Tumor response and clinical outcome in metastatic gastrointestinal stromal tumors under sunitinib therapy: Comparison of RECIST, Choi and volumetric criteria

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

“…Studies have shown that liver metastases in GIST are better assessed as ellipsoids rather than as spheres [11; 12; 29]. Schiavon et al attempted volumetric analysis in assessing response of hepatic metastases from GIST [11; 12].…”

“…On the other hand, using mathematical formulae for spheres and ellipsoids to calculate tumour volume can be feasible where automated software is not available, can be less time-consuming, and help standardization of volume criteria by decreasing operator dependence. Few studies especially in the setting of liver metastases have shown that volume can be estimated with mathematical formulae using the linear measurements obtained from cross-sectional imaging [19; 29]. In an earlier study from our institute, we used estimated volumes calculated from the mathematical formula for ellipsoids to assess response of primary GIST to neoadjuvant imatinib [5], but the accuracy of those volume estimates compared to true tumour volumes was not evaluated.…”

Update on Gastrointestinal Stromal Tumors for Radiologists

“…It is not known if the dramatic density changes seen with imatinib occur when challenged with new TKIs. Few recent studies have attempted to study the various treatment response criteria in metastatic GIST patients treated with second- and third-line TKIs and correlate them with survival (424344). In the study by Schramm et al (42), RECIST, Choi and volumetric criteria were compared in 20 patients with metastatic GIST treated with second-line sunitinib at 3-months and 1-year intervals after start of treatment and were correlated with disease specific survival (DSS).…”

“…Few recent studies have attempted to study the various treatment response criteria in metastatic GIST patients treated with second- and third-line TKIs and correlate them with survival (424344). In the study by Schramm et al (42), RECIST, Choi and volumetric criteria were compared in 20 patients with metastatic GIST treated with second-line sunitinib at 3-months and 1-year intervals after start of treatment and were correlated with disease specific survival (DSS). The authors found that though Choi criteria classified more number of patients as partial responders on 3-month and 1-year scans, partial responders by Choi criteria at 1-year follow-up had shorter DSS than patients with stable disease (SD) or progressive disease (PD) (42).…”

“…The best correlation of DSS was with RECIST. Partial responders as per RECIST had the longest DSS and patients with PD per RECIST had the shortest survival on both 3-month and 1-year scans (42). Accordingly, the authors concluded that Choi criteria may not be helpful in identifying patients who tend to have longer survival on follow-up scans while treating with second-line sunitinib (42).…”