Open AccessThe dose penumbra of a custom‐made shield used in hemibody skin electron irradiation
Author(s) -
Rivers Charlotte I.,
AlDahlawi Ismail,
Wang Iris Z.,
Singh Anurag K.,
Podgorsak Matthew B.
Publication year - 2016
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1120/jacmp.v17i6.6367
Subject(s) - shield , imaging phantom , shielded cable , materials science , irradiation , dosimetry , electromagnetic shielding , penumbra , optics , nuclear medicine , physics , electrical engineering , nuclear physics , composite material , geology , medicine , engineering , ischemia , petrology , cardiology
We report our technique for hemibody skin electron irradiation with a custom‐made plywood shield. The technique is similar to our clinical total skin electron irradiation (TSEI), performed with a six‐pair dual field (Stanford technique) at an extended source‐to‐skin distance (SSD) of 377 cm, with the addition of a plywood shield placed at 50 cm from the patient. The shield is made of three layers of standard 5/8” thick plywood (total thickness of 4.75 cm) that are clamped securely on an adjustable‐height stand. Gafchromic EBT3 films were used in assessing the shield's transmission factor and the extent of the dose penumbra region for two different shield‐phantom gaps. The shield transmission factor was found to be about 10%. The width of the penumbra (80%‐to‐20% dose falloff) was measured to be 12 cm for a 50 cm shield‐phantom gap, and reduced slightly to 10 cm for a 35 cm shield‐phantom gap. In vivo dosimetry of a real case confirmed the expected shielded area dose. PACS number(s): 87.53.Bn