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Forschungsdatenbank PMU-SQQUID

MR-guided percutaneous ethanol ablation of hepatocellular carcinomas before liver transplantation.
Blum, M; Mueller, C; Peck-Radosavljevic, M; Wrba, F; Berlakovich, G; Mühlbacher, F; Steiniger, R; Speiser, M; Pones, M; Hüpfl, M; Lammer, J; Kettenbach, J;
Minim Invasive Ther Allied Technol. 2007; 16(4): 23-40.
Originalarbeiten (Zeitschrift)


Speiser Maria


Linacs equipped with flattening filter-free (FFF) megavoltage photon beams are now commercially available. However, the commissioning of FFF beams poses challenges that are not shared with traditional flattened megavoltage X-ray beams. The planning system must model a beam that is peaked in the center and has an energy spectrum that is softer than the flattened beam. Removing the flattening filter also increases the maximum possible dose rates from 600 MU/min up to 2400 MU/min in some cases; this increase in dose rate affects the recombination correction factor, P(ion), used during absolute dose calibration with ionization chambers. We present the first reported experience of commissioning, verification, and clinical use of the collapsed cone convolution superposition (CCCS) dose calculation algorithm for commercially available flattening filter-free beams. Our commissioning data are compared to previously reported measurements and Monte Carlo studies of FFF beams. Commissioning was verified by making point-dose measurement of test plans, irradiating the RPC lung phantom, and performing patient-specific QA. The average point-dose difference between calculations and measurements of all test plans and all patient specific QA measurements is 0.80%, and the RPC phantom absolute dose differences for the two thermoluminescent dosimeters (TLDs) in the phantom planning target volume (PTV) were 1% and 2%, respectively. One hundred percent (100%) of points in the RPC phantom films passed the RPC gamma criteria of 5% and 5 mm. Our results show that the CCCS algorithm can accurately model FFF beams and calculate SBRT dose distributions using those beams.

Useful keywords (using NLM MeSH Indexing)

Administration, Cutaneous


Carcinoma, Hepatocellular/complications

Carcinoma, Hepatocellular/mortality

Carcinoma, Hepatocellular/therapy*

Combined Modality Therapy



Ethanol/therapeutic use*



Liver Cirrhosis/complications

Liver Cirrhosis/therapy

Liver Neoplasms/complications

Liver Neoplasms/mortality

Liver Neoplasms/therapy*

Liver Transplantation*

Magnetic Resonance Imaging, Interventional


Middle Aged

Neoplasm Recurrence, Local

Find related publications in this database (Keywords)

ethanol injection
hepatocellular carcinoma
MR-guided therapy
tumor ablation
liver transplantation
liver cirrhosis/therapy