MD Anderson Long-Term Experience with Management of Temporal Bone Paragangliomas

 

Introduction: Surgery is often considered the treatment of choice for the management of temporal bone paragangliomas (TBP). However, complete tumor removal carries a high risk of postoperative morbidity, including acute cranial nerve (CN) injury with reduced functional compensation. In patients with preoperatively intact lower cranial nerve function, highly conformal radiotherapy (RT) can be offered as primary or combined therapy to stabilize the disease and avoid or delay the need for surgical intervention. Here, we present long-term outcomes for a large series of treated TBPs.

Methods: We retrospectively reviewed all patients with TBPs treated between 1994 and 2021. Tumor progression was based on radiographic evaluation of pre- and posttreatment imaging. Pre-and post-treatment symptoms at 3 months, 12 months, and 3 years, radiographic characteristics, Fisch classification, and complications were recorded.

Results: Forty-nine patients were analyzed ([Table 1]). The median age was 50 years (range: 16–82 years), and 59.2% were female. Thirty-seven patients (75.5%) had Fisch C or D tumors. At presentation, hearing loss, CN deficit ([Fig. 1A]), and/or pulsatile tinnitus were present in 78%, 69%, and 55.1% of patients, respectively. CN VIII was the most frequently affected nerve (77.5%), followed by X and XII in equal proportions (40.8%). Radiologically, calcifications on CT scans were uncommon (10.2%), whereas homogeneous post-contrast enhancement on MRI was observed in 65.3% of cases. Five patients (10.2%) were treated with surgery alone, 41 (83.7%) with primary radiotherapy (RT), and 3 (6.1%) with surgery and RT ([Table 2]). Among patients treated with RT, 12 (29%) received GK-SRS to a single median dose of 15 Gy prescribed to 50% isodose line; 20 (48.7%) received LINAC-SBRT in 3 fractions (Fx) to a median dose of 27 Gy; 7 (14%) received proton therapy to a median dose of 50 Gy (range: 45–60 Gy) in 25 Fx; and 5 (12.2%) received conventional photon/IMRT to a median dose of 45 Gy (range: 45–50 Gy) in 25 Fx. The RT modality used correlated with tumor volume, and Fisch classification correlated with RT modality ([Fig. 1C]). There was 1 death (intercurrent) in the entire cohort (median follow-up: 38.3 months). There were two recurrences, with a crude failure rate of 4%. The 5-year PFS rate was 93% ([Fig. 1B]). There were no recurrences among patients treated with stereotactic approaches. The CN symptom profiles were unique among the surgery and RT cohorts. RT showed a higher likelihood of CN VIII symptomatology, whereas surgery showed a higher risk of CN VII, IX, X, XI, and XII symptomatology. Longitudinal toxicity profiling after RT showed a transient worsening of symptoms at 3 months followed by a clear improvement over baseline at 1 and 3 years ([Fig. 2A]; p < 0.05), whereas for surgery there was a worsening of CN VII and XII symptoms at 3 months with no improvement over time ([Fig. 2B]).

Conclusions: Either conventionally fractioned or stereotactic RT are valid options for the treatment of TBP in patients with preserved cranial nerve function and provide excellent tumor control with no significant increase in long-term morbidity. However, patients can expect worsening symptomatology within the first 3 months after treatment.

Publication History

Article published online:
05 February 2024

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