1. Correlation of tumor blood volume and apparent diffusion coefficient values with the prognostic parameters of head and neck squamous cell carcinoma
Abdel Razek A. Diagnostic Radiology Department. Mansoura Faculty of Medicine, Mansoura. Egypt.

2. INTRODUCTION
Head and neck squmous cell carcinoma (HNSCC) is a significant cause of world wide morbidity and mortality.
The morphological prognostic factors of HNSCC are tumor size, lymph node status, and histological grade. They correlate significantly with recurrence and overall survival.

3. Diffusion weighted MR imaging has been used in head and neck
Diffusion weighted MR imaging has been used in head and neck. dynamic susceptibility contrast MR imaging has been used in head and neck.

4. AIM OF WORK
To measure tumor blood volume (TBV) through dynamic susceptibility perfusion weighted MR imaging (DSC) and apparent diffusion coefficient (ADC) values through diffusion-weighted MR imaging
to correlate these values with the prognostic parameters of HNSCC.

5. MATERIAL & METHODS Patient populations:
Retrospective study was done upon 43 patients (31 male and 12 female mean age is 65ys) with HNSCC.
MR Examination:
MR unit (1.5 tesla) with EPI.
Routine MR (T1,T2WI, true fispe).
Diffusion weighted MR imaging.
DSC perfusion MR imaging.

6. Diffusion MR imaging:
Single shot spin echo EPI.
TR:10000 ms & TE: 108 ms.
Images were obtained at B0, 300& 600sec/mm2.
ADC map was reconstructed. Scan time 1 min.
Quantitative assessment of ADC value:
ROI was drawn around solid part of the mass.
Mean ADC value was calculated.

7. Dynamic Susceptibility MR imaging
Single Shot GRE EPI:
TR:120 ms, TE:47ms, NEX:1.
Thick: 6mm, Slice no: 15, FOV: cm.
CM injection:
Gd-DTPA. 0.1 mmol/ kg BW.
Rate: 3ml/s followed by 20ml saline.
Time:
Starting after 8 sec every 2 secs
Total acquisition time: 2min.

8. Final diagnosis:
Tru cut biopsy via CT guided biopsy (n=16) and fibro-optic endoscopy (n=12) and surgery (n=7). ?????Surgery was done for all patients.
Histopathological examination:
Size: correlated with UICC classification.
LN: positive or negative.
Path grade: well, poorly differentiated.

9. Interpreation ADC value correlated with: Imaging findings:
Tumor size, distant metastasis.
Pathological findings:
Histologic grade & LN.

10. Image analysis:
Post process ign wasdone with creation fo tumor blood volume map
A ROI was done about the tumor region.

11. HNSCC (A) Axial T2WI shows post cricoid mass
HNSCC (A) Axial T2WI shows post cricoid mass. (B) DSC image shows the lesion. (C ) TBV map shows high tumor volume within the lesion.

12. Statistical analysis Mean & SD: ADC values of each prognostic factor.
T test (P value):
Difference within each prognostic factor.
P value <0.05 was significant.
Pearsons Correlation.
ADC value correlated with:
Morphologic prognostic factors (tumor size)
Pathologic prognostic factors (histologic grade, LN)

13. Sites of pharyngeal carcinoma
RESULTS
Sites of pharyngeal carcinoma
Location
Number
Oropharynx
Hypopharynx
Larynx 20 11 12

14. The HNSCC TBV level was negatively correlated with the ADC value (r =-0.662, P = 0.001).

15. There was a significant difference in the TBV and ADC values at different degrees of tumor differentiation (P = and P = 0.001) and with different GTVs (P = and P = 0.001).

16. The following prognostic parameter categories were used: (a) poorly differentiated and undifferentiated vs. well differentiated to moderately differentiated and (b) HNSCC with GTV < 30 cm3 vs. >30 cm3 GTV. The cut-off values for the TBV and ADC for each category were 23.2, 0.93; and 24.6, 1.11, respectively, and the areas under the curve were 0.822, and 0.726, 0.795, respectively, for each category. .

17. Conclusion
We concluded that the TBF levels determined using DSC and the ADC values using DWI are well correlated with some prognostic parameters of HNSCC.