Peptide receptor radionuclide therapy (PRRT) with 177LuLu-DOTA-Tyr3octreotate has been successfully developed in the last decades for the treatment of neuroendocrine neoplasms. However, different methods to improve the objective response rate and survival are under investigation. This includes changes of the radioligand, dosimetry and combination therapy with different agents, such as radiosensitisers. Hofving et al. recently reported, in the April 2019 issue of Endocrine-Related Cancer, the use of heat-shock protein 90 (Hsp90) modulation to augment radiation effects as a new promising target for radiosensitisation. In this commentary, new developments in the field of PRRT are discussed, placing these new findings about Hsp90 inhibitors into context.