The primary function of nomenclature is to ensure that spoken or written scientific terms and concepts leave no ambiguity in their interpretation, enabling effective and unambiguous communication and understanding within a scientific community.

In order to achieve these goals, the international natural science community agreed to abide by and adopt the use of SI units (1960) and IUPAC rules for chemistry (1921). As the field of radiopharmaceutical chemistry is part of this wider community, it behoves us to also adopt these conventions: to ignore this would be impractical.

Over recent years, within our community, there has been an increased incidence of incorrect usage of established scientific terms and conventions, and even the emergence of ‘self-invented’ terms. In order to address these concerns, a Working Group (WG) on ‘Nomenclature in Radiopharmaceutical Chemistry and related areas’ was established in 2015 to achieve clarification of terms and to generate consensus on the utilisation of a standardised nomenclature pertinent to our field.

The WG is internationally composed by Michael Adam (Canada), Gunnar Antoni (Sweden), Heinz H. Coenen (Germany) (chair), Cathy S. Cutler (USA), Yasuhisa Fujibayashi (Japan), Antony D. Gee (UK) (co-chair), Jae Min Jeong (Korea), Robert H. Mach (USA), Tom Mindt (Austria), Victor W. Pike (USA) and Albert Windhorst (Netherlands) as active members of relevant scientific societies (e.g., European Association of Nuclear Medicine, ‘Society of Radiopharmaceutical Sciences’, ‘Society of Nuclear Medicine’, ‘Society of Radiopharmacology’ and related national societies).

After conducting a worldwide survey by a questionnaire, aims of primary importance were agreed, and the WG produced a summary of its initial recommendations. This was followed by a consultation period.

The consultation phase of the “Consensus Guidelines on Nomenclature” has drawn to a close and endorsed at the International Society of Radiopharmaceutical Sciences meeting in Dresden, Germany in May 2017.
 
We are very grateful for the many constructive, often very detailed and committed replies from all of you. Your reaction indicates broad support, gratitude and encouragement for this initiative and underlines the necessity of our efforts. 
 
It was not possible to give individual responses to all comments, however, all feedback was seriously considered by the working group and a consensus generated.
 
We have initiated contacts with IUPAC representatives to further the harmonisation of nomenclature issues, however this is likely to proceed on a much longer time-scale. To this end, we have appended important and relevant current IUPAC definitions in a footnote at the end of the document for the sake of comparison and completeness