The object of this study was to determine the radiation effect on the urinary bladder and to establish the basic date for optimal fraction schedule on the whole abdominal irradiation of the mice. Although radiation damage of the urinary bladder is one of the dose-limiting factor for treatment of lower abdominal cancer, such as uterine cervical or rectal cancer, systematic histopathological study of total dose and recovery duration is very rare, especially in conventional fractionation regimen of clinical use. Authors used 198 mice and analyzed histopathological findings according to total dose (40&50 GY) and recovery duration (1-15 weeks after completion of irradiation) The results were summarized as follows: 1. No definite difference of radiosensitivity was noted between male and female group. 2. Most of mucosal injuries were recovered within 14 weeks in 40 GY irradiated group. 3. Vascular injury and change of connective tissue were prominent and persisted even mild degree until 15 weeks after completion of irradiation in 50 GY irradiated group. 4. Although follow up duration of this study (105 days) was not enough to compare life span of mice, this study emphasized that precious schedule for treatment planning was necessary for preventing or reducing of late complication.
Animals ; Appointments and Schedules ; Connective Tissue ; Female ; Follow-Up Studies ; Humans ; Male ; Mice* ; Radiation Effects ; Radiation Tolerance ; Rectal Neoplasms ; Urinary Bladder* ; Vascular System Injuries

Clinical estimation of bladder and rectal doses from high dose rate intracavitary irradiation in carcinoma of the cervix uteri has been initiated on a routine basis in an effort to obtain the optimum radiotherapeutic dose. Simulation films with contrast media are used to image the bladder and rectum, and dose rates are estimated at various interesting points with the aid of treatment planning computer, NEC Therac-2300. Fifty-three patients have been reviewed in order to ascertain the correlation between radiation dose at interesting points in the bladder and rectum and the dose at Point A and B. The dose ratio between doses at Point A and interesting points in an important clinical factor in evaluating the treatment planning. This also serves as documentation of the dose to normal structures within the treatment volume. Authors conclude that obtained data are within acceptable ranges and routine simulation films of the bladder and rectum after administration of contrast media with dose calculations at interesting points provide important information for optimizing radiotherapy planning in the treatment of cervical carcinoma without increased time and effort or patient's discomfort.
Cervix Uteri ; Contrast Media ; Female ; Humans ; Radiotherapy ; Rectum ; Urinary Bladder ; Uterine Cervical Neoplasms*

Scatter-air ratios are used for the purpose of calculating scattered dose in the medium. The computation of the primary and the scattered dose separately is particularly useful in the dosimetry of irregular fields with shielding block in radiation field, dose distribution of scattered radiation using 18MeV Linear accelerator and Co-60 teletherapy measured. The effect of scattered radiation dose by protecting block was been ignored in radiation therapy, 2-3% of scattered radiation may be 90-200cGy which could be influence vital complication such as cataract, oligospermia or sterility. So that exact calculate scattered radiation by protecting block exactly for irregular field c small protection of vital organ is very important. The purpose of this article is to calculate scattered radiation by protecting block exactly for irregular field c Linac or Co-60 irradiation and to applicate these data in clinical radiation field. Authors could obtain following results. 1. The lesser angle between shielding block showed more scattered radiation. 2. With decreasing distance between shielding blocks, the dependent of scattered radiation were increased. 3. Output of 18 MeV Linear accelerator and Co-60 was related linear proportion on field size, but independent according to the size of shielding block in 18 MeV Linear accelerator.
Cataract ; Infertility ; Male ; Oligospermia ; Particle Accelerators

The basic strategy of irradiation is to deliver a dose to the cancer that is high enough to make cancer cells incapable of reproduction, while keeping the doses to the various healthy tissues below tolerable levels. In order to improve local control and survival, as a boost therapy after external radiotherapy, high dose rate transcatheteric irradiation using remote control after loading system (RALSTRON-20B) was used for twelve patients with head and neck cancers. Present results showed complete remission of cancer in 9 out of 112 patients without treatment related complications. Although this procedure is easy to operate, well trained skillful hand in essential for good results. Furthermore out experience suggested that meticulous treatment planning should be developed for better results.
Hand ; Head and Neck Neoplasms* ; Head* ; Humans ; Neck ; Radiotherapy ; Reproduction

Since discovery of X-rays, radiotherapy has evolved into one of the most scientific branches of medicine and has established its role as the primary line or the secondary line of attack, after surgery,. in the treatment of malignant cancers. Nowadays its importance is illustrated by the fact that as many as 70 per cent of all pastients with cancer will receive radiation therapy at sometime during their disease process. Biologic effects-of X-rays began to be apparant soon after the discovery by Roentgen in 1895. In clinical radiotherapy, the biologic endpoint of most importance is loss of cellular reproductive ability or clonogenicity. One of the commonest ;nays to assess cell survival is to use an in vitro plating assay. We analyzed radiation effect on colony formation of HaLa. S3(SC) cell line and obtained results are as follows The plating efficiency is 0.464. The shape of cell survival curve is similar to multi-target plus single hit component model. Estimated values of Do, Dq, and extrapolation number are 150 cGy, 80 cGy and 1.7 respectively. We reported these experimental data with review of literature.
Cell Line* ; Cell Survival ; Radiation Effects ; Radiotherapy

Uterine cervical cancer is the most common malignancy in Korean women. In spite of recent development of early diagnostic and therapeutic modalities, about 40% of treated patient will develop relapse. So more aggressive local treatment such as more extensive surgery and higher radiation dose and administration of systemic chemotherapy will promote the curability but treatment related complications cannot be avoidable. We used 22 cases of early cervical cancer, treated with surgery and post-operative radiotherapy, clinical data of these patients were analyzed to determine relationship between clinical parameters and final outcome. Three out of 22 cases revealed relapse and one patient showed rectovaginal fistula and another patient showed small bowel obstruction and the other patient showed rectal obstruction. Two out of three recurrence were stage IIa and the other one case was stage Ib adenocarcinoma with lymphovascular involvement. Nineteen out of 22 cases were followed without remarkable side effect or treatment related complication or sequelae. We concluded that out treatment policy was safe and effective to eradicate high risk postoperative cervical cancer with acceptable side effects or complication.
Adenocarcinoma ; Drug Therapy ; Female ; Humans ; Radiotherapy* ; Rectovaginal Fistula ; Recurrence ; Uterine Cervical Neoplasms*

Bone metastases represent an important and frequent clinical problem in patients with advanced cancers. Especially, painful bone metastases are common features in these patients. Radiotherapy is an effective tool for palliative aim of painful metastatic osseous lesions. Various treatment results have been previously reported. The present retrospective study was aimed to evaluate the efficacy of palliative irradiation on pain relief, with the goal of selecting appropriate irradiation dose schedule. Radiotherapy consisted of 5 times a week with a various fractional dose between 180 and 400cGy. The response of pain relief and the survival time after completion of radiotherapy are related to total dose and most of the patients have shown a similar response by the end of radiotherapy. The higher dose and the more aggressive multimodality treatment, the better pain control and the longer survival time.
Appointments and Schedules ; Humans ; Neoplasm Metastasis* ; Radiotherapy ; Retrospective Studies

Radiotherapeutically, nasopharyngeal caner is an important disease in Korea. Because of its blind anatomic location, early detection is relatively uncommon. Clinically, most of cases are locally advanced and nodal involvements are common. Recently better understanding of nature of the disease and improvement of radio – therapy technique permit better treatment result, including locoregional control and survival rate, and minimal normal tissue damages comparing with previously published date. We analyzed 31 patients of pathologically proven and previously untreated naso – pharyngeal carcinoma with different treatment techniques, retrospectively. Minimal and maximal follow up period of the survivor is 6 months and 68 months, respectively. Thirteen patients with squamous cell carcinoma are included in this analysis. The median age is 49 years (range from 20 to 64 years). Twenty two patients are stage III. Eleven patients are treated with radiotherapy alone and 20 are treated with combined modalities treatment. The degree of response after radiotherapy are categorized by 3-classes, i,e. complete response, partial response. In spite of similarities of complete response rate and 1-year survival rate between two different treatment techniques, those patients with undifferentiated carcinoma appear to benefit from the adjuvant chemotherapy. In addition, systemic failure is more suggest that adjuvant therapy in the radiotherapeutic management of nasopharyngeal cancer needs additional research according to histologic types and future extensive clinical trials.
Carcinoma ; Carcinoma, Squamous Cell ; Chemotherapy, Adjuvant ; Follow-Up Studies ; Humans ; Korea ; Nasopharyngeal Neoplasms* ; Radiotherapy ; Retrospective Studies ; Survival Rate ; Survivors

An analytic expression for equivalent square fields and a table are derived using the empirical representations obtained from the measured field size dependence of output for square field in a phantom. The expression is applicable to radiation fields that consistent with the following two assumptions imposed on these representations. 1) It is a linear function of the logarithm of the field area. 2) It is approximately the same function for both square and circular field of similar areas. In this paper, the derived tables and BJR table were consulted.

In recent years there has been a growing interest in all forms of rotational therapy, and many different types of therapy machines designed for this kind of treatment have become available. To the medical radiation physicist, the dosimetry of rotation therapy has presented a number of interesting problems, and much useful work has been published on the basic date of dose distribution and dosage calculation. The setting dose for ARC therapy were obtained by computer calculation and measurement with cylindrical phantom. Authors compared computer calculation with measured value. And in ARC therapy, the region of maximum dose in shifted from the tumor center. The extent of shift was analyzed by isodose distribution for ARC therapy techniques.
Particle Accelerators*