Gastric Cancer Adjuvant Radiotherapy Target Volume Design:Based On The Postoperative Local Recurrence Spatial Location

ObjectivesTo explore the areas at highest risk for postoperative gastric cancer local recurrence according to the spatial location of local failures,with the aim to provide a precise target volume for gastric cancer adjuvant radiotherapy.MethodsPatients with gastric cancer who had undergone surgery for the primary tumor in stomach at our institution from January 1,2009 to May 31,2012 were retrospectively analyzed.All local recurrences were plotted and distinguished on the computed tomography(CT)image of a representative patient according to the classification of the lymph node stations of the stomach and the perigastric region according to the JGCA.Statistics out of each frequency of lymph node recurrence,according to the frequency from high to low order,and get an intuitive expression of the high-risk relapsing areas of gastric cancer,to design gastric cancer adjuvant radiotherapy target volume based on the local recurrence spatial location.IBM SPSS 23.0 was used to analyze the data.ResultsTo the line of this time period,there are totally 989 cases of patients with gastric cancer radical,a total of 340 cases with postoperative CT review(follow up tim≥3 months)are recorded,and 114(33.5%)patients with local recurrence and/or distant recurrence were included from the 340 postoperative gastric cancer patients who did not receive adjuvant radiotherapy.121 patients did not have adjuvant therapy at all,219(64.4%)patients undergone adjuvant chemotherapy alone.Spatial location of local failure was created.Of the 114 patients,23(20.2%)relapsed in anastomotic stoma,lymph node whose recurrence frequency is beyond 5%are listed as follows:group 16(11.4%),group14(14.0%),group13(9.6%),group12(16.7%),groupll(6.1%),group9(14.9%),group4(5.3%),and group 17(7.9%),group18(5.3%).ConclusionsSmaller adjuvant radiotherapy CTVs targeting the high-risk local failure areas of postoperative gastric cancer were proposed,according to the three-dimensional spatial location of local recurrences.This may help to minimize radiation-related toxicities and reduce local recurrence.