ABSTRACT
Objective@#To study the sensitivity of multi-slice spiral CT in the diagnosis of lymph node metastasis in different lymph node stations of gastric cancer.@*Methods@#A retrospective series of case study was employed in the research. Inclusion criteria: (1) patients undergoing preoperative abdominal CT scan plus enhanced examination, and data in the image archiving and communication system of Sun Yat-sen University Cancer Center; (2) patients undergoing total or subtotal gastrectomy plus D2 or D1+ lymphadenectomy, with more than 15 harvested lymph nodes and more than 1 metastatic lymph node confirmed by postoperative pathology; (3) WHO pathological classification defined as gastric adenocarcinoma; (4) no history of lymph node tuberculosis, giant lymph node hyperplasia, lymphoma or other diseases resulting in enlarged lymph nodes; (5) no history of gastrectomy; (6) no preoperative neoadjuvant therapy. Clinicopathologic data of gastric cancer patients at the Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center from January 2009 to December 2012 were retrospectively analyzed. Using the pathologically positive lymph nodes as a reference, the sensitivity of CT-positive lymph nodes was calculated (total number of positive image lymph nodes/total number of positive pathological lymph nodes) and complete coincidence rate (number of case defined as complete coincidence/number of case with positive pathologic lymph nodes; complete coincidence indicated that the number of positive image lymph nodes was consistent with the number of positive pathologic lymph nodes in each lymph node station). The χ2 test was used to compare the sensitivity of CT in the diagnosis of lymph node metastasis in each lymph node station.@*Results@#A total of 228 patients with pathology-proven gastric cancer were enrolled in the study, including 147 male and 81 female. The overall sensitivity of CT in diagnosis of metastatic lymph nodes in gastric cancer was 68.7% (1769/2576). The sensitivity of CT in diagnosis of lymph node metastasis of groups 1 to 8 from high to low was group 3 [81.1% (506/624)], group 7 [73.9% (246/333)], group 2 [70.3% (111/158)], group 6 [68.7% (248/361)], group 4 [68.1% (262/385)], group 8 [60.4% (116/192)], group 1 [53.8% (155/288)], group 5 [47.1% (82/174)]. The CT diagnostic sensitivity of group 3 was significantly higher than the overall level (χ2=37.689, P<0.001). The CT diagnostic sensitivity of group 5 was significantly lower than the overall level (χ2=34.387, P<0.001). The CT diagnostic sensitivity of group 1 was also significantly lower than the overall level (χ2=25.918, P<0.001). Significant differences were not found in the CT diagnostic sensitivity of group 2, 4, 6, 7, 8 compared with the overall level (all P>0.05). The complete coincidence rate was 56.9% (536/942) between pathological positive lymph nodes and CT positive lymph nodes. The highest complete coincidence rate was observed in group 3 (68.0%, 123/181) and the lowest was in group 1 (41.4%, 46/111), whose difference was statistically significant (χ2=9.673, P=0.002).@*Conclusion@#The sensitivity of CT in diagnosis of lymph nodes in different lymph node stations of gastric cancer is different.
ABSTRACT
Objective To quantify the incidental irradiation dose (ⅡD) to lymph node stations of esophagus when treating patients with T1-4N0 M0 thoracic esophageal squamous cell carcinoma (ESCC) with a dose of 60 Gy/30f.Methods Twenty-nine patients with medically inoperable T1-4N0M0 thoracic ESCC were treated with three-dimensional radiotherapy on involved-field.The conformal CTV was re-created using a 3 cm margin in the proximal and distal direction (following the course of the esophagus) beyond the barium esophagogram,endoscopic examination and CT defined GTV and a 0.5 cm margin in the lateral and anteroposterior directions of the CT defined GTV.The PTV encompassed 1 cm proximal and distal margins,0.5 cm radiaI margin on the basis of CTV.Cervical,mediastinal and abdominal lymph nodes were delineated respectively.Equivalent uniform dose (EUD) and other dosimetric paraneters were calculated for each nodal station.Nodal region whose metastasis rate is greater than 5％ was considered a high risk lymph node subgroups.Results Under a 60 Gy dose prescription,the median Dmean and EUD,V40 and V50 were ≥40 Gy,≥85％ and ≥75％ in most of the high risk nodal regions.For the subgroups whose EUD were less than 40 Gy,most of the ⅡD of these regions was significantly associated with the length and location of esophageal tumor (r =0.892,P =0.000).Conclusions Lymph node stations nearby of ESCC received considerable ⅡD with involved-field irradiation which could control subclinical lesions.But more clinical studies should be needed.