First ex vivo validation of a radioguided surgery technique with β-radiation. Issue 9 (September 2016) - Solfaroli Camillocci, E.
Highlights: A novel radio-guided-surgery technique using beta- radiation is under development. Simulations and lab tests demonstrated its potential compared to state-of-the-art. A proof-of-principle test on patient confirmed tracer uptake and probe sensitivity. It also confirmed that the dose delivered to the medical staff is negligible. This is a proof-of-principle, not a case report, nor a clinical trial. Abstract : Purpose: A radio-guided surgery technique with β - -emitting radio-tracers was suggested to overcome the effect of the large penetration of γ radiation. The feasibility studies in the case of brain tumors and abdominal neuro-endocrine tumors were based on simulations starting from PET images with several underlying assumptions. This paper reports, as proof-of-principle of this technique, an ex vivo test on a meningioma patient. This test allowed to validate the whole chain, from the evaluation of the SUV of the tumor, to the assumptions on the bio-distribution and the signal detection. Methods: A patient affected by meningioma was administered 300 MBq of 90 Y-DOTATOC. Several samples extracted from the meningioma and the nearby Dura Mater were analyzed with a β - probe designed specifically for this radio-guided surgery technique. The observed signals were compared both with the evaluation from the histology and with the Monte Carlo simulation. Results: we obtained a large signal on the bulk tumor (105 cps) and a significant signal on residuals of ∼0.2 ml (28 cps). We also show that simulations predict correctly the observed yields and this allows us to estimate that the healthy tissues would return negligible signals (≈1 cps). This test also demonstrated that the exposure of the medical staff is negligible and that among the biological wastes only urine has a significant activity. Conclusions: This proof-of-principle test on a patient assessed that the technique is feasible with negligible background to medical personnel and confirmed that the expectations obtained with Monte Carlo simulations starting from diagnostic PET images are correct.