Furthermore, 39% of patients had a tumor burden ≥50% of the target liver volume. The institutional therapeutic algorithm, which was based on the BCLC staging system, is shown in Fig. 1. The 108 patients Kinase Inhibitor Library high throughput received 159 sessions of radioembolization with Y-90 glass microspheres, mainly in lobar fashion. Sixty-one patients (56%) received one session, 43 patients (40%) received two sessions, and four patients (4%) received three sessions. Two patients had retreatment of the same target area after 9 and 12 months due to local progression. The mean first treatment dose was 120 (±18) Gy and the corresponding mean lung shunt fraction was 7.96%. Prior to therapy, the occlusion

of collaterals to the intestine vessels by application of platinum coils was done in 41% of cases. Patients who did not fit basic preconditions such as clearly definable margins of the tumor were excluded from the analysis of radiologic response, leaving a total of 76 patients with follow-up data 30 days after treatment initiation. To evaluate a potential bias of the results by this selection

we analyzed group effects comparing the 32 to the 76 patients by explorative statistical tests. As expected, the 32 patients not assessable by radiology had on average a larger tumor burden and correspondingly slightly worse clinical stages; in all other factors like sex, age, or etiology we observed no evidence for differences between the groups. Assessment was done according to four different evaluation guidelines: (1) RECIST; (2) RECIST with the recent find more NCI amendments (tumor necrosis and lack of enhancement/vascularity by −30% = partial response)13; (3) WHO; and (4) WHO with EASL amendments (tumor necrosis and lack

of enhancement/vascularity by −50% = partial response).12 As shown in Table 2, the partial response, stable disease, and progressive disease rate for the entire sample using the conventional RECIST criteria after 3 months was 16%, 74%, and 10%, respectively. When RECIST criteria with NCI amendments were used for analysis, the response rate changed to 6% complete responders, 35% partial responders, 48% stable disease. Applying WHO Sodium butyrate criteria at the same point, partial response was detectable in 15%, stable disease in 79%, and progressive disease in 6% of patients. Incorporation of EASL modifications of WHO criteria lead to improvement of the rates to 3% complete responders, 37% partial responders, 53% stable disease. Progressive disease remained unchanged. Figure 2 shows the Kaplan-Meier plot for time to progression in 76 HCC patients treated with Y-90 glass microspheres for which radiological follow-up data were available. Although the median TTP for all patients was 10.0 months (95% CI 6.1-16.4 months), these numbers change to 8.0 months (95% CI 5.9-∞ months) for those with PVT and 11.8 months (95% CI 6.1-17.2 months) for those without evidence of PVT.