Addendum to the determination of recombination and polarity correction factors, kS and kP, for small cylindrical ionization chambers in pulsed filtered and unfiltered beams: PTW 31023

Gregor Bruggmoser; Rainer Saum; Rafael Kranzer

doi:10.1016/j.zemedi.2018.11.001

Addendum to the determination of recombination and polarity correction factors, k_S and k_P, for small cylindrical ionization chambers in pulsed filtered and unfiltered beams: PTW 31023

Z Med Phys. 2019 Dec;29(4):368-371. doi: 10.1016/j.zemedi.2018.11.001. Epub 2018 Dec 6.

Authors

Gregor Bruggmoser¹, Rainer Saum², Rafael Kranzer³

Affiliations

¹ Universitätsklinikum Freiburg, Klinik für Strahlenheilkunde, Robert Koch Str. 3, 79106 Freiburg, Germany. Electronic address: gregor.bruggmoser@uniklinik-freiburg.de.
² Universitätsklinikum Freiburg, Klinik für Strahlenheilkunde, Robert Koch Str. 3, 79106 Freiburg, Germany.
³ PTW-Freiburg, Lörracher Str. 7, 79117 Freiburg, Germany.

PMID: 30528414
DOI: 10.1016/j.zemedi.2018.11.001

Abstract

This addendum provides correction factors for the recombination and the polarity effect for the new ionization chamber PTW PinPoint (type 31023). The measurements were made in filtered (WFF) and unfiltered (FFF) high-energy photon beams. It could be confirmed that both the initial and the general recombination effect of the chamber mainly depends on dose per pulse at the point of measurement and is independent of the filtration of the photon beam.

Keywords: Ionization chamber; Polarity effect; Recombination; Saturation loss.

MeSH terms

Humans
Proton Therapy / methods*
Radiometry*
Radiotherapy Dosage