Table 1. Results of the test on the first probe prototype. The probe was tested on phantoms sized as possible tumour residuals of interest, filled with 90Y in saline solution to simulate the situation after bulk meningioma removal. The rates measured with two different 90Y activity concentrations (22 and 5 kBq/ml) are reported (Rate). The minimal acquisition time (T) needed to detect tumour residuals with a false-negative probability <5% and a false-positive probability ~1% was estimated extrapolating the laboratory test results to a real case by means of a detailed simulation.
| Phantom | Diameter (mm) | Height (mm) | Volume (ml) | Rate (cps) 22 kBq/ml | T (s) 22 kBq/ml | Rate (cps) 5 kBq/ml | T (s) 5 kBq/ml |
|---|---|---|---|---|---|---|---|
| Residual | 6 | 3.5 | 0.10 | 31.6 | 1 | 6.6 | 2 |
| H1 | 4 | 1 | 0.01 | 12.4 | 2 | 2.6 | >10 |
| H2 | 4 | 2 | 0.02 | 17.7 | 1 | 3.7 | 4 |
| H3 | 4 | 3 | 0.04 | 20.1 | 1 | 4.2 | 4 |