The Effect of Simulation on Recurrence after Breast-Conserving Surgery and Radiotherapy : Preliminary Results / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To evaluate the effect of the simulation method on recurrence among the patients who received radiotherapy after breast-conserving surgery (BCS) for early breast carcinoma. METHODS AND MATERIALS: Between 1995 and 2000, 70 patients with stage I-II breast carcinoma underwent breast-conserving surgery and adjuvant radiotherapy. Twenty nine patients (41.4%) were simulated with the 2D contour-based method (September 1995 to August 1997) and 41 patients (58.6%) were simulated with the 3D CT-based method (September 1997 to February 2000). To analyze the effect of the simulation method, the patient and treatment characteristics were compared. RESULTS: The characteristics were similar for the patients between the 2D contour-based simulation group and the 3D CT-based simulation group. During a median follow-up period of 75 months, 4 (13.8%) of 29 patients who were treated with 2D simulation and 1 (2.4%) of 41 patients who were treated with 3D simulation group devel-oped treatment failure. The five-year survival rates were 89.2% and 95.1% between the 2D and 3D simulation groups (p=0.196). The five-year disease free survival (DFS) rates were 86.2% and 97.5% between the 2D and 3D simulation groups (p=0.0636). On univariate analysis, age > 40 (p= 0.0226) and the number of dissected axillary lymph node > or = 10 (p=0.0435) were independent predictors of improved 5-year DFS. CONCLUSIONS: Although our data showed marginal significance for the DFS between the two groups, it is insufficient, due to the small number of patients in our study, to prove whether 3D CT-based simulation might improve the DFS and reduce the risk of recurrence when compared with 2D contour-based simulation. Further study is needed with a larger group of patients.

A Role of Trial Radiation Therapy in the Pineal Region Tumors / 대한방사선종양학회지

PURPOSE: The aim of this retrospective study was to assess the treatment results of 30 patients with pineal region tumors who were underwent radiation therapy under the diagnosis by either CT or MRI. There was no histological verification. We analyzed the prognostic factors that have a significant effect on the overall survival (OS) and disease free survival (DFS) rates. MATERIALS AND METHODS: A total 30 patients with pineal region tumors were treated between March 1983 and August 1995. After a trial radiation therapy of 20~30 Gy/2~3 weeks, the patients were evaluated for their clinical response and radiological response by either CT or MRI and the final treatment direction was then decided. According to their response to the trial radiation therapy and the involved site, radiation treatment was given in various fields i.e., local, ventricle, whole brain and craniospinal field. The radiation dose ranged from 40.8 to 59.4 Gy (Median 50.4 Gy). The median follow up was 36.5 months (4~172 months). RESULTS: An improvement or stability in the clinical symptoms was observed in 28 patients (93.3%) after the trial RT. Nineteen patients (63.3%) showed a partial or complete response by CT or MRI. The two-year and five-year survival rates of the patients were 66.7% and 55.1%, respectively. No significant difference in the survival rates according to the degree of the radiological response was abserved after the trial RT. The results of univariate analysis showed that age, the primary site, the performance status (KPS>or=70), the degree of response after completing RT and the RT field were significant prognostic factors affecting the survival and disease free survival rates (p<0.05). CONCLUSION: The clinical and histological characteristics of pineal region tumors are quite complex and diverse. Therefore, it is difficult to predict the histological diagnosis and the possibility of radiocurability only with the initial response to RT. We think that the development of less invasive histological diagnostic techniques and tailored treatment to the histological type of each tumor are needed.

The Efficiency of Radiation Therapy in the Treatment of Intracranial Oligodendrogliomas : Factors Influencing the Prognosis / 대한방사선종양학회지

PURPOSE: Oligodendrogliomas (ODG) are a rare, slow growing, tumor in the brain, which can be cured by complete surgical resection, but as yet it is not known if postoperative adjuvant radiation therapy (RT) is essential. We analyzed the treatment results of patients with irradiated ODG to investigate the efficacy of RT in terms of survival rates and other influencing prognostic factors. METHODS AND MATERIALS: Between March 1983 and December 1997, 42 patients with ODG were treated with RT at our hospital. The RT was performed daily at a dose of 1.8~2.0 Gy, at 5 fractions per week, to a total dose of between 39.6 Gy and 64.8 Gy (mean 53.3 Gy). The ages of the patients ranged between 5 and 62 years, with a median age of 39 years. The mean follow-up period was 63.4 months (8-152 months). The Kaplan-Meier method was used to assess the survival, and 5 year survival rates (5-YSR). Log rank tests and Cox regression analyses were used to define the significance of prognostic factors. RESULTS: The majority of ODG in this study were located in the cerebral hemisphere (83.3%). ODG are slightly more common in men than women, and commonly occurs in middle age, between the 3rd and 4th decades. It has been recommended that RT is commenced within 4 weeks following surgery (5-YSR; 86% vs. 49%; p0.05). CONCLUSION: A local involved field irradiation with conventional fractionation, commencing within 4 weeks following surgical excision of the tumor, was beneficial for the 5-YSR, but a total radiation dose exceeding 60 Gy did not improve the 5-YSR.

Treatment of Intracranial Meningioma with Linac Based Radiosurgery / 대한방사선종양학회지

PURPOSE: To evaluate the role of linac based radiosurgery (RS) in the treatment of meningiomas, we retrospectively analyzed the results of clinical and follow up CT/MRI studies. METHODS AND MATERIALS: From the 1988 July to 1998 April, twenty patients of meningioma had been treated with 6 MV linear accelerator based radiosurgery. Of the 20 patients, four (20%) were male and 16 (80%) were female. Mean age was 51 years old (22~78 years old). Majority of intracranial location of tumor for RS were parasagittal and sphenoid wing area. RS was done for primary treatment in 6 (30%), postoperative residual lesions in 11 (55%) and regrowth after surgery in 3 (15%). Mean tumor volume was 5.72 cm3 (0.78~15.1 cm3) and secondary collimator size was 2.04 cm (1~3 cm). The periphery of tumor margin was prescribed with the mean dose of 19.6 Gy (9~30 Gy) which was 40~90% of the tumor center dose. The follow up duration ranged from 2.5 to 109 months (median 53 months). Annual CT/MRI scan was checked. RESULTS: By the follow up imaging studies, the tumor volume was reduced in 5 cases (25%), arrested growth in 14 cases (70%), and increased size in 1 case (15%). Among these responsive and stable 19 patients by imaging studies, there showed loss of contrast enhancement after CT/MRI in four patients. In clinical response, nine (45%) patients were considered improved condition, 10 (50%) patients were stable and one (5%) was worsened to be operated. This partly resulted in necrosis after surgery. CONCLUSION: The overall control rate of meningiomas with linac based RS was 95% by both imaging follow-up and clinical evaluation. With this results, linac based RS is considered safe and effective treatment method for meningioma.