• Radiation Oncology Journal
• /
• v.26 no.1
• /
• pp.35-44
• /
• 2008

Purpose: To evaluate the incidence and prognostic factors of treatment-related pneumonitis in non-small-cell lung cancer(NSCLC) patients treated with intensity modulated radiation therapy(IMRT). Materials and Methods: One-hundred-five patients with NSCLC treated with IMRT between 1 August 2004 and 30 November 2006 were analyzed retrospectively. The mean age of patients was 62.9 years, and squamous carcinomas were confirmed in 81 patients(77%). Sixty-six patients(62.9%) were classified as stage III, and 59 patients had lesions in the right lung. Twenty-seven patients were treated with a dose of 3,060 cGy preoperatively, and 10 patients were given a dose of 5,040 cGy postoperatively. Sixty-eight patients received a dose of 7,020 cGy for curative intent. Sixty-eight patients were treated with the use of the CORVUS planning system and 37 patients were treated with the use of the ECLIPSE planning system. Results: Of 105 patients, 21 patients(20%) had abnormal radiological findings, but only seven patients(6.7%) required treatment for radiation pneumonitis. Six of the seven patients had other serious lesions, including a bronchioesophageal fistula(one patient), recurrence in the treatment field(two patients), brain metastasis(one patient) and lung-to-lung metastasis(two patients); all of these patients died within 19 months after radiation treatment. Sixteen patients(23.5%) that received planning with the CORVUS system had abnormal lung findings. Five patients(13.5%) had abnormal lung findings with the use of the ECLIPSE planning system. Other prognostic factors such as perioperative radiation therapy, a volume over 10% of the V20 volume in the right lung, were also statistically significant. Conclusion: This retrospective analysis suggests that IMRT could be a beneficial treatment modality for the reduction of radiation pneumonitis in NSCLC patients. However, the higher incidence of abnormal radiological findings in perioperative patients treated with relatively lower doses($3,060{\sim}5,040$ cGy) suggest the need for judicious treatment planning in preoperative or postoperative treatment.

• Journal of the Korean Society of Radiology
• /
• v.12 no.3
• /
• pp.403-407
• /
• 2018

Currently, the highest cancer death rate in Korea is lung cancer, which is a typical cancer that is difficult to detect early. Low-dose chest CT is being used for early detection, which has a greater lung cancer diagnosis rate of about three times than regular chest x-ray images. However, low-dose chest CT not only significantly reduces image resolution but also has a weak signal and is sensitive to noise. Also, air filled lungs are low-density organs and the presence of noise can significantly affect early diagnosis of cancer. This study used Visual C++ to set a circle inside a large circle with a density of 2.0, with a density of 1.0, which is the density of water, in which five small circle of mathematics have different densities. Gaussian noise was generated by 1%, 2%, 3%, and 4% respectively to determine the effect of noise on the mean value, the standard deviation value, and the relative noise ratio(SNR). In areas where the density difference between the large and small circles was greatest in the event of 1 % noise, the SNR in the area with the greatest variation in noise was 4.669, and in areas with the lowest density difference, the SNR was 1.183. In addition, the SNR values can be seen to be high if the same results are obtained for both positive and negative densities. Quality was also clearly visible when the density difference was large, and if the noise level was increased, the SNR was reduced to significantly affect the noise. Low-density organs or organs in areas of similar density to cancers, will have significant noise effects, and the effects of density differences on the probability of noise will affect diagnosis.

• Radiation Oncology Journal
• /
• v.15 no.1
• /
• pp.1-10
• /
• 1997

Purpose : To evaluate the role of radiotherapy in the management of incompletely resected supratentorial low grade astrocytoma with the analysis of the survival, the Pattern of failure, and the prognostic variables affecting survival. Material and methods : Between January 1990 and December 1995, fifty-one patients with supratentorial low grade astrocytoma received radiotherapy after subtotal resection(16 patients) or stereotactic biopsy(35 patients) at Asan Medical Center, External radiotherapy was done by conventional fractionation with the total dose of 4820cGy to 6000cGy(median 5580cGy) and partial brain volume. The follow-up was done from 6 to 79 months(median 48 months) Result : Overall actuarial survival rate at 2 and 5 years were $83.4\%\;and\;54.8\%$, respectively. Progression free survival at 2 and 5 years were $67.4\%\;and\;48.7\%$, respectively The significant prognostic factors affecting overall survival rate were the performance status, 1 stage, histologic subtype, radiation field and radiation response. The major pattern of failure was local failure, such as Progressive disease and primary site recurrence in 23 patients $(45.1\%)$. Progression free survivors excluding 2 patients were physically and intellectually intact without major neurologic deficit. Conclusion : Although the follow-up period of this study was relatively short, overall actuarial and progression free survival rate were encouraging. Patients with good performance status, lower T stage, pilocytic subtype, patients treated with small radiation field and radiation responder showed better survival. As the local failure was the major pattern of failure, the various efforts to decrease the local failure is necessary.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.10 no.2
• /
• pp.117-123
• /
• 2012

In order to dispose of the LILW(low and intermediate level radioactive waste) stored at KAERI, the radwaste drum assay system will be introduced to evaluate the radioisotopes inventory of stored drums. At present, the construction project of the dedicated assay facility to operate it and carry out routine maintenance of that equipment has been conducting at the radwaste treatment facility. Since that facility will be constructed in front of a 1st radwaste storage facility as well as the radwaste drums to be assayed and the transmission source in the radwaste drum assay system are in that facility, they could act as the radioactive sources and then, would affect the dose rate at the inside and the outside of the facility. Therefore, the radiation shielding should be evaluated through the concrete wall near to the radioactive sources whether the wall thickness is sufficient against the regulations. In this study, the radiation safety for the concrete wall around the radiation controlled area in the radwaste drum assay facility was evaluated by the MCNP code. From the evaluation results, the thickness of those concrete walls which are under consideration of about 30 cm was enough to shield the radiation from the radioactive sources.

• Radiation Oncology Journal
• /
• v.21 no.3
• /
• pp.199-206
• /
• 2003

Purpose: This study was undertaken to evaluate the efficacy of postoperative radiotherapy, and to investigate the prognostic factors for FIGO stages IB-IIB cervical cancer patients who were treated with simple hysterectomy, or who had high-risk factors following radical hysterectomy and pelvic lymph node dissection. Materials and Methods: Between March 1986 and December 1998, 58 patients, with FIGO stages IB-IIB cervical cancer were included in this study. The indications for postoperative radiation therapy were based on the pathological findings, including lymph node metastasis, positive surgical margin, parametrial extension, lymphovascular invasion, invasion of more than half the cervical stroma, uterine extension and the incidental finding of cervix cancer fellowing simple hysterectomy. All patients received external pelvic radiotherapy, and 5 patients, received an additional intracavitary radiation therapy. The radiation dose from the external beam to the whole pelvis was $40\~50$ Gy. Vagina cuff Irradiation was peformed, after completion of the external beam irradiation, at a low-dose rate of Cs-137, with the total dose of $4488\~4932$ chy (median: 4500 chy) at 5 mm depth from the vagina surface. The median follow-up period was 44 months ($15\~108$ months). Results: The 5-yr actuarial local control rate, distant free survival and disease-free survival rate were $98\%,\;95\%\;and\;94\%$, respectively. A univariate analysis of the clinical and pathological parameters revealed that the clinical stage (p=0.0145), status of vaginal resection margin (p=0.0002) and parametrial extension (p=0.0001) affected the disease-free survival. From a multivariate analysis, only a parametrial extension independently influenced the disease-free survival. Five patients ($9\%$) experienced Grade 2 late treatment-related complications, such as radiation proctitis (1 patient), cystitis (3 patients) and lymphedema of the leg (1 patient). No patient had grade 3 or 4 complications. Conclusion: Our results indicate that postoperative radiation therapy can achieve good local control and survival rates for patients with stages IB-IIB cervical cancer, treated with a simple hysterectomy, as well as for those treated with a radical hysterectomy, and with unfavorable pathological findings. The prognostic factor for disease-free survival was invasion of the parametrium. The prognosic factor identified in this study for treatment failure can be used as a selection criterion for the combined treatment of radiation and che motherapy.

• Radiation Oncology Journal
• /
• v.22 no.3
• /
• pp.200-207
• /
• 2004

Purpose: An analysis was to compare the results of radiation alone with those of radiation with dally low dose cisplatin as a radiation sensitizer in locally advanced cervical cancer. Materials and Methods: A retrospective analysis of 59 patients diagnosed with locally advanced uterine cervix cancer between December 1996 and March 2001 was peformed. Thirty one patients received radiation alone and 28 patients received dally low dose cisplatin, as a radiation sensitizer, and radiation therapy. The median follow-up period was 34 months, ranging from 2.5 to 73 months. The radiation therapy consisted of 4500 cGy external beam irradiation to the whole pelvis (midline block after 3060 cGy), a 900$\~$l,000 cGy boost to the involved parametrium and high dose-rate intracavitary brachytherapy (a total dose of 3,000$\~$3,500 cGy/500 cGy per fraction to point A, twice per week). In the chemoradiation group, 10 mg of daily intravenous cisplatin was given daily from the 1st day of radiation therapy to the 20th day of radiation therapy. According to the FIGO classification, the patients were subdivided into 51 (86.4$\%$) and 8 (13.6$\%$) stages IIB and stage IIIB, respectively. Results: The overall 5 year survival rate was 65.65$\%$ and according to treatment modality were 56.75$\%$ and 73.42$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.180). The 5 year disease-free survival rates were 49.39$\%$ and 63.34$\%$ in the radiation alone and chemoradiatoin groups, respectively (p=0.053), The 5 year locoregional control rates were 52.34$\%$ and 73.58$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.013). The 5 year distant disease-free survival rates were 59.29$\%$ and 81.46$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.477), Treatment related hematologic toxicity were prominent in the chemoradiation group. Leukopenia $\geq$grade) occurred in 3.2$\%$and 28.5$\%$ of the radiation alone and chemoradiation groups, respectively (p=0.02). There were no statistical differences in the incidences of vesical, rectal and small bowel complications between two groups. Conclusion: Radiation therapy with low dose cisplatin did not improve the rates of survival and response rates, but did improve the rate of disease free survival and locoregional control rates In locally advanced cervical cancer. The incidence of bone marrow suppression was higher in the chemoradiation group.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.12 no.1
• /
• pp.13-18
• /
• 2008

Purpose: The image processing method due to the algorism which is various portion nuclear medical image decision is important it makes holds. The purpose of this study is it applies hereupon new image processing method SIEMENS (made by Pixon co.) Onco. flash processing reconstruction and the comparison which use the image control technique of existing the clinical usefulness it analyzes with it evaluates. Materials & Methods: 1. Whole body bone scan-scan speed 20 cm/min, 30 cm/min & 40 cm/min blinding test 2. Bone static spot scan-regional view 200 kcts, 400 kcts for chest, pelvis, foot blinding test 3. 4 quadrant-bar phantom-20000 kcts visual evaluation 4. LSF-FWHM resolution comparison ananysis. Results: 1. Raw data (20 cm/min) & processing data (30 cm/min)-similar level image quality 2. Low count static image-image quality clearly improved at visual evaluation result. 3. Visual evaluation by quadrant bar phantom-rising image quality level 4. Resolution comparison evaluation (FWHM)-same difference from resolution comparison evaluation Conclusion: The study which applies a new method Onco. flash processing reconstruction, it will be able to confirm the image quality improvement which until high level is clearer the case which applies the method of existing better than. The new reconstruction improves the resolution & reduces the noise. This enhances the diagnostic capabilities of such imagery for radiologists and physicians and allows a reduction in radiation dosage for the same image quality. Like this fact, rising of equipment availability & shortening the patient waiting move & from viewpoint of the active defense against radiation currently becomes feed with the fact that it will be the useful result propriety which is sufficient in clinical NM.