Aims and objectives
MRI is to date the reference imaging modality for diagnosing patients with suspected rectal cancer due to excellent soft tissue contrast.
With MRI,
tumor assessment of both morphology and functional information like tumor perfusion is possible.
However,
the additional value of MR perfusion regarding diagnosis,
therapeutic management or prognostic value is unclear and studies are disconcordant [1].
A weakness of MR perfusion imaging is the limited comparability of MR perfusion parameters due to high variability of signal intensity characteristics and lack of 3D angulation a-posteriori...
Methods and materials
We prospectively enrolled in an IRB-approved study 12 patients who underwent dVPCT of newly-diagnosed rectal cancer in coloscopy in the framework of metastasis staging with CT.
All patients underwent conventional additional pelvic MR for local staging.
Informed written consent was obtained from all patients.
CT perfusion aquisition parameters:
•2x 192 slice dual-source CT scanner system (Somatom Force,
Siemens,
Healthcare Sector)
•80,
90 or 100 kV tube voltage (170 to 220 mAs)
•50 ml i.v.
contrast (400mg/mL)
•10 sec Bolus
•5ml/s flow
Perfusion analysis:
•ROI-based approach...
Results
Mean values for M1 and M2 were as following: BF: 72.3 vs.
73.8 mL/100mL/min; BV: 5.0 vs.
5.1 mL/100mL; MTT: 4.8 vs.
4.7 s; and PERM: 20.4 vs.
20.9 mL/100mL/min.
Paired t-testing revealed no statistically significant differences for all four dVPCT parameters between M1 and M2 with a mean difference±SD for BF of 1.5±3.6 mL/100mL/min,
BV 0.1±0.2 mL/100mL,
MTT -0.03±0.2 s and PERM of 0.5±0.8 mL/100mL/min,
all p>0.05.
The coefficients of variation from duplicate measurements M1 and M2 were similar for all parameters with BF=3.7%,...
Conclusion
BF,
BV,
MTT and PERM dVPCT measurements are reproducible within narrow variation ranges in tumor tissue of rectal cancer patients.
Dynamice volume CT perfusion therefore holds potential for assessing and monitoring tumor perfusion e.g. in patients with rectal cancer undergoing anti-angiogenic therapies.
Personal information
Sonja Sudarski,
MD
Institute for Clinical Radiology and Nuclear Medicine
University Medical Center Mannheim,
Medical Faculty Mannheim - Heidelberg University
Theodor-Kutzer-Ufer 1-3
D-68167 Mannheim
GermanyTel.: (+49) (+621) 383 - 2067
Fax: (+49) (+621) 383 - 1910
E-Mail:
[email protected]
Internet: http://www.ikrn.de
References
[1]Multi-parametric MRI of rectal cancer - do quantitative functional MR measurements correlate with radiologic and pathologic tumor stages?.
Attenberger UI,
Pilz LR,
Morelli JN,
Hausmann D,
Doyon F,
Hofheinz R,
Kienle P,
Post S,
Michaely HJ,
Schoenberg SO,
Dinter DJ.
Eur J Radiol.
2014 Jul;83(7):1036-43.
doi: 10.1016/j.ejrad.2014.03.012.
PMID:24791649
[2]Technical prerequisites and imaging protocols for CT perfusion imaging in oncology.
Klotz E et al.; Eur J Radiol.
2015 Dec;84(12):2359-67.
doi: 10.1016/j.ejrad.2015.06.010.
Epub 2015 Jun 24.