18F-fluoro-2-deoxy-D-glucose standardized uptake value in cavitating non-small-cell lung carcinoma

Cavitation in lung tumours has been considered as a specific clinical subentity related to worse prognosis and reduced survival. This study was performed to assess glycolysis as maximum standardized uptake value (SUVmax) on F-fluoro-2-deoxy-D-glucose PET imaging, a known prognostic factor in lung cancer and an index of tumour aggression in cavitated tumours.

Thirty-one patients with biopsy-proved, cavitated, non-small cell lung cancer (NSCLC) underwent PET/computed tomography staging scans. SUVmax readings were compared with those of 37 patients with solid NSCLC tumours but with similar staging. Maximum tumour diameters were recorded together with survival at 2 years.

Mean SUVmax, corrected for body weight, of the cavitated tumours was 14+/-6.8, compared with 13.5+/-10.8 for the solid tumours. No significant difference on paired t-tests was seen (P=0.83). The maximum diameter of the tumour was significantly greater (P<0.05) for the cavitated tumours (5.8+/-2.4 cm) than for solid tumours (4.4+/-2.4 cm). Six patients with cavitated tumours died at 2 years compared with 11 with solid tumours; no significant difference in survival (two-sided P value=0.48, Fisher's exact test) was observed between patients with cavitated tumours and those with solid tumours.

These findings do not support cavitation as a separate prognostic feature in NSCLC. Only tumour diameter was increased overall in the cavitated group. No increased glycolysis on PET/computed tomography imaging, relative to solid tumours, was seen and overall survival at 2 years seemed similar between the two groups.