Total Tumor Volume Should be Considered as an Important Prognostic Factor for Synchronous Multiple Gastric Cancer Patients with Curative Gastrectomy

Synchronous multiple gastric cancer (SMGC) was a special type of gastric cancer with relatively low incidence. This article was designed to demonstrate that the total tumor volume (TTV) should be treated as an important prognostic factor in SMGC patients with curative gastrectomy. This study retrospective analyzed 140 SMGC patients who received curative gastrectomy between December 2004 and December 2014 in our hospital. Clinicopathological features, preoperative evaluation, surgical treatment, and outcome parameters were reviewed and analyzed. This study applied univariate and multivariate analyses to identify the most significant prognostic factors. In the univariate analysis, the TTV, pT_TVNM, pN stage, pT of main tumor were all significant prognostic factors in SMGC patients (all P < 0.05). In the multivariate analysis, pN stage, TTV and pT_TVNM were confirmed to be independent prognostic factors (all P < 0.05). In the comparison of survival analysis, the pT_TVNM stage system (P < 0.05) was superior to the pTNM stage system (P > 0.05) in SMGC patients. In conclusion, the TTV should be considered as an independent prognostic factor in overall survival in SMGC patients who received curative gastrectomy. The pT_TVNM stage should be recommended as a suitable staging system for SMGC patients.

Accuracy and feasibility of estimated tumour volumetry in primary gastric gastrointestinal stromal tumours: validation using semiautomated technique in 127 patients

OBJECTIVES

To validate estimated tumour volumetry in primary gastric gastrointestinal stromal tumours (GISTs) using semiautomated volumetry.

METHODS

In this IRB-approved retrospective study, we measured the three longest diameters in x, y, z axes on CTs of primary gastric GISTs in 127 consecutive patients (52 women, 75 men, mean age 61 years) at our institute between 2000 and 2013. Segmented volumes (Vsegmented) were obtained using commercial software by two radiologists. Estimate volumes (V1-V6) were obtained using formulae for spheres and ellipsoids. Intra- and interobserver agreement of Vsegmented and agreement of V1-6 with Vsegmented were analysed with concordance correlation coefficients (CCC) and Bland-Altman plots.

RESULTS

Median Vsegmented and V1-V6 were 75.9, 124.9, 111.6, 94.0, 94.4, 61.7 and 80.3 cm(3), respectively. There was strong intra- and interobserver agreement for Vsegmented. Agreement with Vsegmented was highest for V6 (scalene ellipsoid, x ≠ y ≠ z), with CCC of 0.96 [95 % CI 0.95-0.97]. Mean relative difference was smallest for V6 (0.6 %), while it was -19.1 % for V5, +14.5 % for V4, +17.9 % for V3, +32.6 % for V2 and +47 % for V1.

CONCLUSION

Ellipsoidal approximations of volume using three measured axes may be used to closely estimate Vsegmented when semiautomated techniques are unavailable.

KEY POINTS

Estimation of tumour volume in primary GIST using mathematical formulae is feasible. Gastric GISTs are rarely spherical. Segmented volumes are highly concordant with three axis-based scalene ellipsoid volumes. Ellipsoid volume can be used as an alternative for automated tumour volumetry.