“Early PET/CT might predict salvage chemotherapy failure and will inform future medical trials investigating early remedy change to nonchemotherapy therapies,” authors of the examine wrote.
Investigators performed PET/CT scans on days 4 (D4) and 21 (D21) of cycle 1 of salvage remedy. They wished to check the worth of early prognostic analysis within the relapsed/refractory (R/R) setting. “We hypothesized that early PET/CT scans might determine refractoriness to salvage chemotherapy,” they wrote.
R/R DLBCL Salvage Remedy
Sufferers with R/R DLBCL following frontline remedy have a poor prognosis of median general survival of lower than 1 yr. The usual salvage remedy is platinum-based chemotherapy, after which sufferers are chosen for high-dose chemotherapy and autologous stem cell transplant (ASCT).
The platinum-based therapies mostly used are rituximab, ifosfamide, carboplatin, and etoposide (R-ICE) and rituximab, dexamethasone, cytarabine, and cisplatin (R-DHAP).
The outcomes for sufferers on these therapies have been related within the CORAL randomized examine, with a 63% response price, 50% ASCT price, and 53% 3-year progression-free survival price in sufferers who continued to transplantation.
Primarily based on these numbers, simply half of sufferers who obtain R-ICE or R-DHAP will likely be eligible for ASCT, and half of these will expertise relapse following ASCT and chemotherapy.
An choice for affected person refractoriness to salvage platinum chemotherapy and lack of suitability for ASCT is anti-CD19 chimeric antigen receptor T-cell remedy, which is related to long-term remissions in as much as half of sufferers.
Methodology and Findings
Investigators mentioned theirs was the primary examine to make the most of PET/CT scans for early prognostic analysis within the R/R setting.
They outlined a response to salvage remedy as a delta SUVmax cutoff of > 50%, which is decrease than the usual 66% cutoff for analysis after 2 cycles of frontline remedy. On this examine, investigators used the extra conservative threshold as a result of PET/CT scans have been performed after simply 1 cycle of salvage remedy.
Early remedy failure and development have been the explanations for remedy adjustments for the ten sufferers who underwent PET/CT scans following cycle 1 of salvage remedy. Twelve (48%) sufferers acquired a second cycle of the identical remedy, and three (8%) have been switched to supportive care.
Investigators mentioned 16 (64%) sufferers have been evaluable for EOT response by PET/CT; of these, 9 (56%) achieved EOT response and seven (44%) didn’t.
Twenty-four sufferers had a PET/CT scan on D4 and 22 on D21. Response was famous in 14 (58% of sufferers on D4 and delta SUVmax was > 50% for 10 (43%).
Amongst sufferers who acquired PET/CT on D21, 7 (32%) had a response and 5 (24%) had a delta SUVmax of > 50%.
“We recognized that early PET/CTs on D4 and D21 can reveal early illness development and/or remedy failure in the course of the first cycle, prompting unplanned change of remedy…and discontinuation of remedy,” investigators concluded.
Early PET/CT response “was not related to EOT response,” however “a persistent response on D4 and D21 was predictive of wonderful long-term illness particular survival,” they mentioned. “This implies that general chemosensitivity may be decided throughout cycle 1 of platinum containing chemotherapy.”
Conversely, sufferers who didn’t obtain a response by D4 or D21 “had considerably worse survival outcomes,” authors wrote.
Cherng HJ, Chuang HH, Steiner R, et al. A potential examine on early PET/CT scans in the course of the first cycle of salvage chemotherapy for relapsed or refractory diffuse giant B-cell lymphoma. J Leuk lymphoma. Revealed on-line August 26, 2021. doi:10.1080/10428194.2021.1971223