Application of simplified intensity modulated radiation therapy in gastric cancer after operation / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To elucidate the application and the dosimetry characteristic of the simplified intensity modulated radiation therapy (sIMRT) for gastric cancer after operation, and to compare the dose distribution with intensity modulated radiation therapy (IMRT) and three-dimension conformal radiation therapy (3D-CRT).</p><p><b>METHODS</b>Twelve patients with gastric cancer after operation were enrolled in this study. 3D-CRT plan, 5-field IMRT plans (20 degree, 80 degree, 180 degree, 280 degree, 340 degree) and 5-field sIMRT plans (20 degree, 80 degree, 180 degree, 280 degree, 340 degree) were performed for each patient. The conformal index (CI), heterogeneity index (HI) of the planning target volume (PTV) and the dose of normal organs were analyzed with the dose volume histogram (DVH). The total MU and treatment time were also compared.</p><p><b>RESULTS</b>The sIMRT and IMRT plans had comparable CI (sIMRT>IMRT>3D-CRT), and showed better dose conformity but worse homogeneity than 3D-CRT. The percentage of volume receiving 20 Gy, 25 Gy, 30 Gy and 40 Gy by liver were significantly lower in sIMRT than that in 3D-CRT, and comparable to IMRT. All the dose volumes to kidneys with sIMRT were still significantly lower as compared to 3D-CRT, and comparable to IMRT. The sIMRT plan was better than IMRT plan in total MU and treatment time.</p><p><b>CONCLUSIONS</b>sIMRT has comparable dose distribution in patients with gastric cancer to IMRT, but is significantly better than 3D-CRT. Treatment time of sIMRT is the shortest. So sIMRT technique can be applied more simply.</p>

Three dimensional conformal radiotherapy with late course accelerated hyper-fractionation for ad- vanced esophageal carcinoma / 肿瘤研究与临床

Objective To evaluate the results and toxic effects in three dimensional radiotherapy (3DCRT)with late course accelerated hyper-fractionation for advanced esophageal carcinoma.Methods From December 2001 to December 2003,115 patients were randomly divided into two groups:in 3DCRT group,55 patients were given late course accelerated hyper-fractionation radiotherapy to a total close of 66 Gy (2.0 Gy per fraction,5 times per week;to a dose of 36 Gy were changed into 1.5 Gy/f,2 f/d).In CF group,60 patients were given late course accelerated hyper-fractionation radiotherapy to a total dose of 66 Gy.Results The 1-, 2-,3-,4-year survival rates in 3DCRT group were 63.6 %, 50.9 %, 38.2 %, 30.9 % compared to 58.3 %, 38.3 %,33.3 %,23.3 % in CF group(X~2=4.44,P=0.031),and local control rates in 1-,2-,3-,and 4- years in 3DCRT group were 72.7 %,58.1%,47.2 % and 36.3 %,compared to 53.3 %,40 %,28.3 %,and 20 %(X~2=5.33,P=0.013)in CF group.However,in the 3DCRT group,the incidence of acute esophagitis was similar to CF group; hematogenous toxic and acute bronchitis were similar between the two groups. Late course lung injury in CF group was higher than that in 3DCRT group.Conclusion 3DCRT is able to improve the local control rate and survival rate,and unable to improve acute and late radiation toxie effects.