Page 105 - Haematologica August 2018

Serial FDG-PET Imaging in PMBCL
Changes in MTV and TLG across serial FDG-PET scans generally mimicked that of SUVmax with greater variability in value between patients within each EOT FDG-PET sub- group [Online Supplementary Figures S2-3].
Discussion
These extended results from our initial study4 show that DA-EPOCH-R in untreated PMBCL patients results in an 8- year EFS and OS of 90.6% and 94.7%, respectively, while obviating the need for radiotherapy in all but 5 (5%) patients. In contrast, retrospective studies suggest R-CHOP alone is inadequate for many PMBCL patients due to an unacceptable rate of primary induction failure up to 21% in one series,9 necessitating the frequent use of post-treatment radiotherapy, as part of combined modality treatment.5- 10,15,19,21 A recent multicenter, retrospective study comparing
R-CHOP to DA-EPOCH-R as front-line therapy for PMBCL showed no significant difference in 2-year PFS or OS between the two treatments; however, this was achieved through significantly greater radiotherapy use with R- CHOP (59% vs. 13%, P<0.001).28 Although excellent out- comes can be achieved via combined modality treatment, routine mediastinal radiotherapy use significantly increases the risk of late toxicity, including premature death from car- diovascular disease and second cancers.11-14 Unfortunately, due to the absence of prospective studies of R-CHOP in PMBCL, an accurate assessment cannot be made of its cur- ative potential and who requires post-treatment radiother- apy. Nonetheless, it is presently accepted that patients with a positive EOT FDG-PET scan following R-CHOP require consolidation radiotherapy, and it remains uncertain if patients with a negative EOT FDG-PET benefit from radio- therapy, which is the endpoint of the IELSG-37 phase III randomized study (clinicaltrials.gov identifier 01599559).
A Event-free Survival (Deauville 1-3 vs. 4-5)
P=0.0010
C Event-free Survival (Deauville 1-4 vs. 5)
P=0.0003
B Overall Survival (Deauville 1-3 vs. 4-5)
P=0.0115
D Overall Survival (Deauville 1-4 vs. 5)
P=0.029
Figure 2. Kaplan–Meier estimates of event-free and overall survival by Deauville group. Event-free survival and overall survival according to EOT FDG-PET Deauville group. (A). Event-free survival 96.0% (95% CI, 84.8-99.0) vs. 71.1% (95% CI, 43.6-86.9) (P=0.0010) for Deauville 1-3 (blue curve) and Deauville 4-5 (red curve), respectively, at 8-years. (B). Overall survival 97.7% (95% CI, 84.6-99.7) vs. 84.3% (95% CI, 56.5-95.0) (P=0.0115) for Deauville 1-3 (blue curve) and Deauville 4-5 (red curve), respectively, at 8-years. (C). Event-free survival 93.3% (95% CI, 82.8-97.5) vs. 50.0% (95% CI, 15.2-77.5) (P=0.0003) for Deauville 1-4 (blue curve) and Deauville 5 (red curve), respectively, at 8-years. (D). Overall survival 95.9% (95% CI, 84.5-99.0) vs. 75.0% (95% CI, 31.5-93.1) (P=0.029) for Deauville 1-4 (blue curve) and Deauville 5 (red curve), respectively, at 8-years.
Table 2. EOT FDG-PET Response Following DA-EPOCH-R Therapy. Lymphoma Status
(N=80 total with EOT FDG-PET)
No treatment failure- no. patients
Treatment failure- no. patients
Deauville Score 12345
Negative (55/80, 69%)
Positive (25/80, 31%)
(30%) (24%)
24* 18
0 1
(15%) (21%)
(10%)
12 16* 4
0 1 4
*Indicates 1 patient death without evidence of disease recurrence; EOT FDG-PET end-of-treatment 18F-fluorodeoxyglucose-positron-emission tomography.
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