was totally removed. The serial follow-up CT showed no evidence of recurrence and he is alive without distant metastasis for 4 years and 10 months after the first operation. A 45-year-old woman (Case 2) presented with suddenly developed headache and visual impairment. Tumor mass occupying right frontal lobe was removed with the preoperative diagnosis of meningioma. It was totally removed with attached sagittal sinus and diagnosed as meningeal HPC. Elective postoperative radiation therapy was peformed to reduce local recurrence with a total dose of 54 Gy/30 fractions to the involved area of right frontal lobe. She is alive for 5 years maintaining normal activity without local recurrence and distant metastasis.

• Radiation Oncology Journal
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• v.21 no.1
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• pp.10-18
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• 2003

Purpose : To evaluate the role of fractlonated sterotactic radiotherapy (FSRT) in the management of benign brain tumors, we reviewed the clinical, and radiographic responses of patients treated. Methods and Materials : Between March 1995 and March 2002, 36 patients with benign brain tumors were treated by FSRT. The pathological diagnoses consisted of pituitary adenomas (12 patients), cranio-pharyngiomas (5 patients), meningiomas (10 patients), and acoustic neurinomas (9 patients). Radiotherapy doses of 25 to 35 Gy (3~6 Gy/fraction, 5~10 fractions) were prescribed to the 85~90% isodose line, depending upon the location, size and volume of the tumors. The median clinical and radiographical follow up periods were 31 (range, 2~74) and 21 (range, 4~56) months, respectively. Results : In the 35 patients that could be evaluated for their clinical response, 13 (37.1%) were considered improved, 16 (45.7%) stable and 6 (17.2%) worse. Of the 33 patients who had radiographic studies, tumor shrinkage was noted in 17 (51.5%), tumor stabilization in 13 (39.4%), and tumor progression in 3 (9.1%). Of the 17 tumor shrinkage patients, 7 (21.2%) showed a complete response. Acute radiation-induced complications occurred iin 11 (30.6%) patients. Conclusions : FSRT is considered a safe and effective treatment method for begin brain tumors, but large numbers of patients, with relatively long follow-up periods are needed to assess the exact role or effect of FSRT.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.1
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• pp.36-43
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• 2011

Purpose: This study was designed to verify intermediate-term functional and radiological results of limb salvage operation using endoprosthetic replacement system ($MUTARS^{(R)}$) used in patients with a malignant bone tumor. Materials and Methods: Thirty one cases which used $MUTARS^{(R)}$ tumor prosthesis were reviewed. The mean age of the patients was 49.2 years and the mean follow up was 39.8 months. We retrospectively reviewed complications, and evaluated functionally and radiologically by Enneking functional score, ISOLS radiological implants evaluation system at last follow-up. Results: 3 patients had died of disease, distant metastasis was seen in 4 patients and local recurrence was seen in 1 patients. Complications were developed in 12 patients. (infection 6, leg length discrepancy 2, aseptic loosening 2, periprosthetic femoral fracture 1, screw loosening 1) Mean value of total functional scores were 81.2% in proximal femur, 77.4% in distal femur, 78.1% in proximal tibia, and 80.2% in proximal humerus. The overall radiological result was relatively satisfactory. Conclusion: Our results suggest limb salvage with the $MUTARS^{(R)}$ endoprosthesis is successful with good functional and radiological results. But we should be careful with complications such as infection.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.55-62
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• 2021

Purpose: This study aims to contribute to the reduction of complications of breast cancer radiation therapy by analyzing skin dose differences due to Set-up error. Materials and Method: Pseudo breast was produced using a 3D printer, applied to the phantom, and images were acquired through CT. Treatment plan was carried out that the PTV, which contains 95% of the prescription dose, could be more than 95% of the volume, so that Dmax did not exceed 107% of the prescription dose. The Set-up error was evaluated by applying ±1mm/±3mm/±5mm to the X-axis, Y-axis, and Z-axis. Results: The dose-variation in skin due to Set-up error was approximately 106% to 123% compared to prescription dose, and the highest dose in skin was 49.24 Gy at 5mm Set-up error in the lateral direction of the X-axis. More than 107% of the prescription dose was the widest at 6.87 cc in skin lateral. Conclusions: If a Set-up error occurs during left breast cancer VMAT, a great difference in skin dose was shown in the lateral direction of the X-axis. If more effort is made to align the X-axis of the breast treated during CBCT registration, the dose-variation of skin will be reduced.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.181-186
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• 1992

A retrospective analysis was undertaken for 22 patients with early glottic cancer ($T_1N_0M_0$; 17, $T_2N_0M_0$; 5) who completed curative radiotherapy at the Department of Therapeutic Radiology, Chonnam University Hospital between November 1985 and December 1990. Median follow-up period was 39 months. The 3 year actuarial survival rate of T1, T2 was $81\%$ and $80\%$. respectively. Three patients ($13\%$) showed second malignant tumors and the site of the new primary was esophagus in two patients and lung in the other one. They were excluded from the local control analysis. The local control rate of T1. T2 group was $66\%$ and $50\%$. respectively. The surgical salvage rate and the ultimate local control rate of T1 group was $80\%$ (4/5) and $93\%$. and that of T2 group was $100\%\;(2/2)\;and\;75\%$. respectively. The local control rates of T1 stage were evaluated according to the various parameters. The local control rate of the superficial and exophytic lesion was better than that of the ulcerative and infiltrative one, and the involvement of anterior commissure was not seemed to be adverse prognostic factor. But the protracted treatment time showed the adverse effect on the local control of the disease. All of the eleven patients controlled by primary radiation therapy have maintained their voice well without any significant complication.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.108-115
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• 2002

Purpose : A retrospective study was undertaken to determine the role of conventional radiotherapy with or without surgery for treating a supraglottic carcinoma in terms of the local control and survival. Materials and Methods : From Jan. 1986 to Oct. 1996, a total of 134 patients were treated for a supraglottic carcinoma by radiotherapy with or without surgery. Of them, 117 patients who had completed the radiotherapy formed the base of this study. The patients were redistributed according to the revised AJCC staging system (1997). The number of patients of stage I, II, III, IVA, IVB were $6\;(5\%),\;16\;(14\%),\;53\;(45\%),\;32\;(27\%),\;10\;(9\%)$, respectively. Eighty patients were treated by radical radiotherapy in the range of $61.2\~79.2\;Gy$ (mean : 69.2 Gy) to the primary tumor and $45.0\~93.6\;Gy$ (mean : 54.0 Gy) to regional lymphatics. All patients with stage I and IVB were treated by radiotherapy alone. Thirty-seven patients underwent surgery plus postoperative radiotherapy in the range of $45.0\~68.4\;Gy$ (mean : 56.1 Gy) to the primary tumor bed and $45.0\~59.4\;Gy$ (mean : 47.2 Gy) to the regional lymphatics. Of them, 33 patients received a total laryngectomy (${\pm}lymph$ node dissection), three had a supraglottic horizontal laryngectomy (${\pm}lymph$ node dissection), and one had a primary excision alone. Results : The 5-year survival rate (5YSR) of all patients was $43\%$. The 5YSRs of the patients with stage I+II, III+IV were $49.9\%,\;41.2\%$, respectively (p=0.27). However, the disease-specific survival rate of the patients with stage I (n=6) was $100\%$. The 5YSRs of patients who underwent surgery plus radiotherapy (S+RT) vs radiotherapy alone (RT) in stage II, III, IVA were $100\%\;vs\;43\%$ (p=0.17), $62\%\;vs\;52\%$ (p=0.32), $58\%\;vs\;6\%$ (p<0.001), respectively. The 5-year actuarial locoregional control rate (5YLCR) of all the patients was $57\%$. The 5YLCR of the patients with stage I, II, III, IVA, IVB was $100\%,\;74\%,\;60\%,\;44\%,\;30\%$, respectively (p=0.008). The 5YLCR of the patients with S+RT vs RT in stage II, III, IVA was $100\%\;vs\;68\%$ (p=0.29), $67\%\;vs\;55\%$ (p=0.23), $81\%\;vs\;20\%$ (p<0.001), respectively. In the radiotherapy alone group, the 5YLCR of the patients with a complete, partial, and minimal response were $76\%,\;20\%,\;0\%$, respectively (p<0.001). In all patients, multivariate analysis showed that the N-stage, surgery or not, and age were significant factors affecting the survival rate and that the N-stage, surgery or not, and the ECOG performance index were significant factors affecting the locoregional control. In the radiotherapy alone group, multivariate analysis showed that the radiation response and N-stage were significant factors affecting the overall survival rate as well as locoregional control. Conclusion : In early stage supraglottic carcinoma, conventional radiotherapy alone is an equally effective modality compared to surgery plus radiotherapy and could preserve the laryngeal function. However, in the advanced stages, radiotherapy combined with concurrent chemotherapy for laryngeal preservation or surgery should be considered. In bulky neck disease, all the possible planned neck dissections after induction chemotherapy or before radiotherapy should be attempted.