Patient Reported Outcomes after Frameless Virtual Cone Radiosurgery for Trigeminal Neuralgia

Abstract

<h3>Purpose/Objective(s)</h3> The Virtual Cone is an MLC delivery sequence designed to mimic the dose distribution of a physical cone. In this prospective trial we assessed the efficacy and patient reported outcomes of frameless MLC-based radiosurgery for trigeminal neuralgia. <h3>Materials/Methods</h3> RAD1501 (ClinicalTrials.gov Identifier: NCT02708810) started enrollment in November 2015. Patients had a BNI score of IV or V and MRI to demonstrate no intracranial lesion to explain symptoms. All patients received 80-85 Gy to Dmax to a 5mm target at the dorsal root entry zone. All patients were treated in an Encompass immobilization device. Image guidance started with orthogonal kV images followed by CBCT. During treatment, the patient position was continuously monitored with optical surface imaging. The primary endpoint was an improvement in the Barrow Neurologic Index from IV/V to III or less. Secondary outcomes were assessed by comparing the mean scores of 8 different scales of SF-36 questionnaire at 3 months and 6 months. <h3>Results</h3> At the time of analysis, 44 patients completed treatment with clinical follow up exceeding 6 months. The mean age was 65.8 years (range 35-94 years). Sex distribution was 56.8 % females and 43.2% males. Post treatment BNI at 3 months was 30.8% BNI of 4, 38.5% BNI of 3, 11.2% BNI of 2 and 19.3% with BNI of 1. Post treatment BNI at 6 months was 19% with BNI of 4, 52.4% BNI of 3, 4.8% BNI of 2 and 23.8% with BNI of 1. Regarding secondary outcomes measured by SF-36 questionnaire there was a statistically significant improvement at 3 months in role limitation due to physical health (<i>p=0.023)</i>, energy (<i>p= 0.014)</i>, emotion wellbeing (<i>p=0.002)</i>, social functioning (<i>p=0.008)</i>, and pain (<i>p<0.001).</i> At 6 month there was statistically significant improvement in energy (<i>p= 0.002)</i>, emotion wellbeing (<i>p<0.001)</i>, social functioning (<i>p=0.030)</i>, and pain (<i>p=<0.001).</i> At 3 months 27/27 (100%) of patients were satisfied with the procedure and would recommend it to family member or friend. <h3>Conclusion</h3> From our initial analysis frameless virtual cone stereotactic radiosurgery for trigeminal neuralgia appears to provide similar outcomes in pain relief (∼80% at 6 months) when compared to stereotactic radiosurgery as demonstrated in previous studies. Patient quality of life improves and there is high satisfaction with the procedure.