Strategies of local recurrence after sphincter preserving surgery for low rectal cancer / 中国医师进修杂志

Objective To investigate the treatment of local recurrence after sphincter preserving surgery for low rectal cancer. Methods Fifty-six patients with local recurrence after sphincter preserving surgery for low rectal cancer were divided into three groups, 20 cases underwent radical resection (group A), 21 cases underwent palliative resection combined with 3 dimensional conformal radiation therapy (group B), and 15 cases only received 3 dimensional conformal radiation therapy (group C). Results All the patients were followed up from 6 months to 3 years. The 1-year,2-year and 3-year survival rates were 100.0%(20/20),80.0% (16/20),65.0% (13/20) in group A,90.5% (19/21),52.4% (11/21),33.3% (7/21) in group B and 80.0%(12/15),40.0%(6/15),20.0%(3/15) in group C respectively. Both 2-year and 3-year survival rates in group A were significantly higher than those in group B and group C (P <0.05). Conclusions The first choice of patients with local recurrence after sphincter preserving surgery for low rectal cancer is radical resection. Palliative resection combined with 3 dimensional conformal radiation therapy is the second choice.

Dosimetry Study of IMRT and 3D-CRT Radiotherapies for Patients with Upper Esophageal Carcinoma / 中国医学物理学杂志

Objective: To compare the difference of intensity modulated radiation therapy (IMRT),3-D imensional conformal radiation therapy (3DCRT) for patients with upper esophageal carcinoma. Methods: Ten patients with upper esophageal carcinoma were treated by intensity modulated radiation therapy and 3-D imensional conformal radiation therapy at the same TPS, the difference of exposure dose between target area and critical organ was compared by dose volume histogram(DVH) with the plan target volume (PTV) must reach 95% of the prescription dose. Results: There was significant difference in dose of 95% plan target volume (PTV) (P 0.05). Compared with 3D-CRT, IMRT planning has better dose distribution and protection of normal tissue. Conclusions: IMRT was better than 3DCRT, IMRT is the best radiation therapy.

Evaluation of Xerostomia Following 3 Dimensional Conformal Radiotherapy for Nasopharyngeal Cancer Patients / 대한방사선종양학회지

PURPOSE: This study is to evaluate the xerostomia following 3-dimensional conformal radiation therapy (3D CRT) in nasopharynx cancer patients using the xerostomia questionnaire score (XQS). MATERIALS AND METHODS: Questionnaire study was done on 51 patients with nasopharynx cancer who received 3D CRT from Dec. 2000 to Aug. 2005. 3D CRT technique is based on "serial shrinking field" concept by 3 times of computed tomography (CT) simulation. Total target dose to the primary tumor was 72 Gy with 1.8 Gy daily fractions. Xerostomia was assessed with 4-questions XQS, and the associations between XQS and time elapsed after RT, age, sex, stage, concurrent chemotherapy, and parotid dose were analyzed. RESULTS: Concurrent chemotherapy was given to 40 patients and RT alone was given to 11 patients. The median time elapsed after 3D CRT was 20 (1~58) months and the mean XQS of all 51 patients was 8.4+/-1.9 (6~14). XQS continuously and significantly decreased over time after 3D CRT (x(2)=-0.484, p or=35 Gy was significantly higher than or=35 Gy were suggested to adversely affect radiation-induced xerostomia.

Evaluating the efficacy of transcatheter arterial chemoembolization combined with hypofractionated 3- dimensional conformal radiotherapy for hepatocellular carcinoma / 中华消化杂志

Objective To evaluate the efficacy of transcatheter arterial chemoembolization (TACE) combined with hypofractionated 3 dimensional conformal radiotherapy for hepatocellular carcinoma (HCC). Methods During May 1998 and Dec. 1999, 81 unresectable HCC patients were divided into two groups. Forty one patients in group A were treated with TACE and hypofractionated 3 dimensional conformal radiotherapy and 40 patients in group B were treated with TACE alone. Acute effects were analyzed and survival rates were assessed from the date of the beginning of treatment using the Kaplan Meier method. The survival rates of two groups were compared using Log rank. The Cox proportional hazards model was used to analyze the prognostic factors in group A. Results The objective response rate in group A was higher than that in group B (85.4% vs. 65.0% , P

Objective Analysis of the Set-up Error and Tumor Movementin Lung Cancer Patients using Electronic Portal Imaging Device / 대한치료방사선과학회지

PURPOSE: The aim of this study is to investigate the random and systematic errors and tumor movement using electronic portal imaging device in lung cancer patients for the adequate margin in the treatment planning of 3-dimensional conformal therapy. METHODS AND MATERIALS: The electronic portal imaging device is matrix ion chamber type(Portal Vision, Varian). Ten patients of lung cancer treated with chest irradiation were selected for this study. Patients were treated in the supine position without immobilization device. All treatments were delivered by an 10 MV linear accelerator that had the portal imaging system mounted to its gantry. AP or PA field portal images were only analyzed. Radiation therapy field included the tumor, mediastinum, and supraclavicular lymph nodes. A total of 103 portal images wereanalyzed for set-up deviation and 10 multiple images were analyzed for tumor movement because of respiration and cardiac motion. RESULTS: The average values of setup displacements in the x, y direction was 1.41 mm, 1.78 mm, respectively. The standard deviation of systematic component was 4.63 mm, 4.11mm along the x,y axis, respectively while the random component was 4.17 mm in the x direction and 3.31 mm in the y direction. The average displacement from respiratory movement was 12.2 mm with a standard deviation of 4.03 mm CONCLUSION: The overall set-up displacement includes both random and systematic component and respiratory movement. About 10 mm, 25 mm margins along x,y axis which considered the set-up displacement and tumor movement were required for initial 3-dimensional conformal treatment planning in the lung cancer patients and portal images should be madeand analyzed during first week of treatment, individually.