Radiotherapy as Primary Treatment of Olfactory Groove Meningiomas is Associated with Preserved Cranial Nerve Function and Excellent Quality of Life

Review Article

Austin J Surg. 2014;1(6): 1028.

Radiotherapy as Primary Treatment of Olfactory Groove Meningiomas is Associated with Preserved Cranial Nerve Function and Excellent Quality of Life

Zaorsky NG1, Andrews DW2, Podrat J1, Gunn V2, Liu H2, Werner-Wasik M1, Farrell C2, Evans JJ2, Moshel YA2, Judy KD2 and Shi W1*

1Department of Radiation Oncology, Thomas Jefferson University, USA

2Department of Neurological Surgery, Thomas Jefferson University, USA

*Corresponding author: Wenyin Shi, Department of Radiation Oncology, Jefferson Medical College & Kimmel Cancer Center, Thomas Jefferson University, 111 S. 11th Street, Bodine Center for Cancer Treatment, Philadelphia, PA 19107, USA

Received: July 28, 2014; Accepted: August 30, 2014; Published: September 04, 2014


Objective: Data on radiotherapy (RT), including fractionated stereotactic radiotherapy (FSRT) and stereotactic radiosurgery (SRS), for olfactory groove meningiomas (OGMs) is limited, in part because of the rarity of the disease in this location. We present the first report of efficacy, toxicity, CN function and quality of life (QOL) in patients treated with primary RT for OGMs.

Methods: We retrospectively identified seven patients who were treated with primary FSRT or SRS. Patients were followed clinically, with magnetic resonance imaging (MRI), and were sent Sino-Nasal Outcome Tests (SNOT- 20s).

Results: At a median follow-up time of 64 months (range, 21 to 125), rates of local control, overall survival, and cause specific survival were 100%, 86%, and 100%, respectively. At presentation, four patients had hypo/anosmia; two, symptomatic deficit of visual acuity or fields; two, facial pain; two, tinnitus. After RT, three patients regained olfaction; two had improvement in visual function; two, decreased facial pain; two, resolved tinnitus. Three patients had a decrease and four had no change in lesion size on radiographic imaging. Headaches resolved in the few patients who presented with them. SNOT-20scores correlated with an excellent QOL pre-RT and on follow-up.

Conclusion: Patients with OGMs treated with primary RT maintained excellent rates of local control and cause-specific survival, had preserved or improved CN function (notably, olfactory nerve function improved in three patients), and maintained excellent QOL. Further prospective studies are necessary to determine the role of RT in the multimodal care of OGMs.

Keywords: Cranial nerves; Olfactory groove meningioma; Radiotherapy; Quality of life


Olfactory groove meningiomas (OGMs) are rare, slow-growing tumors that account for 10% of intracranial meningiomas. Treatment options for OGMs include observation, surgery, and radiotherapy (RT), which includes both stereotactic radiosurgery (SRS) and fractionated stereotactic radiation therapy (FSRT).Surgery has historically been recommended as the primary therapy for OGMs because of excellent control rates and perioperative mortality of nearly 0% [1].

However, surgical resection of an OGM has limitations. First, total resection is limited if the tumor encroaches on critical neurovascular areas or extends laterally much beyond the vertical plane of the medial orbital wall, which challenges endoscopic approaches [1]. Moreover, all patients develop deficits of cranial nerve (CN) I. Other postoperative complications may include cerebrospinal fluid leaks, post-treatment seizures, frontal lobe edema, and other CN dysfunctions [2,3]. Next, studies suggest that OGM recurrence may be as high as 23% at 7 years [2,4]. Finally, patient comorbidities may preclude intubation and increase the risk of postoperative morbidity and mortality.

Currently, RT is reserved for select meningioma locations (e.g. the optic nerve sheath [ONSMs], cavernous sinus, base of skull, acoustic meatus) that are associated with a high surgical morbidity; for tumors that are unresectable; or for patients unable to tolerate surgery [1]. Recent studies have shown that FSRT [5] and SRS [6] have outcomes similar to surgery with limited morbidity. Moreover, RT may also maintain or improve CN function in ONSMs [7,8] and acoustic meningiomas [9]. To our knowledge, there is no published data on the efficacy of RT for OGMs for tumor control and CN function. We hypothesized that in select patients with OGMs, primary RT (either SRS or FSRT) resulted in tumor control, CN function preservation, and maintenance of excellent patient QOL.


After obtaining institutional review board approval, we identified seven consecutive patients with symptomatic and OG Msat XXX between 1994 and 2011who were treated with primary RT. Medical records for these patients were reviewed, including in-patient hospital notes, MRI scans, RT treatment records, and radiation oncology and neurosurgery follow-up encounters. The initial diagnosis was rendered either during surgery or on the basis of the characteristic appearance on a T1-weigthed, contrast-enhanced fat suppression MRI study.


Our institutional policy dictates that all patients be evaluated and discussed by a multidisciplinary tumor board, consisting of neurosurgeons, radiation oncologists, and neuroradiologists. Treatment decisions for SRS versus FSRT are based on a thorough discussion evaluating tumor size, symptoms, nerve function, performance status, and patient preference. Patients with intact CN function and larger lesions are generally offered FSRT. However, patient preference of SRS due to the convenience of single treatment may override this recommendation.

Patients treated before June 2004 with FSRT received RT via a [Varian Clinac-600SR linear accelerator] (LINAC, Varian 600SR; Varian Corp., Palo Alto, CA) and were immobilized with Brown- Roberts-Wells and Gill-Thomas-Cosman relocatable frames, using the Radionics planning system. Patients treated after 2004 with FSRT received RT via a Varian/Brain LAB Novalis stereotactic system, including Brain LAB masks for immobilization, ExacTRAC image guided localization, and Brain SCAN treatment planning system. The stereotactic radiation technique involved a conventional fraction paradigm to maximize the chance of CN preservation and minimize the risk of radiation-induced optic neuropathy and/or optic neuritis. A high conformality was established by non-coplanar arcs or beams and differential beam weighting. Patients treated with SRS before May 2006 received treatment via Gamma Knife Model U (Elekta Instruments, Atlanta, GA) and after with Gamma Knife model 4C.

Toxicity evaluation and follow-up

Patients were initially seen in follow-up three months after treatment by the radiation oncology and neurosurgery teams. Patients were then followed yearly with detailed clinical exams and MRIs for a scheduled period of 10 years. Follow-up was measured from the beginning of RT until the last documented encounter by either team. Tumor control was defined as stable or decreased tumor size on MRI. Toxicity was defined as an event starting within 3 months of SRS or within 3 months from the beginning of FSRT.

Detailed CN examinations were performed prior to RT and on follow-up examinations. Olfaction was based on patients’ subjective report; ophthalmological exams were performed in symptomatic patients. Additionally, SNOT-20s [10] were sent to patients around the time of follow-up. The twenty questions (each graded 0 to 5) of the original SNOT-20 were averaged to create the following symptom subscales: (1) rhinological, including needing to blow one’s nose, sneezing, runny nose, cough, post-nasal discharge, and anosmia; (2) ear/facial, including ear fullness, dizziness, ear pain, and facial pain; (3) sleep, including difficulty sleeping and waking at night; and (4) psychological, including fatigue, reduced productivity, reduced concentration, frustration/restlessness/irritability, sadness, and embarrassment [11].


Patient and treatment characteristics

Patient and tumor characteristics are listed in Table 1. There were four women and three men with a median age of 57 years (range, 50 to 73). Patients were treated because of symptoms, which were: hypo/ anosmia (4 patients), headaches (3 patients), and visual symptoms (3 patients) were common. The median tumor size was 3.3 cm (range, 1.7 to 4.5).