ABSTRACT
OBJECTIVE: Advances in hepatic radioembolization are based on a selective approach with radical intent and the use of multicompartment dosimetric analysis. The objective of this study is to assess the utility of voxel-based dosimetry in the quantification of actual absorbed doses in radiation segmentectomy procedures and to establish cutoff values predictive of response. METHODS: Ambispective study in hepatocarcinoma patients treated with radiation segmentectomy. Calculated dosimetric parameters were mean tumor-absorbed dose, maximum tumor AD, minimal tumor AD in 30, 50, and 70% of tumor volume and mean AD in non-tumor liver. The actual absorbed dose (aAD) was calculated on the Y-90-PET/CT image using 3D voxel-based dosimetry software. To assess radiological response, localized mRECIST criteria were used. The objective response rate (ORR) was defined as CR or PR. RESULTS: Twenty-four HCC patients, BCLC 0 (5), A (17) and B (2) were included. The mean yttrium-90 administered activity was 1.38 GBq in a mean angiosome volume of 206.9 cc and tumor volume 56.01 cc. The mean theoretical AD was 306.3 Gy and aAD 352 Gy. A very low concordance was observed between both parameters (rho_c 0.027). ORR at 3 and 6 m was 84.21% and 92.31%, respectively. Statistically significant relationship was observed between the maximum tumor-absorbed dose and complete radiological response at 3 m (p 0.022). CONCLUSION: A segmental approach with radical intention leads to response rates greater than 90%, being the tumor maximum absorbed dose the dosimetric parameter that best predicts radiological response in voxel-based dosimetry.
ABSTRACT
BACKGROUND: Transarterial chemoembolisation (TACE), having demonstrated survival benefits, is the treatmentof choice in intermediate-stage hepatocellular carcinoma, although there is great heterogeneity in its clinical application. MATERIAL AND METHODS: A survey was sent to the Madrid Regional hospitals to assess applicability, indications and treatment protocols. The assessment was made overall and according to the type of hospital (groups A vs. B and C). RESULTS: Seventeen out of 22 hospitals responded (8/8 group A, 9/ 14 group B-C). All do/indicate transarterial chemoembolisation, 13/17 at their own facilities. Eight of the 17 hospitals have multidisciplinary groups (5/8 A, 3/9 B-C). Nine hospitals perform > 20 procedures/year (7 group A), and 6 from group B-C request/perform < 10/year. It is performed on an "on-demand" basis in 12/17. In 5 hospitals, all the procedures use drug-eluting beads loaded with doxorubicin. The average number of procedures per patient is 2. The mean time from diagnosis of hepatocellular carcinoma to transarterial chemoembolisation is ≤ 2 months in 16 hospitals. In 11/17 hospitals, response is assessed by computed tomography. Radiological response is measured without specific criteria in 12/17 and the other five hospitals (4 group A) assessed using standardised criteria. CONCLUSION: Uniformity among the Madrid Regional hospitals was found in the indication and treatment regimen. The use of DEB-TACE has become the preferred form of TACE in clinical practice. The differentiating factors for the more specialised hospitals are a larger volume of procedures, decision-making by multidisciplinary committees and assessment of radiological response more likely to be standardised.
