Orginal article
Brachial plexus injuries after radiotherapy – analysis of 6 cases

Introduction

Injuries of the brachial plexus due to radiation therapy are rarely observed in medical practice [2,5,6]. This kind of damage is caused by compression of the neural elements of the brachial plexus by fibrotic connective tissue [6,11]. Fibrosis around the brachial plexus has a relatively slow, progressive course [7]. Lesions of the brachial plexus may develop in patients who have had radiotherapy to the supra- and infraclavicular regions and axilla [9,12]. Surgical exploration of the brachial plexus is recommended in advanced stages of the disease [5,12].

Material and methods

The clinical material consisted of 6 women aged from 40 to 64 years with radiation-induced brachial plexus neuropathy treated (surgically – 5, conservatively – 1) at the Department of Trauma and Hand Surgery, Medical University of Wrocław, in the period of 1999-2005. We analysed the basic disease and its treatment, duration of radiotherapy, radiated fields and total dose of radiation. The onset and character of symptoms, location and severity of injury were established. The most important clinical data are shown in Tables I and II. The results of the surgical treatment based on the assessment of remission of pain and improvement of sensory and motor function have also been evaluated.


Results

The results of the surgical treatment are shown in Table III.


Discussion

Injuries of the brachial plexus may occur after radiotherapy of neck and thorax neoplasms [2,3,8,11,12]. In our own material 5 women have had diagnosed breast cancer and 1 woman parotid gland neoplasm. Radiation therapy has been used as
a supplement to surgical treatment in 5 women and in 1 woman as a basic cure (case 3). The total dose of radiation varied in the described cases from 45 to 60 Gy (on average 50 Gy), which confirms the observations of other authors about doses which may cause injuries of the brachial plexus [1,4]. The radiotherapy concerned the supraclavicular area and axilla in 3 patients (cases 1, 2, 5) and only the supraclavicular area in the other patients (case 3, 4, 6). In 2 women (cases 3, 4) with irradiation of the supraclavicular area the injury was localised in the superior part of the brachial plexus (C₅-C₆-C₇). This may confirm observations made by Kori about the greater sensibility of the superior part of the brachial plexus after radiation therapy of the supraclavicular area [8]. However, in case 6, in which the radiation field was limited to the supraclavicular area, a total lesion of the brachial plexus was observed in clinical examination. The symptoms of brachial plexus injury after radiotherapy include pain and sensory and motor disorders of the upper extremities and are classified according to a 4-grade scale of severity of injury – the LENT-SOMA scale [1,2,5]. In our own material in 5 patients a lesion of the brachial plexus reached grade 4 and in one patient (case 4) grade 3 on the LENT-SOMA scale. In 2 cases gradual progression of symptoms from grade 1 to grade 4 during 2 (case 3) and 3 years (case 5) was ascertained. The same events were observed by Bajrovic and co-workers [1]. The interval between completion of the radiotherapy and occurrence of the neurological symptoms was reported to be 1-4 years [1]. In the presented material the time of occurrence of brachial plexus injury symptoms varied from 1 year to 20 years (on average 7 years). Late onset of symptoms was observed in cases 5 and 6. These patients were not treated with chemotherapy, which in the opinion of some authors increased the risk of lesion of the brachial plexus after radiotherapy [10]. However, in case 4, in which chemotherapy was not used, onset of symptoms was as quick (1 year) as in the other 3 cases (case 1, 2, 3) treated with chemotherapy. In the discussed material 5 women were qualified for surgical treatment. The degree of severity (grade 3 and 4 on the LENT-SOMA scale) motivated surgical exploration of the brachial plexus in these cases [5,9,12]. One woman was not operated on due to presence of metastases in the lungs (case 1). In cases with radiation therapy limited to the supraclavicular area only supraclavicular surgical access was realised (cases 3, 4 ,6). In the other 3 cases with radiotherapy both the supraclavicular area and axilla, nerves in this region (axillary area) were in addition exposed (Fig. 1). Compression of the neural elements by dense fibrous connective tissue was intraoperatively observed. The performed neurolysis allowed liberation of the brachial plexus (Figs. 2, 3) and also collection of material for histopathological examination (case 5 – Figs. 4, 5). The result of this exam constitutes a basis for the ultimate differential diagnostics between radiation-induced brachial plexus neuropathy and neoplasm infiltration [7]. After surgical treatment in 2 patients (cases 4, 5) a significant improvement was obtained – release of pain and sensory disorders, reduction of motor deficits. In one case the improvement was temporary – release of pain and sensory recovery after neurolysis performed in 1999 (case 6). The improvement persisted for
a 2-year period and then deterioration occurred. It induced us to repeated exploration of the brachial plexus in 2002. Similarly as after the first operation the improvement was temporary. After surgical treatment in the remaining 2 cases (cases 2, 3) no improvement was observed in clinical conditions. The surgical management was justifiable in these cases because of the possibility of collection of specimens for histopathological examination.

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