PET computed tomography policy variations across the UK: a call for harmonisation and equity of access

PET computed tomography (PET-CT) is a cornerstone imaging modality that integrates functional and anatomical data to assess pathology and physiology. Given its clinical significance, consistent policies and clearly defined indications are essential to ensure equitable access and high standards of care. However, PET-CT commissioning policies across the UK remain fragmented and to some extent misaligned with the latest evidence-based guidance. Policy documents reviewed To explore these discrepancies, we compared PET-CT policies across England, Wales, and Scotland against the most recent evidence-based recommendations in the UK [1]. Six key documents were reviewed: Evidence-based indications for the use of PET-CT in the UK (2022) by the Royal College of Physicians (RCP) and the Royal College of Radiologists (RCR) (RCP/RCR Indications 2022) [1]. Clinical indications for the use of PET-CT in Scotland (2022) by the Scottish Clinical Imaging Network (SCIN Indications 2022) [2]. PET Commissioning Policy: CP50 by GIG Cymru NHS Wales (CP50 Policy Wales 2024) [3]. Clinical commissioning policy statement: PET computed tomography (PET-CT) guidelines (all ages) B02/PS/b (2015) by NHS England (NHS England 2015) [4]. Evidence-based indications for the use of PET-CT in the UK (2013) by the RCP and the RCR (RCP/RCR Indications 2013) [5]. Updated NHS England commissioning policy 2025: prostate-specific membrane antigen radiotracers in PET-CT imaging for individuals with high-risk primary or recurrent prostate cancer (adults) [6]. NHS England currently commissions PET-CT services based on three documents [4–6]. For the purpose of this review, all three documents are considered together under the term NHS England Commissioning Policy 2013/2015/2025. For Northern Ireland, we were unable to identify a specific commissioning policy outlining PET-CT clinical indications. The only relevant document located was the Strategic Framework for Imaging Services within Health and Social Care (2018) [7]. This framework was based on the earlier 2015 review of imaging services, which noted new service budget agreement for PET-CT in anticipation of future growth. It also highlighted that, at the time, there was a single PET-CT scanner in operation located within the Belfast Trust [8]. Categories compared The RCP/RCR evidence-based indications for the use of PET-CT in the UK 2022 guidelines [1] were used as the reference document, as they provide the most comprehensive and detailed framework of clinical indications and subindications, including staging, restaging, and treatment response for oncological and nononcological indications. We assessed alignment across four key categories: [18F]fluorodeoxyglucose (FDG) oncological applications, FDG nononcological applications, non-FDG tracers, and paediatric applications. FDG PET computed tomography: oncological applications All policies included FDG PET-CT for following major tumour types: head and neck cancers, thyroid carcinoma, lung and pleural malignancies, breast cancer, oesophageal and gastrointestinal tumours, hepatopancreatobiliary and colorectal cancers, anal, gynaecological, and musculoskeletal tumours, lymphoma and myeloma, and melanoma and paraneoplastic syndromes. However, certain tumour types were omitted in some policies, leading to inconsistencies in access. These are detailed in Table 1. Table 1 - FDG PET computed tomography oncological application differences FDG PET-CT oncological applications Differences in recommendations and commissioning policies across the UK RCP/RCR Indications 2022 SCIN Policy 2022 CP50 Policy Wales 2024 NHS England Policy 2013/2015/2025 Brain tumoursa ✔ X X ✔ Thymic tumours ✔ X X ✔ Gastric cancerb ✔ X ✔ X HCCc ✔ ✔ X ✔ Testicular cancer ✔ X ✔ ✔ Penile cancer ✔ X X ✔ Urological malignancyd ✔ X X ✔ Skin tumours (other than melanoma)e ✔ X X ✔ NETsf ✔ X ✔ ✔ CT, computed tomography; FDG, [18F]fluorodeoxyglucose; HCC, hepatocellular carcinoma; NETs, neuroendocrine tumours; RCP, Royal College of Physicians; RCR, Royal College of Radiologists.aSCIN Policy 2022 (pg. 5 and 9) does not specifically mention primary brain tumours but instead mention doing FDG PET-CT if there is a suspicion of paraneoplastic syndrome, secondary brain metastasis or may be indicated in primary central nervous system lymphoma only if the result would alter existing management plan.Similarly, CP50 Policy Wales 2024 (pg. 16) does not include primary brain tumours. Instead, they refer broadly to head and neck tumours, focussing on cervical lymphadenopathy, aerodigestive tract tumours, nasopharyngeal tumours, and thyroid cancer.bSCIN Policy 2022 (pg. 7) and NHS England policy 2013/2015/2025 (pg. 5) mention oesophageal, gastroesophageal, and gastrointestinal stromal tumours. However, RCP/RCR Indications 2022 (pg. 16–19) and CP50 Policy Wales 2024 (pg. 15, 16, and 18) explicitly include gastric cancer as an additional indication, alongside the aforementioned cancers.cCP50 Policy Wales 2024 (pg. 15) lists staging of potentially operable primary hepatobiliary malignancies, including cholangiocarcinoma and gallbladder carcinoma, but does not explicitly include HCC as an indication.dNHS England Policy 2013/2015/2025 (pg. 6) and RCP/RCR Indications 2022 (pg. 25–26) indicate PET-CT for renal, ureteric, and bladder carcinoma. However, CP50 Policy Wales 2024 and SCIN Policy 2022 do not specify these indications.eRCP/RCR Indications 2022 (pg. 33) includes indications for skin lymphomas, Merkel cell carcinoma, and paraneoplastic manifestations such as dermatomyositis. NHS England policy 2013/2015/2025 (pg. 8) includes skin lymphomas and paraneoplastic dermatomyositis, but not Merkel cell carcinoma.fSCIN Policy 2022 (pg. 10) does not include indication of FDG PET-CT for NETs. Other guidelines support the use of FDG PET-CT for higher-grade NETs. FDG PET computed tomography: nononcological applications Vasculitis was consistently commissioned across all policies. Other indications (e.g. infection, sarcoidosis, and cardiac inflammation) varied significantly. See Table 2 for a breakdown. Table 2 - FDG PET computed tomogaphy nononcological application differences FDG PET-CT nononcological applications Differences in recommendations and commissioning policies across the UK RCP/RCR Indications 2022 SCIN Indications 2022 CP50 Policy Wales 2024 NHS England Policy 2013/2015/2025 Dementia, neurodegenerative disorders, epilepsy/complex seizurea ✔ X ✔ ✔ Sarcoidosis (including cardiac sarcoidosis)b ✔ X ✔ ✔ Cardiological indications (myocardial viability)c ✔ X ✔ ✔ Infection and inflammatory disorders (excluding vasculitis)d ✔ X ✔ ✔ Pyrexia of unknown origin ✔ X ✔ ✔ CT, computed tomography; MDT, multidisciplinary team; RCP, Royal College of Physicians; RCR, Royal College of Radiologists.aAll documents mention the use of FDG PET scans for evaluating dementia, neurodegenerative disorders, and epilepsy/complex seizures except SCIN Indications 2022. RCP/RCR Indications 2022 (pg. 42) guidelines distinctively add encephalitis.bRCP/RCR Indications 2022 (pg. 43) and NHS England Policy 2013/2015 (pg. 10) detail the use of FDG PET-CT in sarcoidosis, particularly when conventional tests are inconclusive, to assess both cardiac and extracardiac disease activity. CP50 Policy Wales 2024 (pg. 21) has commissioned FDG PET for known or suspected cardiac sarcoidosis but does not clarify its role in evaluating extracardiac sarcoidosis. SCIN Indications 2022 (pg. 1) encourages that specific conditions such as pyrexia of unknown origin and sarcoidosis, which are not covered by current guidelines, undergo MDT review and discussion with the regional PET centre on a case-by-case basis.cNHS England Policy 2013/2015 (pg. 9) and RCP/RCR Indications 2022 (pg. 43) include PET for assessment of cardiac viability when combined with sestamibi/tetrofosmin or rubidium/ammonia perfusion imaging. The use of PET-CT scans with the radioactive tracer rubidium is commissioned from two centres in England (Manchester and London). RCP/RCR Indications 2022 (pg. 43) further detail the use of FDG PET-CT in cardiac inflammation, myocarditis, infective endocarditis, and cardiac implantable device infection. CP50 Policy Wales 2024 (pg. 21) states that referrals to Guy’s and St Thomas’ NHS Foundation hospital for cardiac PET to assess myocardial viability and hibernation will be considered on a named-patient basis only.dRCP/RCR Indications 2022 (pg. 46) gave the most detailed indications for infection, including implantable cardiac devices, central or peripheral vascular grafts, spinal infections, postfracture osteomyelitis, etc. CP50 Policy Wales 2024 (pg. 22) and NHS England Policy 2013/2015 (pg. 9 and 6 in the B02/P/a document) include its use for focal site infections in immunocompromised individuals, graft infections, and implantable cardiac device infections. Non-FDG PET tracers Major differences were found in commissioning of non-FDG tracers such as [18F]fluorodopa, [68Ga]DOTATATE for meningioma, [11C]methionine, and ([18F]/[11C])choline for parathyroid imaging. These are summarised in Table 3. There is a sound evidence base for use of amyloid tracer, but they remained noncommissioned across the UK [1]. Table 3 - Non-FDG PET-CT tracers indication differences Non-FDG PET tracers Differences in recommendations and commissioning policies across the UK. RCP/RCR Indications 2022 SCIN Indications 2022 CP50 Policy Wales 2024 NHS England Policy 2013/2015/2025 [18F]/[11C]Choline PET for parathyroid adenomaa ✔ X ✔ X [18F]/[11C]Choline PET for other tumours (HCC)b ✔ X X ✔ [18F]/[68Ga]PSMA for prostate cancerc ✔ ✔ ✔ ✔ [18F]/[11C]Radiolabelled choline for prostate cancerd ✔ X ✔ ✔ [18F]Fluciclovine for prostate cancere ✔ X X X [82Rb]Rb and [13N]ammonia in myocardial perfusion imagingf ✔ X X ✔ [68GA]DOTATATE/DOTANOC for neuroendocrine tumours ✔ ✔ ✔ ✔ [68GA]DOTATATE/DOTANOC for meningiomag ✔ X X X [18F]Fluorodopa for tumour assessmenth ✔ X X ✔ [18F]Fluoride for bone imagingi ✔ X X ✔ [18F]Labelled amyloid tracers (florbetapir, florbetaben, and flutemetamol)j ✔ X X X [18F]Fluoroethyltyrosine and [18F]fluciclovine for brain tumoursk ✔ X X X [¹¹C]Methionine for glioma and parathyroid adenoma in difficult casesl ✔ X X ✔ CT, computed tomography; HCC, hepatocellular carcinoma; NET, neuroendocrine tumour; PSMA, prostate-specific membrane antigen; RCP, Royal College of Physicians; RCR, Royal College of Radiologists.aRCP/RCR Indications 2022 (pg. 54) and CP50 Policy Wales 2024 (pg. 19) both include choline PET for parathyroid adenoma, while NHS England Policy 2013/2015 and SCIN Indications 2022 did not commission it.bRCP/RCR Indications 2022 (pg. 55) recommends use of choline PET ([18F]choline/[11C]choline, [11C]acetate) for assessment of patients with HCC being considered for transplant or other radical treatment where the results would directly influence patient management same as in NHS England Policy 2013/2015 policy (pg. 11).cPSMA has been recommended in all documents: RCP/RCR Indications 2022, CP50 Policy Wales 2024 (pg. 20), and SCIN Indications 2022 (pg. 10). It was not mentioned in the NHS England Policy 2013/2015, however, it has been commissioned by a new updated interim policy in 2025 [6].dSCIN Indications 2022 do not mention choline in relation to prostate cancer.eOnly RCP/RCR Indications 2022 (pg. 50) mentioned the use of [18F]fluciclovine for prostate cancer if PSMA was unavailable (pg. 50); not produced any longer in the UK.f[82Rb]Rb and [13N]ammonia for myocardial perfusion imaging are also recommended in the RCP/RCR Indications 2022 (pg. 57). The use of PET-CT scans with the radioactive tracer rubidium is commissioned at two centres in England, Manchester and London (pg. 6) [4].g[68GA]DOTATATE and [68GA]DOTANOC for meningioma only mentioned by RCP/RCR Indications 2022 (pg. 60) for delineation prior to resection and defining optimal radiotherapy target volume.h[18F]Fluorodopa is mentioned in the RCP/RCR Indications 2022 (pg. 61) guidelines for tumour assessment in brain tumours, medullary thyroid cancer, pheochromocytoma/paragangliomas, and selected cases of NET. The NHS England Policy 2013/2015 (pg. 11 and 12) includes [18F]fluorodopa for congenital hyperinsulinism and selected cases of NET.i[18F]Fluoride for bone imaging is included in both the RCP/RCR Indications 2022 (pg. 63) and NHS England Policy 2013/2015 (pg. 12) for the assessment of benign and malignant bone diseases in selected patients.j[18F]Labelled amyloid tracers are recommended by RCP/RCR Indications 2022 (pg. 64). However, The NHS England Policy 2013/2015 stated that, at the time, florbetapir was the only amyloid imaging agent commercially available in the UK (pg. 12). However, they did not commission the use of amyloid radioactive tracers for brain imaging because of deemed insufficient evidence available to demonstrate impact on outcomes of people living with dementia.k[18F]Fluoroethyltyrosine and [18F]fluciclovine in brain tumours are mentioned only in the RCP/RCR Indications 2022 (pg. 66) for assessing tumour grade and extent in some patients with glioma, for staging, targeted biopsy, or treatment planning. They are also used to differentiate between posttreatment progression and pseudoprogression.l[¹¹C]methionine is noted in the RCP/RCR Indications 2022 (pg. 66) for assessing tumour extent in low- and intermediate-grade gliomas and for identifying the site of a pituitary adenoma before surgery or locating residual tumour post-surgery. The NHS England Policy 2013/2015 (pg. 10) mentions [¹¹C]methionine for assessing gliomas and for localising parathyroid tumours in difficult cases where conventional anatomical and functional imaging has failed. Paediatric applications Only RCP/RCR evidence-based indications included a dedicated paediatric section, covering both oncological and nononcological indications, including use of non-FDG tracers [1]. It provided guidance for: Oncological: Ewing sarcoma, osteosarcoma, Wilms tumour, neuroblastoma, hepatoblastoma, Langerhans cell histiocytosis, lymphoma, leukaemia, soft tissue sarcoma, malignant peripheral nerve sheath tumour, and brain and germ cell tumours. Nononcological: Epilepsy, paediatric dystonia, congenital hyperinsulinism. Other policies offered limited or ambiguous paediatric guidance: NHS England 2013/2015 [4,5]: commissioned PET-CT for osteosarcoma and Ewing sarcoma; other indications considered case-by-case for patients with Wilms tumour, metaiodobenzylguanidine-negative neuroblastoma, hepatoblastoma, and Langerhans cell histiocytosis (pg. 8 and 9). For nononcological applications, it has included the potential use of [18F]fluorodopa in the assessment of congenital hyperinsulinism (pg. 11). Also, it included the use of [13N]ammonia and [82Rb]chloride for the assessment of perfusion in selected patients with coronary anomalies with congenital disease, postevaluation (pg. 10). These indications are likewise reflected in the RCP/RCR Indications 2022 within the non-FDG tracer section (pg. 57). SCIN 2022 and CP50 Wales 2024 [2,3]: included paediatric tumours under general sarcoma for example Ewing sarcoma, osteosarcoma, soft tissue sarcoma, and gastrointestinal stromal tumour sections without specifying age groups. Conclusion To ensure equitable access and evidence-based care, PET-CT commissioning policies across the UK should be harmonised and updated in line with the UK PET-CT RCP/RCR Indications 2022 [1]. Aligning policies would help close current gaps, reduce unwarranted regional variation, and support consistent clinical decision-making. Given ongoing financial constraints, however, a clear and sustainable model for adopting new indications, non-FDG tracers and paediatric indications is urgently required. NHS England [9] is considering a ‘test directory’ approach for introducing new indications, similar to the system used for rare genetic conditions, which has yet to be fully proposed and tested. While discrepancies in oncological FDG indications could be relatively straightforward to harmonise across the UK, the adoption of nononcological FDG and non-FDG tracers, together with new indications, will necessitate phased investment and a carefully prioritised rollout. Acknowledgements Data presented previously at British Nuclear Medicine Society Autumn Meeting 2024 on 14–15 October 2024 in Norwich as a poster and published as abstract in NMC. Reference: Amro S, Punchihewa C, Elsewafy M, Dizdarevic S. Spotlight on PET-CT indications: uncovering the differences in guidelines and policies across the UK. Nuclear Medicine Communications 2025;46(1):110. Abstract P15. British Nuclear Medicine Society Autumn Meeting 2024. The manuscript has been read and approved by all the authors that the requirements for authorship as stated have been met and each author believes that the manuscript represents honest work. Conflicts of interest There are no conflicts of interest.