Heterogeneity of intratumoral 111In-ibritumomab tiuxetan and 18F-FDG distribution in association with therapeutic response in radioimmunotherapy for B-cell non-Hodgkin’s lymphoma

摘要

Background The purpose of this study was to quantitatively evaluate the tumor accumulation and heterogeneity of~(111)In-ibritumomab tiuxetan (Zevalin?) and tumor accumulation of~(18)F-fluoro-deoxyglucose (FDG) and compare them to the tumor response in B-cell non-Hodgkin’s lymphoma patients receiving~(90)Y-ibritumomab tiuxetan (Zevalin?) therapy. Methods Sixteen patients with histologically confirmed non-Hodgkin’s B-cell lymphoma who underwent~(90)Y-ibritumomab tiuxetan therapy along with~(111)In-ibritumomab tiuxetan single-photon emission computerized tomography (SPECT)/CT and FDG positron emission tomography (PET)/CT were enrolled in this retrospective study. On pretherapeutic FDG PET/CT images, the maximum standardized uptake value (SUVmax) was measured. On SPECT/CT images, a percentage of the injected dose per gram (%ID/g) and SUVmax of~(111)In-ibritumomab tiuxetan were measured at 48?h after its administration. The skewness and kurtosis of the voxel distribution were calculated to evaluate the intratumoral heterogeneity of tumor accumulation. As another intratumoral heterogeneity index, cumulative SUV-volume histograms describing the percentage of the total tumor volume above the percentage thresholds of pretherapeutic FDG and~(111)In-ibritumomab tiuxetan SUVmax (area under the curve of the cumulative SUV histograms (AUC-CSH)) were calculated. All lesions ( n ?=?42) were classified into responders and non-responders lesion-by-lesion on pre- and post-therapeutic CT images. Results A positive correlation was observed between the FDG SUVmax and accumulation of~(111)In-ibritumomab tiuxetan in lesions. A significant difference in pretherapeutic FDG SUVmax was observed between responders and non-responders, while no significant difference in~(111)In-ibritumomab tiuxetan SUVmax was observed between the two groups. In contrast, voxel distribution of FDG demonstrated no significant differences in the three heterogeneity indices between responders and non-responders, while~(111)In-ibritumomab tiuxetan demonstrated skewness of 0.58?±?0.16 and 0.73?±?0.24 ( p ?