1. by: Prof.Dr. Hosna Moustafa Cairo University, Egypt
Brain Imaging
by: Prof.Dr. Hosna Moustafa Cairo University, Egypt

2. Brain Imaging
Radionuclide brain imaging is differnet from anatomic imaging as C.T., M.R.I. in being functional imaging.
Radionuclides may be used to study:
Brain tumour:
Tl-201
Tc99m-MIBI
Tc99m-DMSA(V)
Fl18- FDG

3. Radiopharmaceuticals in Brain Tumors
KeV
Scan start time
Dose
80 KeV
20 min,
3 hours
3 mCi
Tl-201
140 KeV
30 min,
20 mCi
Tc99m-MIBI
1 hour,
Tc99m- DMSA (V)
511 KeV
1 hour
mCi
Fl18- FDG

4. Main clinical indications
Detection of residual functioning tumour following surgery, for planning radiotherapy.
Assessment of treatment response.
Detection of residual or recurrent brain tumors following radiotherapy or chemotherapy.

5. Scan Findings
If residual or recurrent tumor is present, a focal area of increased uptake is seen.
Post-radiation or chemotherapy gliosis shows no uptake.

6. A B C
Residual viable astrocytoma grade III in right occipital region using Tl-201.
CT with equivocal residual brain lesion.
6 weeks after radiotherapy, no viable tumour in the same area.

7. Limitation of Tl-201 Imaging
Poor physical characteristics (low photon energy kev).
Longer half life (73 h) which limit the injected dose to mCi.
Normal uptake in salivary gland, thyroid, heart, kidneys, and muscles.
Not available for daily used (Abdel Dayem et al., 1998).

8. 99mTc-MIBI and 99mTc-Tetrafosmine Imaging
Higher doses 5-10 times more than Tl-201 lead to higher image quality and better resolution.
Early imaging at minutes in both isotopes and late imaging (MIBI) at 2-3 hours
Available as daily kits.
Main limitation is uptake in choroid plexus which may interfere with interpretation of small deep para-ventricular brain lesions.

9. CT: Recurrent glioblastoma in both frontal regions with solid and cystic changes.
TC-Myoview: Recurrent viable glioblastoma in both frontal regions with radiotracer uptake in solid area in CT.

10. Tc V-DMSA scan
MRI: Recurrent temporal astrocytoma grade II following radiotherapy.
SPECT: Viable tumour in the left temporal region.

11. 99mTc-(v)DMSA: Viable tumour in the left temporal region with no uptake in midline.
99mTc-MIBI: Viable tumour in the left temporal region with overlap of choroid plexus uptake in midline.

12. FDG-PET in recurrent brain tumor
Fluorine-FDG is metabolic agent, which reflect the metabolism of glucose
High uptake is seen in high grade tumors as well as GMF.
Carbon-11 methionine can be used in evaluation of low grade tumors.

13. Recurrent glioblastoma in frontal lobe evidenced in MRI with viable tumor in FDG PET.

14. Advantages of Radionuclide Brain Tumour Imaging
Good indicator of tumour viability.
Can assess tumour response to therapy.
Can detect residual or recurrent tumours.
Can differentiate post therapy fibrosis from recurrent tumour, if CT or MRI are equivocal.

15. Thank you