Introduction:Previous studies comparing tomotherapy (TOMO) and three dimensional (3D) conformal radiotherapy (3DCRT) in gastric radiotherapy are limited and tend to be based on dosimetry. The aim of the present study was to evaluate the clinical outcomes of these two treatment modalities. Methods:A total of 51 patients diagnosed with gastric cancer who were treated with postoperative adjuvant chemoradiotherapy and had subtotal/total gastrectomy and D2 lymphatic dissection were recruited to the present study: 30 patients were treated with TOMO and 21 patients were treated with 3DCRT.Results:The 3DCRT and TOMO treatment regimens were compared. There was no difference in planning target volume (PTV) 95%, but TOMO was statistically significant in regard to PTV 105% (P<0.05). TOMO was also significantly different when compared with 3DCRT when evaluating liver mean dose, liver V40, right/left kidneys mean dose, right/left kidneys V20 and spinal cord mean dose values (P<0.05). Grade 2 acute side effects were more frequent (85.7%) following 3DCRT. In addition, the median overall survival time for TOMO treated patients was 62 months while in 3DCRT treated patients it was 22.05 months. The difference in disease free survival was also significantly increased in patients treated with TOMO (66.7% vs. 19.0%; P<0.05). Conclusion:TOMO treatment resulted in lower acute side effects with better patient survival following gastric cancer radiotherapy.

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Background and purpose: During the radiotherapy of breast cancer, especially when the supraclavicular lymph nodes are planned to be treated, a portion of thyroid gland may also be included in the treatment field. In this study we compared thyroid gland dose volume histograms (DVHs) of breast cancer patients receiving radiotherapy, planned in both CT-based three-dimensional planning system and MVCT-based image guidance aspect of helical tomotherapy system.Material and method: 20 breast carcinoma patients who were treated with 3-D conformal radiotherapy technique were evaluated concerning their thyroid gland dose distribution. The estimated minimum, mean and maximum thyroid gland doses were calculated for both 3-D conformal radiothreapy and tomothreapy planning systems. Additionally the volume of thyroid gland that received less than 30 Gy and more than 30 Gy were determined. Results:The maximum, mean and minimum doses of thyroid glands supposed to receive were found to be better with tomotherapy comparing to 3-D conformal therapy plans. The thyroid gland volume that receives more than 30 Gy was smaller in tomothreapy planning system comparing to 3-D conformal therapy planning system. Conclusion:Lower doses of radiation exposure to thyroid gland is possible with Tomotherapy.

Objective: Sodium 2-mercaptoethanosulphinate (mesna) is a synthetic thiol known to prevent hemorrhagic cystitis and nephrotoxicity induced by alkylating anti-neoplastic drugs such as cyclophosphamide and iphosphamide. We proposed that mesna might be effective on protection of radiation induced renal injuries because of its low molecular weight, its ability to concentrate in the kidneys, its conversion to active -SH compounds in the tubular epithelium and its antioxidant potential. Results:There was no statistical difference between the radiotherapy and radiotherapy+mesna groups in terms of creatinine clearance (p>0.05). However; there was statistically significant difference between the control group and radiotherapy/mesna+radiotherapy in terms of blood BUN levels (p<0.05). Inability of mesna to prevent radiotherapy injuries was also confirmed by light microscopy and electron microscopy (p>0.05). Conclusion:Our study may pioneer studies searching for other agents instead of mesna for preventing hemorrhagic cystitis induced by cyclophosphamide and iphosphamide because it showed that mesna cannot protect kidneys from radiation nephrotoxicity on histopathologic evaluation. This is also the first study demonstrating ineffectiveness of mesna as a radioprotectant.