Top Line: Is there a dosimetric threshold to predict anemia after prostate radiation?
The Study: While prostate cancer patients don’t typically experience significant hematologic toxicity, there may still be room to reduce the effects of pelvic radiation on their marrow. In this study of 203 patients treated with prostate radiation, the pelvic bones from L3/4 to the ischial tuberosity were contoured as a surrogate for bone marrow. As would be expected, patients fell into two categories: those with low volume marrow exposure (<1000 cc, 35%), and those with high volume exposure (>1000 cc, 65%). Most patients in the former group (83%) received prostate only radiation compared to 12.1% in the high volume group. They found that patients who received ≥15 Gy to >1000 cc had lower hemoglobin levels than those who did not at 90 days (12.8 v 14.5 g/dL). More useful was the finding that the volume of marrow receiving 15 Gy could be reduced to <1000 cc with plan reoptimization without affecting OAR dose or target coverage.
TBL: Keeping the volume of bone between L3/4 and the ischial tuberosity receiving 15 Gy to <1000 cc may reduce the risk of anemia after prostate radiation. | Fenlon, Int J Radiat Oncol Biol Phys 2023
The Study: While prostate cancer patients don’t typically experience significant hematologic toxicity, there may still be room to reduce the effects of pelvic radiation on their marrow. In this study of 203 patients treated with prostate radiation, the pelvic bones from L3/4 to the ischial tuberosity were contoured as a surrogate for bone marrow. As would be expected, patients fell into two categories: those with low volume marrow exposure (<1000 cc, 35%), and those with high volume exposure (>1000 cc, 65%). Most patients in the former group (83%) received prostate only radiation compared to 12.1% in the high volume group. They found that patients who received ≥15 Gy to >1000 cc had lower hemoglobin levels than those who did not at 90 days (12.8 v 14.5 g/dL). More useful was the finding that the volume of marrow receiving 15 Gy could be reduced to <1000 cc with plan reoptimization without affecting OAR dose or target coverage.
TBL: Keeping the volume of bone between L3/4 and the ischial tuberosity receiving 15 Gy to <1000 cc may reduce the risk of anemia after prostate radiation. | Fenlon, Int J Radiat Oncol Biol Phys 2023