18F-FLT PET changes during radiotherapy combined with cetuximab in head and neck squamous cell carcinoma patients.
OBJECTIVE
Early treatment response of head and neck cancer to radiotherapy concomitant with cetuximab was monitored by repetitive PET imaging with the proliferation tracer 18F-FLT.


METHODS
Five head and neck cancer patients, treated with radiotherapy and concomitant cetuximab following cetuximab induction, received four 18F-FLT PET-CT scans before and during treatment. Changes in SUVpeak, SUVmean and CT- and PET-segmented gross tumour volumes were evaluated, as were correlations with immunohistochemical staining for Epidermal Growth Factor Receptor (EGFR) and Ki-67 (proliferation marker) in pre-treatment tumour biopsies.


RESULTS
18F-FLT PET measured tumor responses to the induction dose of cetuximab varied from 43% SUVpeak decrease to 47% increase. After start of radiotherapy 18F-FLT PET parameters decreased significantly in all patients. No associations were found between PET parameters and EGFR or Ki-67 expression levels.


CONCLUSIONS
Proliferation of head and neck carcinomas shows a varying response to cetuximab induction, but consistently decreases after addition of radiotherapy.
Bianca A.W. Hoeben, MD Radboud University Medical Center, Department of Radiation Oncology 874, P. O. Box 9101, 6500 HB Nijmegen, The Netherlands, Tel. +31/24/361 45 15; Fax +31/24/361 07 92, E-mail: b.hoeben@radboudumc.nl.
B A W
BA
Hoeben
E G C
EG
Troost
J
J
Bussink
C M L
CM
van Herpen
W J G
WJ
Oyen
J H A M
JH
Kaanders
D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000628:therapy*; D000068818:Cetuximab; D059248:Chemoradiotherapy / Q000379:methods; D015224:Dideoxynucleosides; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D020266:Radiotherapy, Conformal / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000077195:Squamous Cell Carcinoma of Head and Neck; D016896:Treatment Outcome
D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D015224:Dideoxynucleosides; D019275:Radiopharmaceuticals; C002854:alovudine; D000068818:Cetuximab
[18F] fluorothymidine PET; cetuximab; early response monitoring; head and neck cancer; radiotherapy