Textural features of hypoxia PET predict survival in head and neck cancer during chemoradiotherapy

• Published in: European journal of nuclear medicine and molecular imaging Vol. 47; no. 5; pp. 1056 - 1064
• Main Authors: Sörensen, A., Carles, M., Bunea, H., Majerus, L., Stoykow, C., Nicolay, N. H., Wiedenmann, N. E., Vaupel, P., Meyer, P. T., Grosu, A. L., Mix, M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2020; Springer Nature B.V
• Subjects: Cancer; Cardiology; Chemoradiotherapy; Chemotherapy; Coefficient of variation; Correlation; Evaluation; Fluorodeoxyglucose F18; Head & neck cancer; Head and Neck Neoplasms - diagnostic imaging; Head and Neck Neoplasms - therapy; Homogeneity; Humans; Hypoxia; Imaging; Mathematical analysis; Medicine; Medicine & Public Health; Nonuniformity; Nuclear Medicine; Oncology; Oncology – Head and Neck; Original Article; Orthopedics; Positron emission; Positron-Emission Tomography; Prospective Studies; Radiation therapy; Radiology; Rank tests; Squamous cell carcinoma; Survival; Tomography; Tumors; FMISO; FDG; Hypoxia; CRT; HNSCC; Radiomics
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-019-04609-9

Purpose
The aim of this study was to investigate whether textural features of tumour hypoxia, assessed with serial [
18
F]fluoromisonidazole (FMISO)-PET, were able to predict clinical outcome in patients with head and neck squamous cell carcinoma (HNSCC, T1-4, N+, M0) during chemoradiotherapy (CRT).
Methods
In a preliminary evaluation of a prospective trial, tumour hypoxia was evaluated in 29 patients via serial FMISO-PET before and during CRT. All patients received an initial [
18
F]fluorodeoxyglucose (FDG)-PET before CRT, and tumour regions were defined on this FDG-PET. The first-order metrics tumour-to-background ratio (TBR
mean
, TBR
max
, TBR
peak
), coefficient of variation, total lesion uptake and integral non-uniformity were calculated for all scans. Further, 3 second-order (textural) features from two grey-level matrices were calculated, as well as differential non-uniformity (
u
diff
). Prognostic value was examined by median split for group separation (GS) in Kaplan-Meier estimates and correlated with overall survival (OS), quantified via log-rank tests (
p
≤ 0.05) and group-relative hazard ratios (HR).
Results
Within a median follow-up of 29.6 months (95% CI: 16.8–48.0 months), no first-order metrics predicted OS with a significant GS (all
p
> 0.05) on any FMISO-PET scan. Only
u
diff
before and in week 2 during CRT (
p
= 0.03, HR = 10.8 and
p
= 0.05, HR = 5.2) and non-uniformity from grey-level run length matrix in week 2 separated prognostic groups (
p
= 0.05, HR = 5.3); lower values were correlated with better OS. Further, the decrease in
u
diff
from before CRT to week 2 was correlated with better OS (
p
= 0.04, HR = 9.4). FDG-PET before CRT did not predict outcome in any measure.
Conclusions
Textural features on FMISO-PET scans before CRT, in week 2 and, to a limited degree, the change of features during CRT, were able to identify head and neck squamous cell carcinoma patients with better OS, suggesting that a higher homogeneity of the degree of hypoxia in tumours could correlate with a better outcome after CRT.