1. PET/CT in Oncology
George Segall, M.D.
Stanford University

2. Evolution of TechnologyCT
PET/CT
PET
2001
1973
2000 3

3. 3

4. Imaging Protocol Patient CT PET - Inject tracer
- Fast 4 hrs prior to exam
- Inject tracer
- Start scan 60 min later CT
- Topogram (scout)
- CT scan (1 min)
PET
- Brain (10 min)
- Heart (10 min)
- Body (20 min)
<130

5. PET Tracer: FDG Glucose FDG Glucose-6-P FDG-6-P
Plasma Cell
18F-fluorodeoxyglucose (FDG) is taken up by cells proportionate to their metabolic rates

6. PET CT PET/CT CT (1 min) FDG Bed 15 mCi 1 min KVs mAs Slice 130 kV
5 mm
H.S.,

7. What Are the Advantages of PET/CT?
Advantages of CT
• high spatial resolution
Advantages of PET
• better lesion characterization
• enhanced lesion detection

8. Applications of PET-CT
Brain 5%
Heart 5%
• epilepsy
• perfusion
• tumor
• viability
Body 90%
76%
• dementia
1.5 million exams performed annually
• tumor
• infection
• bone 3

10. PET - CT in Tumor Imaging
• Detect radiographically occult lesions
• Characterize radiographic abnormalities
• Evaluate extent of disease
• Evaluate response to therapy 3

11. Normal PET - CT Body Scan3

12. Normal PET/CT scan CT
PET/CT
PET

13. Abnormal PET - CT Body Scan3

14. Medicare Approved Indications for PET-CT
Diagnosis, Staging, and Restaging (unless otherwise indicated)
• Head & Neck
• Thyroid
• Breast
• Lung
• Esophagus
• Colon & Rectum
• Cervix
• Lymphoma
• Melanoma
• Other Cancers
follicular: I -131 neg, Tg >10 ng/dL
not breast masses or regional nodes
only non-small cell
Medicare approved indications for PET include 9 cancers. PET is approved for diagnosis, staging, and restaging in most cases, with a few notable exceptions.
CT/MRI neg for extra-pelvic mets
not regional nodes
when enrolled in NOPR 3

15. National Oncologic PET Registry
Sponsored by AMI and managed by ACR for CMS
April 15, 2008
1,728 facilities - 74,541 scans since May 2006

16. National Oncologic PET Registry
Pre PET/CT Form
• Indication for PET/CT
• Cancer type and extent
• Management plan
Post PET/CT Form
• Change in assessment of extent of disease
• Change in management plan

17. National Comprehensive Cancer Network
The National Comprehensive Cancer Network is a consortium of 19 U.S. cancer centers that meet regularly to make evidence based recommendations on cancer diagnosis, staging, and treatment.

18. Practice Guidelines in Oncology
National Comprehensive Cancer Network
Practice Guidelines in Oncology
Acute Myeloid Leukemia
Bladder Cancer
Bone Cancer
Breast Cancer
Central Nervous System Tumors
Cervical Cancer
Chronic Myelogenous Leukemia
Colorectal Cancer
Esophageal Cancer
Gastric Cancer
Head and Neck Cancer
Hepatobiliary Cancer
Hodgkin’s Disease
Kidney Cancer
Melanoma
Myelodysplastic Syndromes
Multiple Myeloma
Neuroendocrine Tumors
Non Hodgkin’s Lymphoma
Non-Small Cell Lung Cancer
Occult Primary Cancer
Ovarian Cancer
Pancreatic Cancer
Prostate Cancer
Soft Tissue Sarcoma
Skin Cancer (except Melanoma)
Small Cell Lung Cancer
Testicular Cancer
Thyroid Cancer
Uterine Cancer
The NCCN publishes practice guidelines for 30 types of cancer. These guidelines are available at

19. Practice Guidelines in Oncology
National Comprehensive Cancer Network
Practice Guidelines in Oncology
Bone Cancer
Breast Cancer
Cervical Cancer
Colorectal Cancer
Esophageal Cancer
Head and Neck Cancer
Hodgkin’s Disease
Melanoma
Multiple Myeloma
Non Hodgkin’s Lymphoma
Non-Small Cell Lung Cancer
Occult Primary Cancer
Ovarian Cancer
Soft Tissue Sarcoma
Small Cell Lung Cancer
Testicular Cancer
Thyroid Cancer
Cancers in which PET/CT is recommended.

20. Lesion Characterization
T y/o man incidentally discovered lung nodule following MVA 12/20/05. PET on 1/9/06 showed high FDG uptake. Thoracotomy on 2/24/06, frozen section showed no cancer, so patient had a wedge resection. Final path report showed poorly differentiated lung cancer, so patient had a left upper lobectomy on 3/6/06.
47 year old man with multiple trauma from a MVA who was incidentally discovered to have a pulmonary nodule 3

21. Lesion Characterization
V year old man with chronic cough. CXR on 6/10/05 showed a pulmonary nodule. CT on 7/16/05 showed a 13 mm nodule in the LLL with subtle rim calcification. No change on CXR done 11/22/05. PET on 12/12/05 was negative. No further imaging as of 3/28/06.
84 year old man with chronic cough found to have a 13 mm nodule on CXR 3

22. Enhanced Detection
73 year-old woman who had a hemi-colectomy for colon cancer. Her CEA level began to rise post-operatively. She had CT, but intravenous contrast could not be used because her creatinine level was elevated. CT was normal, but PET showed a solitary hypermetabolic focus in the left lobe of the liver. The patient had a laporotomy and wedge resection based on the PET findings. Pathological examination confirmed metastatic colon cancer.
73 year old woman s/p resection for colon cancer, rising CEA level and negative CT

23. Enhanced Detection
H6636. CT (VA Fresno 5/2008) PET/CT 6/20/2008

24. Enhanced Detection
70 y/o male with H&N cancer

25. Enhanced Detection I-131 FDG PET
47 year old man who had biopsy proven recurrent thyroid cancer 3 months after thyroidectomy. The PET scan shows multiple hypermetabolic lymph nodes in the right neck and supraclavicular region, which were not visible with radioiodine.
I-131
FDG PET
47 year old man with biopsy proven recurrent thyroid cancer 3 months after thyroidectomy

26. Unknown Primary 68 year old man who presented with right neck mass
E1638. PET/CT 10/17/07.
68 year old man who presented with right neck mass

27. Staging 49 year old man with new lung cancer
49 year-old man with newly diagnosed lung cancer. CT of the thorax showed a mass in the upper lobe of the upper lobe of the left lung. There was no sign of metastatic disease.
PET showed the primary tumor, as well as a hypermetabolic mass in the pelvis. Fused transaxial PET-CT images showed probable metastatic disease behind the left psoas muscle. CT with IV contrast was subsequently performed, and showed an enhancing mass in the same area.
The patient developed additional distant metastases and died a few months later.
49 year old man with new lung cancer

28. Recurrent Disease 64 year old man s/p laryngectomy, now has dysphagia
M6736. PET/CT 9/25/07.
64 year old man s/p laryngectomy, now has dysphagia

29. Monitoring Response
H5493. PET/CT before chemotherapy 7/24/07; after chemotherapy 11/1/07
63 year old man stage 3A lung cancer, has received 4 cycles of chemotherapy

30. CT + PET/CT vs PET/ CT MOST CASES
• Standard CT followed by PET/CT if needed
SOME CASES
• PET/CT
CT component can be low resolution or optimized

31. Problems and Pitfalls • False negative findings
Tumor histology
Lesions smaller than 8 mm
Diabetes/Non-fasting patients
• False positive findings
Normal physiology
Granulomas and other infections
Adenomas

32. Standard CT
PET/CT
D1693. PET/CT 5/24/07.
56 year man with HCV, end stage liver disease, and presumed hepatoma

33. Physiologic Uptake: Brown Fat

34. Infection
68 year old man with solitary lung nodule. Biopsy: aspergillosis 3

35. Granulomatous Disease
A8665. PET/CT 6/6/07.
62 year old man with hilar and mediastinal adenopathy. Biopsy: sarcoidosis

36. Adenoma 82 year old man with wt loss and liver masses
L0918. PET/CT 9/11/07.
82 year old man with wt loss and liver masses

37. Adenoma 82 year old man with wt loss and liver masses
L0918. PET/CT 9/11/07.
82 year old man with wt loss and liver masses

38. Clinical Impact of PET/CT
• More accurate diagnosis
• Avoidance of unnecessary tests, and (potentially) harmful procedures
• Better treatment or management

39. National Oncologic PET Registry
36.5% change in decision to treat or not treat

40. Conclusions 1. CT is the first imaging test of choice in most cases
2. PET - CT is more accurate than CT alone
• Characterizing lesions difficult to biopsy
• Detecting occult cancer
• Determining extent of cancer and response to therapy
3. PET - CT changes management 36%

41. Why PET-CT?