3660 - Early-Stage Laryngeal Cancer Treatment Outcomes with Whole vs. Partial Laryngeal Radiotherapy
Presenter(s)
A. S. Wanna1, M. Salomon2, D. Barbee3, J. Xiao1,4, R. White5, Z. Li5, K. Csehak5, M. Rybstein6, A. E. Vaezi7, A. Jacobson8, M. Persky9, L. Moses9, U. Duvvuri9, M. Tam1, K. S. Hu2, and C. Hill10; 1Department of Radiation Oncology, NYU Grossman School of Medicine, New York, NY, 2NYU Langone Health, New York, NY, 3Sun Nuclear Corporation, Melbourne, FL, 4New York University Grossman School of Medicine, Department of Radiation Oncology, New York, NY, 5Department of Medicine, NYU Grossman School of Medicine, New York, NY, 6Department of Medicine, NYU Grossman Long Island, Mineola, NY, 7Department of Otolaryngology, NYU Grossman Long Island, New York, NY, 8NYU Grossman School of Medicine, New York, NY, United States, 9Department of Otolaryngology, NYU Grossman School of Medicine, New York, NY, 10Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD
Purpose/Objective(s):
Early-stage glottic laryngeal squamous cell carcinoma (SCCa) is amenable to larynx-preserving surgery or radiotherapy (RT) with curative intent. Treatment selection is individualized based on tumor extent and desired voice and swallowing outcomes. Historically, whole larynx RT (WLRT) using 3D conformal RT (3DCRT) provided excellent local control but was associated with dysphagia, voice toxicity, and cerebrovascular injury. Intensity modulated RT (IMRT) has improved dosimetric sparing of critical structures. Partial larynx IMRT (P-IMRT) has emerged as a strategy to further reduce toxicity by limiting irradiation to the involved laryngeal subsite, though prospective outcome data remain limited. We report treatment outcomes of P-IMRT compared to WLRT for early-stage laryngeal SCCa at a high-volume institution.Materials/Methods:
Patients (pts) with clinical stage T0-T2, N0 laryngeal SCCa treated between 2015–2025 were retrospectively reviewed. P-IMRT utilized 8mm superior-inferior and 3mm radial expansions with an additional 3mm isotropic margin, and daily setup was matched to laryngeal soft tissue. WLRT included pts treated with 3DCRT or whole-larynx IMRT. Prescribed doses were 63 Gy in 28 fractions for cT0-T1 and 65 Gy in 29 fractions for cT2 disease. Statistical comparisons employed chi-squared, Fisher's exact, Welch's t-test, Kaplan-Meier analysis with log-rank testing, and Firth's penalized logistic regression as appropriate.Results:
Ninety-one pts were identified. Median follow-up was 32 months (mo.) (23 mo. P-IMRT vs. 37 mo. WLRT, p=0.099). Most were cT1 (54%) or cT2 (31%), and 73% had anterior commissure (AC) involvement. Sixty-seven pts received WLRT (74%) and 24 received P-IMRT (26%). Baseline characteristics were well-balanced. Local failure (LF) occurred in 6/67 (9.0%) and regional failure (RF) in 1/67 (1.5%) WLRT pts. There were no failures with P-IMRT. All LF pts had AC involvement, and no LF extended beyond the initially involved laryngeal subsite. The 2-year PFS was 100% vs. 94.7% for P-IMRT and WLRT, respectively (p=0.264). Salvage included total laryngectomy in 5 pts and microlaryngoscopy in 1. The RF was managed with neck dissection and chemoradiation. Given the low event rate (7/91, 7.7%), no variable was independently associated with recurrence on multivariable analysis. Grade =2 acute dysphagia was significantly less common with P-IMRT vs. WLRT (16.7% vs. 67.2%, p<0.001), with no significant differences in late dysphagia or hoarseness. Cerebrovascular accidents (CVA) occurred in 4 pts (4.4%), all receiving 3DCRT, at a median of 34 mo. after RT.Conclusion:
P-IMRT was associated with significantly reduced acute dysphagia and no CVAs without compromising disease control compared to WLRT. The pattern of LF supports the oncologic rationale for partial laryngeal target volumes. Prospective investigation is warranted.