Dosimetric verification of complex radiotherapy with a 3D optically based dosimetry system: dose painting and target tracking

Acta Oncol. 2013 Oct;52(7):1445-50. doi: 10.3109/0284186X.2013.813965. Epub 2013 Aug 19.


Background: The increasing complexity of radiotherapy (RT) has motivated research into three-dimensional (3D) dosimetry. In this study we investigate the use of 3D dosimetry with polymerizing gels and optical computed tomography (optical CT) as a verification tool for complex RT: dose painting and target tracking.

Materials and methods: For the dose painting studies, two dosimeters were irradiated with a seven-field intensity modulated radiotherapy (IMRT) plan with and without dose prescription based on a hypoxia image dataset of a head and neck patient. In the tracking experiments, two dosimeters were irradiated with a volumetric modulated arc therapy (VMAT) plan with and without clinically measured prostate motion and a third with both motion and target tracking. To assess the performance, 3D gamma analyses were performed between measured and calculated stationary dose distributions.

Results: Gamma pass-rates of 95.3% and 97.3% were achieved for the standard and dose-painted IMRT plans. Gamma pass-rates of 91.4% and 54.4% were obtained for the stationary and moving dosimeter, respectively, while tracking increased the pass-rate for the moving dosimeter to 90.4%.

Conclusions: This study has shown that the 3D dosimetry system can reproduce and thus verify complex dose distributions, also when influenced by motion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Image Processing, Computer-Assisted*
  • Imaging, Three-Dimensional*
  • Male
  • Prostatic Neoplasms / diagnostic imaging*
  • Prostatic Neoplasms / radiotherapy*
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted*
  • Radiotherapy, Image-Guided*
  • Radiotherapy, Intensity-Modulated
  • Tomography, X-Ray Computed*