Overview & State of the Art Val J. Lowe, MD Val J. Lowe, MD - PowerPoint PPT Presentation

PET/CT in Cancer: A General Overview & State of the Art Val J. Lowe, MD Val J. Lowe, MD PET Facility Mayo Clinic Lowe,VJ

Radioisotopes Unstable parent nucleus Positron combines  with electron and annihilates  Proton decays to Positron and neutron in nucleus neutrino emitted Two 511 keV photons produced ~180  apart Positron Emission and Annihilation Lowe,VJ

[18]F-2-deoxy-2-flouro-D-glucose (FDG) Increased glucose metabolism in cancer (Warburg 1930) [18]F-2-deoxy-2-flouro-D-glucose (FDG) trapping in tumor cells has been described and is the result of the increased glucose metabolism in tumors (Gallagher, 1978) Lowe,VJ

FDG Physiology OH OH O O OH OH HO HO OH OH OH OH D-Glucose 2-Deoxy-D-Glucose O OH HO OH F 2-Deoxy-2-Fluoro-D-Glucose Lowe,VJ

FDG Physiology Vascular Capillary Extra- Intracellular metabolism compartment membrane cellular space Glycogen Phosphorylase 'a' G - 1 - PO4 Glucose Hexokinase G - 6 - PO4 Glucose G - 6 - P F - 6 - PO4 CO2 + H2O 18 FDG Hexokinase 18FDG - 6 - PO4 18 FDG G - 6 - P Cell membrane Lowe,VJ

PET/CT Development 15 years ago: PET Lung Scan 20 minute emission for 20 cm axial field of view + 20 minutes for attenuation correction = 40 minutes for 20 cm Lowe,VJ

PET/CT Development 7 years ago: CT unit fusion to PET: Responded to the need for anatomic information coupled to PET Provided a faster way to get attenuation correction leading to 40 minute body scans Lowe,VJ

PET/CT Development Summary Today: Imaging Speed: Different machines can give 15-40 minute whole-body images Anatomic CT fusion: A selection of CT resolutions Lowe,VJ

PET/CT Development In the works for tomorrow’s “State of the Art”: Imaging Speed: ?? 5 minute whole body scans Improved Accuracy: New tracers Time of flight reconstruction Lowe,VJ

A B C D Coronal images of an average patient with a BMI of 27 kg/cm2. A) 2D acquisition, 5 min per bed; B) 3D acquisition, 5 min per bed; C) 3D acquisition, 3 min per bed; D) 3D acquisition, 2 min per bed.

PET/CT Equipment PET component Respiratory gate triggering Allows respiratory gating and positioning of a lung nodule more accurately The data is sparse but this could improve the characterization of some lung nodules Lowe,VJ

PET New Developments Respiratory gating: After WB scan, acquire respiratory gated study centered on lesion 3D, list mode, 8 bin, 10 min, one bed Summed Gated, bin 3 Lowe,VJ

PET/CT in Cancer: A General Summary of Performance  PET/CT can perform the most accurate N and M staging in almost all aggressive cancers compared to CT, MRI or US.  PET has great potential to evaluate cancer therapy; results better than CT  PET may provide more specific molecular targeting capability in the future Lowe,VJ

Medicare and Insurance Coverage  Steady indication by indication approval by CMS of PET/CT in oncology in the last 2 decades  Still, FDA approvals lagging for its use but not hampering clinical use and reimbursement  Specific language needs to be used in ordering Lowe,VJ

CMS Coverage List Final Fram ework Solid Tumo r Ty pe Ini tial Tre atm ent Subs eque nt Strat egy* Tre atment Strat egy ** Colorectal Cover Cover Es op hagus Cover Cover Head & Neck (not thyroid or CNS) Cover Cover Lymphoma Cover Cover Non - s mall ce ll lung Cover Cover Ovary Cover Cover Brain Cover CED Cervix 1 or CED Cover 1) Cervix: Covered for the detection of pre- treatment metastases (i.e., staging) in newly Small ce ll lung Cover CED diagnosed cervical cancer subsequent to Soft Tis sue Sarcoma Cover CED conventional imaging that is negative for extra-pelvic metastasis. All other uses are CED. 
 (2) Breast: Noncovered for diagnosis Panc re as Cover CED and/or initial staging of axillary lymph nodes. Test es Cover CED Covered for initial staging of metastatic disease. 
 (3) Melanoma: Noncovered for Bre ast (fe male and male) 2 Cover initial staging of regional lymph nodes. All other uses for initial staging are Melanoma 3 Cover covered. 
 (4) Thyroid: Covered for subsequent treatment strategy of recurrent Prostate N/ C CED or residual thyroid cancer of follicular cell origin previously treated by thyroidectomy Thyroid Cover 4 or CED and radioiodine ablation and have a serum thyroglobulin >10ng/ml and have a negative All o the r sol id tu mors Cover CED I-131 whole body scan. All other uses for subsequent treatment strategy are CED. Myeloma Cover Cover All o the r cance rs no t l is ted her e in CED CED