Image-guided robotic radiosurgery for glomus jugulare tumors-Multicenter experience and review of the literature

Stereotactic radiotherapy for head and neck paragangliomas: How long should we wait for treatment response?

BACKGROUND AND PURPOSE

Stereotactic radiotherapy (SRT) is an effective treatment for head & neck (H&N) paragangliomas. Nevertheless, the timeline for achieving a tumor-volume-reduction (TVR) remains unclear.

MATERIALS AND METHODS

Sixty-three cases with H&N paragangliomas received definitive SRT and were evaluated retrospectively. Statistical Package for the Social Sciences (SPSS) v23.0 (IBM, Armonk, NY, USA) was used for statistics.

RESULTS

Sixty-eight lesions were irradiated, with glomus jugulotympanicum being the most common location (44 %). Median tumor diameter and volume were 3 cm (range, 1-7.6 cm) and 15.4 cm3 (range,1-185 cm3), respectively. Median dose was 25 Gy (range, 12-37.5 Gy) in 5 fractions (range, 1-5 fractions). Median follow-up was 40 months (range, 3-184 months). Treatment response, evaluated at a median 4.6 months post-SRT (range: 3-11 months), revealed TVR in 26 cases (41 %). During follow-up, 13 additional cases showed TVR, resulting in an overall TVR rate of 62 %. The median duration for attaining TVR was 9 months (range, 3-36 months) after SRT, and TVR occurred ≥ 12 months in 42 % of cases. Patients without prior surgery (p = 0.03) and with a longer follow-up (p = 0.04) demonstrated a higher rate of TVR. The likelihood of TVR tends to increase as the SRT dose increases (p = 0.06). Overall local control (LC) rate was 100 %. No ≥ grade 3 acute or late toxicities were observed.

CONCLUSION

While SRT demonstrates an excellent LC rate for H&N paragangliomas, it's important to note that the response to treatment may require time. TVR may last beyond the initial year of treatment in a substantial proportion of patients.

The Radiosurgery Society Case-Based Discussion of the Management of Head and Neck or Skull Base Paragangliomas with Stereotactic Radiosurgery and Radiotherapy

Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) have been used for the treatment of head and neck or skull base paraganglioma for a considerable time, demonstrating promising local control rates and a favorable safety profile compared with surgical approaches. Nevertheless, the choice of treatment must be carefully tailored to each patient's preferences, tumor location, and size, as well as anticipated treatment-related morbidity. This case-based review serves as a practical and concise guide for the use of SRS and FSRT in the management of head and neck or skull base paragangliomas, providing information on the diagnosis, treatment, follow-up considerations, and potential pitfalls.

The Long-Term Outcome of CyberKnife-Based Stereotactic Radiotherapy for Head and Neck Paragangliomas: A Single-Center Experience

OBJECTIVE

To assess long-term outcomes of hypofractionated stereotactic radiotherapy (hSRT) for head and neck paragangliomas (HNPGs).

METHODS

Patients who underwent hSRT with CyberKnife for HNPGs from 2010 to 2019 were retrospectively reviewed.

RESULTS

A total of 34 HNPGs in 29 patients were identified. Mean patient age was 50 ± 16 years, and 15 patients (52%) were female. Fifteen patients (55%) had undergone previous procedures. Four cases (14%) were functional in hormone production. According to the Fisch classification, 1 (3%) case was B, 12 (42%) cases were C, 14 (48%) cases were D, and 2 (7%) cases were unclassified.¹ The median prescribed dose covering 95% of the planning target volume was 2500 cGy (interquartile range 2100-2600 cGy), and the median target volume was 10 cm³ (interquartile range 6.0-18.3 cm³). The local control rate was 97%. The median progression-free survival was 66 months (interquartile range 28-95 months), and 96% of patients were free of tumor progression at 8 years. During follow-up, 1 case (3%) resulted in permanent facial nerve palsy (House-Brackmann grade II), and another case (3%) resulted in asymptomatic cerebellar radiation necrosis. Univariate and multivariate analysis showed that no previous surgical history (odds ratio 8.58, 95% confidence interval 1.2-59.7, P = 0.03) was a positive predictor of symptomatic improvement.

CONCLUSIONS

hSRT for HNPGs was an effective treatment with minimal side effects over the long term and may have a role as first-line therapy, especially for symptomatic nonfunctional HNPGs, for better symptom control.