CONTRIBUTION OF IN VIVO DOSE MEASUREMENT TO THE INTENSITY MODULATED RADIOTHERAPY TECHNIQUEIN THE TREATMENT OF NASOPHARYNGEAL CANCER


Selek S., TUNÇEL N., CATAN N. İ., GENÇ M., ÜNAL N.

ICMP 2103, Brighton, United Kingdom, 1 - 04 September 2013, vol.1, no.2, pp.568

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • City: Brighton
  • Country: United Kingdom
  • Page Numbers: pp.568
  • Akdeniz University Affiliated: Yes

Abstract

The contribution of in-vivo dose measurement of organs at risk by TLD-LiF100 and IDF-thin IBA diode during IMRT in treatment of nasopharyngeal cancer was studied.

METHODS

IMRT planning were fusion on CT images of rando phantom. For PTVI-II-III the equally angel ninefields IMRT plans were designed using 6MV energy with 200cGy/fr to 50, 60 and 70Gy respectively. The dose measurements for the quality control evaluation of IMRT plans were done. Nasal-cavity location was selected for PTVs. The selected locations for parotid and thyroid were oral-cavity and ear-cavity, and on the skin. Each dosimeter was selected and located on measurement region. In-vivo dose measurements were performed and repeated, the dose for PTV and OARs compared with TPS.

RESULTS

The percentage dose differences between TPS and TLD for nasal-cavity location where represented higher by diode that may be reduced by using suitable fixation. By diode the %dose differences in the ear and oral cavity that recommended locations for parotid were %1.7 and %8.7 in phase-I, %1.5 and %6.7 in phase-II respectively. The calculated and measured dose of thyroid in phase-II (5.8cGy) and phase-III (2cGy) was compatible. In phase-I dose difference were obtained 39%.

CONCLUSION

QA of IMRT nasopharyngeal cancer patients dose by in-vivo dosimetry was determined as an ideal and reliable dose control method in terms of PTV and OARs by TLD or diode.