• Staging of potentially radically treatable non small cell carcinoma
• There is emerging evidence of its use as an indicator of response to therapy for small cell carcinoma
• Evaluation of an indeterminate solitary pulmonary nodule
• Evaluation of suspected disease recurrence
• In suspected mesothelioma for guiding biopsy and staging prior to surgery or radical radiotherapy

• Paediatric and adult patients with Hodgkin’s disease should be scanned at diagnosis and after 2 cycles of chemotherapy. An end of treatment scan should be performed in patients with a residual mass unless the interim scan was negative
• Adult patients with high grade non-Hodgkin’s lymphoma should be scanned at diagnosis and at the end of treatment
• May be helpful in patients with early stage follicular lymphoma who are to be treated aggressively pre-treatment to confirm staging
• Evaluation of suspected relapse of Hodgkin’s disease or aggressive NHL
• To assess response to 2nd line and subsequent treatments for aggressive lymphoma if disease was positive on PET CT when relapse was diagnosed

Patients ideally should be recruited into current clinical trials if applicable (EuroNet, RATH-L etc)

• Evaluation of extent of metastatic disease prior to resection (*MRI of the liver has a valuable complementary role in this patient group, particularly for detection small liver metastases which may be below the resolution of FDG PET-CT).
• Detecting/confirming recurrence where there is rising CEA with negative or equivocal findings on cross-sectional imaging
• Evaluation of indeterminate pre-sacral masses post treatment
• Restaging of rectal cancer following neo-adjuvant chemoradiotherapy

• Staging of potentially radically treatable oesophageal carcinoma
• Response assessment following neo-adjuvant treatment in potentially radically treatable oesophageal carcinoma
• Evaluation of suspected recurrence of oesophago-gastric tumours when cross-sectional imaging is negative or equivocal

• To assess baseline staging prior to treatment
• To assess response to chemotherapy

• To help identify the primary site in patients with proven metastatic squamous cell carcinoma in cervical lymph nodes and no definite primary site following conventional imaging and endoscopic evaluation
• In selected patients with proven squamous cell carcinoma of the head and neck and nodal metastases where there is uncertainty on conventional imaging regarding staging.
• Indicated for evaluation of suspected tumour recurrence in patients with equivocal or indeterminate conventional imaging
• For response assessment post chemoradiotherapy in patients with residual masses following treatment

• Indicated in patients with treated differentiated thyroid carcinoma with an elevated thyroglobulin, negative whole body iodine scintigraphy and equivocal or normal cross-sectional imaging.
• Indicated in patients with treated medullary thyroid carcinoma, elevated calcitonin levels, equivocal or normal cross-sectional imaging, bone and octreotide scintigraphy.

• Indicated for staging in patients with potentially operable metastatic disease prior to resection
• Indicated prior to consideration of radical nodal dissection

• Indicated in the assessment of patients with metastatic seminoma or teratoma with a residual mass following treatment.
• Indicated in the assessment of patients with suspected recurrence of seminoma or teratoma and equivocal or normal conventional imaging.

• Indicated in the assessment of suspected malignant transformation within plexiform neurofibromata in patients with Neurofibromatosis Type 1
• Indicated in the assessment of disease burden in patients with metastatic sarcoma potentially suitable for liver or lung metastatectomy where clinical doubt remains following conventional imaging or cross-sectional imaging has not identified any extra-thoracic or extra-hepatic disease which would preclude surgery

• High risk cervical cancer staging, i.e. for patients with locally advanced disease or those with suspicious findings on conventional imaging, e.g. abnormal pelvic nodes on MR
• Indicated for evaluation of suspected recurrent endometrial and cervical carcinoma when conventional imaging is equivocal
• Indicated in restaging prior to exenteration surgery
• May be useful in selected patients with ovarian carcinoma who have rising CEA 125 levels and equivocal or negative cross-sectional imaging
• To assess response to chemoradiotherapy in selected patients with a residual mass following treatment

• Indicated in patients with potentially operable pancreatic adenocarcinoma where conventional imaging is equivocal for metastatic disease, who are fit for resection and a positive PET CT would lead to a decision not to operate
• Indicated in patients with potentially operable primary hepato-biliary malignancy (cholangiocarcinoma/gallbladder carcinoma/hepatocellular carcinoma) where conventional imaging is equivocal or negative for metastatic disease, who are fit for resection and a positive PET CT would lead to a decision not to operate
• Indicated in selected patients with suspected recurrence of hepato-pancreatico-biliary cancer where conventional imaging is equivocal or negative

• Indicated in selected patients with non metastatic manifestations of neoplastic disease e.g. neurological signs or raised antibodies to exclude or confirm an occult primary tumour when conventional imaging is negative or equivocal

• Indicated is selected patients with dense breast disease for evaluation of suspected recurrence
• Indicated in selected patients for assessment of metastatic disease burden prior to surgical resection of disease
• Occasionally useful for early assessment of response to chemotherapy in high risk patients

• FDG PETCT may be of value in highly selected patients with poorly differentiated neuroendocrine tumours for staging prior to treatment
• Specialised Gallium-68 labelled peptides e.g. DOTA-Octreotate may be of value for staging and assessment of suspected recurrence in selected patients with well differentiated neuroendocrine tumours (currently very limited availability)

• Limited indications at present but may be helpful for assessment of metastatic disease and evaluation of equivocal nodes

• Indicated when conventional imaging and histopathology has failed to show a primary site and palliative chemotherapy is indicated.

• PET CT may be helpful on an individual case basis in paediatric or adolescent patients with rare tumours e.g. advanced Wilms’ tumours, Neuroblastoma, Hepatoblastoma etc.

• Useful to distinguish between radiation necrosis and tumour recurrence in selected patients with brain tumours which have been treated with radiotherapy and follow up cross-sectional imaging raises concern (but is not definite) of tumour recurrence.
• Indicated to distinguish between cerebral tumour and atypical infection in immunocompromised patients with new cerebral lesions which are indeterminate on cross-sectional imaging

• To determine the side of anterior temporal lobectomy or (in children) multi-lobar resections in patients with complex partial seizures
• Evaluation of memory loss/neurological signs suggestive of dementia and differentiation of types of dementia in selected patients
• F-DOPA may be useful in the assessment of Parkinsons in specialised centres

• In specialist centres, useful in the assessment of reversible ischaemia and myocardial hibernation in selected patients where other tests including conventional isotopes are equivocal

• Useful in the assessment of patterns of vasculitis and disease response
• May have value in the assessment of aortic aneurysm follow up post stenting/ surgical intervention and might have diagnostic value if graft infection is suspected

• Useful for identifying disease foci and excluding malignancy in highly selected patients where conventional imaging is negative or equivocal

• New radiotracers such as choline based derivatives may be useful in selected patients with prostate cancer, hepatocellular carcinoma or brain tumours. There is also emerging evidence of their use in gynaecological malignancy
• Fluorine-18 Sodium Fluoride imaging may be useful for evaluating benign bone lesions and metastases in selected patients