Page 187 - 2020_11-Haematologica-web

Letters to the Editor
The role of 18F-FDG-PET in detecting Richter transformation of chronic lymphocytic leukemia in patients receiving therapy with a B-cell receptor inhibitor
Chronic lymphocytic leukemia (CLL) is a low grade B-cell malignancy. Approximately 2-10% of CLL can undergo Richter transformation (RT) to an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL).1-3 Management of RT is extremely challenging and the clinical outcome is dismal.4 In CLL
patients with suspected disease progression, distin- guishing between progressive CLL and RT is critically important, as the management and prognosis are dif- ferent.
While tissue biopsy is the gold standard for diagnosing progressive CLL versus RT, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) may play an impor- tant role in the diagnostic workup. In the chemoim- munotherapy (CIT) era, several studies showed that a maximum standardized uptake value (SUVmax) ≥5 had high sensitivity (88-91%) and varied specificity (47-80%) in detecting RT,5-7 and a French study8 reported high sen-
Table 1. Baseline characteristics at the time of B-cell receptor pathway inhibitors initiation.
Total (N=92)
68 (43-89)
23 (25.0%)
69 (75.0%)
90 (97.8%) 2 (2.2%)
13 (14.1%)
79 (85.9%)
14 (15.4%) 26 (28.6%) 51 (56.0%) 1
60 (80.0%) 15 (20.0%) 17
19 (27.5%) 16 (23.2%) 10 (14.5%) 12 (17.4%) 8 (11.6%) 4 (5.8%) 23
Without biopsy (N=38)
70 (47-89)
12 (31.6%)
26 (68.4%)
37 (97.4%) 1 (2.6%)
7 (18.4%)
31 (81.6%)
5 (13.2%) 8 (21.1%) 25 (65.8%) 0
25 (83.3%) 5 (16.7%) 8
8 (25.8%) 8 (25.8%) 4 (12.9%) 2 (6.5%) 6 (19.4%) 3 (9.7%) 7
23 (71.9%) 9 (28.1%) 6
6 (22.2%) 14 (51.9%) 7 (25.9%) 11
With biopsy P (N=54)
Age at BCRi initiation Median
Range
Sex
Female
Male BCRi
Ibrutinib
Idelalisib
BCRi as first-line treatment
Yes
No
Rai category
Rai 0: Low risk
Rai 1 or 2: Intermediate risk Rai 3 or 4: High risk
Missing
IGHV mutation Unmutated Mutated Missing
CLL FISH category Del(17p)
Del(11q) Trisomy 12 Normal Del(13q) Other Missing
67 (43-81)
11 (20.4%)
43 (79.6%)
53 (98.1%) 1 (1.9%)
6 (11.1%)
48 (88.9%)
9 (17.0%) 18 (34.0%) 26 (49.1%) 1
35 (77.8%) 10 (22.2%) 9
11 (28.9%) 8 (21.1%) 6 (15.8%) 10 (26.3%) 2 (5.3%) 1 (2.6%) 16
26 (68.4%) 12 (31.6%) 16
6 (18.2%) 17 (51.5%) 10 (30.3%) 21
0.36
0.22
0.80
0.32
0.27
0.56
0.13
0.75
0.90
TP53 disruption (TP53 mutation or FISH del(17p)
No
Yes Missing
CLL-IPI risk group Intermediate (2-3) High (4-6)
Very High (7-10)
Missing
49 (70.0%) 21 (30.0%) 22
12 (20.0%) 31 (51.7%) 17 (28.3%) 32
BCRi: B-cell receptor pathway inhibitor; IGHV: immunoglobulin heavy-chain variable region gene; CLL: chronic lymphocytic leukemia; FISH: fluorescence in situ hybridiza- tion; IPI: international prognostic index.
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