VEGF-SPECT with ¹¹¹In-bevacizumab in stage III/IV melanoma patients
Wouter B Nagengast1, Marjolijn N Lub-de Hooge, Esther M E van Straten
1Department of Medical Oncology, University Medical Center Groningen, Hanzeplein 1, Postbus 30.001, 9700 RB Groningen, Netherlands.
Purpose:
A feasibility study was performed to investigate the presence of VEGF in melanoma lesions by VEGF-SPECT with (111)In-bevacizumab. In addition the effect of a single therapeutic bevacizumab dose on (111)In-bevacizumab uptake was compared with VEGF levels in resected melanoma lesions.
Patients And Methods:
Eligible were patients with stage III/IV melanoma who presented with nodal recurrent disease. VEGF-SPECT was performed after administration of 100 Mbq (111)In-bevacizumab (8 mg) at days 0, 2, 4 and 7 post injection. Tumour visualisation and quantification were compared with CT and FDG-PET. On day 7 a single dose of 7.5mg/kg bevacizumab was administered intravenously. On day 21, a second tracer dose (111)In-bevacizumab was administered and scans were obtained on days 21, 25 and 28. Metastases were surgically resected within 2 weeks after the last VEGF-SPECT scan and immunohistological (IHC) VEGF tumour expression was compared with (111)In-bevacizumab tumour uptake.
Results:
Nine patients were included. FDG-PET and CT detected both in total 12 nodal lesions which were all visualised by VEGF-SPECT. At baseline, (111)In-bevacizumab tumour uptake varied 3-fold between and 1.6 ± 0.1-fold within patients. After a therapeutic dose of bevacizumab there was a 21 ± 4% reduction in (111)In-bevacizumab uptake. The (111)In-bevacizumab tumour uptake in the second series positively correlated with the VEGF-A expression in the resected tumour lesions.
Conclusion:
VEGF-SPECT could visualise all known melanoma lesions. A single dose of bevacizumab slightly lowered (111)In-bevacizumab uptake. Future studies should elucidate the role of VEGF-SPECT in the selection of patients and the individual dosing of bevacizumab treatment.
