Nuclear‐medicine probes: Where we are and where we are going

Abstract

Nuclear medicine probes turned into the key for the identification and precise location of sentinel lymph nodes and other occult lesions (i.e., tumors) by using the systemic administration of radiotracers. Intraoperative nuclear probes are key in the surgical management of some malignancies as well as in the determination of positive surgical margins, thus reducing the extent and potential surgery morbidity. Depending on their application, nuclear probes are classified into two main categories, namely, counting and imaging. Although counting probes present a simple design, are handheld (to be moved rapidly), and provide only acoustic signals when detecting radiation, imaging probes, also known as cameras, are more hardware‐complex and also able to provide images but at the cost of an increased intervention time as displacing the camera has to be done slowly. This review article begins with an introductory section to highlight the relevance of nuclear‐based probes and their components as well as the main differences between ionization‐ (semiconductor) and scintillation‐based probes. Then, the most significant performance parameters of the probe are reviewed (i.e., sensitivity, contrast, count rate capabilities, shielding, energy, and spatial resolution), as well as the different types of probes based on the target radiation nature, namely: gamma (γ), beta (β) (positron and electron), and Cherenkov. Various available intraoperative nuclear probes are finally compared in terms of performance to discuss the state‐of‐the‐art of nuclear medicine probes. The manuscript concludes by discussing the ideal probe design and the aspects to be considered when selecting nuclear‐medicine probes.

Accuracy of DOTATATE PET imaging in the preoperative planning of small bowel neuroendocrine tumor resection

“…Though the data are limited to mostly case series so far, some centers have employed pre‐ and postoperative PET imaging while others have opted to use a high‐energy gamma probe for intraoperative guidance 39–41 . While early studies show some promise, the application of such techniques is nascent and the technology itself can be expensive, costing up to $500 000 in some cases 42 . As technology continues to improve and we become more experienced with its use, handheld gamma technology could provide real‐time visual guidance during complete robotic resection for sbNETs.…”

“…[39][40][41] While early studies show some promise, the application of such techniques is nascent and the technology itself can be expensive, costing up to $500 000 in some cases. 42 As technology continues to improve and we become more experienced with its use, handheld gamma technology could provide real-time visual guidance during complete robotic resection for sbNETs. However, until there are further technological developments, our study demonstrates that manual palpation for secondary sbNET lesions likely cannot be replaced by contemporary DOTATATE PET imaging in the preoperative setting as sensitivity and NPV for multifocal sbNETs was weak and detection of nodal burden was quite poor.…”

Imaging skins: stretchable and conformable on-organ beta particle detectors for radioguided surgery

“…In clinical settings, β-radiation have energies in the ∼100-1000 keV range [37], as reported in table 1. It is important to note that many radioisotopes are tuned for PET imaging, thus catching positron (β + )/electron annihilation.…”

“…Another solution, the detector must be designed to only catch β − -radiation-electron of a few MeV [19,37]. β − -imaging does not suffer from background noise due to tracer uptake in surrounding healthy tissues since electrons can only travel a few millimetres in water and tissues [37]. As a result, these radiations can only be detected through direct contact [40].…”