Transcanal Endoscopic Management of Middle Ear Paragangliomas

OBJECTIVE

To evaluate the clinical and audiological outcomes of transcanal endoscopic resection of middle ear paragangliomas.

STUDY DESIGN

Retrospective multicenter study.

SETTING

Tertiary referral center and private otology clinic.

PATIENTS

Patients who underwent transcanal endoscopic surgery between January 2015 and September 2020.

INTERVENTIONS

Transcanal endocope-assisted resection of middle ear paragangliomas.

MAIN OUTCOME MEASURES

Demographic data.

RESULTS

Twenty-three patients (2 men, 21 women) with a mean (standard deviation [SD]) age of 50.5 (11.8) years and stage 1 or 2 disease were included in the study. The mean follow-up time was 2.7 years (range, 1-5 yr). Preoperatively, the mean (SD) air-conduction threshold was 33.8 (17.9) dB, and the mean (SD) air-bone gap was 13.1 (13.9) dB. Postoperatively, the mean (SD) air-conduction threshold was 25.7 (10.2) dB, the mean (SD) air-bone gap was 6.3 (6.1) dB. The mean (SD) hospital stay was 27.7 (9.9) hours. No tumor regrowth was detected on magnetic resonance imaging during postoperative follow-up.

CONCLUSIONS

Endoscopic transcanal tumor resection is effective and feasible in the treatment of stage 1 and 2 tumors and is associated with short operative time, low risk of perioperative and postoperative complications, and rapid discharge.

A dosimetric comparison of proton versus photon irradiation for paediatric glomus tumour: a case study

Background:

Intensity-modulated radiation therapy (IMRT) has revolutionised the way head and neck cancers can be treated. It allows for a more conformal treatment plan when compared to 3D conformal radiation therapy. In paediatric patients, however, IMRT continues to deliver higher doses than desirable. Proton beam therapy on the other hand has the potential to further spare organs-at-risk.

Methods:

A 16-year-old boy with a left-sided paraganglioma of the left base of skull manifested by headaches, neck pain and tongue cramping was simulated, planned and treated with proton therapy with significant contralateral organ-at-risk sparing.

Results:

For this patient, dosimetric plan comparison between photon and proton plans clearly showed better sparing of contralateral organs-at-risk with protons. The contralateral parotid gland received a mean dose of 386·3 cGy with photons, whereas it received 1·3 cGy (CGE) in the proton plan.

Conclusions:

The dosimetric advantage of proton beam over photon beam therapy has successfully been demonstrated in this case study for a paediatric patient with a head and neck tumour. Sparing of contralateral structures is especially important in paediatric patients who are at a greater risk of secondary malignancies due to possible long life expectancy.

[New indications of protontherapy for adults intracranial tumours]

Considering intracranial tumours, only few indications of protontherapy, such as chordoma, chondrosarcoma or uveal melanoma, are uniformly approved in the world. Other indications, excluding paediatric pathologies, are still debated. The aim of this article is to describe the rationale for the use of protonbeam irradiation for meningioma, pituitary adenoma, craniopharyngioma, paraganglioma, glioma, and schwannoma, and to inform the radiation oncologists if prospective studies or randomized studies are opened for inclusions. This article deals only with indications for adults.

Proton therapy for head and neck paragangliomas: A single institutional experience

BACKGROUND

Although slow growing, head and neck paragangliomas (HNPG) can cause significant morbidity. We evaluated the efficacy of proton therapy in the management of HNPG.

METHODS

Retrospective review of an institutional proton therapy experience of treating patients between 1997 and 2016; 37 patients and 40 tumors were included.

RESULTS

Proton therapy was delivered to a median of 50.4 Gy(RBE) (range: 45-68). Having a genetic/family predisposition for HNPG was associated with multifocal tumors (P = .02) and younger diagnosis age (P = .02). Twenty-six (70%) patients had symptom improvement posttreatment, and 65% of treated tumors showed ≥20% volumetric shrinkage. The 5-year recurrence-free and overall survival rates were both 97%. Grade 2 to grade 3 toxicities (54%) included subjective hearing impairment (19%), middle ear inflammation (14%), and dry mouth (8%). There were no grade 4-5 toxicities.

CONCLUSIONS

Patients with HNPGs can be effectively and safely treated with proton therapy with excellent tumor control, successful volumetric tumor reduction, and symptomatic improvement.

Proton therapy for treatment of intracranial benign tumors in adults: A systematic review

INTRODUCTION

The depth-dose distribution of a proton beam, materialized by the Bragg peak makes it an attractive radiation modality as it reduces exposure of healthy tissues to radiations, compared with photon therapy Prominent indications, based on a long-standing experience are: intraocular melanomas, low-grade skull-base and spinal canal malignancies. However, many others potential indications are under investigations such as the benign morbid conditions that are compatible with an extended life-expectancy: low grade meningiomas, paragangliomas, pituitary adenomas, neurinomas craniopharyngioma or recurrent pleomorphic adenomas.

MATERIALS

Given the radiation-induced risk of secondary cancer and the potential neurocognitive and functional alteration with photonic radiotherapy, we systematically analyzed the existing clinical literature about the use of proton therapy as an irradiation modality for cervical or intracranial benign tumors. The aim of this review was to report clinical outcomes of adult patients with benign intracranial or cervical tumors treated with proton therapy and to discuss about potential advantages of proton therapy over intensity modulated radiotherapy or radiosurgery.

RESULTS

Twenty-four studies were included. There was no randomized studies. Most studies dealt with low grade meningiomas (n = 9). Studies concerning neurinoma (n = 4), pituitary adenoma (n = 5), paraganglioma (n = 5), or craniopharyngioma (n = 1) were fewer. Whatever the indication, long term local control was systematically higher than 90% and equivalent to series with conventional radiotherapy.

CONCLUSION

Proton-therapy for treatment of adult benign intracranial and cervical tumors is safe. Randomized or prospective cohorts with long term cognitive evaluations are needed to assess the real place of proton-therapy in the treatment of adults benign head and neck tumors.

Protontherapy of head and neck paragangliomas: A monocentric study

PURPOSE

The aim of this study was to assess efficacy and safety of proton beam therapy of paragangliomas of the head and neck, rare benign tumours developed close to crucial structures such as cranial nerves and vascular tissues.

PATIENTS AND METHODS

Ten patients with a paraganglioma of the head and neck were treated from 2001 to 2014 with image-guided proton therapy. Neurological and ear nose throat symptoms were collected in addition to audiometric testing, before and after the treatment. Acute and late toxicities were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.

RESULTS

Median age at diagnosis was 52.6years (range: 18.2-65.8years). Proton therapy was the exclusive treatment in six patients and four patients had a postoperative radiotherapy. Median dose was 50.4Gy relative biological effectiveness (RBE; range: 45.0-67.0Gy). With a median follow-up of 24.6months (range: 6.7-46.2 months), local tumour control rate was 100% (stable, n=10). No upper grade 2 acute toxicity was reported. To the latest news, seven patients had controlled symptoms (improved, n=1, stabilized, n=6). One patient out of seven with initial tinnitus had a decrease in his symptoms, while the six other patients had a sustained stabilization.

CONCLUSION

Proton beam therapy is an effective and well-tolerated treatment modality of skull base paragangliomas, with documented functional benefit. A longer follow-up is planned in order to assess local control and long-term toxicities.