Intraoperative beta probe: a device for detecting tissue labeled with positron or electron emitting isotopes during surgery.
An intraoperative beta probe was designed, built, and tested for detection of radio-labeled malignant tissues that has the advantage of being selectively sensitive to beta while insensitive to gamma radiation. Since beta radiation (electrons or positrons) has a short range in tissue, this probe is ideal for detecting tracers in tumors at the surface of the surgical field. This probe contains a plastic scintillation detector sensitive to beta rays and to a lesser degree some background gamma rays. A second detector counts spurious gamma rays and allows for their subtraction from the activity measured by the first detector. Sensitivity of the dual probe for I-131 and F-18 was measured to be 108 counts/s/kBq (4000 counts/s/microCi). The dual-detector probe faithfully measured the 10:1 "tumor" to background ratio of radioactivity concentrations in a simulated environment of a tumor in the presence of intense background 511 keV photons. In another phantom experiment, simulating abdominal tumor deposits with various realistic I-131 radioactive concentrations, the probe was able to accurately identify tumors of approximately 50 mg with a tumor/normal radioactivity concentration of 3/1 in 10 s.
Daghighian
F
F
Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Mazziotta
J C
JC
Hoffman
E J
EJ
Shenderov
P
P
Eshaghian
B
B
Siegel
S
S
Phelps
M E
ME
D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D001610:Beta Particles; D055592:Biophysical Phenomena; D001703:Biophysics; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D004583:Electrons; D005462:Fluorine Radioisotopes; D005720:Gamma Rays; D006801:Humans; D007432:Intraoperative Period; D007457:Iodine Radioisotopes; D008961:Models, Structural; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D011874:Radiometry / Q000295:instrumentation* / Q000706:statistics & numerical data; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity
D005462:Fluorine Radioisotopes; D007457:Iodine Radioisotopes