Submission: October 05, 2016; Published: October 24, 2016
*Corresponding author: Luis Moreno Sánchez. Radiation oncologist, Intra and Extracranial radiosurgery, brachytherapy, Coordinador de Radioncología, Instituto Nacional del Cáncer Rosa de Tavares (INCART), C/Correa y Cidrón, esq. Rafael Sánchez Ravelo. Zona Universitaria, Santo Domingo, Dominican Republic
How to cite this article: Luis M S, Jacksson S, Moisés D. Brachial Plexus Neurofibroma Treated with Volumetrically Modulated Arc Therapy (VMAT): A Case Report.. Canc Therapy & Oncol Int J. 2016; 2(2): 555585. DOI: 10.19080/CTOIJ.2016.02.555585
Neurofibromatosis was first described in 1882 by Friedrich Daniel von Reckling hausen, a German pathologist. Neurofibroma is a benign peripheral nerve sheath tumor that consists of Schwann cells, associated or unassociated with axons, perineural cells, and fibroblasts. Whenever possible, the treatment of choice should be surgical, but the management depends on the location and growth pattern. We present the case of a patient with left axillary neurofibroma without neurofibromatosis (NF) in whom surgery was delayed due to involvement of the brachial plexus, so was sent to radiotherapy, planned and treated with volumetrically modulated arc therapy (VMAT).
Abbreviations: NF: Neurofibromatosis; VMAT: Volumetrically Modulated Arc Therapy; CRO: Radiation Oncology Center; INCART: Institute Rosa Emilia Sánchez Pérez de Tavares; CW: Clockwise; NTO: Normal Tissue Objective; OAR: Organ at Risk
Neurofibromas are benign tumors that arise from nerves and are composed of Schwann cells, perineural cells, and fibroblasts ; typically arise in the setting of neurofibromatosis type I (NF I) , but may also occur independently, when it comes to multiple tumors is the main clinical manifestation of the different types of neurofibromatosis and are processes that are transmitted with autosomal dominant inheritance with variable penetrance. In most cases are treated by surgery, especially when they are symptomatic or with evident anatomical changes [3,4], but when a neurofibroma involves a particularly long segment of nerve or nerves, are generally impossible to remove without removing the entire nerve, causing a major neurological deficit, therefore, these variants are not usually subjected to surgery. In this report, we describe an axillar neurofibroma in a patient without NF I, which was treated with radiotherapy using volumetrically modulated arc therapy (VMAT).
Female patient, 55 years old, who had previously presented
to an external surgery department was remitted to the Radiation Oncology Center (CRO) at National Cancer Institute Rosa Emilia Sánchez Pérez de Tavares (INCART), in Santo Domingo, Dominican Republic, with history of pain and volume increase in left armpit, diagnosed as non-surgical axillar neurofibroma. Medical record, including MRI, CT and pathologic specimen, were reviewed. The patient was considered initially for surgery like standard treatment, but during process evidenced brachial plexus commitment, because of this was omitted the surgery and was referred to radiation oncology. The Physical exam reported: Karnofsky (KPS) 100%, ECOG 0, in the left axillary region was felt a mass about 10 cm in diameter (Figure 1), mobile, painful, hard consistency with left arm weakness. A shoulder MRI with gadolinium reported: oval image 8.5 x 5.3 cm anteroposterior, anterior to the subclavian neurovascular bundle located in the anatomical path of the brachial plexus, highly suggestive of neural image type neurofibroma. Described image shows a bottom center 1.9 cm cystic degeneration, in turn shows an intense post gadolinium enhancement and heterogeneous accordance with important vascularization (Figure 2).
The patient was positioned in supine using a table for breast
carbon fiber of the CIVCO® brand. Package tumor localization
(TumorLOC®) Brilliance CT was used for the location of tumor
tomography simulation. This tool allows you to place the
isocenter manually depending on the selected organs and can
create orthogonal beams associated with that default position of
isocenter. Tomographic scanning technique was 120kV, axial cut,
over 200,3 mm apart.
The treatment technique corresponded to volumetrically
modulated arc therapy (VMAT) for this, two semi-arches were used. The first from 0° to 179° towards the direction of clockwise
(CW) and the second reverse direction arc (179° to 0°). They were
established for each arc 98 control points with maximum speed
of gantry 4.8 deg / s. Each semi-arch lasted 48 seconds (0.8min)
(Figure 3 & 4). The bodies’ risks were considered for planning
spinal cord, left lung, left humeral head and left mammary gland.
As establishment of an NTO (normal tissue objective) use the
automatic option. Resolutions (mm) and priorities (%) planning
for OAR (organ at risk) were, respectively: spinal cord 2 mm and
35%, humeral head 2.65 mm and 25%, left lung 3 mm and 30%,
left breast 3 mm and 25%.
Evaluating different plane cuts ensure that 100% of the
prescribe dose is within the volume of total dose planning
5940 cGy. The bodies assessed risks are below the limits set by
Quantec / RTOG (Figure 5).
One of the benefits of this proposal lies among other things
in the runtime patient treatment compared to some other CRT3D
or IMRT technique. The maxim and average doses to OAR were:
27.3 Gy / 10.5 Gy (VMAT) and 36 Gy / 9.12 Gy (IMRT)for left
humeral head (green); 60.0 Gy / 5.2 Gy (VMAT) and 60.5 Gy / 5.7
Gy (IMRT) for left breast (yellow); 8.5 Gy / 2.7 Gy (VMAT) and
9.6 Gy / 2.9 Gy (IMRT)for spinal cord(purple) and finally 17.3 Gy
/ 1.77 Gy (VMAT) and 35.5 Gy / 2.5 Gy (IMRT) for left lung (blue)
The two semi-arches were evaluated for creep refers using
an amorphous silicon system to perform dosimetry portal.
Descriptors parameters for evaluation were the index gamma
3% and distance agreement (DTA) 3mm. Predicted doses vs.
the portals doses obtained successfully passed the evaluation criteria (Figure 7).
Left axillary neurofibroma. The microscopic biopsy
description reported: sections showed mesenchymal neoplasm,
partially encapsulated, constituted by the proliferation of
spindle cells, elongated nuclei arranged in swirling pattern and
fibrillar collagenous stroma storiform on congestive vessels with
thickened walls and areas of bleeding. Differential diagnoses
included: schwannoma, malignant peripheral nerve sheath
tumor and desmoid tumor .
Neurofibromatosis was first described in 1882 by Friedrich
Daniel von Recklinghausen, a German pathologist. It is a
disease caused by an abnormality in a gene on chromosome
17.Thediagnosis of Neurofibromatosis type I (NF1) is confirmed
If 2 or more of these criteria are met in an individual: six or
more stains coffee with milk greater than 5 mm in pre pubertal
patients and over 15 mm in post pubertal patients; two or more
neurofibromas of any type or one plexiform neurofibroma;
sign Crowe (axillary or inguinal freckling); [6-9] Glioma optic
nerve; two or more Lisch nodules (iris harmartomas); typical
bone lesions (dysplasia of the sphenoid dysplasia or thinning of
long bone cortex with or without pseudoarthrosis); history of
neurofibromatosis type I in parents or siblings . Meanwhile,
to make the diagnosis of NF 2 is necessary to have the following
criteria: bilateral masses in the eighth cranial demonstrated
techniques by appropriate images or first-degree relative with
NF2 and one of the following: unilateral mass the eighth cranial
nerve, or two of the following: neurofibroma, meningioma,
glioma, schwannoma, subcapsular lenticular opacity youth back
In the case of our patient, it has none of the criteria for NF1or
2. Neurofibroma is a benign peripheral nerve sheath tumor that
consists of Schwann cells, associated or unassociated with axons,
perineural cells, and fibroblasts. The tumor routinely expresses
S-100 protein. Benign neurofibromas most often occur in
association with neurofibromatosis type 1 (NF1) but may also
occur sporadically [1,2], like in our case report.
The biological behavior of neurofibromas is usually benign,
but it is not rare sarcomatous degeneration in plexiform.
Neurofibromas occur in multiple locations, exhibit different growth patterns and morphologies at highly variable rates,
a classification system stratifies these tumors into 5 types:
localized cutaneous, diffuse cutaneous, localized intraneural,
plexiform, and massive soft tissue neurofibromas .
The management depends on the location and growth
pattern. Whenever possible, the treatment of choice should be
surgical, especially when they produce functional or cosmetic
déficits, ideally with complete removal of the tumor, but some
tumors diffusely involve adjacent normal tissues such as nerves
and blood vessels, making complete remove of the tumoral
most impossible [1,3,4,6,8,9]. Medical therapies have been
investigated, most are still investigational  and Radiotherapy
has been rarely used like initial treatment, but by default in
patients with incomplete resection [1,4]. Needle et al. 
reported 121 children with plexiform neurofibromas who
underwent resection and were followed for over 20 years. Those
that were entirely removed were less likely to recur and had a
longer median time to failure. Near-total and subtotal resections
demonstrated recurrence rates of 39.5% and 44%, respectively.
We must emphasize team work and multi disciplinary
approach to tackling the disease. The commitment caused by
neurofibromas depends in much of their location, skin lesions
usually cause deformity, while more injuries shallow tend to
generate functional compromise. Despite being mostly benign,
some cause destruction secondary to the pressure exerted, so the
symptoms are depend on the size of the lesion. The therapeutic
approach should be multidisciplinary, with the initial treatment
recommended surgery, but in case of not being able to perform
or partial resection, radiotherapy with doses between 54-60 Gy
can achieve adequate local control. In reviewing the literature
an extensive description of the disease and epidemiological
data was found are scarce, so studies to know the disease more
accurately are needed.