Lung lesion doubling times: values and variability based on method of volume determination.

Purpose: To determine doubling times (DTs) of lung lesions based on volumetric measurements from thin-section CT imaging.

Methods: Previously untreated patients with > or = two thin-section CT scans showing a focal lung lesion were identified. Lesion volumes were derived using direct volume measurements and volume calculations based on lesion area and diameter. Growth rates (GRs) were compared by tissue diagnosis and measurement technique.

Results: 54 lesions were evaluated including 8 benign lesions, 10 metastases, 3 lymphomas, 15 adenocarcinomas, 11 squamous carcinomas, and 7 miscellaneous lung cancers. Using direct volume measurements, median DTs were 453, 111, 15, 181, 139 and 137 days, respectively. Lung cancer DTs ranged from 23-2239 days. There were no significant differences in GRs among the different lesion types. There was considerable variability among GRs using different volume determination methods.

Conclusions: Lung cancer doubling times showed a substantial range, and different volume determination methods gave considerably different DTs.