Tomotherapy for neurofibromatosis Type 2: case report and review of the literature

Oculomotor nerve palsy in neurofibromatosis type 2

Neurofibromatosis (NF) type 2 is a rare neurological, autosomal dominant and genetic disorder. It is caused by a mutation in the tumor suppressor gene, called NF2 gene. The disorder results in several benign tumors of the nervous system. These typically include vestibular schwannomas, meningiomas, and ependymomas. Multiple cranial nerve abnormalities affect the brain, spinal cord, nerves, and skin and cause significant morbidity in patients. We describe a 20-year-old patient, with a family history of brain tumors, with symptoms of left sided third nerve palsy. Magnetic Resonance Imaging (MRI) of the brain and orbits revealed a small sized cavernous sinus meningioma and bilateral vestibular schwannomas. As per the differential diagnosis and optimal resolution brain imaging, NF2 was diagnosed. The patient was referred for specific treatment to the neuro-oncology unit. The case is distinct as the patient presented with a parasellar meningioma leading to third nerve palsy besides bilateral vestibular schwannomas. Manchester criteria and high contrast MR imaging proved more beneficial in our patient for the diagnosis of a wider clinical spectrum of NF2.

Two giant connected retroperitoneal schwannomas: a rare case report

Schwannoma is a type of tumor originating from Schwann cells of peripheral nerves. In this study, we report a rare case of two giant connected retroperitoneal schwannomas. The patient presented to our department with a 1-day history of abdominal pain and without other symptoms. There were no abnormalities in the patient’s tumor markers. Abdominal plain computed tomography (CT) revealed two (combined) retroperitoneal masses appearing as soft tissue-density shadows with uneven internal density, cystic low-density shadows, and patchy calcification shadows. The larger mass measured approximately 12.0 cm × 12.3 cm in size. The tumors were completely excised by a reasonable surgical approach while the surrounding organs closely related to the tumor were preserved. Postoperative pathology confirmed that the tumors were benign schwannomas. In the 18-month follow-up, the patient had no recurrences and was asymptomatic. We summarize the diagnosis and treatment of two rare combined giant retroperitoneal schwannomas in a single patient. Laparotomy for the management of retroperitoneal giant schwannomas may be safe and effective.

Radiotherapy in Patients with Vestibular Schwannoma and Neurofibromatosis Type 2: Clinical Results and Review of the Literature

Aims and Background

To evaluate the long-term outcome of patients with vestibular schwannoma (VS) and neurofibromatosis type 2 (NF2) treated with fractionated stereotactic radiotherapy (FSRT) or stereotactic radiosurgery (SRS).

Patients and Methods

Sixteen VS in 14 patients with NF2 were treated with FSRT (n = 14) and SRS (n = 2). Patients with tumor progression and/or progression of clinical symptoms were selected for treatment. For patients treated with FSRT a median total dose of 57.6 Gy was prescribed with a median fractionation of 5 × 1.8 Gy per week. For patients who underwent SRS a median single dose of 17 Gy was prescribed to the 80% isodose.

Results

FSRT and SRS were well tolerated. Local control rate was 94% for a median follow-up time of 131 months; 2- and 5-year progression-free survival were 100%. The probability of maintaining the pretreatment hearing level was 44%. Useful hearing preservation was 33%. Cranial nerve toxicity was moderate. Trigeminal nerve function worsened in 2 patients (12%) and facial nerve function in 3 patients (19%). One patient developed a new tinnitus.

Conclusion

FSRT and SRS are both safe and effective noninvasive and minimally invasive treatment options for patients with VS in the setting of NF2. The long-term local control rates are excellent. Functional hearing preservation is worse in patients with VS and NF2 than in patients with sporadic VS.

[Early type 2 neurofibromatosis and congenital retinal hamartoma]

Neurofibromatosis type 2 (NF2) is a heritable syndrome characterized by multifocal proliferation of neural crest-derived cells. It has long been regarded as an adolescent- and adult-onset disease. We report here on a case of a 6-year-old girl with infantile-onset clinical signs. The girl, who had a history of amblyopia and congenital retinal hamartoma, presented with rough dimness of visual acuity. Cerebral magnetic resonance imaging found a left voluminous fronto-temporal tumor including the chiasma and optical nerves. Vestibular and cervical nerve schwannomas were also found. She underwent a first neurosurgical partial excision and histopathology revealed meningioma. Postoperative radiotherapy was necessary due to a secondary increase of the tumor size. Subsequent molecular testing revealed a NF2 gene abnormality. NF2 can become evident in infancy but clinical early symptomatology is often different: ocular symptoms and neurological problems are common. There is no consensus on the treatment of tumors involving the central and peripheral nervous system, abstention being usual. In case of severe signs, surgery and radiotherapy can be proposed. The diagnosis of a hamartoma must lead to multidisciplinary follow-up.

[Neurofibromatosis type 2 and its head and neck manifestations: literature review and population study in the Community of Cantabria and the province of Las Palmas]

INTRODUCTION AND OBJECTIVES

Neurofibromatosis type 2 (NF2) is an infrequent autosomal dominant disease characterised by the appearance of viii nerve schwannomas, meningiomas and ocular abnormalities. Incidence of 1:25,000 and prevalence above 1:80,000 are estimated in general. The objectives of our study were to determine current prevalence of NF2 in the Community of Cantabria and the province of Las Palmas, and its head and neck manifestations.

MATERIAL AND METHODS

This was a population-based, retrospective study in 3 tertiary hospitals.

RESULTS

The study population showed prevalence of 1:600,000 in the Community of Cantabria and 1:280,000 in the province of Las Palmas. The most frequently diagnosed tumour was acoustic neuroma (n=15), followed by trigeminal neurinoma (n=2) and vagus (n=1).

CONCLUSIONS

Cases of NF2 are infrequent in Cantabria and Las Palmas, lower than that reported in the literature. The most frequently described head and neck tumour in the literature is acoustic neuroma, followed by schwannoma of cranial nerves v and x. Other tumours such as nasal, laryngeal, chorda tympani or cranial nerve vii schwannomas are also described. The most frequent ENT manifestation is hearing loss, especially unilateral, followed by cervical mass, tinnitus and headache. Early diagnosis and multidisciplinary management in specialised centres could improve life expectancy and quality of life for these patients.

Dosimetric and clinical review of helical tomotherapy

As a modality for delivering rotational therapy, helical tomotherapy offers dosimetric advantages by combining a continuously rotating gantry with a binary multileaf collimator. Helical tomotherapy, embodied in the TomoTherapy(®) Hi-Art II(®) system, delivers intensity-modulated fan beams in a helical pattern using binary multileaf collimator leaves while the couch is translated through the gantry. Helical tomotherapy offers the possibility of treating a variety of cases--from simple to complex--with improved target conformality and sensitive structure sparing compared with 3D or conventional static field IMRT plans, thereby allowing biologically effective dose escalation. For precise irradiation and possible treatment adaptation, the fully integrated on-board image-guidance system provides online volumetric images of patient anatomy using 3.5-MV x-ray beams and the xenon computed tomography detector. Several review articles were published before the year 2007 but emphasized the technical aspects of helical tomotherapy. In this article, we review very recent papers and focus on the dosimetric and clinical aspects of helical tomotherapy.