Imaging of tumour hypoxia and metabolism in patients with head and neck squamous cell carcinoma

van Elmpt, Wouter; J. P. Hoebers, Frank; G. C. Troost, Esther; M. Mottaghy, Felix; Lambin, Philippe; M. L. Zegers, Catharina; C. Öllers, Michel

doi:10.6084/m9.figshare.1580053.v1

1062913_suppl.pdf (338.18 kB)

Imaging of tumour hypoxia and metabolism in patients with head and neck squamous cell carcinoma

journal contribution

posted on 2015-10-20, 11:31 authored by Wouter van Elmpt, Frank J. P. Hoebers, Esther G. C. Troost, Felix M. Mottaghy, Philippe Lambin, Catharina M. L. Zegers, Michel C. Öllers

ABSTRACT

Background. Tumour hypoxia and a high tumour metabolism increase radioresistance in patients with head and neck squamous cell carcinoma (HNSCC). The aim of this study was to evaluate the correlation between hypoxia ([¹⁸F]HX4 PET) and glucose metabolism ([¹⁸F]FDG PET) molecular imaging.

Material and methods. [¹⁸F]HX4 and [¹⁸F]FDG PET/CT images of 20 HNSCC patients were acquired prior to (chemo)radiotherapy, in an immobilisation mask, with a median time interval of seven days (NCT01347281). Gross tumour volumes of the primary lesions (GTV_prim) and pathological lymph nodes (GTV_ln) were included in the analysis. [¹⁸F]FDG PET/CT images were rigidly registered to the [¹⁸F]HX4 PET/CT images. The maximum and mean standardised uptake values (SUV_max, SUV_mean) within both GTVs were determined. In addition, the overlap was compared between the [¹⁸F]HX4 high volume ([¹⁸F]HX4 HV) with a tumour-to-muscle ratio > 1.4 and the [¹⁸F]FDG high volume ([¹⁸F]FDG HV) with an SUV > 50% of the SUV_max. We report the mean± standard deviation.

Results. PET/CT scans including 20 GTV_prim and 12 GTV_lnwere analysed. There was a significant correlation between several [¹⁸F]FDG and [¹⁸F]HX4 parameters, the most pronounced being the correlation between [¹⁸F]FDG HV and [¹⁸F]HX4 HV (R = 0.93, p < 0.001). The fraction of the GTV_prim with a high HX4 uptake (9 ± 10%) was on average smaller than the FDG high fraction (51 ± 26%; p < 0.001). In 65% (13/20) of the patients, the GTV_prim was hypoxic. In four of these patients the [¹⁸F]HX4 HV was located within the [¹⁸F]FDG HV, whereas for the remaining nine GTV_prim a partial mismatch was observed. In these nine tumours 25 ± 21% (range 5–64%) of the HX4 HV was located outside the FDG HV.

Conclusions. There is a correlation between [¹⁸F]HX4 and [¹⁸F]FDG uptake parameters on a global tumour level. In the majority of lesions a partial mismatch between the [¹⁸F]HX4 and [¹⁸F]FDG high uptake volumes was observed, therefore [¹⁸F]FDG PET imaging cannot be used as a surrogate for hypoxia. [¹⁸F]HX4 PET provides complementary information to [¹⁸F]FDG PET imaging.