Review of the results of the in vivo dosimetry during total skin electron beam therapy

Abstract

This work reviews results of in vivo dosimetry (IVD) for total skin electron beam (TSEB) therapy, focusing on new methods, data emerged within 2012. All quoted data are based on a careful review of the literature reporting IVD results for patients treated by means of TSEB therapy. Many of the reviewed papers refer mainly to now old studies and/or old guidelines and recommendations (by IAEA, AAPM and EORTC), because (due to intrinsic rareness of TSEB-treated pathologies) only a limited number of works and reports with a large set of numerical data and proper statistical analysis is up-to-day available in scientific literature. Nonetheless, a general summary of the results obtained by the now numerous IVD techniques available is reported; innovative devices and methods, together with areas of possible further and possibly multicenter investigations for TSEB therapies are highlighted.

A novel Hemi-Body Irradiation technique using electron beams (HBIe−)

“…In addition, the homogeneity index (C.V.) of the Upper HBIetreatment dose distribution was 7% for the total 6 single fields. For TSEB sessions of the similar setup and in vivo dosimetry (6 dual-fields with scatter) the TLD measurements homogeneity was 15.4% for 67 cases [29]. Lower HBIeproduces a greater C.V. and that is mainly due to the limited area on which readings were taken due to phantom size limitations.…”

“…The TLD calibration in HBIesetup was selected to present the surface dose results on the anthropomorphic phantom, since it reflects more adequately the conditions during the patient's irradiation. The number of the TLDs used in Upper and Lower HBIedose verification were 42 and 44 respectively, almost twice the average number of TLDs used for in-vivo dosimetry during TSEB sessions [29]. The average doses on upper or lower body were almost identical with the prescribed dose for both techniques (Upper and Lower HBIe -)yielding a 1.5% difference.…”

Improving treatment geometries in total skin electron therapy: Experimental investigation of linac angles and floor scatter dose contributions using Cherenkov imaging

“…Typical dose measurement techniques used for TSET commissioning are limited to sparse point measurements using thermoluminescent dosimeters (TLDS), diodes, optically stimulated luminescent dosimeters (OSLDs), ionization chambers, or more regional two‐dimensional (2D) film measurements . As a result of this, in conjunction with the large field sizes and extended source to surface distances (SSDs) required for this treatment, there are limited techniques to quickly evaluate the dose distribution in the treatment field as a whole at high resolution.…”

The dose penumbra of a custom‐made shield used in hemibody skin electron irradiation

“…Measurements of doses in shielded sites (i.e., the forehead and upper body) are consistent with the transmission factor results at a dose 10% of prescription. The doses delivered to the lower‐body skin are about 14%–18% higher than the prescribed 180 cGy dose, which exceeds the typically desired dose uniformity of 10% in total skin electron irradiation (TSEI) (11) . This might be explained by the large anatomy of this particular patient.…”