1. CLINICAL USE OF SPECT-CT IN BREAST & PROSTATE CANCERS
Emerita A. Barrenechea, MD
Department of Nuclear Medicine
St Luke’s Medical Center
& Veterans Memorial Medical Center
Philippines

2. Introduction
SPECT-CT: emerging dual-modality imaging technique with many established and potential clinical applications in the field of oncology.
As with PET-CT, accurate co-registration of anatomical and functional data from combined SPECT-CT camera often provides complementary diagnostic information.
Collection of both sets of imaging data in the same exam increases the likelihood of 1:1 mapping and improved diagnostic accuracy.

4. SPECT Radiopharmaceuticals
More specific
Longer half-lives allowing for delayed or increased imaging
Like PET, extremely useful in determining organ or tissue function, which is augmented with anatomical correlation with CT scanning

5. SPECT-CT guided Bone Scintigraphy
Bone scintigraphy is often used to detect possible areas of metastases, but the scans are so nonspecific that further radiological follow-up is always needed when abnormal uptake is present. Using the hybrid scanner, a patient undergoes SPECT imaging alone; if abnormality is detected, the patient remains on the table for a focused CT scan of the suspect region.

6. Applications: Detection of primary or metastatic lesions
Staging of malignant disease
Assessment of chemotherapy or radionuclide therapy
Sentinel node identification
Locating difficult lesions in oncology

7. Clinical Applications in Oncology
Endocrine tumors
Lymphoscintigraphy
Lung cancer
Brain tumors
Bone scan
Liver perfusion studies
Liver hemangiomas

8. Breast Cancer It is the most prevalent cancer worldwide in women.
PET with FDG may be the most single sensitive imaging test to detect primary and systemic metastases but fails to detect microscopic disease smaller than 5-10mm lesions as well as limited capabilities in axillary nodal evaluation where SPECT/CT lymphoscintigraphy is preferred

9. Tc99m Sestamibi Scintimammography

10. Tc99m Sestamibi Scintimammography

11. Sentinel Node - Breast

12. Sentinel Node - Melanoma

13. Sentinel Node Mapping

14. Indications on planar lymphoscintigraphy for additional SPECT-CT
Unusual lymphatic drainage patterns
Extraaxillary drainage in breast cancer patients
Drainage to more than one lymph node basin
Drainage not to nearest lymph node basin

15. Indications (cont’d) Lymphatic patterns difficult to interpret
Sentinel lymph node close to injection site
Deeply located sentinel lymph nodes
Non-visualization
No lymphatic drainage on late planar images

16. SPECT-CT Imaging: Breast Cancer
A = Anterior
B = L Lateral
No lymphatic
drainage 4hrs
C = Axillary Sentinel Node

17. SPECT-CT Imaging: Breast Cancer
® Axillary sentinel node
No lymphatic drainage
® Internal Mammary sentinel node

18. SPECT-CT Imaging: Breast Cancer
2nd Echelon LN
Int Mam LN

19. SPECT-CT Imaging: Breast Cancer
Axillary LN
Int Mam LN
SLN Breast

21. Adenosylcobalamin:
New radiopharmaceutical under investigation for use in SPECT-CT
Indium111 DTP adenosylcobalamin (Vit B12 analogue)
Action: Vitamin B12 involved in methylation reactions important in Krebs’ cycle, thymidine production required for DNA synthesis. These processes are increased in metabolically active tissues like cancers

22. Ductal Breast Carcinoma in 4 Women using Adenosylcobalamin

23. Prostate Cancer
Prostate cancer: leading form of cancer for men, and leading cause of cancer-related deaths.
Slow growing, but lethal once it has metastasized.
Indium111 Capromab Pendetide (ProstaScint) imaging is indicated for staging and recurrence detection as well as for metastases.
Interpretation without correlated structural information becomes challenging as the radiopharm demonstrates non-specific uptake in the normal vasculature, bowel, bone marrow and prostate gland

24. ProstaScint Agent: Indium111 ProstaScint Half-life: 2.8 days
For assessment of nodal metastases
Detection of occult metastatic disease in post-prostatectomy patients

26. Prostate CA: Widespread Osseous Metastases
Interpretation dependent on pattern of tracer distribution according to expected physiology or pathophysiology

27. Prostate CA with Degenerative Joint Disease
Highly sensitive for metabolic increases in osteoblastic activity
Poorly specific:
also accumulates in inflammation or areas of hypervascularization

28. SPECT
Useful in localizing lesions in complex bony structures such as the skull, vertebral column, or pelvis
Prostate CA with neck pains revealed to be of degenerative origin

29. SPECT
Typical bone scan agents like Tc-99m MDP or HDP are taken up by osteoblasts in bone formation and chemoabsorbed in the hydroxyapatite mineral component of the osseous matrix
Even with CT correlation, however, the characteristics of Tc99m HDP or MDP limits the study

31. Conclusion
SPECT-CT imaging in breast, prostate and other cancers has been proven effective through improved specificity and diagnostic confidence helping to guide conventional management and assess suitability for targeted therapy.
SPECT-CT combines anatomic and functional techniques to allow accurate localization of tumors, increased detection of recurrent and metastatic disease, and exclusion of physiologic uptake.

32. Conclusion
Both functional and morphologic information can be obtained in a single imaging session.
With SPECT-CT, it is now possible to have the “best of both worlds”, providing functional information on lesions within an adequate anatomic context.

33. Thank you for youe attention
Thank you for your attention.