Kinetic analysis of dynamic 18F-fluoromisonidazole PET correlates with radiation treatment outcome in head-and-neck cancer.
BACKGROUND
Hypoxia compromises local control in patients with head-and-neck cancer (HNC). In order to determine the value of [18F]-fluoromisonidazole (Fmiso) with regard to tumor hypoxia, a patient study with dynamic Fmiso PET was performed. For a better understanding of tracer uptake and distribution, a kinetic model was developed to analyze dynamic Fmiso PET data.


METHODS
For 15 HNC patients, dynamic Fmiso PET examinations were performed prior to radiotherapy (RT) treatment. The data was analyzed using a two compartment model, which allows the determination of characteristic hypoxia and perfusion values. For different parameters, such as patient age, tumor size and standardized uptake value, the correlation to treatment outcome was tested using the Wilcoxon-Mann-Whitney U-test. Statistical tests were also performed for hypoxia and perfusion parameters determined by the kinetic model and for two different metrics based on these parameters.


RESULTS
The kinetic Fmiso analysis extracts local hypoxia and perfusion characteristics of a tumor tissue. These parameters are independent quantities. In this study, different types of characteristic hypoxia-perfusion patterns in tumors could be identified. The clinical verification of the results, obtained on the basis of the kinetic analysis, showed a high correlation of hypoxia-perfusion patterns and RT treatment outcome (p = 0.001) for this initial patient group.


CONCLUSIONS
The presented study established, that Fmiso PET scans may benefit from dynamic acquisition and analysis by a kinetic model. The pattern of distribution of perfusion and hypoxia in the tissue is correlated to local control in HNC.
Thorwarth
Daniela
D
Section for Biomedical Physics, Clinic for Radiation Oncology, University Hospital Tübingen, Germany. daniela.thorwarth@med.uni-tuebingen.de
Eschmann
Susanne-Martina
SM
Scheiderbauer
Jutta
J
Paulsen
Frank
F
Alber
Markus
M
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000532:radiotherapy*; D006801:Humans; D000860:Hypoxia; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D008920:Misonidazole / Q000031:analogs & derivatives* / Q000494:pharmacology; D015233:Models, Statistical; D049268:Positron-Emission Tomography / Q000379:methods*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D012984:Software; D016896:Treatment Outcome
D011838:Radiation-Sensitizing Agents; C031843:fluoromisonidazole; D008920:Misonidazole