First ex vivo validation of a radioguided surgery technique withβ-radiation.

Abstract

Purpose: A radio-guided surgery technique with β − -emitting radiotracers 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 * co-first-author † corresponding author, e-mail: riccardo.faccini@roma1.infn.it 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.

Radioguided surgery with radiolabeled somatostatin analogs: not only in GEP-NETs

“…This feature allows administration of radiopharmaceuticals with lower activity, development of more accessible and compact probes, which are preferred by surgeons and may provide higher TBRs, that could help in the definition of lesion's extension and margins. In addition, thanks to the lower absorbed dose and the short range of electrons, there is a negligible radiation exposure for medical personnel, which could therefore allow a larger number of RGSs per year for surgeon [39].…”

Radioguided surgery with β radiation: a novel application with Ga68

“…In particular, the actual probe prototype, which has been tested on β − radiation in a clinical trial with meningioma ex - vivo samples 7 , is composed by a sensitive cylinder of p-terphenyl with a radius of 2.55 mm and a 3-mm depth. To maximise the accuracy on the direction of the incoming radiation, the sensitive region is screened by 3 mm of polyvinylchloride.…”

“…This probe is characterised by high sensitivity to particles, whilst being substantially transparent to contamination. In the recent years, this proposed novel technique of RGS has been proved not only to be theoretically possible 5,6 , but also its actual feasibility has been demonstrated with ex - vivo tests on meningioma samples marked with 90 Y-DOTATOC 7 .…”

CdTe compact gamma camera for coded aperture imaging in radioguided surgery

“…Detection of bone tumors and parathyroid adenoma, radioimmunoguided surgery for colon cancer, sentinel-node mapping for breast tumor or melanoma tumor therapy, are typical applications of RGS [3]. In RGS, though gamma-ray radiotracers are typically adopted [4][5][6][7], also βradioisotopes can be used [8][9][10] as well as β + sources [11][12][13][14]. The success of RGS depends on the progress of the research on radiopharmaceuticals and intraoperative probes.…”