Radiation therapy for glomus tumors of the temporal bone

Glomus jugulotympanicum tumor treated with radiation therapy: A case report with review of literature

Glomus tumors (or paragangliomas) are rare, benign tumors of neuroendocrine origin that appear in tissues of paraganglionic origin. This clinical entity poses a significant treatment challenge due to its proximity to critical neurovascular structures, thus the potential of morbid functional damage caused by disease progression and/or treatment approach. While surgery remains the standard of care for such cases, there has been an increasing trend toward management with radiotherapy or close observation. Here, we present a case of a large and irregularly shaped glomus jugulotympanicum tumor that was treated with volumetric arc radiotherapy. Given the risk of cranial neuropathy with surgery, radiation was the preferred treatment modality. This case demonstrated the safety and efficacy of volumetric arc radiotherapy in the management of a large glomus tumor with a complex shape.

Jugular and vagal paragangliomas: Systematic study of management with surgery and radiotherapy

BACKGROUND

The definitive treatment for head and neck paraganglioma (PG) is surgical excision. Unfortunately, surgery, particularly of vagal paraganglioma (VPG; "glomus vagale") and foramen jugulare ("glomus jugulare") tumors, may be complicated by injuries to the lower cranial nerves, a high price to pay for treatment for a benign tumor. Alternatively these tumors may be followed without treatment, or irradiated. The purpose of this review was to compare the existing evidence concerning the efficacy and safety of surgery, external beam radiotherapy (EBRT), and stereotactic radiosurgery (SRS), for jugular paragangliomas (JPGs) and VPGs.

METHODS

Relevant articles were reviewed using strict criteria for systematic searches. Forty-one surgical studies met the criteria which included 1310 patients. Twenty articles including 461 patients treated with EBRT, and 14 radiosurgery studies comprising 261 patients were also evaluated. Results were compared between treatment modalities using analysis of variance (ANOVA) tests.

RESULTS

A total of 1084 patients with JPGs and 226 VPGs were treated with different surgical procedures. Long-term control of the disease was achieved in 78.2% and 93.3% of patients, respectively. A total of 715 patients with JPG were treated with radiotherapy: 461 with EBRT and 254 with SRS. Control of the disease with both methods was obtained in 89.1% and 93.7% of the patients, respectively. The treatment outcomes of a JPG treated with surgery or radiotherapy were compared. Tumor control failure, major complication rates, and the number of cranial nerve palsies after treatment were significantly higher in surgical than in radiotherapy series. The results of SRS and EBRT in JPGs were compared and no significant differences were observed in tumor control. Because only 1 article reported on the treatment of 10 VPGs with radiotherapy, no comparisons with surgery could be made. Nevertheless, the vagus nerve was functionally preserved in only 11 of 254 surgically treated patients (4.3%).

CONCLUSION

There is evidence that EBRT and SRS offer a similar chance of tumor control with lower risks of morbidity compared with surgery in patients with JPGs. Although the evidence is based on retrospective studies, these results suggest that surgery should be considered only for selected cases, but the decision should be individual for every patient.

A meta-analysis of tumor control rates and treatment-related morbidity for patients with glomus jugulare tumors

Object

Because of the rarity of glomus jugulare tumors, a variety of treatment paradigms are currently used. There is no consensus regarding the optimal management to control tumor burden while minimizing treatment-related morbidity. In this study, the authors assessed data collected from 869 patients with glomus jugulare tumors from the published literature to identify treatment variables that impacted clinical outcomes and tumor control rates.

Methods

A comprehensive search of the English-language literature identified 109 studies that collectively described outcomes for patients with glomus jugulare tumors. Univariate comparisons of demographic information between treatment cohorts were performed to detect differences in the sex distribution, age, and Fisch class of tumors among various treatment modalities. Meta-analyses were performed on calculated rates of recurrence and cranial neuropathy after subtotal resection (STR), gross-total resection (GTR), STR with adjuvant postoperative radiosurgery (STR+SRS), and stereotactic radiosurgery alone (SRS).

Results

The authors identified 869 patients who met their inclusion criteria. In these studies, the length of follow-up ranged from 6 to 256 months. Patients treated with STR were observed for 72 ± 7.9 months and had a tumor control rate of 69% (95% CI 57%–82%). Those who underwent GTR had a follow-up of 88 ± 5.0 months and a tumor control rate of 86% (95% CI 81%–91%). Those treated with STR+SRS were observed for 96 ± 4.4 months and had a tumor control rate of 71% (95% CI 53%–83%). Patients undergoing SRS alone had a follow-up of 71 ± 4.9 months and a tumor control rate of 95% (95% CI 92%–99%). The authors' analysis found that patients undergoing SRS had the lowest rates of recurrence of these 4 cohorts, and therefore, these patients experienced the most favorable rates of tumor control (p < 0.01). Patients who underwent GTR sustained worse rates of cranial nerve (CN) deficits with regard to CNs IX–XI than those who underwent SRS alone; however, the rates of CN XII deficits were comparable.

Conclusions

The authors' analysis is limited by the quality and accuracy of these studies and may reflect source study biases, as it is impossible to control for the quality of the data reported in the literature. Finally, due to the diverse range of data presentation, the authors found that they were limited in their ability to study and control for certain variables. Some of these limitations should be minimized with their use of meta-analysis methods, which statistically evaluate and adjust for between-study heterogeneity. These results provide the impetus to initiate a prospective study, appropriately controlling for variables that can confound the retrospective analyses that largely comprise the existing literature.

Bilateral glomus tumor treated with PET-CT based conformal radiotherapy: a case report

Introduction

Glomus tumors are benign, slow growing tumors originating from paraganglionic tissue, mostly located at the carotid bifurcation, jugular foramen, cervical portion vagus nerve, and middle ear cavity. Radiotherapy is treatment of choice for patients with intracranial extension, and patients with bilateral and multiple tumors, or patients who are inoperable.

Case presentation

We present a 53-year-old female patient with a glomus tumor treated with positron emission tomography computed tomography planning and 3D conformal radiotherapy, and the patient has remained free of disease progression 2 years after.

Conclusion

It is suggested that radiotherapy is a good treatment modality in patients with glomus tumor, and metabolic imaging and treatment planning with positron emission tomography computed tomography is superior to other imaging modalities.