Central Nervous System
PV QA 2 - Poster Viewing Q&A 2
MO_3_2509 - Palliative Radiation Therapy for Vertebral Metastases and Metastatic Cord Compression in Patients Treated with anti-PD-1 Therapy
Monday, October 22
10:45 AM - 12:15 PM
Location: Innovation Hub, Exhibit Hall 3
Palliative Radiation Therapy for Vertebral Metastases and Metastatic Cord Compression in Patients Treated with anti-PD-1 Therapy
M. M. Fareed1, L. R. G. Pike2, A. Bang3, A. Taylor1, A. Spektor4, M. M. Awad5, P. Ott5, M. S. Krishnan4, T. A. Balboni1, and J. D. Schoenfeld1; 1Brigham and Women's Hospital and Dana-Farber Cancer Institute, Boston, MA, 2Harvard Radiation Oncology Program, Massachusetts General Hospital, Boston, MA, 3Department of Radiation Oncology, Princess Margaret Cancer Centre / University of Toronto, Toronto, ON, Canada, 4Brigham and Women's Hospital/Dana-Farber Cancer Institute, Boston, MA, 5Brigham and Women's Hospital and Dana-Farber/Harvard Cancer Center, Boston, MA
Purpose/Objective(s): There is increasing use of immune checkpoint blockade (ICB) across multiple cancer types, including in patients at risk for vertebral metastases and cord compression. These patients are often treated with palliative radiotherapy; however, data evaluating the combination of palliative radiation and ICB in patients with vertebral metastases is limited. Furthermore, patients with metastatic cord/cauda compression are generally excluded from prospective clinical trials. Therefore, we retrospectively evaluated outcomes following palliative radiation and PD-1 inhibition in patients with vertebral column metastases.
Materials/Methods: We performed a retrospective chart review of 37 consecutive patients treated with radiation for vertebral column metastases at 4 affiliated institutions who also received PD-1 inhibitor therapy. Patient, treatment and outcomes data were abstracted from the medical records.
Results: Histologies included non-small cell lung cancer (n=21), renal cell carcinoma (n= 9) and melanoma (n=7). A total of 57 lesions were irradiated, 18 involving >1 segments of the vertebral column as well as more isolated lesions in thoracic (16), lumbar (9), cervical (6) and sacral (8) vertebrae. Presenting symptoms included pain (19), numbness (10) and weakness (3). Eleven patients were asymptomatic. Radiologic cord compression was present in 12, epidural extension in 28, and compression fracture in 14. Eleven patients underwent surgical decompression prior to the onset of RT. Median radiation dose was 22.5 Gy (range 8 – 30 Gy). Stereotactic radiation was delivered in 4 patients; 33 patients received conformal RT. Twenty-one patients received PD-1 inhibition after RT, 9 before RT and 7 concurrent with RT. Radiation therapy was delivered within 30 days of immunotherapy in 17 patients. Two patients received intervening systemic therapy and two patients received concurrent CTLA-4 inhibitors with anti-PD-1 therapy.
Treatment was in general well tolerated; documented toxicities included fatigue (6), transient pain flare (1), nausea/vomiting (1) and G1 skin changes (1). All patients reported some degree of pain relief. Neurologic improvement was observed in 6 of 13 patients with baseline deficits (46%). The majority of patients (22 of 33 evaluable patients, 67%) had stability of irradiated lesions on subsequent follow up imaging performed at a median of 30 days from RT, whereas 3 had a complete local response and 4 had a partial local response. Disease progression within the RT field was seen in 4 patients.
Conclusion: We demonstrate that palliative radiation administered to vertebral metastases was well tolerated and effective in patients treated with PD-1 inhibitors. There was an encouraging rate of pain reduction and neurological improvement after treatment compared to historical series.
Author Disclosure: M.M. Fareed: None. L.R. Pike: None. A. Bang: None. A. Spektor: Employee; Boston University. Honoraria; Bayer Pharmaceuticals, Astellas Pharma, Inc. P. Ott: Research Grant; ARMO BioSciences, AstraZeneca/MedImmune, Bristol-Myers Squibb, Merck & Co., Inc, Celldex. Consultant; Alexion Pharmaceuticals, Amgen, Bristol-Myers Squibb, Celldex, CytomX Therapeutics, Genentech, Neon Therapeutics. M.S. Krishnan: None. T.A. Balboni: Employee; Dana-Farber Cancer Institute. Research Grant; Templeton Foundation. Steering Committee Member; ASCO Palliative Care Steering Committee Member. J.D. Schoenfeld: Research Grant; Merck, BMS. Consultant; Tilos. Advisory Board; Nanobiotix, AstraZeneca, Debiopharm, BMS. Travel Expenses; BMS. Translational PI; NCI Match Subprotocol Z1D.