Tumor long-axis diameter and SUVmax predict long-term responders in 90Y-ibritumomab tiuxetan monotherapy

Abstract

90Y-ibritumomab tiuxetan (90Y-IT) is widely used, but the factors responsible for its optimal treatment effects are unknown. We enrolled 34 patients with relapsed indolent lymphoma treated with 90Y-IT monotherapy at Gunma University Hospital between 2003 and 2014 in the present study. Clinical data including computed tomography and 18-Fluoro-deoxyglucose positron emission tomography were retrospectively analyzed. The overall response rate and complete response rate were 91% and 82%, respectively. The median progression-free survival (PFS) and overall survival were 32 months and not reached, respectively. In univariate analysis, tumor long-axis diameter ≤ 2.5 cm, maximum standardized uptake value (SUVmax) ≤ 6.5, localized disease, normal levels of serum soluble interleukin-2 receptor, and the number of involved nodal sites ≤ 3 immediately prior to 90Y-IT were associated with median PFS greater than 6 years. However, in multivariate analysis, only tumor long-axis diameter ≤ 2.5 cm and SUVmax ≤ 6.5 affected PFS [hazard ratio (HR) 0.130, P = 0.0021 and HR 0.283, P = 0.0311, respectively]. Patients with only one prior regimen needed less granulocyte colony-stimulating factor and platelet transfusion. Thus, 90Y-IT treatment should be considered for patients with indolent lymphoma in first relapse who have tumor long-axis diameter ≤ 2.5 cm and SUVmax ≤ 6.5.

The standardized uptake value calculated from ¹¹¹In-ibritumomab tiuxetan single-photon emission computed tomography/computed tomography is a useful predictor of the clinical response in patients treated by ⁹⁰Y- ibritumomab tiuxetan therapy

“…In previous studies of relapsed refractory low-grade B-cell lymphoma, the ORR and CRR of 90 Y-IT therapy were 73-91% and 30-82%, respectively, [2][3][4][5][6] whereas in our study, the ORR and CRR were 56% and 25%, respectively. As a reason for the low response, our study included more patients with a poor prognosis than previous studies because the median age of the patients was higher, the number of patients with a high LDH was higher, and half of the patients had a high FLIPI.…”

“…Tsukamoto et al reported that the FDG-SUVmax was an independent prognostic factor. 6 In comparison, our study enrolled a smaller number of patients and their observation period was short. In addition, we were unable to unify the interval between 18 F-FDG PET/CT and 90 Y-IT therapy due to the retrospective nature of our study.…”

“…Previous studies reported the tumor diameter as a prognostic factor. 4,6 To evaluate the prognostic power of IT-SUVmax, the tumor diameter should be incorporated into the analysis in combination with the IT-SUVmax data. In our study, there were two patients with a large tumor diameter and low IT-SUVmax, and they had the most favorable course among our patients; however, no further analysis was possible.…”

“…[1][2][3] Although 90 Y-IT therapy can be safely applied to the elderly or patients with severe complications, there are some cases in which the therapeutic effects are insufficient. Several predictors of insufficient therapeutic effects have been reported, [4][5][6] including tumor diameter and number, clinical stage, number of previous treatment regimens, and maximum standardized uptake value (SUVmax) calculated from 2-deoxy-2-[F-18]fluoro-Dglucose (FDG) positron emission tomography-computed tomography (PET/CT). 111 In-IT scintigraphy is performed to exclude patients who are not eligible for 90 Y-IT treatment in whom a higher bone marrow accumulation of 90 Y-IT can be expected, followed by severe pancytopenia.…”

Prognostic Value of Heterogeneity Index Derived from Baseline 18F-FDG PET/CT in Mantle Cell Lymphoma

“…Tsukamoto et al. stated that SUV max ≤ 6.5 had significant correlation with PFS in patients with relapsed indolent lymphoma treated with 90 Y-ibritumomab tiuxetan ( 34 ). Feng et al.…”