In 1942, eighty years ago, Dr. Hertz first conducted radioiodine (RAI) diagnosis and therapy for thyroid disorders followed later by the successful treatment of thyroid cancer patients using RAI. In 2022, memorial 80 years later, alpha emitter astatine (At), an analogue for iodine, was successfully administered to a patient with refractory thyroid cancer in Japan as a phase-1 clinical trial (first-in-human). Over the past two decades, the use of  Ga labeled peptides for somatostatin receptor (SSTR)-targeted PET imaging followed by beta or alpha emitters labeled SSTR-analogues for peptide receptor radionuclide therapy (PRRT) has demonstrated remarkable success in the management of neuroendocrine neoplasms. In addition, theranostics targeting prostate-specific membrane antigen (PSMA) have dramatically changed the management and treatment of advanced prostate cancer patients. Novel radionuclides and new targets, ligands targeting the tumor microenvironment, optimized peptides and antibodies, combinations of radioligands with immunotherapy, radioprotectors and radiosensitizers as well as new delivery strategies are currently systematically explored. Now the dream of conquering cancer, that Saul Hertz began eight decades ago is coming to fruition.