Optical emission of 223 Radium: in vitro and in vivo preclinical applications

²²³ Radium (²²³ Ra) is widely used in nuclear medicine to treat patients with osseous metastatic prostate cancer. In clinical practice ²²³ Ra cannot be imaged directly; however, gamma photons produced by its short-lived daughter nuclides can be captured by conventional gamma cameras. In this work, we show that ²²³ Ra and its short-lived daughter nuclides can be detected with optical imaging techniques. The light emission of ²²³ Ra was investigated in vitro using different setups in order to clarify the mechanism of light production. The results demonstrate that the luminescence of the ²²³ Ra chloride solution, usually employed in clinical treatments, is compatible with Cerenkov luminescence having an emission spectrum that is almost indistinguishable from CR one. This study proves that luminescence imaging can be successfully employed to detect ²²³ Ra in vivo in mice by imaging whole body ²²³ Ra biodistribution and more precisely its uptake in bones.

Monte Carlo simulations support non-Cerenkov radioluminescence production in tissue

There is experimental evidence for the production of non-Cerenkov radioluminescence in a variety of materials, including tissue. We constructed a Geant4 Monte Carlo simulation of the radiation from P32 and Tc99m interacting in chicken breast and used experimental imaging data to model a scintillation-like emission. The same radioluminescence spectrum is visible from both isotopes and cannot otherwise be explained through fluorescence or filter miscalibration. We conclude that chicken breast has a near-infrared scintillation-like response with a light yield three orders of magnitude smaller than BGO.

Cerenkov luminescence imaging: physics principles and potential applications in biomedical sciences

Cerenkov luminescence imaging (CLI) is a novel imaging modality to study charged particles with optical methods by detecting the Cerenkov luminescence produced in tissue. This paper first describes the physical processes that govern the production and transport in tissue of Cerenkov luminescence. The detectors used for CLI and their most relevant specifications to optimize the acquisition of the Cerenkov signal are then presented, and CLI is compared with the other optical imaging modalities sharing the same data acquisition and processing methods. Finally, the scientific work related to CLI and the applications for which CLI has been proposed are reviewed. The paper ends with some considerations about further perspectives for this novel imaging modality.

Cerenkov luminescence imaging (CLI) for image-guided cancer surgery

Cerenkov luminescence imaging (CLI) is a novel molecular optical imaging technique based on the detection of optical Cerenkov photons emitted by positron emission tomography (PET) imaging agents. The ability to use clinically approved tumour-targeted tracers in combination with small-sized imaging equipment makes CLI a particularly interesting technique for image-guided cancer surgery. The past few years have witnessed a rapid increase in proof-of-concept preclinical studies in this field, and several clinical trials are currently underway. This article provides an overview of the basic principles of Cerenkov radiation and outlines the challenges of CLI-guided surgery for clinical use. The preclinical and clinical trial literature is examined including applications focussed on image-guided lymph node detection and Cerenkov luminescence endoscopy, and the ongoing clinical studies and technological developments are highlighted. By intraoperatively guiding the oncosurgeon towards more accurate and complete resections, CLI has the potential to transform current surgical practice, and improve oncological and cosmetic outcomes for patients.

Unified approach for bioluminescence, Cerenkov, β, X and γ rays imaging

The goal of this work is to demonstrate that a CCD-based system can be used as a unified device which allows visible, β, X and γ rays imaging. A system composed of a CCD coupled with lens mounted on a black light-tight box and a high resolution intensifying screen for the radiations conversion were used. In order to investigate the detection of different type of radiations in vitro and in vivo experiments were performed. The comparison of the results obtained with our prototype and those obtained with dedicated commercial devices showed a good agreement.

Novel biomedical applications of Cerenkov radiation and radioluminescence imaging

The main goals of this review is to provide an up-to-date account of the different uses of Cerenkov radiation (CR) and radioluminescence imaging for pre-clinical small animal imaging. We will focus on new emerging applications such as the use of Cerenkov imaging for monitoring radionuclide and external radiotherapy in humans. Another novel application that will be described is the monitoring of radiochemical synthesis using microfluidic chips. Several pre-clinical aspects of CR will be discussed such as the development of 3D reconstruction methods for Cerenkov images and the use of CR as excitation source for nanoparticles or for endoscopic imaging. We will also include a discussion on radioluminescence imaging that is a more general method than Cerenkov imaging for the detection using optical methods of alpha and gamma emitters.