• Radiation Oncology Journal
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• 제32권2호
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• pp.84-94
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• 2014

Purpose: To quantify the cardiac dose reduction during breathing adapted radiotherapy using Real-time Position Management (RPM) system in the treatment of left-sided breast cancer. Materials and Methods: Twenty-two patients with left-sided breast cancer underwent CT scans during breathing maneuvers including free breathing (FB), deep inspiration breath-hold (DIBH), and end inspiration breath-hold (EIBH). The RPM system was used to monitor respiratory motion, and the in-house self respiration monitoring (SRM) system was used for visual feedback. For each scan, treatment plans were generated and dosimetric parameters from DIBH and EIBH plans were compared to those of FB plans. Results: All patients completed CT scans with different breathing maneuvers. When compared with FB plans, DIBH plans demonstrated significant reductions in irradiated heart volume and the heart $V_{25}$, with the relative reduction of 71% and 70%, respectively (p < 0.001). EIBH plans also resulted in significantly smaller irradiated heart volume and lower heart $V_{25}$ than FB plans, with the relative reduction of 39% and 37%, respectively (p = 0.002). Despite of significant expansion of lung volume using inspiration breath-hold, there were no significant differences in left lung $V_{25}$ among the three plans. Conclusion: In comparison with FB, both DIBH and EIBH plans demonstrated a significant reduction of radiation dose to the heart. In the training course, SRM system was useful and effective in terms of positional reproducibility and patient compliance.

• Radiation Oncology Journal
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• 제33권4호
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• pp.301-309
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• 2015

Purpose: To identify prognostic factors for disease progression and survival of patients with extracranial oligometastatic breast cancer (EOMBC), and to investigate the role of radiation therapy (RT) for metastatic lesions. Materials and Methods: We retrospectively reviewed the medical records of 50 patients who had been diagnosed with EOMBC following standard treatment for primary breast cancer initially, and received RT for metastatic lesions, with or without other systemic therapy between January 2004 and December 2008. EOMBC was defined as breast cancer with five or less metastases involving any organs except the brain. All patients had bone metastasis (BM) and seven patients had pulmonary, hepatic, or lymph node metastasis. Median RT dose applied to metastatic lesions was 30 Gy (range, 20 to 60 Gy). Results: The 5-year tumor local control (LC) and 3-year distant progression-free survival (DPFS) rate were 66.1% and 36.8%, respectively. High RT dose (${\geq}50Gy_{10}$) was significantly associated with improved LC. The 5-year overall survival (OS) rate was 49%. Positive hormone receptor status, pathologic nodal stage of primary cancer, solitary BM, and whole-lesion RT (WLRT), defined as RT whose field encompassed entire extent of disease, were associated with better survival. On analysis for subgroup of solitary BM, high RT dose was significantly associated with improved LC and DPFS, shorter metastasis-to-RT interval (${\leq}1month$) with improved DPFS, and WLRT with improved DPFS and OS, respectively. Conclusion: High-dose RT in solitary BM status and WLRT have the potential to improve the progression-free survival and OS of patients with EOMBC.

• Radiation Oncology Journal
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• 제37권3호
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• pp.156-165
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• 2019

Purpose: Prophylactic cranial irradiation (PCI) is a standard treatment for limited-stage small cell lung cancer (LS-SCLC) showing a response to initial treatment, but many patients do not receive PCI due to comorbidities or refusal. This study aims to define the patient group for whom PCI can be omitted with minimal risk. Materials and Methods: Patients with LS-SCLC who underwent radiotherapy with curative aim at our institution between January 2004 and December 2015 were retrospectively reviewed. Patients who did not receive PCI were evaluated for brain metastasis-free survival (BMFS), progression-free survival (PFS), overall survival (OS), and prognostic factors for survival, and treatment outcomes were compared with a patient cohort who received PCI. Results: A total of 350 patients achieved a response following thoracic radiotherapy, and 190 of these patients did not receive PCI. Stage I-II and a complete response (CR) to initial therapy were good prognostic factors for BMFS and OS on univariate analysis. Patients with both stage I-II and a CR who declined PCI showed comparable 2-year BMFS to those who received PCI (92% vs. 89%). In patients who achieved CR, PCI did not significantly improve OS or PFS. Conclusion: There should be less concern about omitting PCI in patients with comorbidities if they have stage I-II or a CR, with brain metastasis control being comparable to those patients who receive PCI.

• Radiation Oncology Journal
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• 제36권3호
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• pp.227-234
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• 2018

Purpose: We compared how doses delivered via two-dimensional (2D) intracavitary brachytherapy (ICBT) and three-dimensional (3D) ICBT varied anatomically. Materials and Methods: A total of 50 patients who received 30 Gy of 3D ICBT after external radiotherapy (RT) were enrolled. We compared the doses of the actual 3D and 2D ICBT plans among patients grouped according to six anatomical variations: differences in a small-bowel V_2Gy, small bowel circumference, the direction of bladder distension, bladder volume, sigmoid V_3.5Gy, and sigmoid circumference. Seven dose parameters were measured in line with the EMBRACE recommendations. Results: In terms of bladder volume, the bladder and small-bowel D_2cc values were lower in the 150-250 mL bladder volume subgroup; and the rectum, sigmoid, and bladder D_2mL values were all lower in the >250 mL subgroup, for 3D vs. 2D ICBT. In the sigmoid V_3.5Gy >2 _mL subgroup, the sigmoid and bladder D_2mL values were significantly lower for 3D than 2D ICBT. The bladder D_2mL value was also significantly lower for 3D ICBT, as reflected by the sigmoid circumference. In patients with a small bowel V_2.0Gy >10 mL or small bowel circumference >15%, most dose parameters were significantly lower for 3D than 2D ICBT. The bladder distension direction did not significantly affect the doses. Conclusion: Compared to 2D ICBT, a greater bladder volume can reduce the internal 3D ICBT organ dose without affecting the target dose.

• 대한방사선기술학회지:방사선기술과학
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• 제41권6호
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• pp.567-572
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• 2018

Radiation therapy is one of the beneficial choices in the treatment of cancer. This is a comparison of TPS(Treatment Planning System) and GEANT4-DICOM, which should be preceded by the best radiation therapy. A treatment plan for prostate cancer was established with Eclipse and the point doses 366.1 cGy, 189.1 cGy, 213.4 cGy, 127 cGy, 105.7 cGy of any five prostate, bladder, rectum, right femoral head and left femoral head were identified. GEANT4-DICOM simulation showed that the results of Eclipse and ${\pm}2%$ dose error were confirmed. The monthly X-ray output agreement management value recommended by TG-142 is ${\pm}2%$, which means that the experimental results can be meaningful. In conclusion, GEANT4-DICOM is an infinite way to obtain more extended dose information once the time constraints are overcome in the simulation.

• 대한위암학회:학술대회논문집
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• 대한위암학회 2004년도 제17회 춘계학술대회
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• pp.35-35
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• 2004

• Journal of Radiation Protection and Research
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• 제6권1호
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• pp.45-52
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• 1981

The March 1979 accident at Three Mile Island provided physicians specializing in radiation medicine an opportunity to observe the field under conditions never seen before. Since no, injuries occurred at the site or within the community, medical personnel were immediately involved in efforts to allay fear, provide accurate information, and replace labortory resources rendered ineffective by the release in the reactor building. Valuable insights concerning medical emergency planning are derived from the accident; suggestions are made for handling any future mishaps.

• 미생물학회지
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• 제11권4호
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• pp.181-188
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• 1973

For the bulk sterilization, there are two traditional methods of autoclaving and exposure to ethylene oxide. However, autoclaving involves high temperatures and pressures and ethylene oxide is chemically highly reactive, so these methods are radiation, we have carried out sterility and safety tests on some medical products irradiated at varying radiation levels. The results obtained were as follows ; 1) The minimum dose of radiation for the sterilization of medical products was 2.5 Mrad. 2) The radiosterilization dose varied depending on the initial population of microorganisms. 3) In transfusion sets, a level of radiation of 2.5Mrad at room temperature produced no pyrogen and they remained bacteriologically sterile.

• Asian Pacific Journal of Cancer Prevention
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• 제16권13호
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• pp.5585-5585
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• 2015

• 대한방사선치료학회지
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• 제9권1호
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• pp.40-45
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• 1997

When therapeutic irradiation is indicated for the orbital tumors, the greatest concern is the risk of radiation-induced cataract. Conjunctival lymphoma is one of the good examples. We would like to report the procedure of the lens shielding device(L.S.D) and the result of irradiated dose to the lens. L.S.D. consistes of two parts : load alloy to attenuate electron beam, and dental acryl which completely covers the lead alloy to avoid discomfort of cornea from contacting directly with cerrobend and side scattering by cerrobend. And for easy location and removal, side bars were made on each side. Radiation doses were meaured with TLD(TLD 3500 Hawshaw). Markus chamber in a polystyrene phantom. The phantom was irradiated with 9MeV electron beams from Clinac 2100C with $6{\times}6cm$ electron cone. The relative dose at 6mm depth where the lens is located was $4.2\%$ with TLD and $5.1\%$ with Markus chamber clinically when 2600 cGy are irradiated to the eyeball, the mapinary dose to the lens will be 109 cGy or 132 cGy, which will significently reduce the cataract.