A Rapchak¹*, S Dutta² , A Sadeghi³ , S Inamdar⁴ , T Sokolowski⁵ , C Page⁶ , S Sapareto⁷ , K Rege⁸ , K Subramaniam⁹ , (1) Banner MD Anderson Cancer Center, Gilbert, AZ, (2) Arizona State University, Tempe, AZ, (3) Banner MD Anderson Cancer Center, Gilbert, AZ, (4) Arizona State University, Tempe, AZ, (5) Banner MD Anderson Cancer Center, Gilbert, AZ, (6) Banner MD Anderson Cancer Center, Gilbert, AZ, (7) Banner - University Medical Center Phoenix, Phoenix, AZ, (8) Arizona State University, Tempe, AZ, (9) Arizona State University, Tempe, AZ

• 
  A Rapchak

(Wednesday, 8/1/2018) 10:15 AM - 12:15 PM

Room: Karl Dean Ballroom A1

Purpose: High dose gradient characteristic of the brachytherapy makes in vivo dosimetry challenging.To address this, we have developed a novel nanotechnology based gel dosimeter that changes color upon incidence of ionizing radiation.

Methods: The gel dosimeter contains monovalent gold ions which are converted to zerovalent gold atoms by ionizing radiation. These gold nanoparticles have a characteristic pink/maroon color which can be used to quantify radiation exposure via a basic spectrophotometer. The 1 mm thick gels are placed uniformly onto the caps of Valencia and Leipzig applicators and irradiated to prescription dose.

Results: This intensity of color change corresponds to the intensity of radiation dose delivered to the patient’s surface. The gel response to radiation dose is linear from 100 cGy to 800 cGy which is the typical dose range for HDR skin brachytherapy.

Conclusion: This study concludes that the nanotechnology based gel is a promising and reliable dosimeter for skin HDR in vivo dosimetry with clinically acceptable accuracy. In vivo gel dosimetry provided a true dose spectrum across the surface of the applicators. This novel method holds great promise in the field of HDR Brachytherapy.

Keywords

Gel Dosimeter, Brachytherapy, In Vivo Dosimetry

Taxonomy

TH- Radiation dose measurement devices: 3D solid gel/plastic

Contact Email