RT Journal Article SR Electronic T1 Overview of the First NRG Oncology–National Cancer Institute Workshop on Dosimetry of Systemic Radiopharmaceutical Therapy JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1133 OP 1139 DO 10.2967/jnumed.120.255547 VO 62 IS 8 A1 Emilie Roncali A1 Jacek Capala A1 Stanley H. Benedict A1 Gamal Akabani A1 Bryan Bednarz A1 Vikram Bhadrasain A1 Wesley E. Bolch A1 Jeffrey C. Buchsbaum A1 Norman C. Coleman A1 Yuni K. Dewaraja A1 Eric Frey A1 Michael Ghaly A1 Joseph Grudzinski A1 Robert F. Hobbs A1 Roger W. Howell A1 John L. Humm A1 Charles A. Kunos A1 Steve Larson A1 Frank I. Lin A1 Mark Madsen A1 Saed Mirzadeh A1 David Morse A1 Daniel Pryma A1 George Sgouros A1 Sara St. James A1 Richard L. Wahl A1 Ying Xiao A1 Pat Zanzonico A1 Katherine Zukotynski YR 2021 UL http://jnm.snmjournals.org/content/62/8/1133.abstract AB In 2018, the National Cancer Institute and NRG Oncology partnered for the first time to host a joint workshop on systemic radiopharmaceutical therapy (RPT) to specifically address dosimetry issues and strategies for future clinical trials. The workshop focused on current dosimetric approaches for clinical trials, strategies under development that would optimize dose reporting, and future desired or optimized approaches for novel emerging radionuclides and carriers in development. In this article, we review the main approaches that are applied clinically to calculate the absorbed dose. These include absorbed doses calculated over a variety of spatial scales, including whole body, organ, suborgan, and voxel, the last 3 of which are achievable within the MIRD schema (S value) and can be calculated with analytic methods or Monte Carlo methods, the latter in most circumstances. This article will also contrast currently available methods and tools with those used in the past, to propose a pathway whereby dosimetry helps the field by optimizing the biologic effect of the treatment and trial design in the drug approval process to reduce financial and logistical costs. We also briefly discuss the dosimetric equivalent of biomarkers to help bring a precision medicine approach to RPT implementation when merited by evidence collected during early-phase trial investigations. Advances in the methodology and related tools have made dosimetry the optimum biomarker for RPT.