Clinical efficacy of irradiation in CLL patients: predictive value of in vitro radio-induced apoptosis.
In order to identify CLL patients for whom irradiation could be beneficial, we investigated the relationship between in vitro radio-induced apoptosis of leukemic cells and response to low-dose splenic or lymph node radiotherapy. Fourteen patients were included in the in vitro study. Leukemic cells were analyzed by Hoechst staining immediately after collection or 24h of culture following in vitro irradiation of 0-10 Gy. The tumor response rate was 47% (one CR and six PR), with a mean duration of response of 3 months (range: 1-4). A high correlation between tumor response and in vitro tests was observed (p < 0.01) and the positive predictive value of the in vitro tests for tumor and hematological responses was 100% at 5 Gy. These results suggest that the sensitivity of leukemic cells to irradiation should be first evaluated in an in vitro assay to spare refractory patients from the useless toxicity radiotherapy.
Decaudin
Didier
D
Service d'Hématologie, Institut Curie, Paris, France. didier.decaudin@curie.net
Delic
Jozo
J
Dumont
Janine
J
Tertian
Gérard
G
Blot
Emmanuel
E
Dubray
Bernard
B
Grandpeix
Catherine
C
Peffault de Latour
Régis
R
Cosset
Jean-Marc
JM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis / Q000528:radiation effects*; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged