Treatment of Gastric Peritoneal Carcinomatosis by Association of Complete Surgical Resection of the Lesions and Intraperitoneal Immunotherapy Using Catumaxomab

Inclusion Criteria: * consent form signed * Age \>= 18 * Carcinomatosis pre operative known or discivered in intraoperative * Patients uin good general condition who may have extent surgery associated to specific inflammatory syndrom of immunotherapy * Patients in good general condition * Patient insured to social care Inclusion Criteria (intraoperative): * Gastric adenocarcinoma with macroscopic peritoneal carcinomatosis (PC) confirmed by extemporaneous histological examination * CP extension minimal or moderate (peritoneal index ≤ 12). * Resection of the entire macroscopic lesions detectable (primary tumor, lymph nodes and CP). cleaning D2 lymph node (or D1.5). Exclusion Criteria: * Presence of metastasis in reach * Previous treatment with a non-humanized monoclonal AC- (mice or rat) * Hypersensitivity to any type of antibody. * History of cancer within 5 years preceding the entry in the trial other than basal cell skin carcinoma or in situ of the cervix, * Patients already included in another clinical trial with experimental molecule * Pregnant, or likely to be or breastfeeding, (Women of childbearing potential should have a pregnancy test (blood) negative 15 days before the date of the surgery) Using of a suitable method of contraception for patients of childbearing age during treatment. adequate contraception Methods includeare: an intrauterine device, hormonal contraception, condom use combined with a spermicide * Persons deprived of liberty or Trust (including curatorship) * Unable to undergo medical test for geographical, social or psychological. Exclusion Criteria (intraoperative): * Persistent peritoneal lesions visible to the end of the surgery * Resection of the tail of the pancreas or pancreatic break (because no drainage post-op); break pleural (for K cardia) * Presence of metastasis in reach during surgery (except for ovarian metastasis