Clinical And Dosimetric Study Of Conformal Radiation Therapy For Cervical Cancer

Cervical cancer is one of the most common gynecological malignancies in women worldwide, which seriously threat to the health of women. Radiotherapy is the primary treatment of cervical cancer. It could be confirmed that the effect of radiotherapy to improve the local control and the overall survival rate for cervical cancer at last century. Conventional radiotherapy, however due to its technical restriction, the more volume of normal tissue, such as small intestine, rectum, bladder might be involved in radiation field, causing significant a serious of acute and chronic side effects. The dose of radiation treatment for tumor is limited at the same time. The three-dimensional radiotherapy techniques, including conformal radiotherapy and intensity modulated radiation therapy makes it possible to deliver highly conformal doses to the tumor while reduce the volume of normal tissues receiving radiation. However, the techniques of three-dimensional radiotherapy applied in gynecologic malignancy underwent in a short period time relatively. The safety and efficacy of conformal radiotherapy for cervical cancer need to be confirmed further. The study is to probe the clinical efficacy of three-dimensional conformal radiation therapy in cervical cancer and compare treatment plannings in dosimetric study among conventional radiotherapy, three-dimensional conformal radiotherapy and intensity modulated radiation therapy. Objective: To investigate the safety, efficacy and clinical value of the proposal about conformal radiotherapy in cervical cancer. Method: We collected the data of patients who were hospitalized in the department of gynecology oncology of Guangxi Tumor Hospital from April 2005 to June 2008. Forty-eight patients in cervical cancer with confirmed the International Federation of Gynecology and Obstetrics stageâ… b1-â…¢b lesions were studied retrospectively. The study Group divided in the three-dimensional conformal radiotherapy group (23 cases) and the conventional radiotherapy group (25 cases) for the control group, respectively. Then compared the short-term efficacy and toxicity and survival. Results: There were no significant rate between two groups with pain relief, short-term effect, tumor progression ,cumulative survival and toxicity in blood. Significant at urinary system and digestive system of the early and late response to radiotherapy between study group and control group, which no one appeared gradeâ…¢serious side effects or above in study group, P<0.05. Conclusion: Three-dimensional conformal radiation therapy for cervical cancer satisfied short-term efficacy and provide fewer side effects at digestive system and urinary system. It is superiority at the protection of normal tissues. Objective: To evaluate the characteristics of conventional radiotherapy, three-dimensional conformal radiotherapy and intensity modulated radiation therapy plans of cervical cancer and to find out the best technique to achieve improved dose homogeneity and sparing of normal tissues for cervical cancer. Methods: We selected 9 cervical cancer to compare the treatment plan, who hospitalized in the Department of gynecology oncology of Guangxi Tumor Hospital form June 2007 to December 2008 and were accepted 3D-CRT or IMRT. This contained of 3 postoperative adjuvant radiotherapy, 3 pelvic recurrence after operation and 3 pelvic recurrence after radical radiotherapy. Designed two-field (AP-PA) radiotherapy (2FC), box three-dimensional conformal radiotherapy (4FC) and 5 or 7 fields intensity modulated radiation therapy (IMRT) treatment plans for each patient by Precise PLAN 2.13 3D treatment system. Evaluation contents included the target isodose distribution, dose-volume histogram (DVH) of target and normal tissue. Results: Among the plans, a statistically significant differences were found in CI (p<0.01), with the best for IMRT and worst for 2FC. Target isodose distribution in conformal radiotherapy plan was superior to the conventional radiotherapy plan, P<0.05. Results of rectum V40, bladder V40, small bowel V30 and spinal cord Dmax in each plan respectively were different with statistically significant . All above parameters were lowest in IMRT plan and highest in 2FC plan. Furthermore, a significant lower mean dose of rectum, bladder and small bowel in IMRT compared to those in 2FC plan, P<0.05. Mean dose of femoral head in 4FC was higher than other plans, while those between IMRT and 2FC plan were resemblance. However, the femoral head V40 was smaller for IMRT than 2FC plan. Conclusion: IMRT and 4FC plan is better than 2FC plan for cervical cancer. It is advantage that dose distribution, target homogeneity, and sparing of normal tissues in IMRT plan for cervical cancer, especially for target dose homogeneity and the sparing of rectum, bladder and spinal cord.