A Dosimetric Study And Observation Of Tolerability Among Two Radiation Therapy In Postoperative Treatment Of Cervical Cancer

Part one A dosimetric study among two radiation therapy in postoperative treatment of cervical cancerObjective:To evaluate dosimetric characteristics of three-dimensional conformal radiotherapy and intensity modulated radiation therapy and to provide a reference for the design of the radiotherapy plans in postoperative treatment of cervical cancer.Method:We collected the data of twenty postoperative cervical cancer patients who were hospitalized in the department of radiotherapy in Affiliated Hospital of Guilin Medical College from October2010to October2011. Treatment plans were designed by Pinnacle3V7.0treatment system for all the patients:4fields three-dimensional conformal radiotherapy (4FC) and7fields Intensity Modulated Radiation Therapy (7f-IMRT). The prescribed dose was Unified, To evaluate the dosimeteric characteristics, the target dose distribution of PTV and OAR.Results:(1)The minimum dose distribution parameters in IMRT and4FC plans were (43.1±0.3)Gy and(46.8±0.2)Gy,the maximum dose distribution parameters in IMRT and4FC plans were (55.6±1.0)Gy and(53.7±0.4) Gy, the CI in IMRT and4FC plans were0.82±0.03and0.48±0.07, the HI in IMRT plans and4FC plans were1.10±0.02and1.04±0.02,all of the differences have statistical significance(p<0.001);(2)At radiation level of≥30Gy,the irradiated volume of small intestine, rectum, and bladder were smaller in IMRT than in4FC plans, the difference has statistical significance(p<0.001); the irradiated volume of colon (at radiation level of≥45Gy) and bone marrow(at radiation level of≥20Gy) were smaller in IMRT than in4FC plans, the difference has statistical significance(p<0.001); At radiation level of10Gy,the irradiated volume of small intestine and colon were larger in IMRT than in4FC plans, the difference has statistical significance(p<0.05).Conclusion:Both the IMRT and4FC plan could satisfied with the clinical dosimetry requirments. protection of normal tissues and target homogeneity in IMRT was superior to the4FC plan. IMRT plan was better than4FC plan in postoperative treatment of cervical cancer at dosimetric characteristics analysis. Part two Clinical observation of concurrent intensity modulated radiation therapy and chemotherapy in postoperative treatment of cervical cancerObjective:To investigate the tolerace of treatment and adverse effects of the concurrent intensity modulated radiation therapy and chemotherapy in postoperative treatment of cervical cancer.Method:We collected the data of sixty-two patients who were hospitalized in the department of radiotherapy in Affiliated Hospital of Guilin Medical College from October2009to November2011.All of the patients were following primary surgery, and were divided into two groups. The experimental group included32cases who had undergone intensity modulated radiation therapy. The control group included30cases, who had undergone conventional radiotherapy.All of the two patients received two cycles of intravenous chemotherapy (PTX135mg/m2d1+DDP30mg/m2d1-3),The differences in rate of early concurrent chemoradiation side effects were observed.Results:The severity of acute radiation damage in gastrointestinal and hematology between the two groups has no statistical significance(P>0.05). The severity of acute radiation damage in the urinary system in the experimental group was lower than control group, the difference was statistically significant (P<0.05). The severity of acute radiation damage in skin in the experimental group was lower than control group, the difference was statistically significant (P<0.001).The filling of the bladder was better in the experimental group.Conclusion:The tolerability was good for cervical cancer patients who followed IMRT concurrent with chemotherapy in postoperative treatment IMRT had an advantage in the protection of normal tissues. It could reduce side effects at urinary system and was superiority at protection of the skin. IMRT could also improve the patients’quality of life.