Advertisement

Springer Nature is making Coronavirus research free. View research | View latest news | Sign up for updates

Investigation of a MOSFET dosimetry system for midpoint dose verification in prostate 3D CRT/IMRT

Abstract

The suitability of MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) for use in in-vivo dosimetry for IMRT prostate treatment and patient setup errors has been investigated in this work. MOSFETs were placed on entrance and exit surfaces of a number of different phantoms (with varying complexities from homogeneous to anthropomorphic). Dose measurements were then used to calculate a midpoint dose, which was compared with an IC placed at the isocentre. The agreements found between the calculated (MOSFETs) and the measured midpoint dose (IC) was: 0.7 % for a prostate treatment verification and 3.5 % for an IMRT treatment. MOSFETs placed on entry and exit surfaces can detect patient setup offsets of 2 cm, but do not have the sensitivity to confidently detect offsets of 1 cm or smaller.

This is a preview of subscription content, log in to check access.

References

  1. 1.

    Varadhan, R., Miller, J., Garrity, B. and Weber, M.,In vivo prostate IMRT dosimetry with MOSFET detectors using brass buldup caps, Jnl. Appl. Clin. Med. Phys., 7(4), p. 22–32, 2006.

  2. 2.

    Chuang, C.F., Verhey, L.J. and Xia, P.,Investigation of the use of MOSFET for clinical IMRT dosimetric verification, Med. Phys. 29(6), p.1109–1115, 2002.

  3. 3.

    Broggi, S., Fiorino, C. and Calandrino, R.,A simple and robust method for in-vivo midline dose map estimations using diodes and portal detectors, Radiother Oncol., 58(2), p. 169–78, 2001.

  4. 4.

    Jones, A.O. and Kleiman, M.T.,Patient setup and verification for intensity modulated radiation therapy (IMRT), Medical Dosimetry, 28(3), p. 175–183, 2003.

  5. 5.

    Oldham, T.R. and McLean, F.B.,Total ionizing dose effects in MOS Oxides and devices, IEEE Transactions on Nuclear Science, 50(3), p. 483, 2003.

  6. 6.

    Rosenfeld, A.B.,MOSFET dosimetry on modern radiation oncology modalities, Radiation Protection Dosimetry, 101, (1–4), p. 393–398, 2002

  7. 7.

    Huyskens D., Van Dam J. and Dutreix A.,Midplane dose determination using in-vivo dose measurements in combination with portal imaging, Phys. Med. Biol., 39, p. 1089–1101, 1994.

  8. 8.

    Noel, D. and Taylor R., Med. Phys., July 15(3): 254–307, 1994

  9. 9.

    International Commission on Radiation Units and Measurements (ICRU) Report 50:Prescribing, Recording and Reporting Photon Beam Therapy, 1987.

  10. 10.

    Bridier, A and Dutreix, A,A method for dose calculation for high energy photon beams based on measurements performed at reference depth, Acta Oncol. 32(4), p. 525–533, 1993.

Download references

Author information

Correspondence to T. Wiese.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wiese, T., Bezak, E. & Nelligan, R. Investigation of a MOSFET dosimetry system for midpoint dose verification in prostate 3D CRT/IMRT. Australas. Phys. Eng. Sci. Med. 31, 180–190 (2008). https://doi.org/10.1007/BF03179342

Download citation

Key words

  • in-vivo dosimetry
  • MOSFET
  • prostate treatment
  • IMRT