Open AccessUtility of positron emission tomography-computed tomography in patients with chronic lymphocytic leukemia following B-cell receptor pathway inhibitor therapy
Author(s) -
Anthony R. Mato,
William G. Wierda,
Matthew S. Davids,
Bruce D. Cheson,
Steven Coutre,
Michael Y. Choi,
Richard R. Furman,
Leonard T. Heffner,
Paul M. Barr,
Herbert Eradat,
S Ford,
Lang Zhou,
Maria Verdugo,
Rod A. Humerickhouse,
Jalaja Potluri,
John C. Byrd
Publication year - 2019
Publication title -
haematologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.782
H-Index - 142
eISSN - 1592-8721
pISSN - 0390-6078
DOI - 10.3324/haematol.2018.207068
Subject(s) - venetoclax , medicine , positron emission tomography , ibrutinib , chemoimmunotherapy , chronic lymphocytic leukemia , biopsy , nuclear medicine , standardized uptake value , lymphoma , leukemia
The utility of positron emission tomography-computed tomography (PET-CT) in distinguishing Richter's transformation versus chronic lymphocytic leukemia (CLL) progression after ibrutinib and/or idelalisib was assessed in a post hoc analysis of a phase II study of venetoclax. Patients underwent PET-CT at screening and were not enrolled/treated if Richter's transformation was confirmed pathologically. Of 167 patients screened, 57 met criteria for biopsy after PET-CT. Of 35 patients who underwent biopsy, eight had Richter's transformation, two had another malignancy, and 25 had CLL. A PET-CT maximum standardized uptake value (SUVmax) ≥10 had 71% sensitivity and 50% specificity for detecting Richter's transformation [Odds Ratio (OR): 2.5, 95%CI: 0.4-15; P =0.318]. Response rate to venetoclax was similar for screening SUVmax <10 versus ≥10 (65% vs. 62%) (n=127 enrolled), though median progression-free survival was longer at <10 months (24.7 vs. 15.4 months; P =0.0335). Six patients developed Richter's transformation on venetoclax, of whom two had screening biopsy demonstrating CLL (others did not have a biopsy) and five had screening SUVmax <10. We have defined the test characteristics for PET-CT to distinguish progression of CLL as compared to Richter's transformation when biopsied in patients treated with B-cell receptor signaling pathway inhibitors. Overall diminished sensitivity and specificity as compared to prior reports of patients treated with chemotherapy/chemoimmunotherapy suggest it has diminished ability to discriminate these two diagnoses using a SUVmax ≥10 cutoff. This cutoff did not identify venetoclax-treated patients with an inferior response but may be predictive of inferior progression-free survival. (Registered at clinicaltrials.gov identifier: 02141282 ).