Indications and Referrals for PET Scans

Indication: PET for biopsy proven or clinical diagnosis of pulmonary or system sarcoidosis.

Eligibility criteria: Patients with biopsy proven or clinical diagnosis of pulmonary or systemic sarcoidosis, with cardiac MRI suggestive for cardiac sarcoidosis, to screen for cardiac involvement.

Indication: PET for unexplained high grade conduction system disease in patients 70 years of age or younger.

Eligibility criteria: Patients (age 70 years or younger) presenting with unexplained significant conduction system disease (defined as high grade Mobitz second degree or third degree AV block), to screen for cardiac sarcoidosis as underlying etiology.

Indication: PET for response to treatment in patients with known cardiac sarcoidosis.

Eligibility criteria: Patients with proven cardiac sarcoidosis (with a positive baseline FDG PET scan) to assess response to treatment when considering a change in treatment, or to assess for disease relapse. A maximum of three follow-up scans may be booked up to three years post initial diagnostic FDG PET scan.

Referral information:

For the cardiac sarcoidosis indications, download the Cardiac FDG PET Requisition Form to make a referral.

For patients who do not meet the above cardiac sarcoidosis indications, apply for a PET scan through the Cardiac Special Access Program using the Cardiac Special Access Program FDG PET Requisition Form.

Indication: PET for the diagnosis and clinical management of patients with unexplained cardiomyopathy and associated ventricular tachycardia or fibrillation.

Eligibility criteria: View the Cardiac Special Access Program FDG PET Requisition Form for details.

Referral information: Download the Cardiac Special Access Program FDG PET Requisition Form.

Indication: PET for the diagnosis and clinical management of patients with suspected infection of pacemaker, ICD, CRT, or left ventricular assist devices (LVAD) where there is a high clinical suspicion and/or laboratory evidence of infection.

Eligibility criteria: View the Cardiac Special Access Program FDG PET Requisition Form for details.

Referral information: Download the Cardiac Special Access Program FDG PET Requisition Form.

Indication: PET for the diagnosis and clinical management of patients where, using modified Duke criteria there is a high clinical suspicion and/or laboratory evidence of infection.

Eligibility criteria: View the Cardiac Special Access Program FDG PET Requisition Form.

Referral information: Download the Cardiac Special Access Program FDG PET Requisition Form for details.

Indication: PET for the diagnosis and clinical management of patients where there is a high clinical suspicion and/or laboratory evidence of myocarditis.

Eligibility criteria: View the Cardiac Special Access Program FDG PET Requisition Form for details.

Referral information: Download the Cardiac Special Access Program FDG PET Requisition Form.

Eligibility criteria:

• Stress PET for the assessment of patients with known or suspected coronary artery disease (CAD) with an intermediate (10% to 90%) pre-test likelihood of significant ischemia secondary to coronary stenosis where:
  • there is a high likelihood of attenuation artifact with SPECT imaging or
  • a high degree of functional accuracy or quantitative flow measurements is required or
  • functional imaging is required and a low radiation dose is preferable (such as younger patients) or
  • the results of prior non-invasive imaging are equivocal or inconclusive or
  • in patients with known CAD where the need for intervention is uncertain
• Quantitative PET flow imaging may be particularly helpful when there is a need for absolute MBF measurements, such as:
  • patients without known CAD who present with symptoms suspect for ischemia
  • patients with known CAD, where specific physiological assessment is desired
  • identifying patients with an increased suspicion for multivessel CAD
  • to assess possible microvascular dysfunction
  • heart transplant patients when there is a question of vasculopathy

Referral information: Contact one of the following locations directly to refer your patient for a PET scan related to this indication.

• University of Ottawa Heart Institute
• St. Joseph’s Health Care in Hamilton
• University Health Network in Toronto

Indication: PET for myocardial viability assessment.

Eligibility criteria: PET in a patient being considered for cardiac revascularization, cardiac transplantation, or other cardiac procedures with either: moderate to severe ischemic left ventricular dysfunction (left ventricular ejection fraction of 40% or less) despite maximal therapy; or moderate to severe persistent perfusion abnormality without significant (moderate or severe) ischemia.

Indication: PET for myocardial viability assessment. Eligibility criteria: PET in a patient being considered for cardiac revascularization, cardiac transplantation, or other cardiac procedures with either: moderate to severe ischemic left ventricular dysfunction (left ventricular ejection fraction of 40% or less) despite maximal therapy; or moderate to severe persistent perfusion abnormality without significant (moderate or severe) ischemia. Referral information: Download the Cardiac FDG PET Requisition Form. Download the Cardiac FDG PET Requisition Form.

Indication: PET for the diagnosis and clinical management of patients where there is a high clinical suspicion or lab evidence of pericarditis.

Eligibility criteria: View the Cardiac Special Access Program FDG PET Requisition Form for details.

Referral information: Download the Cardiac Special Access Program FDG PET Requisition Form.

Indication: PET for the diagnosis and determination of clinical management of patients where there is a high clinical suspicion and/or laboratory evidence of vasculitis/aortitis.

Eligibility criteria: View the Cardiac Special Access Program FDG PET Requisition Form for details.

Referral Information: Download the Cardiac Special Access Program FDG PET Requisition Form.

Eligibility Criteria: Compelling evidence may be submitted through the Cardiac Special Access Program FDG PET Requisition Form.

Referral Information: Download the Cardiac Special Access Program FDG PET Requisition Form.

Eligibility criteria: PET for patients with medically-intractable epilepsy being assessed for epilepsy surgery.

Referral information: Download the Epilepsy PET Registry Requisition Form.

Eligibility criteria: PET for the evaluation of patients with suspected paraneoplastic neurologic syndromes with negative conventional imaging, with or without positive onconeuronal antibodies.

Referral information: Download the Paraneoplastic Syndrome Expedited PET Access Requisition Form.

Locally advanced invasive ductal breast cancer

• Eligibility criteria:
  • PET for the staging of patients with histologically confirmed clinical stage 2b or stage 3 breast cancer being considered for curative intent combined modality treatment; and/or repeat PET on completion of neoadjuvant therapy, prior to surgery (when there is clinical suspicion of progression)
  • PET for re-staging of patients with locoregional recurrence, after primary treatment, being considered for ablative or salvage therapy.

Oligometastatic invasive ductal breast cancer

Eligibility criteria: PET for staging or re-staging of patients with oligometastatic disease (four or fewer metastases) on conventional imaging prior to radical intent or ablative therapy.

Referral Information: Download the Breast Requisition Form.

Melanoma (staging)

Eligibility criteria: PET for the staging of patients with localized “high risk” melanoma, or for the evaluation of patients with isolated melanoma metastases when surgery or other ablative therapies are being considered.

Metastatic melanoma (immunotherapy)

• Eligibility criteria:
  • Baseline staging: PET for the staging of patients before starting immunotherapy; or for patients receiving immunotherapy and have not previously had a baseline PET
  • Early response assessment: PET after two to four cycles of immunotherapy for early response assessment of patients with metastatic melanoma currently receiving immunotherapy
  • End of therapy response assessment: PET for response assessment of patients with metastatic melanoma at end of immunotherapy

Referral Information: Download the Melanoma Requisition Form.

Esophageal or Gastroesophageal (GE) Junction

Eligibility criteria: PET for baseline staging assessment of those patients diagnosed with esophageal/GE Junction cancer being considered for curative therapy and/or repeat PET/CT scan on completion of pre-operative/neoadjuvant therapy, prior to surgery; or for re-staging of patients with locoregional recurrence, after primary treatment, being considered for definitive salvage therapy.

Colorectal (apparent limited metastatic)

Eligibility criteria: PET for the staging or re-staging of patients with apparent limited metastatic disease (for example, organ-restricted liver or lung metastases) or limited local recurrence, who are being considered for radical intent therapy.

As chemotherapy may affect the sensitivity of the PET scan, it is strongly recommended to schedule PET at least six weeks after last chemotherapy, if possible.

Colorectal (recurrent)

Eligibility criteria: PET where recurrent disease is suspected on the basis of an elevated and/or rising carcinoembryonic antigen (CEA) level(s) during follow-up after surgical resection but standard imaging tests are negative or equivocal.

Anal canal (staging or re-staging)

Eligibility criteria: PET for the initial staging of patients with stages II (two) to IV (four) squamous cell carcinoma of the anal canal or when conventional imaging is equivocal for a specific stage; or for re-staging of patients with limited recurrence, after primary treatment, being considered for definitive salvage therapy.

Referral Information: Download the Gastrointestinal Requisition Form.

Bladder (muscle invasive)

Eligibility criteria: PET for the staging of patients with newly diagnosed muscle-invasive urothelial carcinoma of the bladder being considered for curative intent treatment with either radical cystectomy or radiation-based bladder preservation therapy; TNM stage T2a-T4a, N0-3, M0.

Referral information: Download the Genitourinary Requisition Form.

Note: For patients with M1a or M1b disease, apply for a PET scan through the PET Access Program.

Germ cell tumours (recurrent/persistent disease)

• Eligibility criteria:
  • PET where recurrent disease is suspected on the basis of elevated tumour marker(s) – (beta human chorionic gonadotrophin (HCG) and/or alpha fetoprotein) and standard imaging tests are negative or
  • Where persistent disease is suspected on the basis of the presence of a residual mass after primary treatment for seminoma when curative surgical resection is being considered

Referral information: Download the Genitourinary Requisition Form.

Prostate (PSMA PET)

• Eligibility criteria: Prostate Specific Membrane Antigen (PSMA) PET in the following patient populations:
• Initial staging of patients with a new diagnosis of high-risk prostate cancer being considered for radical (curative) therapy or
• Staging of patients with recurrent prostate cancer who fall into one of the following pre-defined cohorts:
  • Post-prostatectomy node positive disease or persistently detectable PSA
  • Biochemical failure post-prostatectomy
  • Biochemical failure following radical prostatectomy followed by adjuvant or salvage radiotherapy
  • Rising PSA post-prostatectomy despite salvage hormone therapy
  • Biochemical failure following treatment for oligometastatic disease
  • Biochemical failure following primary radiotherapy
  • Rising PSA and/or progression on conventional imaging despite prior second line hormone therapy or chemotherapy for castrate resistant prostate cancer
  • Where confirmation of site of disease and/or disease extent may impact clinical management over and above the information provided by conventional imaging (requires a case-by-case review)

Referral information: Download the PSMA-PET Requisition Form and Eligibility Checklist. For cohort seven patients, PSMA-PET Access Program Requisition Form and supporting documentation are also required.

Cervical cancer (staging)

• Eligibility criteria: PET for the staging of locally advanced cervical cancer when:
  • CT/MRI shows positive or indeterminate pelvic nodes (greater than 7 millimetres and/or suspicious morphology) or
  • CT/MRI shows borderline or suspicious para-aortic or
  • CT/MRI shows suspicious or indeterminate distant metastases (for example, chest nodules)

Gynecology (recurrent, prior to salvage therapy)

Eligibility criteria: PET for re-staging of patients with recurrent gynecologic malignancies under consideration for radical salvage surgery (for example, pelvic exenteration)

Referral Information: Download the Gynecology Requisition Form.

Unknown primary

Eligibility criteria: PET for the evaluation of metastatic squamous cell carcinoma in neck nodes when the primary disease site is unknown after standard radiologic and clinical investigation.

A panendoscopy is not required prior to the PET scan.

Nasopharyngeal (baseline staging)

Eligibility criteria: PET for the staging of nasopharyngeal cancer.

For cervical esophageal cancer, refer to Gastrointestinal Cancers.

Head and Neck node positive (baseline staging)

Eligibility criteria: PET for the baseline staging of node positive (N1-N3) head and neck cancer where PET will impact radiation therapy (for example, radiation volume or dose)

Head and Neck (re-staging after chemoradiotherapy)

Eligibility criteria: PET to assess patients with N1-N3 metastatic squamous-cell carcinoma of the head and neck after chemoradiation (HPV negative); or who have residual neck nodes equal to or greater than 1.5 centimetres on re-staging CT performed 10 to 12 weeks post therapy (HPV positive).

Thyroid (recurrent)

Eligibility criteria: PET where recurrent or persistent disease is suspected on the basis of elevated and/or rising tumour markers (for example, thyroglobulin) with negative or equivocal conventional imaging work-up.

Anaplastic Thyroid (staging)

Eligibility criteria: PET for the staging of histologically proven anaplastic thyroid cancer with negative or equivocal conventional imaging work-up.

Medullary Thyroid (staging and recurrent)

Eligibility criteria: PET for the baseline staging of histologically proven medullary thyroid cancer being considered for curative intent therapy or where recurrent disease is suspected on the basis of elevated and/or rising tumour markers (for example, calcitonin) with negative or equivocal conventional imaging work-up.

Complete the Ga68-DOTATATE PET Requisition Form if you’d prefer your patient receive a Ga68DOTATATE PET scan instead of an FDG PET scan

Esophageal or Gastroesophageal (GE) Junction

Eligibility criteria: PET for baseline staging assessment of those patients diagnosed with esophageal/GE Junction cancer being considered for curative therapy and/or repeat PET/CT scan on completion of pre-operative/ neoadjuvant therapy, prior to surgery; or for re-staging of patients with locoregional recurrence, after primary treatment, being considered for definitive salvage therapy.

Referral Information Download the Head and Neck PET Requisition Form.

Lymphoma

• Eligibility criteria:
  • Staging: PET for the baseline staging of patients with Hodgkin’s or non-Hodgkin’s lymphoma
  • Interim response assessment for Hodgkin’s lymphoma: PET for the assessment of response in Hodgkin's lymphoma following two or three cycles of chemotherapy when curative therapy is being considered.
  • Interim response assessment for non-Hodgkin’s lymphoma (pediatrics only, under 18 years old; or 18 to 20 years old and treated at a pediatric centre): PET for the assessment of response in non-Hodgkin’s lymphoma after a minimum of two cycles of chemotherapy when curative therapy is being considered.
  • End of therapy response assessment:
    • PET for the evaluation of residual mass(es) or lesion(s) (for example, bone) following chemotherapy in a patient with Hodgkin's or non-Hodgkin's lymphoma when further potentially curative therapy (such as radiation or stem cell transplantation) is being considered; or
    • PET to assess response to chimeric antigen receptor (CAR) T-cell therapy, 90 days post transfusion

Referral information: Download the Lymphoma Requisition Form.

Myeloma or plasmacytoma

• Eligibility criteria: To evaluate the impact of PET on the management of patients with plasmacytoma or myeloma for the following indications:
  • Solitary plasmacytoma: For patients with presumed solitary plasmacytoma who are candidates for curative intent radiotherapy (to determine whether solitary or multifocal/extensive disease)
  • Smoldering myeloma: Workup of patients with smoldering myeloma (to determine whether smoldering or active myeloma)
  • Nonsecretory myeloma, oligosecretory myeloma, or POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes): Baseline staging and response assessment
  • Newly-Diagnosed Secretory Multiple Myeloma: Workup of patients with newly-diagnosed secretory multiple myeloma

Referral information: Download the Multiple Myeloma/Plasmacytoma Requisition Form.

• Eligibility criteria:
  Diagnosis:
  • PET for the evaluation of a pancreatic, small bowel or mesenteric mass with findings suggestive of a NET (for example, hypervascular pancreatic mass, desmoplastic mesenteric mass) on conventional imaging
  • PET for the evaluation of extra-adrenal mass (for example, carotid body nodule), with conventional imaging and/or elevated biomarkers suggestive of a pheochromocytoma/paraganglioma (PPGL)
  • PET for a patient with a genetic syndrome predisposing to NETs and a biochemical and/or morphological suspicion of a NET in whom PET results would measurably impact management
• Special considerations for diagnosis:
  • Patients with a suspicious mass in another anatomical location (for example, lung) without elevated biochemical markers should be considered for further workup and/or biopsy before the PET. PET could be considered after a failed biopsy or if a biopsy is not feasible.
  • Patients with a pancreatic tail mass suggestive of a NET should have a Tc-99m Sulpha Colloid or Red Blood Cell scan to exclude intrapancreatic accessory spleen as both can present Ga-68 DOTATATE avid.
• Initial staging (initial staging PET scans should be requested within one year from the initial diagnosis):
  • PET for a histologically proven well-differentiated NET (G1-G3), including unknown primary, or pheochromocytoma/paraganglioma (PPGL)
  • PET for a histologically proven medullary thyroid cancer being considered for curative intent therapy
• Special considerations for initial staging:
  • PET is not appropriate for patients with Type 1 Gastric NET, neuroendocrine carcinomas (NEC) and adenocarcinomas with NET features.
  • Unless there are unique clinical and/or structural concerns, PET is not routinely appropriate for patients with Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH).
  • PET for the initial staging of a patient with an appendiceal NET should be considered when there are positive lymph nodes, the tumour is greater than 1 centimetre, and/or the tumour is invading through the serosa into the mesoappendix.
• PET for the initial staging of a patient with medullary thyroid cancer should be considered when the patient has yet to have a thyroidectomy or following it when biomarkers are positive with negative or equivocal structural imaging.

• Re-staging:
  • PET for a patient with progressive NETs disease and is being considered for publicly funded Peptide Receptor Radionuclide Therapy (PRRT). For PRRT consideration, a PET scan should be completed within 12 months. However, a more recent PET scan should be considered if there are concerning clinical features (for example, de-differentiation).
  • New baseline PET scan for patients with new metastatic disease on conventional imaging and/or clinical suspicion of de-differentiation.
  • PET for a patient with medullary thyroid cancer when recurrent disease is suspected on the basis of elevated and/or rising tumour markers (e.g., calcitonin), with negative or equivocal conventional imaging work-up
• The following are preliminary indications and are likely to be refined:
  • PET for a patient with NETs disease when surgery (for example, de-bulking, focal ablation, liver-directed therapy) is being considered.
  • PET for a patient with NETs disease where conventional imaging is negative or equivocal at the time of clinical and/or biochemical progression.
• Special considerations for routine surveillance:
  • Requests for routine surveillance when there is no clinical or biochemical suspicion of recurrence or progression are not eligible.

Referral information: Download the Ga68-DOTATATE PET Requisition Form.

Sarcoma (initial staging/re-staging)

Eligibility criteria: PET for the initial staging of patients with histologically confirmed high grade (equal to or greater than grade 2), or ungradable, soft tissue or bone sarcomas, when conventional workup is negative or equivocal for metastatic disease, prior to curative intent therapy; or for re-staging of patients with suspicion of, or histologically confirmed, recurrent sarcoma (local recurrence of limited metastatic disease) when radical salvage therapy is being considered.

Plexiform Neurofibromas (diagnosis)

Eligibility criteria: PET for patients with suspicion of malignant transformation of plexiform neurofibromas.

Referral Information: Download the Sarcoma Requisition Form.

Esophageal or Gastroesophageal (GE) Junction

Eligibility criteria: PET for baseline staging assessment of those patients diagnosed with esophageal/GE Junction cancer being considered for curative therapy and/or repeat PET/CT scan on completion of pre-operative/ neoadjuvant therapy, prior to surgery; or for re-staging of patients with locoregional recurrence, after primary treatment, being considered for definitive salvage therapy.

Lung – non-small cell lung cancer (NSCLC; clinical stage 1 to 3)

• Eligibility criteria:
  • PET for initial staging of patients with NSCLC (clinical stage 1 to 3) being considered for potentially curative therapy or
  • For re-staging of patients with locoregional recurrence, after primary treatment, being considered for definitive salvage therapy
  • for staging of patients with oligometastatic NSCLC being considered for definitive local therapy.

Histological proof is not required prior to PET if there is high clinical suspicion for NSCLC (for example, based on patient history and/or prior imaging).

PET is appropriate for patients with either histological proof of locoregional recurrence or strong clinical and radiological suspicion of recurrence who are being considered for definitive salvage therapy.

Lung – small cell lung cancer (SCLC; clinical stage 1 to 3)

• Eligibility criteria: PET for initial staging of patients with limited disease SCLC where combined modality therapy with chemotherapy and radiotherapy is being considered.

Lung – solitary pulmonary nodule (SPN)

• Eligibility criteria: PET for a semi-solid or solid lung nodule for which a diagnosis could not be established by a needle biopsy due to unsuccessful attempted needle biopsy; the SPN is inaccessible to needle biopsy; or the existence of a contra-indication to the use of needle biopsy.

Lung – mesothelioma

• Eligibility criteria: PET for the staging of patients with histologic confirmation of malignant mesothelioma.

Referral Information: Download the Thoracic Requisition Form.

Pediatric Oncology Registry

• Eligibility criteria: Pediatric Registry Indications (data collection/partnership with the Pediatric Oncology Group of Ontario):
  • For the following cancer types (ICCC – International Classification of Childhood Cancer):
    • Bone/cartilage – osteosarcoma, Ewing sarcoma
    • Connective/other soft tissue – rhabdomyosarcoma, other
    • Kidney – renal tumour
    • Liver – hepatic tumour
    • Primary brain – astrocytoma, medulloblastoma, ependymoma, other
    • Reproductive – germ cell tumour
    • Sympathetic nervous system – neuroblastoma MIBG negative
    • Other – LCH, melanoma of the skin, thyroid
  • For the following indications:
    • Initial staging
    • Monitoring response during treatment or determine response-based therapy
    • Rule out progression prior to further therapy
    • Suspected recurrence or relapse
    • Rule out persistent disease
    • Select optimal biopsy site

Referral information: To submit Pediatric Oncology Registry referrals, you must log in to the PET Scans Ontario E-Tool.