2821 - Outcomes in Patients with Benign Tumors of the Head and Neck Treated with LINAC-Based Stereotactic Body Radiation Therapy
Presenter(s)
A. Patel1, A. Lee2, H. Wang3, X. A. Wang4, A. C. Moreno2, J. Reddy2, M. T. Spiotto2, D. I. Rosenthal2, S. M. Raza5, F. DeMonte5, P. W. Gidley6, M. E. Nader6, S. Y. Su6, E. Y. Hanna6, A. S. Garden2, and J. Phan2; 1Paul L. Foster School of Medicine, Texas Tech Health Sciences Center El Paso, El Paso, TX, 2Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, 3Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 4Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX, 5Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, TX, 6Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX
Purpose/Objective(s): Benign tumors of the head & neck involving cranial nerves (CN) are rare entities that are difficult to treat given their proximity to critical structures. While slow growing, surgical resection can be associated with high morbidity rates. We present our institutional experience in treating benign head & neck tumors with LINAC-based stereotactic body radiation therapy (SBRT).
Materials/Methods: Patients enrolled in our prospective SBRT registry between 2017-2023 were included in this analysis. All patients were evaluated for surgery, with radiation therapy considered primarily due to the risk of potential CN injury. Tumors that were ineligible for single-session non-invasive stereotactic radiosurgery due to factors such as large volume or location below C1, but measured <60 cc, were considered for SBRT. Outcomes of interest included local control (LC), overall survival (OS), toxicity and symptomatology. Local control was defined as radiographic evidence of lack of progression.
Results: The cohort consisted of 30 patients with a median age of 51 years. Among them, 23 cases were paragangliomas (PGL), distributed as follows: jugulotympanic PGL (n=7), jugular PGL (n=13), and vagal PGL (n=3). Additionally, 7 cases were non-vestibular schwannomas, involving the hypoglossal nerve (CN XII, n=4) & vagus nerve (CN X, n=3). The primary indication for treatment was tumor growth or symptomatic progression. At the time of SBRT, 29 patients had gross disease & 1 received adjuvant treatment after surgical resection. Among those with gross disease, 5 patients had prior treatment before SBRT: 4 underwent surgery, & 1 received prior fractionated radiation. Median target volume was 13.5 cm³ (range: 1.32–48.5 cm³), and the median prescribed dose was 27 Gy in 3 fractions (range: 21–36 Gy in 3–5 fractions), with a median prescription coverage of 96% (range: 86–100%). With a median follow-up of 36 months, all 30 patients treated for gross disease had radiographically stable tumors, while the patient treated adjuvantly remained disease-free. Hearing loss, tinnitus, and dizziness were the most commonly reported pre-treatment symptoms in patients with paragangliomas, while dysphagia and hoarseness were the most frequent symptoms among those with schwannomas. 17 patients (55%) reported an improvement in symptoms and 14 (45%) reported no worsening symptoms. Following treatment, there was 1 grade 1 tinnitus and 1 grade 2 nausea, but no grade 3 or higher toxicities were observed.
Conclusion: In the largest study to date, LINAC-based SBRT for benign head and neck tumors with cranial nerve involvement demonstrated excellent tolerability with minimal toxicity. With a median follow up of 36 months, most patients experienced stable or improved pre-treatment symptoms, with optimal local control. These findings support LINAC-based SBRT as an effective treatment option for benign head and neck tumors arising from jugular foramen or involving cranial nerves. Longer follow up is needed to validate these outcomes.