Feasibility and repeatability of PET with the hypoxia tracer [18F]HX4 in oesophageal and pancreatic cancer. Issue 1 (July 2015) - Klaassen, Remy
Abstract Background and purpose To investigate the feasibility and to determine the repeatability of recurrent [18F]HX4 PET scans in patients with oesophageal (EC) and pancreatic (PC) cancer. Materials and methods 32 patients were scanned in total; seven patients (4 EC/3 PC) were scanned 2, 3 and 4 h post injection (PI) of [18F]HX4 and 25 patients (15 EC/10 PC) were scanned twice 3.5 h PI, on two separate days (median 4, range 1–9 days). Maximum tumour to background ratio (TBRmax) and the tumour hypoxic volume (HV) (TBR > 1.0) were calculated. Repeatability was assessed using Bland–Altman analysis. Agreement in localization was calculated as the distance between the centres of mass in the HVs. Results For EC, the TBRmax in the tumour (mean ± SD) was 1.87 ± 0.46 with a coefficient of repeatability (CoR) of 0.53 (28% of mean). The HV ranged from 3.4 to 98.8 ml with a CoR of 5.1 ml. For PC, the TBRmax was 1.72 ± 0.23 with a CoR of 0.27 (16% of mean). The HV ranged from 4.6 to 104.0 ml with a CoR of 7.8 ml. The distance between the centres of mass in the HV was 2.2 ± 1.3 mm for EC and 2.1 ± 1.5 mm for PC. Conclusions PET scanning with [18F]HX4 was feasible in both EC and PC patients. Amount and location of elevated [18F]HX4 uptake showed good repeatability, suggesting [18F]HX4 PET could be a promising tool for radiation therapy planning and treatment response monitoring in EC and PC patients.