Introduction. McDonald study is the gold standard in gastric cancer treatment. NTCP is a guidance tool for planning and to evaluate organs at risk tolerance. Objectives. Analyzed the results of 230 patients of our area of reference treated for gastric cancer and compare liver and kidney NTCP in 3D vs IMRT in 40 patients on based of the analytical parameters. Material and method. We have retrospectively analyzed the results of 230 patients in the area of Vigo diagnosed with gastric cancer,

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... d with radio-chemotherapy after surgery from January 2000 to March 2011. We analysed 40 patients who were treated by 3D radiotherapy, relating data of kidney and hepatic NTCP (XIO method) in function of clinical and analytic parameters and comparing NTCP with those that would be planned with IMRT. Results. The global survival was 65 months of average (0.98-137.9 months). Tolerance was good, only enteritis grade 3:1.8%, diarrhea grade 3: 0.89%, vomit grade 3: 0.87%. In most of the 40 patients analysed and treated with 3D, we found a minimal data of NTCP in the liver; in 10 patients we observed a NTCP more than 10; in the analytical, only hepatopathy grade 2 in 3 patients as the same time of metastasis and in one patient grade 3 (patient with long term alcoholism). IMRT improved the NTCP in all patients. We did not observe differences between both techniques related to NTCP of kidney. Conclusions. We have obtained similar results as in the McDonald study in terms of global survival. The treatment tolerance was good, with low grade of toxicity. IMRT improves the NTCP but we did not find serious alterations in the majority of the patients treated with 3D, only in one patient hepatic toxicity grade 3. We can use IMRT in selected cases with intercurrent pathology to reduce hepatic involvement. http://dx. Purpose. To evaluate high-dose neoadjuvant radiochemotherapy (RCT) followed by surgery in MRI and EUS-Defined Poor-Risk rectal cancer.