Clinical & translational oncology : official publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico
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There are several potential advantages of using 18-fluor-fluorodeoxiglucose (18F-FDG) PET for target volume contouring, but before PET-based gross tumor volumes (GTVs) can reliably and reproducibly be incorporated into high-precision radiotherapy planning, operator-independent segmentation tools have to be developed and validated. The purpose of the present work was to apply the adaptive to the signal/background ratio (R(S/B)) thresholding method for head and neck tumor delineation, and compare these GTV(PET) to reference GTV(CT) volumes in order to assess discrepancies. ⋯ The present study highlights the considerable challenges involved in using FDG PET imaging for the delineation of GTV in head and neck neoplasms. The methods that rely mainly on SUV(max) for thresholding, as the RS/B method, are very sensitive to partial volume effects and may provide unreliable results when applied on small lesions.
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Angiogenesis and lymphangiogenesis are essential processes for the formation of blood and lymphatic vessels that allow tumour growth and spread. The binding of VEGF and VEGF-C factors with their receptors (VEGFR2, VEGFR3) in endothelial cells triggers signals that regulate these processes. We compared preoperative serum VEGF and VEGF-C levels with samples obtained after completion of surgery and adjuvant treatment in patients with gastric cancer. In addition, we determined the prognostic value and relationship to survival of serum VEGF and VEGF-C levels. ⋯ Serum VEGF levels decreased after the completion of treatment in patients with resected tumours, suggesting VEGF tracking may be useful in monitoring progression. Preoperative measurement of serum VEGF may help us identify patients with a poor prognosis.