ABSTRACT
Category: Outcomes of treatment (including chemotherapy, chemo-RT and RT) Purpose: Hypofractionated (5#) radiotherapy for non-metastatic pancreatic cancer was introduced during the COVID-19 pandemic as an alternative to conventional treatment pathways. This study was performed to evaluate clinical outcomes and acute toxicity of 5# radiotherapy. Methods and materials: We retrospectively identified pancreatic cancer patients treated with 5# radiotherapy at Addenbrookes Hospital from March 2020 to September 2021. Patient characteristics, response on follow-up computed tomography (CT) scans, dosimetry and toxicity data were analysed using Excel and SPSS. Result(s): 40 patients were treated with 5# radiotherapy, 60% (n=24) had locally advanced pancreatic cancer, 30% (n=12) operable disease, 7.5% (n=3) postoperative recurrences and 2.5% (n=1) borderline resectable disease. 45% of patients (n=19) had induction chemotherapy. Radiotherapy was delivered as 35 Gy (67.5%, n= 27) and 30 Gy (32.5%, n=13) in 5# in 1.5 weeks using volumetric-modulated arc therapy (VMAT) technique. Median overall survival (mOS) for all patients was 14.2 months (95% CI 10.3-15.6 months). For induction chemotherapy + radiotherapy versus radiotherapy alone, mOS was 14.2 months (95% CI 8.2-17.7 months) versus 13.9 months (95% CI 10.3-15.7 months), p=0.97. Median progression-free survival (mPFS) for all patients was 10.2 months (95% CI 8.0-11.9 months). For induction chemotherapy + radiotherapy versus radiotherapy alone, mPFS was 10.5 months (95% CI 9.5-12.4 months) versus 10.1 months (95% CI 5.5-10.4 months), p=0.99. There were no grade 3 acute toxicities. When compared to 28# radiotherapy, the 5# regimen reduced patient hospital visits by 82%. Conclusion(s): The observed mOS is comparable with mOS of conventional 28# radiotherapy (14.2 versus 15.2 months (SCALOP trial)), 5# radiotherapy for non-metastatic pancreatic cancer is a safe alternative treatment pathway. Copyright © 2022
ABSTRACT
Purpose or Objective CD19 CAR-T therapy is the most effective salvage treatment for relapsed/refractory DLBCL. However the manufacture of CAR-T cells takes several weeks and patients (pts) are at risk of progression during this time and usually require some form of bridging therapy to contain their disease. Radiotherapy (RT) is an attractive bridging option, as the chance of response to further conventional cytotoxic therapy is low. RT is generally delivered in the window between apheresis and infusion and requires careful scheduling. The aim of this study is to evaluate the feasibility, toxicity and early outcome of bridging RT in a cohort of pts undergoing CAR-T therapy for DLBCL. Materials and Methods This was a prospective analysis of pts receiving bridging RT since the start of CAR-T programme at our institution. We collected data on pt demographics, disease and RT details, as well as outcomes including early response, relapse, survival and toxicity. Results (Table presented.) Between April 2019 & January 2021 a total of 27 pts have received bridging RT. Of these 23 have been infused (1 not infused due to COVID19, 1 due to cardiac function & 2 pending). The CAR-T therapy was delivered in 1 Haematology Institution, but bridging RT in 9 different referring centres. Pt and disease characteristics and RT details are shown in table 1. The median time from CT planning scan to start of RT was 10 days (4-42). The median time between apheresis and start of RT was 5 days (-37-21;3 patients received RT prior to apheresis at -37,-35 &-29 days) and median time between end of RT and CAR-T infusion was 19 days (10-116). No pts were delayed due to RT toxicity. Toxicity data was available for 22 pts. 10 (45.5%) reported no toxicity. Only 1 pt had grade 3 toxicity (vomiting & diarrhoea) and RT was stopped. The most common toxicities were skin reaction (n=5) & fatigue (n=4). 25/27 (92.6%) pts underwent a PET-CT between bridging RT & infusion. In 22 (88%) pts there was response in treatment field (CMR=2, PMR=20). In 13 (59.1%) of those pts there was evidence of progressive disease (PD) outside the field, but none were prevented from receiving CAR-T infusion due to PD. With median FU of 8.8 (0.6-20.6) months from date of CAR-T infusion, 12/ 23 (52.2%) infused pts have relapsed, (2 infield, 5 out of field, 5 in both) with a local control rate of 69.6%;CMR (12;52.2%) and PMR (4;17.4%). 7 pts have died since infusion, 6 due to PD and 1 due to sepsis. Median PFS was 5.1 months (95% CI 0.0-11.9 months) and median OS 17.8 months (95% CI 12.7-22.9 months). 1 pt had infusion delayed due to COVID19 infection and died of PD. Conclusion RT was a safe and effective bridging option in this cohort of DLBCL pts pre CAR-T therapy. With close collaboration between Haematologists and Radiation Oncologists, it is possible to deliver a course of radical dose RT in the narrow window between apheresis and infusion, even across a wide geographical network. Further work is required to determine which pts benefit most from bridging RT and the optimal dose and schedule.