PET/CT: A New Era in Nuclear Medicine?

Transcription

1 September 18, 2003 PET/CT: A New Era in Nuclear Medicine? Brook J Hill, Harvard Medical School, Year IV, Beth Israel Deaconess Hospital and Harvard Medical School

2 What is PET/CT? One machine Patient not moved Anatomical AND functional data 2

3 + = Schoder et al.,

4 History of PET/CT Developed late 1990 s, University of Pittsburgh, Dr. David Townsend First clinical scanner: Johns Hopkins, 7/01 ~ U.S. centers now have PET/CT ~ clinical papers on PET/CT thus far 4

5 Review of PET Cyclotron 11 C, 13 N, 15 O, 18 F Radioisotope + parent molecule radiotracer Radiotracer + patient localization according to parent molecule Decay positron travels 3-5 mm collides with electron annihilation (2) 511-keV (gamma) photons traveling at 180 Gamma camera Image construction 5

6 Radiotracers RADIOTRACER: 18 F-fluoro-deoxyglucose (FDG) 15 O-O 2 15 O-CO 2 15 O-H 2 O 13 N-NH 3 15 O-CO 11 C-acetate 18 F-FMISO 11 C-methionine 11 C-palmitate 18 F-fluorodopa 11 C-SCH C-flumazenil MEASURES: Metabolism Metabolism Blood flow Blood flow Blood flow Blood volume Regional O2 consumption Tissue hypoxia Amino acid metabolism Lipid metabolism Dopamine metabolism Dopamine receptors Benzodiazepine receptors 6

7 Attenuation Correction Before correction: After correction: Rim of falsely increased activity Internal organs not well visualized Actual peripheral activity Internal organs better visualized Schoder et al.,

8 PET/CT Protocols 1. Radiotracer uptake period 2. Non-contrast spiral CT Anatomic data Attenuation correction data 3. PET scan Whole body Single-field high-count density Dynamic Gated 4. Contrast-enhanced CT 8

9 Theoretical Benefits of PET/CT Increased accuracy of PET interpretation More convincing to referring physician More likely to affect patient care Decreased imaging time 9

10 Bar-Shalom R, et. al, 2003: 204 oncology patients with 586 suspicious lesions PET/CT vs. PET+CT PET/CT: provided additional information in 99 patients (49%) with 178 sites (30%) changed diagnosis from equivocal to benign in 10% changed diagnosis from equivocal to malignant in 5% precisely defined malignant lesion location in 6% retrospectively detected lesion in 8% impacted patient management in 28 (14%) 10

11 Keidar Z et. al, 2002: 134 cancer patients PET/CT vs. PET alone PET/CT: led to retrospective discovery of 34 sites of malignancy directed further studies in 10 patients excluded cancer in 3 patients changed stage in 3 patients altered patient care in 12% 11

12 Schoder H et al, 2003: 100 patients, no selection criteria PET/CT vs. PET alone Equivocal lesions: 50/154 with PET alone 22/154 with PET/CT (p<0.05) PET/CT altered patient management in 18% 12

13 Burger J et. al, 2002: 65 Pts with colorectal CA PET/CT vs. PET alone Accuracy of image interpretation: Recurrent disease: PET 85% PET/CT 97% Metastases: PET 72% PET/CT 96% Incorrect Staging: PET 31% PET/CT 10% 13

14 Lardinois D et. al, 2003: 49 Pts with Non Small Cell Lung CA PET/CT vs. PET vs. CT vs. PET+CT PET/CT provided additional information beyond PET+CT in 20/49 Correctness of T staging: PET 40% CT 58% PET+CT 65% PET/CT 88% PET/CT most accurate for assessment of nodal mets 14

15 Theoretical Problems with PET/CT Imperfect attenuation correction Overestimation of radioactivity in dense tissues Motion artifact Imprecise localization of lesion Inaccurate calculation of radioactivity Initial CT is non-diagnostic Who reads the images? 15

16 Cohade C et. al, 2003: 36 patients with cancerous lung lesions Measured accuracy of PET/CT spatial registration Distance between centers of lesion: All lesions: 8 mm Lower lung lesions: 10 mm Upper lung lesions: 7 mm 16

17 Patient #1: 49F With Lung Mass Subclavicular Nodes 17

18 Patient #1: 49F With Lung Mass Internal Mammary Node 18

19 Patient #1: 49F With Lung Mass Huge RUL mass 19

20 Patient #1: 49F With Lung Mass Hilar Nodes 20

21 Patient #1: 49F With Lung Mass Right Inguinal Node 21

22 Patient #1: 49F With Lung Mass Diagnosis? Non Small Cell Lung Cancer (NSCLC) 22

23 Patient #1: 49F NSCLC s/p Chemo + XRT Primary lesion Persistent adenopathy 23

24 Patient #1: 49F NSCLC s/p Chemo + XRT More nodes 24

25 Patient #1: 49F NSCLC s/p Chemo + XRT Esophageal radiation changes 25

26 Patient #1: 49F NSCLC s/p Chemo + XRT Primary 26

27 Patient #2: 69M with abnormal CXR RUL mass invading chest wall 27

28 Patient #2: 69M with abnormal CXR 28

29 Patient #2: 69M with abnormal CXR Bilateral adrenal masses No FDG uptake 29

30 Patient #2: 69M with abnormal CXR Diagnosis? Lung Cancer, Bilateral Adrenal Adenomas 30

31 Patient #3: 77M with back and leg pain Spinal disease Pelvic disease 31

32 Patient #3: 77M with back and leg pain Femoral disease 32

33 Patient #3: 77M with back and leg pain Paraspinous disease 33

34 Patient #3: 77M with back and leg pain Diagnosis? Non Hodgkin s Lymphoma 34

35 Patient #4: Night sweats Femoral disease 35

36 Patient #4: Night sweats Acetabular disease 36

37 Patient #4: Night sweats Massive splenic involvement 37

38 Patient #4: Night sweats Pericardial disease Spinal disease 38

39 Patient #4: Night sweats Subclavicular disease 39

40 Patient #4: Night sweats Diagnosis? Hodgkin s Lymphoma 40

41 Summary Benefits of PET/CT: Increased accuracy of PET interpretation Probably better than separate PET+CT More convincing to referring physician More likely to affect patient care Decreased imaging time Problems with PET/CT: Artifact: Attenuation correction Motion Initial CT non-diagnostic Who reads what? 41

42 Acknowledgements BIDMC Radiology Staff and Residents Dr. Gillian Lieberman Pamela Lepkowski Larry Barbaras Javier, David, Grace, and Asti 42

43 References Bar-Shalom R, Yefremov N, Guralnik L, Gaitini D, Frenkel A, Kuten A, Altman H, Keidar Z, Israel O. Clinical performance of PET/CT in evaluation of cancer: additional value for diagnostic imaging and patient management. J Nucl Med Aug;44(8): Burger I, Goerres G, von Schulthess G, Seifert B, Hany T. PET/CT: diagnostic improvement in recurrent colorectal carcinoma compared to PET alone. Radiology 2002; 225 (p):424. Cohade C, Osman M, Marshall LN, Wahl RN. PET-CT: accuracy of PET and CT spatial registration of lung lesions. Eur J Nucl Med Mol Imaging May;30(5): Israel O, Mor M, Gaitini D, Keidar Z, Guralnik L, Engel A, Frenkel A, Bar-Shalom R, Kuten A. Combined functional and structural evaluation of cancer patients with a hybrid camera-based PET/CT system using (18)F-FDG. J Nucl Med Sep;43(9): Jang S, Greskovich JF, Milla BA, Zhang Y, Nelson AD, Devlin AL, Faulhaber PF. Effects of PET/CT image registration on radiation treatment planning in lung cancer. Int J Radiat Oncol Biol Phys Oct 1;57(2 Suppl):S Keidar Z, Bar-Shalom R, Guralnik L, et al. Hybrid imaging using PET/CT with 18 F-FDG in suspected recurrence of lung cancer: diagnostic value and impact on patient management. J Nucl Med 2002; 43:32P. Lardinois D, Weder W, Hany TF, Kamel EM, Korom S, Seifert B, von Schulthess GK, Steinert HC. Staging of non-small-cell lung cancer with integrated positron-emission tomography and computed tomography. N Engl J Med 2003; 348: Nakamoto Y, Tatsumi M, Cohade C, Osman M, Marshall LT, Wahl RL. Accuracy of image fusion of normal upper abdominal organs visualized with PET/CT. Eur J Nucl Med Mol Imaging Apr;30(4): Osman MM, Cohade C, Nakamoto Y, Marshall LT, Leal JP, Wahl RL. Clinically significant inaccurate localization of lesions with PET/CT: frequency in 300 patients. J Nucl Med Feb;44(2): Schoder H, Erdi YE, Larson SM, Yeung HW. PET/CT: a new imaging technology in nuclear medicine. Eur J Nucl Med Mol Imaging Sep 5 (e-pub). Townsend DW, Beyer T, Blodgett TM. PET/CT scanners: a hardware approach to image fusion. Semin Nucl Med Jul;33(3): Wang Y, Yu J, Liu J, Tong Z, Sun X, Yang G. PET-CT in the diagnosis of both primary breast cancer and axillary lymph node metastasis: initial experience. Int J Radiat Oncol Biol Phys Oct 1;57(2 Suppl):S