Vaginal malignant peripheral nerve sheath tumor treated with complete surgical resection and postoperative radiation therapy.

Malignant peripheral nerve sheath tumors (MPNSTs) are neoplasms originating from or differentiating into nerve sheaths of peripheral nerves. Vaginal origin is rare, with only six vaginal primary cases reported to date. A 55-year-old woman presented to our hospital with a 7 cm vulvar mass. Tumor biopsy results were suspicious of sarcoma, and pelvic magnetic resonance imaging and hysterofiberscopy showed that the tumor originated from the lower vagina. The mass was transvaginally excised, and histological examination confirmed the diagnosis of a vaginal MPNST with negative surgical margins. The patient underwent radiotherapy because the risk of recurrence was high, owing to the large tumor size and high mitotic index. The patient remained recurrence-free for 1 year after the primary treatment. This is the first case of a high-risk vaginal MPNST that avoided early disease recurrence with additional radiotherapy after complete tumor resection.

Role of perioperative chemotherapy and radiotherapy for localized high-grade malignant peripheral nerve sheath tumor at the extremities and trunk wall: a population-based cohort study.

BACKGROUND: Primary tumor resection is the mainstay of treatment for malignant peripheral nerve sheath tumors. However, the efficacy of perioperative chemotherapy and radiotherapy for malignant peripheral nerve sheath tumors has not been elucidated. METHODS: This retrospective analysis based on a Japanese registry included patients with localized malignant peripheral nerve sheath tumors arising at the extremities and trunk wall. Disease-specific overall survival and local recurrence-free survival were estimated using the Kaplan-Meier method. A Cox regression model was used to identify prognostic factors. Characteristics of groups with or without chemotherapy were adjusted using propensity score matching. RESULTS: In total, 291 patients were included. The 5-year disease-specific overall survival rate was 70.6%. Multivariate analysis of disease-specific overall survival revealed that deep-seated tumors were a poor prognostic factor, but perioperative chemotherapy was not associated with disease-specific overall survival (hazard ratio, 0.81; 95% confidence interval, 0.45-1.43, P = 0.46). Local recurrence was observed in 55 patients (19.0%), and surgical margins (R1 and R2) were significant risk factors. Overall, perioperative chemotherapy did not prolong disease-specific overall survival (5-year disease-specific overall survival: 74.1% vs. 69.3%, P = 0.75) and had limited efficacy in the group with tumor size ≥ 5 cm, although the difference was not statistically significant (5-year disease-specific overall survival: 77.2% vs. 68.6%, respectively, P = 0.13). After adjustment by propensity score matching, perioperative chemotherapy significantly prolonged disease-specific overall survival (5-year disease-specific overall survival: 74.9% vs. 57.1%, P = 0.03), but this effect was not observed in local recurrence-free survival. In all patients, perioperative radiotherapy did not correlate with local recurrence-free survival (hazard ratio, 1.43; 95% confidence interval 0.78-2.62, P = 0.25). CONCLUSIONS: Perioperative chemotherapy had limited efficacy for disease-specific overall survival in patients with localized malignant peripheral nerve sheath tumors.

A case report on a novel use of intraoperative Intrabeam™ radiation therapy for a recurrent malignant peripheral nerve sheath tumor with sciatic nerve involvement.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNST) are sarcomas that arise from peripheral nerves. They generally have a poor prognosis which is exacerbated by high local recurrence rates. This case report discusses the treatment of a patient with a MPNST with local recurrence. This case report is novel due to the use of intraoperative Intrabeam™ (Zeiss, Dublin, CA) radiation therapy use in the protection of neurovascular structures such as the sciatic nerve. CASE PRESENTATION: The patient was a 65-year-old male who noticed a right posterior thigh mass slowly increasing in size over two months. A planned positive margin wide-resection excision was performed due to sciatic nerve abutment. The mass was determined to be a MPNST via postoperative pathology with positive margins along the sciatic nerve. The patient began adjuvant radiation therapy to the upper and lower thigh fields over a period of three months. Thirty-two months later, the patient was found to have a hypermetabolic mass with venous congestion and hyperemia at the prior surgical site which was confirmed by core needle biopsy to be local recurrence of the MPNST. Re-excision of the tumor was planned and performed followed by intraoperative Intrabeam™ radiation therapy. At two years of follow-up, the patient was doing well with minimal pain in his right buttock region with no new or recurrent neurological deficits. Radiologic imaging was negative for local recurrence of the MPNST. CONCLUSION: We believe this case report demonstrates a novel treatment strategy for sarcoma management. The unique use of intraoperative Intrabeam™ radiation therapy, which had not previously been used for this indication, may be efficacious in cases involving neurovascular structures. In this case, focal radiation from the intraoperative Intrabeam™ radiation device was used in a way to affect the recurrent tumor yet protect the sciatic nerve.

Successful Radiotherapy of Primary Malignant Peripheral Nerve Sheath Tumor of the Lung.

A 71-year-old man presented with cough and bloody sputum. Computed tomography showed a mass in the lower lobe of the left lung. Histological findings in biopsy tissue revealed a malignant peripheral nerve sheath tumor (MPNST). The patient was diagnosed with primary lung MPNST based on a systemic examination. Although initial chemotherapy treatment with doxorubicin failed to control the disease, radiotherapy considerably shrank the tumor. Primary lung MPNSTs are rare, and there is no established treatment for inoperable cases. This case suggests that radiotherapy is a treatment option for primary lung MPNST.

Giant Malignant Peripheral Nerve Sheath Tumor of the Head and Neck: A Case Report and Literature Review.

Malignant peripheral nerve sheath tumor (MPNST) is a malignant soft tissue sarcoma with high mortality, low morbidity, and poor prognosis. The MPNST occurs mostly in the limbs and torso, and rarely in the head and neck. However, MPNST is insensitive to radiotherapy and chemotherapy, and complete surgical resection with negative margin is the most important and effective strategy. We present a case of MPNST in the head and neck. The tumor invades the left temporal bone, petrous bone, and mastoid bone, and compression changes in the focal cerebellum and sigmoid sinus. The patient underwent the left temporal region tumor resection + surgical reconstruction with temporalis muscle flap and pectoralis major myocutaneous flap. Adjuvant radiotherapy (55 Gy) was given after surgery, and there were no local recurrence and distant metastasis after 31-month follow-up.

Carbon Ion Radiotherapy in the Management of the Tumors of the Peripheral Nervous System.

BACKGROUND/AIM: Malignant peripheral nerve sheaths tumors (MPNST) are rare, highly aggressive and radioresistant tumors of soft tissue. Carbon ion radiotherapy (CIRT) seems to be an attractive treatment option when surgery is not possible or refused by the patient. The aim of this study was to report our preliminary results (outcomes and toxicity) of CIRT in the treatment of MPNSTs. PATIENTS AND METHODS: Our study retrospectively analyzed 13 patients (median age=54 years; range=23-72 years) with MPNST treated with CIRT for a median total dose of 73.6 Gy (relative biological effectiveness) (range=70.4-76.8 Gy) between 2013 and 2016. RESULTS: Six local progressions were recorded, with a median local progression-free survival of 23.2 months (range=2.2-45.4 months). Acute toxicities were mild. Late toxicity of grade 2 or more was noted in two patients. CONCLUSION: CIRT yielded good local control with a low rate of acute and late toxicities.

High dose hypofractionated frameless volumetric modulated arc radiotherapy is a feasible method for treating canine trigeminal nerve sheath tumors.

The aim of this prospective pilot study was to evaluate the feasibility and effectiveness of curative intent high dose hypofractionated frameless volumetric modulated arc radiotherapy for treatment of canine trigeminal peripheral nerve sheath tumors. Client-owned dogs with a presumptive imaging-based diagnosis of trigeminal peripheral nerve sheath tumor were recruited for the study during the period of February 2010 to December 2013. Seven dogs were enrolled and treated with high dose hypofractionated volumetric modulated arc radiotherapy delivered by a 6 MV linear accelerator equipped with a micro-multileaf beam collimator. The plans were computed using a Monte Carlo algorithm with a prescription dose of 37 Gy delivered in five fractions on alternate days. Overall survival was estimated using a Kaplan-Meier curve analysis. Magnetic resonance imaging (MRI) follow-up examinations revealed complete response in one dog, partial response in four dogs, and stable disease in two dogs. Median overall survival was 952 days with a 95% confidence interval of 543-1361 days. Volumetric modulated arc radiotherapy was demonstrated to be feasible and effective for trigeminal peripheral nerve sheath tumor treatment in this sample of dogs. The technique required few sedations and spared organs at risk. Even though larger studies are required, these preliminary results supported the use of high dose hypofractionated volumetric modulated arc radiotherapy as an alternative to other treatment modalities.

Clinical and imaging findings, treatments, and outcomes in 27 dogs with imaging diagnosed trigeminal nerve sheath tumors: A multi-center study.

The clinical behavior of canine trigeminal nerve sheath tumors and benefits of previously reported treatments are incompletely defined. Aims of this retrospective, multicenter, observational study were to describe clinical signs, tumor localization characteristics, treatments, and clinical outcomes in a group of dogs with this neoplasm. Databases at four hospitals were reviewed for dogs with a trigeminal nerve sheath tumor diagnosis, magnetic resonance imaging (MRI) studies, and presentation between 2004 and 2014. A single observer recorded medical record findings and two observers recorded MRI characteristics by consensus. A total of 27 dogs met inclusion criteria (15 treated with stereotactic radiation therapy and 12 unirradiated). Two unirradiated dogs were excluded from outcome analyses. The most common presenting signs were masticatory muscle atrophy (26 dogs), neurologic signs referable to intracranial disease (13), and ocular disease (12). Based on MRI findings, all dogs had disease extending centrally at the level of the brainstem. The most commonly affected trigeminal nerve branches were the mandibular (26 dogs), maxillary (22), and ophthalmic (10). Of 15 dogs treated with stereotactic radiation therapy, one had improved muscle atrophy, and six had poor ocular health after treatment. Neurologic signs improved in 4/5 dogs with intracranial signs. Overall median survival time for the 10 unirradiated dogs with available follow-up was 12 days and 441 days for the 15 stereotactic radiation therapy dogs. Mean survival times between these groups were not significantly different (mean 95% CI for unirradiated dogs was 44-424 days and mean 95% CI for stereotactic radiation therapy dogs was 260-518 days).

Malignant peripheral nerve sheath tumor of the superficial cervical plexus with parotid extension.

INTRODUCTION: Cervical locations of malignant peripheral nerve sheath tumor (MPNST) are rare, at less than 1% of malignant tumors of this region. CASE REPORT: A 53-year-old woman presented with a lateral cervical swelling involving the parotid region. Histology was in favor of MPNST. Adjuvant radiotherapy was indicated because of the infiltrating nature of the tumor. At 2 years' follow-up, there was no recurrence. DISCUSSION: Clinical diagnosis is difficult in cervical MPNST. Only histology with immunohistochemistry can establish the correct diagnosis. Treatment requires complete surgical resection and regular clinical follow-up.

Tumor maligno de vaina de nervio periférico: reporte de caso / Malignant peripheral nerve sheath tumor: case report

Se presenta un caso de tumor sacro voluminoso con características de Tumor Maligno de Vaina de Nervio Periférico (MPNST) que tras una resección inicial y recidiva se reintervino y trató con radioterapia complementaria. Tras ocho años se ha observado una buena evolución.

A case of voluminous sacral tumor with Malignant Peripheral Nerve Sheath Tumor (MPNST) characteristics is reported, that after a first resection and later recurrence is reoperated and treated with complementary radiotherapy. After eight years a good evolution has been observed.

Malignant peripheral nerve sheath tumours in the head and neck region: retrospective analysis of clinicopathological features and treatment outcomes.

Malignant peripheral nerve sheath tumours (MPNST) are rare soft tissue sarcomas. The aim of this study was to assess clinicopathological characteristics and prognostic factors in order to improve the treatment of such tumours in the head and neck region. We performed a retrospective analysis of head and neck MPNST patients in our hospital between 1996 and 2012. Clinical features and pathological findings of these cases (n=43) were summarized. In addition, prognostic variables were evaluated by univariate and multivariate analyses. The median age of the patients at presentation was 41 years. Surgery was the main treatment approach. Pertinent information regarding the presence of neurofibromatosis type 1 was found in 13 patients (30.2%). Two-thirds of these patients were admitted for a primary tumour (n=27, 62.8%), while one-third (n=16, 37.2%) were treated for recurrent neoplasms. The overall survival rate was 46.5%. Multivariable analysis identified tumour size, surgical margins, and postoperative radiotherapy to be independent prognostic factors. MPNST of the head and neck is extremely difficult to manage. Surgery with postoperative radiation may be the optimum choice of treatment for primary head and neck MPNST.

Malignant peripheral nerve sheath tumors of the trigeminal nerve: a systematic review of 36 cases.

OBJECT: Malignant peripheral nerve sheath tumors (MPNSTs) are a rare form of malignancy arising from the Schwann cells of peripheral nerves. MPNSTs of the trigeminal nerve are exceptionally rare, with only a handful of reports in the literature. These tumors are typically very aggressive, resulting in significant patient morbidity and a generally grim prognosis. Most current reports suggest that radical resection with radiation therapy offers the best benefit. In this study, the authors systematically reviewed the world English-language literature on MPNSTs of the trigeminal nerve to analyze the presentations, treatment options, and outcomes for patients with this disease. METHODS: A literature search for MPNSTs of the trigeminal nerve confined to nonanimal, English-language articles was conducted utilizing the PubMed database, with additional cases chosen from the references of selected articles. Only cases of confirmed MPNSTs of the trigeminal nerve or its peripheral branches, based upon surgical, pathological, or radiological analysis, were included. RESULTS: From the literature search, 29 articles discussing 35 cases of MPNSTs of the trigeminal nerve were chosen. With the addition of 1 case from their own institution, the authors analyzed 36 cases of trigeminal MPNSTs. The average age of onset was 44.6 years. These tumors were more commonly seen in male patients (77.1%). The gasserian ganglion was involved in 36.1% of the cases. Of the cases in which the nerve distribution was specified (n = 25), the mandibular branch was most commonly involved (72.0%), followed by the maxillary branch (60.0%) and the ophthalmic branch (32.0%), with 44.0% of patients exhibiting involvement of 2 or more branches. Altered facial sensation and facial pain were the 2 most commonly reported symptoms, found in 63.9% and 52.8% of patients, respectively. Mastication difficulty and diplopia were seen in 22.2% of patients, facial weakness was seen in 19.4%, and hearing loss was present in 16.7%. With regard to the primary treatment strategy, 80.6% underwent resection, 16.7% underwent radiation therapy, and 2.9% received chemotherapy alone. Patients treated with complete resection followed by postoperative radiation therapy had the most favorable outcomes, with no patients showing evidence of disease recurrence with a mean follow-up of 34.6 months. Patients treated with incomplete resection followed by postoperative radiation therapy had more favorable outcomes than patients treated with incomplete resection without radiation therapy or radiation therapy alone. CONCLUSIONS: Trigeminal MPNSTs most commonly present as altered facial sensation or facial pain, although they exhibit a number of other clinical manifestations, including the involvement of other cranial nerves. While a variety of treatment options exist, due to their highly infiltrative nature, aggressive resection followed by radiation therapy appears to offer the greatest chance of recurrence-free survival.

Follow-up MR findings of spinal foraminal nerve sheath tumors after stereotactic irradiation.

PURPOSE: The purpose of this study was to investigate follow-up MR findings of spinal foraminal nerve sheath tumors after stereotactic irradiation. MATERIALS AND METHODS: Thirty-five foraminal nerve sheath tumors in 28 patients who underwent stereotactic radiosurgery (SRS) (n = 28) or stereotactic radiotherapy (SRT) (n = 7) were included. The MR images were reviewed to identify serial changes in tumor volume and intratumoral necrosis. Growth and shrinkage were defined as volume changes of ±19.7 % or more; stability was within ±19.7 %. Transient swelling was defined as shrinkage preceded by significant growth. A tumor with shrinkage or stability was regarded as tumor control. RESULTS: Of 35 tumors, 16 (46 %) were stable, 14 (40 %) shrunk, and 5 (14 %) grew. Transient swelling was seen for 13 (37 %) lesions. Newly developed intratumoral necrosis was observed for 19 (54 %) of 35 tumors and was significantly associated with transient swelling (p = 0.039) and with tumor control (p = 0.017). SRS was not significantly associated with transient swelling. CONCLUSION: In follow-up MR images of spinal foraminal nerve sheath tumors after stereotactic irradiation, newly developed intratumoral necrosis and transient swelling were often seen. Intratumoral necrosis was associated with transient swelling and tumor control.

Excellent response of malignant peripheral nerve sheath tumour of retroperitoneum to radiation therapy.

Malignant peripheral nerve sheath tumours are high-grade sarcomas originating from Schwann cells or nerve sheath cells. Most of these tumours are associated with major nerves of the body wall and extremities. The lower extremity and the retroperitoneum are the most common sites. Surgery is the cornerstone of treatment, however, radiation therapy is usually used as an adjuvant treatment. In this paper we present a 57-year-old Iranian woman with malignant peripheral nerve sheath tumour of retroperitoneum who was operated subtotally and then underwent radiation therapy which led to disappearance of all gross residual disease.

Idiopathic vocal cord paralysis in the radiated neck: a harbinger for malignant peripheral nerve sheath tumour.

OBJECTIVE: Patients with previous neck external beam radiotherapy (XRT) diagnosed with idiopathic vocal cord paralysis (VCP) can harbour sinister pathology. A case series of such patients found to have vagal malignant peripheral nerve sheath tumours (MPNSTs) is presented and combined with a literature review. Management and survival outcomes are analyzed. DESIGN: Case series and systematic literature review. SETTING: Academic tertiary care cancer centre. METHODS: The University of Alberta's head and neck mass database was gleaned for vagal XRT-induced MPNSTs (2001-2011). Charts were reviewed for patient and tumour demographics, diagnostic methods, pathology, treatment, and survival. A systematic literature review identified similar patients. MAIN OUTCOME MEASURES: Kaplan-Meier estimated actuarial survival rates were the primary outcome. Secondary outcomes included the mean time from XRT to presentation and to tumour recurrence as well as a summary of patient/tumour characteristics, diagnostic methods, and treatment options. RESULTS: Two institutional and seven additional literature-wide cases were found. The median age was 34 years, the median time from XRT to MPNST was 22 years, and all patients were surgically treated. The median time from surgery to recurrence was 2.5 years. Estimated 2- and 5-year survival rates were 71% and 54%, respectively. CONCLUSION: XRT-induced MPNST can present as idiopathic VCP two decades post-XRT. Treatment is surgical and offers acceptable survival.

Favorable outcome after radical resection and subsequent local irradiation of malignant peripheral nerve sheath tumor in the cervical spine.

A 25-year-old man presented with malignant transformation to malignant peripheral nerve sheath tumor (MPNST) in the cervical spine associated with neurofibromatosis type 1. He presented with a 3-week history of rapidly increasing weakness and numbness in all four extremities. Magnetic resonance (MR) imaging of the cervical spine demonstrated a dumbbell-shaped tumor, which compressed the spinal cord at the C2-3 level. The tumor was excised, mainly within the spinal canal to decompress the spinal cord. The histological diagnosis was benign neurofibroma. Three months after surgery, he rapidly developed progressive tetraparesis and MR imaging revealed marked regrowth of an extradural mass into the spinal canal. At reoperation, the regrown mass in the spinal canal was totally excised. The histological diagnosis revealed MPNST. He underwent radiation therapy, with a total dose of 32 Gy, for approximately 3 weeks after the second surgery, but MR imaging showed tumor regrowth within the spinal canal, and his condition deteriorated. The decision was made to remove the tumor radically, including the involved facet and extradural lesion. Posterior fusion using a pedicle screw was performed one month later. He manifested no additional neurological deficits. He has been free of relapse for 46 months. Radical resection remains the most effective treatment for MPNST, although complete removal with a clear tumor margin is often impossible in practice.

Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding.

This study highlights the use of adaptive planning to accommodate testicular shielding in helical tomotherapy for malignancies of the proximal thigh. Two cases of young men with large soft tissue sarcomas of the proximal thigh are presented. After multidisciplinary evaluation, preoperative radiation therapy was recommended. Both patients were referred for sperm banking and lead shields were used to minimize testicular dose during radiation therapy. To minimize imaging artifacts, kilovoltage CT (kVCT) treatment planning was conducted without shielding. Generous hypothetical contours were generated on each "planning scan" to estimate the location of the lead shield and generate a directionally blocked helical tomotherapy plan. To ensure the accuracy of each plan, megavoltage fan-beam CT (MVCT) scans were obtained at the first treatment and adaptive planning was performed to account for lead shield placement. Two important regions of interest in these cases were femurs and femoral heads. During adaptive planning for the first patient, it was observed that the virtual lead shield contour on kVCT planning images was significantly larger than the actual lead shield used for treatment. However, for the second patient, it was noted that the size of the virtual lead shield contoured on the kVCT image was significantly smaller than the actual shield size. Thus, new adaptive plans based on MVCT images were generated and used for treatment. The planning target volume was underdosed up to 2% and had higher maximum doses without adaptive planning. In conclusion, the treatment of the upper thigh, particularly in young men, presents several clinical challenges, including preservation of gonadal function. In such circumstances, adaptive planning using MVCT can ensure accurate dose delivery even in the presence of high-density testicular shields.

Plan robustness in proton beam therapy of a childhood brain tumour.

INTRODUCTION: The concern of secondary cancer induction and normal tissue complications have motivated a more frequent use of protons in radiotherapy (RT) of children. However, proton RT is likely to be less robust to anatomical changes occurring during therapy. In this study we present a recent clinical case to illustrate this issue. MATERIAL AND METHODS: A five-year-old boy with a highly proliferating malignant intracranial nerve sheath tumour underwent a partial resection prior to RT and developed a post-surgery oedema close to the surgical cavity. RT was delivered with volumetric modulated arc therapy (VMAT) to a total tumour dose of 61.2 Gy. The most critical organs at risk (ORs) were the right optical nerve, brainstem and chiasm. Proton plans were constructed for the purpose of this study. In order to simulate a worst-case scenario, the extent of the oedema observed in the last part of the treatment was used to modify the oedema on the planning computed tomography (CT). Both the photon and proton plans were then re-calculated, as follows: Scenario A: Treatment planning based on the planning CT with oedema and dose calculated as if it was delivered without oedema. Scenario B: Treatment planning on the modified planning CT without oedema, but re-calculated with oedema. These two scenarios were compared to the situation where the oedema was present at treatment planning and unchanged during RT. RESULTS: Total dose to critical ORs remained unchanged for the photon plans, with changes within 0.3 Gy for the normal tissues and nearly identical target coverage. For protons, scenario A led to increased maximal doses in all critical ORs, 5.1 Gy in the brainstem, 6.1 Gy in the chiasm and 6.4 Gy in the right optical nerve. For scenario B the proton plans resulted in a loss in target coverage. CONCLUSION: This case study shows that RT with protons were far less robust to anatomical changes than when treated with photons, emphasising the increased need for adaptive approaches in RT with protons.