Hot spot to bone within a PTV calculated as 82.3Gy, 76.8Gy, and 73.3Gy for Dw, AAA, and Dm, respectively.
- Dosimetric commissioning measurements and dose calibration are done in water.
- Our historical clinical experience for tumor response has been using dose-to-water calculation algorithms.
- There are inherent issues involved in using material conversion tables to convert HU values in determining tissue composition for Dm calculations.
- The dose-to-medium mode best represents the true dose based on tissue composition.
- Reporting as Dw requires a stopping power ratio conversion, and there is uncertainty in this conversion.
- Differences in the two reporting modes are not significant for most tissues.
With the debate being far from settled, which reporting method do you use? A Twitter poll of clinical users revealed that 53.8% prefer Dm while 30.8% use Dw in the clinic for patient calculations (and 15.4% aren’t sure). Two other votes were provided via email, both in favor of dose-to-medium reporting. What does your clinic use?
written by Tyler Blackwell