Therapeutic applications of radioactive sources: from image-guided brachytherapy to radio-guided surgical resection

Abstract

it is well known nowadays that radioactivity can destroy the living cells it interacts with. it is therefore unsurprising that radioactive sources, such as iodine-125, were historically developed for treatment purposes within radiation oncology with the goal of damaging malignant cells. however, since then, new techniques have been invented that make creative use of the same radioactivity properties of these sources for medical applications. here, we review two distinct kinds of therapeutic uses of radioactive sources with applications to prostate, cervical, and breast cancer: brachytherapy and radioactive seed localization. in brachytherapy (BT), the radioactive sources are used for internal radiation treatment. current approaches make use of real-time image guidance, for instance by means of magnetic resonance imaging, ultrasound, computed tomography, and sometimes positron emission tomography, depending on clinical availability and cancer type. Such image-guided BT for prostate and cervical cancer presents a promising alternative and/or addition to external beam radiation treatments or surgical resections. radioactive sources can also be used for radio-guided tumor localization during surgery, for which the example of iodine-125 seed use in breast cancer is given. radioactive seed localization (rSl) is increasingly popular as an alternative tumor localization technique during breast cancer surgery. Advantages of applying RSL include added flexibility in the clinical scheduling logistics, an increase in tumor localization accuracy, and higher patient satisfaction; safety measures do however have to be employed. We exemply the implementation of rSl in a clinic through our experiences at the netherlands cancer institute.

Intraoperative Gamma Cameras: A Review of Development in the Last Decade and Future Outlook

“…Alongside the continued development of low-energy-gamma-emitting radionuclide tracers, recent trends in radioguided surgery and IGC development have seen an increase in the use of beta-emitting isotopes and those traditionally used for therapeutic applications [3,45], such as the use of 125 I seed sources as tumour markers during radioactive occult lesion localization (ROLL) procedures. By implanting a focal, sealed source within the tumour, this technique can aid localisation in cases where either no suitable tracer for radioguidance exists, or poor/diffuse uptake/retention of liquid tracers would render traditional radioguidance techniques ineffective [159]. As the gamma-photon energies emitted by therapeutic isotopes typically provide suboptimal imaging performance when imaged by gamma cameras intended for diagnostic radionuclide imaging, this area appears to be an ideal candidate for the development of application-specific devices.…”