Therapy response assessment in metastatic melanoma patients treated with a BRAF inhibitor: adapted Choi criteria can reflect early therapy response better than does RECIST.

PURPOSE: Targeted therapy can lead to considerable tumor reduction and may result initially in altered tissue at constant tumor size. In this setting, Response Evaluation Criteria in Solid Tumors (RECIST) can be inadequate for assessing early treatment response. Choi-criteria combine both size and density measurements. Our purpose was to evaluate computed tomography (CT) images of melanoma patients under BRAF-inhibitor therapy according to Choi-criteria which were adapted to our study (aChoi). MATERIAL AND METHODS: Twelve patients (four male, eight female, mean age 49) with stage IV melanoma treated with a BRAF inhibitor were included. Response was assessed according to RECIST for 39 lesions in contrast-enhanced CT. Target volumes are semiautomatically segmented to calculate mean density for aChoi-criteria, thus using a two-dimensional nonstandardized region of interest could be prevented. RESULTS: Eight patients are RECIST responders. aChoi-criteria indicate therapy response earlier compared to RECIST in five of eight patients. In seven cases, tumor density in CT had decreased 8 weeks after therapy start, whereas in some cases tumor size diminished less or even increased. Response according to aChoi was diagnosed in seven patients who showed in RECIST-evaluation stable disease in five and partial response in two cases. Fifteen weeks after therapy start almost all patients within the aChoi responders were RECIST responders, too. Only one aChoi responder showed still stable disease in RECIST. CONCLUSION: Our initial data indicate that aChoi-criteria can reflect response to vemurafenib earlier compared to RECIST. This is of clinical significance as BRAF-inhibitors are cost-intensive targeted therapies and can cause severe side effects, so criteria for early therapy response have to be evaluated.

Quantitative therapy response assessment by volumetric iodine-uptake measurement: initial experience in patients with advanced hepatocellular carcinoma treated with sorafenib.

OBJECTIVES: To investigate the volumetric iodine-uptake (VIU) changes by dual-energy CT (DECT) in assessing the response to sorafenib treated hepatocellular carcinoma (HCC) patients, compared with AASLD (American Association for the Study of Liver Diseases) and Choi criteria. MATERIALS AND METHODS: Fifteen patients with HCC receiving sorafenib, monitored with contrast-enhanced DECT scans at baseline and a minimum of one follow-up (8-12 weeks) were retrospectively evaluated. 30 target lesions in total were analyzed for tumor response according to VIU and adapted Choi criteria and compared with the standard AASLD. RESULTS: According to AASLD criteria, 67% target lesions showed disease control: partial response (PR) in 3% and stable disease (SD) in 63%. 33% lesions progressed (PD). Disease control rate presented by VIU (60%) was similar to AASLD (67%) and Choi (63%) (P>0.05). For disease control group, change in mean VIU was from 149.5 ± 338.3mg to 108.5 ± 284.1mg (decreased 19.1 ± 42.9%); and for progressive disease group, change in mean VIU was from 163.7 ± 346.7 mg to 263.9 ± 537.2 mg (increased 230.5 ± 253.1%). Compared to AASLD (PR, 3%), VIU and Choi presented more PR (33% and 30%, respectively) in disease control group (P<0.05). VIU has moderate consistency with both AASLD (kappa=0.714; P<0.005) and Choi (kappa=0.648; P<0.005), while VIU showed a better consistency and correlation with AASLD (kappa=0.714; P<0.005; r=0.666, P<0.005) than Choi with AASLD (kappa=0.634, P<0.005; r=0.102, P=0.296). CONCLUSION: VIU measurements by DECT can evaluate the disease control consistent with the current standard AASLD. Measurements are semi-automatic and therefore easy and robust to apply. As VIU reflects vital tumor burden in HCC, it is likely to be an optimal tumor response biomarker in HCC.

Assessment of thoracic aortic conformational changes by four-dimensional computed tomography angiography in patients with chronic aortic dissection type b.

To characterize the heartbeat-related distension of dissected and non-dissected thoracic aortic segments in chronic aortic dissection type b (CADB) ECG-gated computed tomography angiography was performed in ten CADB patients. For 20 time points of the R-R interval, multiplanar reformations were taken at non-dissected (A, B) and dissected (C) aorta: ascending aorta (A), aortic vertex (B), 10 cm distal to left subclavian (Ct, true channel; Cf, false channel). Relative amplitudes of aortic area and major and minor axis diameter changes were quantified. Area amplitudes were 12.9 +/- 3.7%, 11.4 +/- 1.8%, 16.5 +/- 5.9% and 10.5 +/- 5.7% at A, B, Ct and Cf, respectively. Area amplitudes were significantly greater at Ct than at Cf and B (p < 0.05). Major axis diameter amplitudes were 7.7 +/- 1.9%, 6.2 +/- 1.3%, 5.9 +/- 2.0% and 6.1 +/- 3.6% at A, B, Ct and Cf, respectively. There were no differences in major axis diameter amplitudes. Minor axis diameter amplitudes were 6.7 +/- 2.1%, 8.4 +/- 1.9%, 12.7 +/- 6.3% and 6.0 +/- 2.2% at A, B, Ct and Cf, respectively. Minor axis diameter amplitudes were significantly the greatest at Ct (p < 0.05). In CADB, the heartbeat-related distension of aortic area and diameter is evenly distributed over the non-dissected aortic arch. As a result from different blood flow properties, there are significantly greater conformational changes in the true channel of the dissected aorta.