Main Session
Sep
28
PQA 04 - Breast Cancer, Patient Reported Outcomes/QoL/Survivorship, Functional Radiation Medicine, Hematologic Malignancies, Palliative Care, and International/Global Oncology
Presenter(s)
Shannon Jiang, MD - Washington University/B-JH/SLCH Consortium, St. Louis, MO
S. J. Jiang1, Z. D. Crees2, J. Huang1, J. Lee1, M. Schroeder2, M. Slade2, K. Stockerl-Goldstein2, M. A. Thomas1, R. Vij2, and J. C. Yang1; 1WashU Medicine, Department of Radiation Oncology, St. Louis, MO, 2WashU Medicine, Department of Internal Medicine, Division of Oncology, St. Louis, MO
Purpose/Objective(s):
Patients with multiple myeloma (MM) often need palliative radiation (RT) yet limited safety data on concurrent systemic therapy with RT (CCRT) in MM leads to unplanned treatment breaks to pursue RT due to concern for overlapping toxicities. We hypothesize that appropriately monitored palliative RT can be delivered safely without disrupting systemic therapy. We report institutional CCRT practices and outcomes.Materials/Methods:
All patients with MM seen for RT consult or follow up (2021-2024) at one institution were reviewed for prior palliative RT to MM bone lesions and assessed for CCRT (no systemic therapy break during RT) and reviewed for grade =3 serious adverse events (SAEs) within 90 days post-RT per CTCAE v5.0. Non-CCRT patients were assessed for reason and time off therapy.Results:
A total of 120 patients (median age 66, KPS 70, 49% female) received 231 RT courses. Common regimens were 20Gy/5-10fx or 30Gy/10-15fx. Most RT sites (85%) had active marrow: axial (pelvis, spine, sternum, rib, skull) or proximal long bone. Among CCRT courses (n=136, 59%), 54% were at disease relapse with median 1 prior line of therapy. In total 42 grade 3 SAEs occurred (31% of CCRT courses), 23 possibly RT-related (17% of CCRT courses): 12 neutropenia, 6 thrombocytopenia, 9 anemia, 1 colitis. For neutropenia, 11/12 had RT to active marrow (10 axial); agents included targeted [daratumumab (8% of drug exposures), lenalidomide (8%), bortezomib (9%), pomalidomide (10%), carfilzomib (7%)], cytotoxic chemotherapy (68%) and teclistimab (33%). For thrombocytopenia, 6/6 had RT to axial bone; agents included targeted [lenalidomide (7%), daratumumab (3%), bortezomib (4%), carfilzomib (7%)], cytotoxic chemotherapy (59%) and teclistimab (33%). For anemia, 9/9 had RT to active marrow (8 axial); agents included targeted [daratumumab (8%), lenalidomide (3%), bortezomib (6%), pomalidomide (5%), carfilzomib (7%)] and cytotoxic chemotherapy (55%). There was 1 case of colitis in a patient who received 6Gy/2fx to pelvis plus daratumumab, bortezomib, and lenalidomide. No grade 4 or 5 SAEs occurred, and no SAEs led to treatment discontinuation. Reasons for non-CCRT (n=94, 41%) were: not yet on therapy (34%), RT for isolated relapse (28%), pre-emptive hold for possible toxicity (14%; 9 for Bortezomib), hospitalized (10%), bridge to CAR-T or trial (7%), social barriers (6%), systemic therapy toxicity (2%). Treatment breaks delayed systemic therapy a median of 28 days. All had relapsed disease, more prior therapy (median 3 lines), more RT to active marrow (89%), younger age (median 59), similar KPS (median 70). Median delay of therapy due to hospitalization was 26 days.Conclusion:
Among this cohort, CCRT toxicities caused no unintended treatment breaks. Grade 3 SAEs were mainly hematologic. Given frequent need for palliative RT in MM, these data suggest it is reasonable to consider CCRT with close hematologic monitoring.