Top Line: Can simple tweaks to whole brain radiation fields reduce salivary toxicity?
The Study: In this multi-institutional trial, 48 patients planned to receive standard whole brain radiation with conventional fields (30-35 Gy in 10-15 fractions) were randomized to standard planning or parotid sparing. Both used conventional planning, so no IMRT. The standard whole brain fields conformed to the skull base and anterior cervical spine down to the level of C1 or C2. In the parotid sparing arm, the parotid was contoured along with the brain to allow as much of the parotid to be blocked as possible while still covering the brain to the foramen magnum. On a lateral DRR, the parotids typically fell in line with the upper cervical vertebral bodies near the skull base. Ideally, <25% of the parotid received 20 Gy. The result: mean parotid dose was reduced from 17→ 10 Gy with reductions across all metrics. Xerostomia score was significantly lower at the end of radiation in the parotid sparing arm, although symptoms improved over time. There were no marginal misses or local relapses with parotid sparing.
TBL: Parotid dose and acute xerostomia can be reduced by simply contouring and partially blocking the parotid glands when designing conventional whole brain fields. | Wang, Int J Radiat Oncol Biol Phys 2025
The Study: In this multi-institutional trial, 48 patients planned to receive standard whole brain radiation with conventional fields (30-35 Gy in 10-15 fractions) were randomized to standard planning or parotid sparing. Both used conventional planning, so no IMRT. The standard whole brain fields conformed to the skull base and anterior cervical spine down to the level of C1 or C2. In the parotid sparing arm, the parotid was contoured along with the brain to allow as much of the parotid to be blocked as possible while still covering the brain to the foramen magnum. On a lateral DRR, the parotids typically fell in line with the upper cervical vertebral bodies near the skull base. Ideally, <25% of the parotid received 20 Gy. The result: mean parotid dose was reduced from 17→ 10 Gy with reductions across all metrics. Xerostomia score was significantly lower at the end of radiation in the parotid sparing arm, although symptoms improved over time. There were no marginal misses or local relapses with parotid sparing.
TBL: Parotid dose and acute xerostomia can be reduced by simply contouring and partially blocking the parotid glands when designing conventional whole brain fields. | Wang, Int J Radiat Oncol Biol Phys 2025