Background: Positron emission tomography (PET) is an imaging procedure that became widespread in the 1990s and is now also used in everyday clinical practice. In Austria, PET diagnostics is mainly used in the field of oncology, especially in primary and secondary diagnostics and dignity assessment, in (pre-)therapeutic staging (N- and M-staging), in therapy monitoring and therapy control, in the detection of residual tumours after chemo- and radiotherapy, in the planning of radiotherapy as well as in recurrence and metastasis diagnostics.

Methods: The report is based on that of the LBI-HTA of 2015 and the updates of 2018 and 2020. Various guideline databases and policies were searched to identify the recommended oncological indications for the use of PET/PET-CT applications. The (hand) search was guided by the previously mentioned reports. In addition to guideline databases, recommendations and non-recommendations from professional societies were considered; systematic reviews or meta-analyses were not part of the search.

Results: A total of 28 indication areas were considered: Sufficient evidence for a recommendation for a PET examination was found in three areas: Bronchial carcinoma, lymphoma (non-Hodgkin lymphoma and Hodgkin lymphoma) and neuroendocrine tumours. Recommendation for a restricted use a PET examination was found for in 13 indication areas: Brain tumours, head and neck carcinoma, oesophageal carcinoma, pancreatic carcinoma, melanoma, breast carcinoma, endometrial carcinoma, cervical carcinoma, ovarian carcinoma, prostate carcinoma, penile carcinoma, carcinoma of the mesothelial or soft tissue and myeloma. In nine indications, there was insufficient or no evidence in favour of PET examination (although case-by-case decisions are possible): gastric cancer, colorectal cancer, liver cancer, bladder cancer, urothelial cancer, kidney cancer, vulvar cancer and CUP (cancer with unknown primary tumour).

Conclusion: The overall recommendations of the present 2023 update (as in the previous year's 2015 & 2018 reports, as well as the 2020 update) indicate little benefit from PET as a primary or standard diagnostic (not least because of radiation exposure). The summarised evidence from guidelines can be used as a guideline for investment decisions. For the (individual) clinical decision, the indication by the treating physician is indispensable. In general, the indication for PET diagnostics should be determined with the support of an interdisciplinary team in the tumour board (surgeons, internal oncologists, nuclear medicine specialists, radiologists, radiotherapists, etc.). The quality of the indication with knowledge of the patient's information is decisive.