1. 227 Early outcomes for a single-arm, single-stage phase I/II trial of Selective Avoidance of nodalVolumEs at minimal Risk (SAVER) in the contralateral neck of patients with p16-positiveoropharynx cancer.
- Author
-
Witek, Matthew E, Molitoris, Jason K, Mehra, Ranee, Taylor, Rodney J, Regine, William, and Hatten, Kyle M
- Subjects
- *
CANCER patients , *PROTON therapy , *SURGICAL robots , *PAROTID glands , *RADIOTHERAPY - Abstract
Most patients with p16-positive oropharynx cancer (p16+OPC) receive elective nodal radiation therapy that improves regional control but increases acute and long-term toxicity. We evaluated the efficacy and toxicity profile of a reduced contralateral elective nodal volume in patients with p16+OPC receiving definitive or adjuvant radiation therapy. Patients with newly diagnosed p16+OPC without contralateral nodal involvement treated with primary proton or photon-based (chemo)radiation therapy or adjuvant (chemo)radiation therapy following transoral robotic surgery (TORS) were eligible for enrollment. The reduced contralateral nodal volume included high-risk regions of levels II and III1. The primary endpoint was elective out-of-field contralateral nodal failure. Dosimetric studies comparing standard versus reduced elective nodal volumes were analyzed with the t-test. Acute toxicity was collected using CTCAE v4.0. Fifty-two patients were enrolled of which 36 (69.2%) received definitive (chemo)radiation therapy. Sixteen (30.8%) patients underwent adjuvant radiation therapy following TORS of which 5 (31.2%) received concurrent chemotherapy. Proton therapy was used in 38 (73.1%) of patients. There were no elective nodal failures at a median follow up of 15 months (range 1-24 months). For the first 20 patients enrolled, dosimetric comparison of the reduced contralateral elective nodal volume to a consensus elective nodal volume demonstrated a decrease in mean dose (14.1 Gy to 18.5 Gy [p<0.05]) and V30 Gy (11.6% to 21.3% [p<0.01]) of the contralateral parotid gland. Significant differences were independent of radiation modality or technology. Acute grade 3 toxicity was observed in 13 (25%) patients including 6 (11.5%) who received a gastrostomy tube during treatment. There were no grade 4-5 acute toxicities, and no patients with 6 months of follow up retained gastrostomy tube. Precise delivery of radiation therapy to high-risk areas for contralateral nodal disease results in excellent regional control regardless of treatment approach. Dose to contralateral organs at risk and toxicity profile were favorable. Longer follow-up is needed to further support this de-intensification strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF