CLINICAL PRACTICE GUIDELINES Clinical …

1 186 Annals Academy of MedicineClinical indications for PET ScanningClinical indications for Positron Emission Tomography (PET) ScanningThe Workgroup for the Chapter of Radiologists, Academy of Medicine, SingaporeAddress for Correspondence: Dr Anthony S W Goh, Department of Nuclear Medicine, Singapore General Hospital, Outram Road, Singapore purpose of these GUIDELINES is to provide a broadframework for clinicians considering the use of positronemission tomography (PET) scanning for their imaging is a rapidly evolving field, with ongoingdevelopments in imaging technology, radiochemistry,isotope production, animal research and clinicalapplications.

2 There is a need for regular review of theseguidelines, to incorporate new evidence and results ofscientific most diagnostic tests, meta-analyses or systematicreviews are not available for PET in every clinicalapplication. Nonetheless, CLINICAL PRACTICE should be guidedby the best available evidence. Whilst some of the followingrecommendations are based on mature scientific evidence,others simply represent the current consensus of experts inthis of the published data on PET scanning refer tostudies using traditional PET scanners.

3 Combined PET-computed tomography (CT) scanners became commerciallyavailable in 2002, and a wealth of new data will emergeover the next few years on the incremental value of fusingPET with CT images. Preliminary experience suggests afurther enhancement of diagnostic accuracy, impact onpatient management and outcome, and extension of usefulclinical applications, particularly in oncology PRACTICE . Asclinical PET services were introduced in Singapore only inmid-2003, all the currently installed scanners are PET radiotracer compounds will also emerge fromexperimental use into routine CLINICAL application.

4 Futureupdates to these GUIDELINES will need to keep pace withthese developments. In addition, as PET technology hasspread more recently in Asian countries, more scientificdata relevant to our disease context will need to be sought, for hepatocellular and nasopharyngeal research into these areas should therefore is not possible to be dogmatic or prescriptive aboutthe role of PET in a given CLINICAL situation, as this maydepend on CLINICAL factors, socio-economiccircumstances, patient attitudes and other factors.

5 Theserecommendations should therefore not be interpretedas mandatory for compliance in every stated clinicalsituation. For ease of reference, the recommendationshave been classified into 3 categories:** Useful application for CLINICAL PET imaging.* Potentially useful application not indicatedroutinely, but may be helpful in individual cases,or there is currently limited data to prove cost-effectiveness.# Not recommended at otherwise stated, routine CLINICAL PET imaging isdeemed to be performed with the glucose analog , in certain situations, other PET radiotracers areneeded, to visualise other metabolic processes.

6 These arenot yet routinely available at most CLINICAL PET sites(including those in Singapore).The following recommendations are intended as a guidefor physician referral and patient selection for CLINICAL PETimaging. For more details on the scientific evidence, thereader is advised to refer to the publications in the and Spinal Cord Tumours(PET scanning using both 18F-FDG and 11C-methionine isrecommended.) Distinguishing residual or recurrent disease from post-therapy scarring or radionecrosis, when anatomicalimaging is difficult or equivocal.

7 ** Benign versus malignant lesions, where there isuncertainty on anatomical imaging and a relativecontraindication to biopsy, intra-cranial lymphomaversus toxoplasmosis.** Grading of primary brain tumours.* Evaluation of response to therapy.* Identifying site of recurrent brain tumour for biopsy.* PET is not recommended as a primary imaging tool forsuspected brain metastases.# CLINICAL PRACTICE GUIDELINESM arch 2004, Vol. 33 No. 2187 CLINICAL indications for PET ScanningHead and Neck Cancers (other than nasopharyngeal,thyroid cancer, or brain tumours) Staging.

8 * Restaging.** Evaluation of suspected recurrence.** Evaluation of response to therapy.* Search for unknown primary tumour in patients withcervical nodal metastases.** For parotid tumours, however, PET is not helpful fordistinguishing benign from malignant pathology.#Nasopharyngeal Cancer Staging.* Restaging.** Localising or differentiating recurrence from therapy-induced radiological changes.** Evaluation of response to therapy.*Thyroid Cancer Detection of recurrent or residual tumour (follicular orpapillary cancer), when serum thyroglobulin is elevatedbut radioiodine scan is negative or appears tounderestimate the extent of disease.

9 ** Not recommended for routine assessment ofthyroglobulin-positive recurrence with radioiodineuptake.# Assessment of tumour recurrence in medullary carcinomaof the thyroid.*Parathyroid Adenoma Preoperative localisation of parathyroid adenomausing 11C-methionine, when other investigations arenegative.*Solitary Pulmonary Nodule Characterisation of a newly discovered indeterminatelung nodule, or a nodule that shows interval increase insize on chest X-ray or CT scan.**Non-small Cell Lung Cancer Staging.

10 ** Restaging.** Assessment of recurrent disease in previously treatedareas where anatomical imaging is unhelpful.** Evaluation of response to therapy.*Small Cell Lung Cancer Staging.*Breast Cancer Staging.* Restaging.* Evaluation of suspected recurrence, brachialplexopathy (radiation effects versus malignantinfiltration), when anatomical imaging results are non-diagnostic or equivocal.* Evaluation of response to therapy.*Oesophageal Cancer Staging and restaging.** Suspected recurrent disease useful for distant lymphnodes and distant metastases, but of limited value fordetection of locoregional disease near to the primarytumour.