FAZA PET/CT hypoxia imaging in patients with squamous cell carcinoma of the head and neck treated with radiotherapy: results from the DAHANCA 24 trial.
OBJECTIVE
Hypoxia is a cause of resistance to radiotherapy, especially in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to evaluate (18)F-fluoroazomycin arabinoside (FAZA) positron emission tomography (PET)/computed tomography (CT) hypoxia imaging as a prognostic factor in HNSCC patients receiving radiotherapy.


METHODS
Forty patients with HNSCC treated with radiotherapy (66-76 Gy) were included. Static FAZA PET/CT imaging 2h post injection was conducted prior to irradiation. The hypoxic volume (HV) was delineated using a tumor-to-muscle value ≥ 1.4. In 13 patients, a repetitive FAZA PET/CT scan was conducted during the radiotherapy treatment.


RESULTS
A hypoxic volume could be identified in 25 (63%) of the 40 tumors. FAZA PET HV varied considerably with a range from 0.0 to 30.9 (median: 0.3) cm(3). The T(max)/M(med) ranged from 1.1 to 2.9 (median: 1.5). The distribution of hypoxia among the Human Papillomavirus (HPV) positive (12/16) and negative (13/24) tumors was not significant different. In the FAZA PET/CT scans performed during radiotherapy, hypoxia could be detected in six of the 13 patients. For these six patients the location of HV remained stable in location during radiotherapy treatment, though the size of the HV decreased. In 30 patients a positive correlation was detected between maximum FAZA uptake in the primary tumor and the lymph node. During a median follow up of 19 months a significant difference in disease free survival rate with 93% for patients with non hypoxic tumors and 60% for patients with hypoxic tumors could be detected.


CONCLUSIONS
This study emphasizes the role of FAZA PET/CT imaging as a suitable assay with prognostic potential for detection of hypoxia in HNSCC.
Aarhus University Hospital, Denmark. lsm@oncology.dk
Lise Saksø
LS
Mortensen
Jørgen
J
Johansen
Jesper
J
Kallehauge
Hanne
H
Primdahl
Morten
M
Busk
Pernille
P
Lassen
Jan
J
Alsner
Brita S
BS
Sørensen
Kasper
K
Toustrup
Steen
S
Jakobsen
Jørgen
J
Petersen
Henrik
H
Petersen
Jørn
J
Theil
Marianne
M
Nordsmark
Jens
J
Overgaard
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000401:mortality / Q000532:radiotherapy*; D015687:Cell Hypoxia / Q000502:physiology*; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009593:Nitroimidazoles; D049268:Positron-Emission Tomography; D011379:Prognosis; D014057:Tomography, X-Ray Computed
D009593:Nitroimidazoles; C498052:fluoroazomycin arabinoside