Radiation dosimetry in the combined cohorts.
tumor, tumors
TUMOR, TUMORS
To better characterize the tumor coverage by the prescription dose, additional dosimetric comparisons were made between partial-Rx and complete-Rx tumors. The planning target volume (PTV) is the target of the prescription dose and is commonly defined as the tumor plus margin to allow for setup uncertainty. Coverage of the PTV by the radiation prescription dose was assessed using 2 metrics: the percentage of the prescription dose received by 100% of the PTV (D100%) and the percentage of the prescription dose received by the hottest 90% of the PTV (D90%). The study protocol required that sparing of OARs be prioritized over tumor coverage. Therefore, the D100% and D90% in this patient cohort are lower than what are commonly seen in conventional SBRT plans. For complete-Rx versus partial-Rx tumors, the median (interquartile range) D100% was 75% (52%–90%) and 49% (18%–82%), respectively, and the median D90% was 99% (85%–102%) and 82% (46%–99%), respectively. Comparing complete-Rx versus partial-Rx tumors, both the D100% (