Gel Dosimetry in the BNCT Facility for Extra-Corporeal Treatment of Liver Cancer at the HFR Petten

Liver metastases are one of the most frequent kinds of malignancies and represent the most diffused site of recurrence of any primary tumour. Surgical techniques have yielded a remarkable improvement in the results of hepatic resection, but for deep, multiple, huge lesions, which cannot be resected, the prognosis remains extremely poor. In 2000, the BNCT group in Pavia pioneered the extracorporeal treatment of the liver metastases by BNCT, yielding an important impact on life expectation. Consequently, extracorporeal liver treatment is planned at the BNCT facility in the High Flux Reactor located in Petten (The Netherlands) in collaboration with the University Hospital Essen (Germany). The preparation of the human liver treatment starts from the evaluation of the dosimetry of the problem. Therefore several calculations have been performed using Monte Carlo simulations, in order to design a facility optimised to provide as much as possible a homogeneous thermal neutron fluence in the liver. The validation of the calculations is based on the evaluation of the thermal neutron flux inside the liver facility making use of activation foils and gel dosimeters. The gel dosimeter technique is based on the lighting response of a particular gel to gamma interaction. This technique gives an indication of the thermal neutron flux and the doses in the holder. The gel dosimeters are positioned in the liver holder and fixed in position using another gel, whose hydrogen composition is low enough as not to influence the gel dosimeters. The thermal neutron flux calculated appears to be consistent with that obtained by the activation foils. The neutron fluence mappings obtained through the gel dosimeters confirm that the BNCT liver facility in Petten should be able to provide a proper homogeneous neutron distribution in the liver, as required for the successful treatment of the liver metastases.

GAMBARINI Grazia;  DAQUINO Giuseppe Giovanni;  CARRARA Mauro;  NIEVAART Victor Alexander;  MOSS Raymond;  VANOSSI Elena; 

2007-05-30

Oxford University Press

JRC33056

https://publications.jrc.ec.europa.eu/repository/handle/JRC33056,   

10.1093/rpd/ncm123,