A dosimetry intercomparison phantom for intraoperative radiotherapy

Suitability of radiochromic films for dosimetry of low energy X‐rays

“…However, the combination of rapid energy change with distance in water with the energy dependencies found here suggest a level of accuracy that is well surpassed by using a low‐energy ionization chamber. In contrast however, Armoogum and Watson (34) investigated the Gafchromic XR Type‐R film with the same type of intraoperative source and found an energy response that was sufficiently small (less then 6% across the range 30 kVp to 50 kVp) to enable use of the film for dosimetric intercomparison between devices. They irradiated films at a fixed source‐to‐film distance in their experiments and varied energy by adjusting the kV of the source.…”

An investigation into the INTRABEAM miniature x‐ray source dosimetry using ionization chamber and radiochromic film measurements

“…Radiochromic films, such as Gafchromic models, have been used in previous studies to investigate the relative and absolute dosimetry of the INTRABEAM system. 19,21,22 Accurate dosimetry with these films is challenging, as they are known to have an energy-dependent response at low photon energies. [23][24][25] Eaton and Duck reported differences of up to 6.9% between percent depth dose curves measured with an ionization chamber and Gafchromic EBT film, 19 and up to 8.8% local difference (<10 mm from applicator surface) and 4.8% absolute (>10 mm from applicator surface) difference from the manufacturer (i.e., TARGIT) depth dose curve.…”

“…Radiochromic films, such as Gafchromic models, have been used in previous studies to investigate the relative and absolute dosimetry of the INTRABEAM system . Accurate dosimetry with these films is challenging, as they are known to have an energy‐dependent response at low photon energies .…”

Quality assurance and independent dosimetry for an intraoperative x‐ray device

“…Radiochromic film is selfdeveloping, reducing the variation due to wet processing, and more tissue equivalent, but requires careful handling to reduce other uncertainties, such as nonuniformity. Early investigators of the PRS system used radiochromic film to measure isotropy 6, 7, 42 and depth doses, 22,29,42 and more recently it has been used to intercompare different sources, 44 validate novel applicator designs, 12 or for in vivo dosimetry. 24 Hakim et al 42 used Gafchromic MD-810 film (International Specialty Products, ISP) in a solid water phantom (Gammex) to confirm the inverse cube dependence of dose on distance from the source (without applicator attached).…”