Radioguided Occult Lesion Localization in Deep Schwannomas of the Peripheral Nerves: Results of a Preliminary Case Series.

BACKGROUND: The detection of small deep schwannomas of the peripheral nerves has been increasing since the the use of precise neuroimaging techniques has become more widespread; however, although nonpalpable lesions can be well defined by images, it is often difficult to identify them during the surgical procedure. The authors report seven cases of nonpalpable small deep schwannomas surgically treated after their identification using the radioguided occult lesion localization (ROLL) technique. METHODS: Seven men, whose ages ranged from 34 to 70 years (mean 52 years), presented with symptomatic nonpalpable peripheral nerve lesions; two cases involved the sciatic nerve, two the femoral nerve, two the radial nerve, and one the tibial nerve. Before the operation, all the patients were studied by ultrasonography and magnetic resonance imaging (MRI); 1 h before the surgery 3-5 MBq of 99mTc labeled with human albumin macroaggregates was injected into the lesion. A gamma detection probe permitted the preoperative and intraoperative detection of the nonpalpable schwannomas. CONCLUSIONS: The ROLL technique provides good support for identifying small lesions of the peripheral nerves both preoperatively and intraoperatively. This technique permits the use of minimally invasive approaches performed with local anesthesia, with good cosmetic results and acceptance by the patients.