• Title/Summary/Keyword: ${\beta}$-rays

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Results of Concurrent Chemoradiotherapy and Intraluminal Brachytherapy in Esophageal Carcinoma - Retrospective Analysis with Respect to Survival - (식도암에서 동시 항암화학방사선요법과 관내근접치료의 결과 -생존율을 중심으로 한 후향적 분석-)

  • Nam Taek-Keun;Nah Byung-Sik;Chung Woong-Ki;Ahn Sung-Ja;Song Ju-Young
    • Radiation Oncology Journal
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    • v.22 no.1
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    • pp.25-32
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    • 2004
  • Purpose : Evaluate the efficacies and toxicities of concurrent chemoradiotherapy (CCRT), with or without intraluminal brachytherapy (ILB), using a retrospective analysis in esophageal carcinomas with respect to survival. Materials and Methods : From April 1995 to July 2001, a total of 65 patients, diagnosed with an esophageal carcinoma, were treated by CCRT, with 21 also treated by ILB after CCRT. External radiotherapy was peformed using 6 or 10 MV X-rays, with a dose range of $46.8~\69.6$ Gy (median; 59.4). The ILB was peformed using high-dose-rate brachytherapy with Ir-192. The fractionation of ILB was 3 Gy by 4, or 5 Gy by 2 fractions. Cisplatin $(75\;mg/m^2)$ was given on each first day of weeks 1, 5, 9 and 13, and 5-FU $(1,000\;mg/m^2)$ as a continuous infusion for the first 4 days of each course. Results : The median survival time of all patients was 15 months, and the 1, 2 and 3-year survival rates were 55.4, 29.2 and $20.7\%$, respectively. The 2-year survival rates of the patients with and without ILB were 33.3 and $27.3\%$, respectively (p=0.80). The 2-year survival rates of the patients with a complete, partial and no response were 44.1, 13.8 and $0\%$, respectively (p=0.02). The response to treatment was the only significant factor affecting the overall survival from a multivariate analysis. Conclusion : This study has shown that the survival outcomes of CCRT were much better than previous results with radiotherapy alone. However, the addition of ILB after CCRT showed no advantage over that of CCRT alone.

Radiation Absorbed Dose Calculation Using Planar Images after Ho-166-CHICO Therapy (Ho-166-CHICO 치료 후 평면 영상을 이용한 방사선 흡수선량의 계산)

  • 조철우;박찬희;원재환;왕희정;김영미;박경배;이병기
    • Progress in Medical Physics
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    • v.9 no.3
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    • pp.155-162
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    • 1998
  • Ho-l66 was produced by neutron reaction in a reactor at the Korea Atomic Energy Institute (Taejon, Korea). Ho-l66 emits a high energy beta particles with a maximum energy of 1.85 MeV and small proportion of gamma rays (80 keV). Therefore, the radiation absorbed dose estimation could be based on the in-vivo quantification of the activity in tumors from the gamma camera images. Approximately 1 mCi of Ho-l66 in solution was mixed into the flood phantom and planar scintigraphic images were acquired with and without patient interposed between the phantom and scintillation camera. Transmission factor over an area of interest was calculated from the ratio of counts in selected regions of the two images described above. A dual-head gamma camera(Multispect2, Siemens, Hoffman Estates, IL, USA) equipped with medium energy collimators was utilized for imaging(80 keV${\pm}$10%). Fifty-nine year old female patient with hepatoma was enrolled into the therapeutic protocol after the informed consent obtained. Thirty millicuries(110MBq) of Ho-166-CHICO was injected into the right hepatic arterial branch supplying hepatoma. When the injection was completed, anterior and posterior scintigraphic views of the chest and pelvic regions were obtained for 3 successive days. Regions of interest (ROIs) were drawn over the organs in both the anterior and posterior views. The activity in those ROIs was estimated from geometric mean, calibration factor and transmission factors. Absorbed dose was calculated using the Marinelli formula and Medical Internal Radiation Dose (MIRD) schema. Tumor dose of the patient treated with 1110 MBq(30 mCi) Ho-l66 was calculated to be 179.7 Gy. Dose distribution to normal liver, spleen, lung and bone was 9.1, 10.3, 3.9, 5.0 % of the tumor dose respectively. In conclusion, tumor dose and absorbed dose to surrounding structures were calculated by daily external imaging after the Ho-l66 therapy for hepatoma. In order to limit the thresholding dose to each surrounding organ, absorbed dose calculation provides useful information.

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In the Treatment I-131, the Significance of the Research that the Patient's Discharge Dose and Treatment Ward can Affect a Patient's Kidney Function on the Significance of Various Factors (I-131 치료시 환자의 신장기능과 다양한 요인으로 의한 퇴원선량 및 치료병실 오염도의 유의성에 관한 연구)

  • Im, Kwang Seok;Choi, Hak Gi;Lee, Gi Hyun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.17 no.1
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    • pp.62-66
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    • 2013
  • Purpose: I-131 is a radioisotope widely used for thyroid gland treatments. The physical half life is 8.01 and characterized by emitting beta and gamma rays which is used in clinical practice for the purpose of acquiring treatment and images. In order to reduce the recurrence rate after surgery in high-risk thyroid cancer patients, the remaining thyroid tissue is either removed or the I-131 is used for treatment during relapse. In cases of using a high dosage of radioactive iodine requiring hospitalization, the patient is administered dosage in the hospital isolation ward over a certain period of time preventing I-131 exposure to others. By checking the radiation amount emitted from patients before discharge, the patients are discharged after checking whether they meet the legal standards (50 uSv/h). After patients are discharged from the hospital, the contamination level is checked in many parts of the ward before the next patients are hospitalized and when necessary, decontamination operations are performed. It is expected that there is exposure to radiation when measuring the ward contamination level and dose check emitted from patients at the time of discharge whereby the radiation exposure by health workers that come from the patients in this process is the main factor. This study analyzed the correlation between discharge dose of patients and ward contamination level through a variety of factors such as renal functions, gender, age, dosage, etc.). Materials and Method: The study was conducted on 151 patients who received high-dosage radioactive iodine treatment at Soon Chun Hyang University Hospital during the period between 8/1/2011~5/31/2012 (Male: Female: 31:120, $47.5{\pm}11.9$, average dosage of $138{\pm}22.4$ mCi). As various factors expected to influence the patient discharge dose & ward contamination such as the beds, floors, bathroom floors, and washbasins, the patient renal function (GFR), age, gender, dosage, and the correlation between the expected Tg & Tg-Tb expected to reflect the remaining tissue in patients were analyzed. Results: In terms of the discharge dose and GFR, a low correlation was shown in the patient discharge dose as the GFR was higher (p < 0.0001). When comparing the group with a dosage of over 150mCi and the group with a lower dosage, the lower dosage group showed a significantly lower discharge dose ($24{\pm}10.4uSv/h$ vs $28.7{\pm}11.8uSv/h$, p<0.05). Age, gender, Tg, Tg-Tb did not show a significant relationship with discharge dose (p> 0.05). The contamination level in each spot of the treatment ward showed no significant relationship with GFR, Tg, Tg-Tb, age, gender, and dosage (p>0.05 ). Conclusion: This study says that discharge of the dose in the patient's body is low in GFR higher and Dosage 150mCi under lower. There was no case of contamination of the treatment ward, depending on the dose and renal association. This suggests that patients' lifestyles or be affected by a variety of other factors.

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