Evaluation of the GELTAMO guidelines for surveillance in follicular lymphomas after first‐line immunochemotherapy: a real‐world prospective study

Abstract

Introduction: CT scans have been traditionally recommended in the surveillance of patients (pts) with follicular lymphoma (FL) by international societies. In asymptomatic FL pts responding to first line (1L) immunochemotherapy, the Spanish GELTAMO FL guidelines recommends CT scan every 6 months for 2 years (during rituximab maintenance). The real value of surveillance with CT scans remains an open question, even more after the incorporation of PET in the response evaluation of FL. Our aim was to evaluate the detection rate of relapses by CT surveillance according to GELTAMO guidelines in FL pts with complete metabolic response (CMR) or partial metabolic response (PMR). Methods: observational prospective study in a single center between 2008 and 2020. Newly diagnosed FL who had CMR or PMR to 1L therapy were identified. Evaluation for both relapse and method of relapse detection, having special interest in the CT surveillance according to GELTAMO guidelines. Results: From 108 FL treated pts, 81 were included in the final analysis. Median age and female proportion were 59 years (range 24–83) and 49.4%. Treatment: R-CHOP/R-CHOP-like 63%, R-CVP 15% and rituximab 22%. Response: CMR 82%, PMR 18%. Median follow-up was 79.7 months (IQR 57.8–117.3). A total of 29 pts relapsed or progressed (35.8%) during the whole study period: 24 from CMR and 5 from PMR. Of these pts, 9 relapsed in the first 2-y (31.0% of all relapses and 11.1% of all patients) and were more common in pts in PMR versus CMR (60% vs. 25%, p = 0.1238). Relapse detection method in the first 2-y was: 5 (55.5%) by CT scan, 2 by physical examination and 2 by other methods. Beyond 2-y, 12 (60%) were detected by physical examination, 5 (25%) by CT scan, 2 (10%) by blood tests and 1 (5%) by ultrasound echography. Protocol adherence was 75.3%. A total of 262 CTs were performed in first 2-y with only 5 positive CT scans in this time-lapse (diagnostic yield 2%). Globally, 17.2% of all relapses were diagnosed by GELTAMO recommended surveillance CT scans. Time from first relapse to second line treatment was 4.02 months in those with relapse detected by CT in schedule versus 2.03 months in those detected by other methods (p = 0.81) (Figure 1A). In relapsed pts, OS at 3-y from relapse was 30.0 months in those with relapse detected by CT in schedule versus 66.2 months in the other patients (p = 0.077) (Figure 1B), probably because of the enrichment of POD24 cases in the first group. However, OS at 3-y from relapse in those patients in which relapse was detected by CT at any time (in or out schedule) was 43.8 months versus 66.9 months in those detecting relapse by other methods (p = 0.19). Keywords: Imaging and Early Detection, Indolent non-Hodgkin lymphoma, PET-CT No conflicts of interests pertinent to the abstract.