Patients aren’t the only ones holding their breath during ablative radiation delivery for targets immediately below the diaphragm. Here is the experience at a Miami center employing a SMART workflow when targets were within 5 mm of sensitive structures such as bowel. Across 138 patients with 183 oligometastatic targets below the diaphragm receiving a median prescription dose of 50 Gy in 5 fractions, the local control at 1 and 2 years was an impressive 91% and 84%. Most notably, the two-year late grade 3+ toxicity rate was only 2%. The SMART protocol was used for roughly two-thirds of targets due to OAR proximity, mostly to account for daily fluctuations in luminal GI structures (think relation of stomach to left adrenal met). As expected, distant failure accounted for almost all failure with only three patients experiencing isolated local failure. This is particularly important to note for targets whose local growth could cause significant detriments to quality-of-life and performance status (think celiac axis nodes). | Akdemir, Int J Radiat Oncol Biol Phys 2025
