Localized tumor delivery of radiosensitizers and chemotherapeutics using ‘INCeRT’ implants

Systemic chemotherapy is often used with radiation therapy in the management of prostate cancer, but leads to severe systemic toxicities. We have introduced a new modality of loco-regional chemoradiation therapy termed in-situ image guided radiation therapy (BIS-IGRT) that offers the potential to deliver planned, localized and sustained delivery of chemotherapy agent, without systemic toxicities, as part of routine minimally invasive image guided radiation therapy procedures. Such image guided chemoradiation therapy replaces inert spacers with no therapeutic impact currently used in brachytherapy, with drug eluting spacers that provide the same spatial benefit with the added localized chemotherapeutic. This new therapeutic modality requires characterization of the drug distribution produced by implantable drug eluters. This work presents imaging based means to measure and compare temporal and spatial properties of diffusion distributions around spacers loaded with multi-sized dye-doped nanoparticles or with free dye. The spacer with optimal diffusive properties was then loaded with chemotherapeutics and inserted intratumorally for efficacy of the local chemotherapy versus the standard systemic dosing.