Medical applications of radioisotopes

Diagnostic and therapeutic radioisotope based techniques have gained increasing importance in cancer related healthcare in recent years. While radio-iodine scans and treatment of thyroid cancer is well known, many other applications of radioisotopes are now in routine clinical use. Increasing sophistication of techniques of conjugating radioisotopes to targeting molecules has enabled the new age radiopharmaceutical drugs to enter the molecular age of precision medicine for imaging, treatment and sometimes for both. An excellent example of such molecular targeted imaging is PSMA-PET for prostate cancer. In India, Bhabha Atomic Research Centre (BARC) has the skill and expertise to make these conjugates. Coupled with the advent of biosimilars of important monoclonal antibodies such as rituximab and trastuzumab, the time is now most appropriate for the development of indigenous RICs. Tata Memorial Centre in collaboration with BARC has undertaken this project. Biodistribution studies in xenograft models of NHL and breast cancer has been completed. ¹³¹I-Rituximab and ¹³¹I-Transtuzumab RICs were evaluated in two separate studies using Raji cell xenograft (CD20+) bearing nude mice and MDA-MB-361 cell (Her2+) xenograft bearing NOD-SCID mice, respectively. More recently, human study of Lu-trastuzumab has been started in TMC. Other radiopharmaceutical including alpha emitters will also be discussed during the presentation