ABSTRACT
BACKGROUND: The present study aimed to better define the usefulness of F-FDG PET/CT in predicting pathological tumor response (PTR) and survival in patients with noncardia gastric cancer treated with preoperative chemotherapy. METHODS: Seventy-one patients were recruited in 6 Italian centers. The SUV of F-FDG PET/CT was measured at baseline and after treatment, and the difference (dSUV) was computed. The association between PET indexes and PTR, assessed by the Becker score, was evaluated by nonparametric regression. The discriminant power of PET indexes with respect to the absence of PTR (Becker 2/3) was studied by receiver operating characteristic (ROC) curve and synthesized by the area under the curve (ROC-AUC). RESULTS: dSUV allowed to partially discriminate between absence/presence of PTR, when expressed as either absolute value (ROC-AUC, 0.73; 95% confidence interval, 0.59-0.87) or percentage (ROC-AUC, 0.74; 95% confidence interval, 0.59-0.89). However, only extreme values of percent dSUV were really informative. All 7 patients whose F-FDG uptake had increased despite preoperative treatment showed no tumor regression at pathologic examination. Seven of the 10 patients whose metabolic response had been 70% or greater had complete or nearly complete pathologic tumor regression (Becker score 1a or 1b). The metabolic response of the remaining 54 patients, which ranged between 0% and 70%, did not permit to reliably forecast pathologic tumor regression. Survival significantly decreased with increasing Becker score but was unaffected by metabolic response. CONCLUSIONS: The present study suggests that F-FDG PET/CT has limited usefulness in predicting cancer regression. The lack of metabolic response in serial measurements indicates the probable ineffectiveness of preoperative treatment.
Subject(s)
Neoplasm Recurrence, Local/drug therapy , Positron Emission Tomography Computed Tomography/standards , Postoperative Complications/diagnostic imaging , Stomach Neoplasms/diagnostic imaging , Aged , Fluorodeoxyglucose F18 , Gallium Isotopes , Gallium Radioisotopes , Humans , Male , Membrane Glycoproteins , Organometallic Compounds , Predictive Value of Tests , Radiopharmaceuticals , Stomach Neoplasms/drug therapy , Stomach Neoplasms/surgeryABSTRACT
The optimal management of patients with resection line involvement after endoscopic or surgical treatment for gastric cancer is debated. In contrast to previous reports, we examined both the experience of endoscopists and surgeons in early-stage lesions and the wide variation in treatments proposed for advanced disease in case of infiltration of resection margins. A PubMed search for papers using the key words: gastric or stomach cancer, or Carcinoma; gastrectomy and positive margins; surgical margins or resection line or endoscopic margin involvement; and R1 resection, from January 2000 to July 2015 was undertaken. Fifty-three studies were considered pertinent to the study. Many endoscopists report that some cases of early gastric cancer with resection line involvement after endoscopic resection have good outcomes notwithstanding incomplete resection, but few surgeons share this opinion. Conversely, it is unanimously agreed that very advanced stages should not be surgically retreated because they are expression of systemic disease. Between early and very advanced cancer the usefulness of re-resection for microscopic resection lines involvement is still debated and surgery may be proposed only when radicality can be achieved. When surgery is not feasible, radiochemotherapy may represent a valid alternative.
