Radiological evaluation of oncologic treatment response: current update

Cancer Imaging

Table 1 Treatment response categories and tumor measurement techniques

Category	Bi-dimensional[5,6]	Uni-dimensional[8]	Volumetric[8]
	*Cross-product	Diameter	**Volume
CR	Tumor disappearance	Tumor disappearance	Tumor disappearance
PR	>50% reduction in cross-product	>30% reduction in diameter	>65% reduction in volume
SD	Size intermediate to that for partial response and that for progressive disease
DP	>25% increase in cross-product	>20% increase in diameter	>73% increase in volume

*Cross-product: the largest diameter and its maximum perpendicular diameter are multiplied to obtain cross-product. The individual cross-products are summed in patients with multiple lesions.
**Volume: volumetric measurement is obtained by multiplying the sum of areas from each slice with the reconstruction interval.

ISSN: 1470-7330