Microdosimetry of irregular field paraffin collimation in fast neutron therapy
Mahyoub, F.; Obeid, M.; Kadachi, A.; Waheed, A.
Strahlentherapie und Onkologie Organ der Deutschen Rontgengesellschaft . 169(6): 377-380
1993
ISSN/ISBN: 0179-7158 PMID: 8316940 Document Number: 407556
The King Faisal Specialist Hospital and Research Center is the only fast neutron therapy facility to utilize paraffin collimation for irregular beam ports. The application of this treatment modification to clinical practice required the microdosimetric characteristics of paraffin to be established. Measurements were made with a tissue equivalent (Rossi) proportional counter at different spatial locations in a water phantom and in air. The neutron beam was shaped by a 10 times 10 cm paraffin collimator. The analytically derived effective relative biological effectiveness (RBE) for 80% survival was approximately 3.5, which is similar to the standard 10 times 10 cm Benelex collimator and is in good agreement with epirical biological observations for this neutron beam.