RSs.
RS, tumor
SOLID TUMORS, TUMOR, METASTASIS, METASTASES
RSs were calculated using previously reported methods from pretreatment CT simulation images acquired from a Philips CT scanner (RS was calculated for each irradiated tumor (metastasis-level) and for each patient (patient-level). The patient-level RS was generated by averaging the RSs from all irradiated metastases within each patient. First, the RS was analyzed as a continuous variable at both the metastasis and patient levels. Second, the RS was dichotomized into 2 groups using the previously reported low- and high-RS cutoff values in patients with large, advanced, solid tumors (