Top Line: The adrenal gland is a common site of metastatic disease, particularly in the heavy hitters like primary lung cancer.
The Study: It’s a shame, then, that this can be one of the most challenging sites to deliver ablative radiation. In fact, a secondary analysis of SABR-COMET revealed 100% of adrenal targets required planning target volume coverage to be compromised in order to meet organ-at-risk constraints. Could this be a potential avenue for clinically meaningful adaptive radiation planning? A large Dutch retrospective look at 70 cases of 5-fraction, MRI-guided ablative radiation to 40-50 Gy for adrenal mets described how tumor volumes changed throughout the relatively short treatment course. Treatments were typically delivered every other day with a breath-hold technique employed for motion management. Roughly half of all tumors decreased in size from fraction 1 to fraction 5. What’s more, a variation in tumor size (bigger or smaller) of at least 20% occurred in 59% of cases. When it comes to tumor control, only 6% experienced a local recurrence at a median of 20 months, and 23% achieved a completed radiographic response that was more likely when a decrease in tumor volume was appreciated during treatment.
TBL: The target volume for adrenal mets can change significantly during a 5-fraction course of ablative radiation. | Giraud, Radiother Oncol 2023
The Study: It’s a shame, then, that this can be one of the most challenging sites to deliver ablative radiation. In fact, a secondary analysis of SABR-COMET revealed 100% of adrenal targets required planning target volume coverage to be compromised in order to meet organ-at-risk constraints. Could this be a potential avenue for clinically meaningful adaptive radiation planning? A large Dutch retrospective look at 70 cases of 5-fraction, MRI-guided ablative radiation to 40-50 Gy for adrenal mets described how tumor volumes changed throughout the relatively short treatment course. Treatments were typically delivered every other day with a breath-hold technique employed for motion management. Roughly half of all tumors decreased in size from fraction 1 to fraction 5. What’s more, a variation in tumor size (bigger or smaller) of at least 20% occurred in 59% of cases. When it comes to tumor control, only 6% experienced a local recurrence at a median of 20 months, and 23% achieved a completed radiographic response that was more likely when a decrease in tumor volume was appreciated during treatment.
TBL: The target volume for adrenal mets can change significantly during a 5-fraction course of ablative radiation. | Giraud, Radiother Oncol 2023