CHICAGO — Treating ventricular tachycardia (VT) with a single, high dose of radiotherapy led to immediate and long-term reductions in episodes of rapid, abnormal heartbeats, a phase I/II trial found.
Among 18 evaluable patients in ENCORE-VT, 94% had reductions in their VT episodes — as recorded by implantable cardiac defibrillator (ICDs) — in the 6 months following electrophysiology-guided radioablation compared with the 6-month period prior to treatment, reported Clifford Robinson, MD, of Washington University School of Medicine in St. Louis, Missouri.
And 78% had fewer VT episodes across a 2-year span compared to that same 6-month period prior to treatment, which took about 15 minutes on average.
“We were able to significantly reduce VT using a workflow combining noninvasive imaging with a noninvasive single treatment with radiation,” Robinson said during a press briefing here at the 2019 American Society for Radiation Oncology (ASTRO) meeting. He added that the approach is best suited for high-risk patients who have failed all conventional treatments, and should be performed ideally as part of a trial.
There were nine deaths during the course of the trial, six cardiac and three non-cardiac. Survival estimates were 89.4% at 6 months, and 73.7% and 52.5% at 1 and 2 years, respectively. Quality of life was either maintained or improved in the majority of patients, and most who were alive at 1 year were able to reduce their need for amiodarone.
Serious toxicity due to radiation was low, said Robinson, but some late events did occur, making long-term follow-up “critical.” One patient had grade 3 pericarditis at 80 days, and toxicity beyond 2 years included two grade 3 events of pericardial effusion and one grade 4 gastropericardial fistula.
ENCORE-VT included patients with at least three VT episodes in the 6 months prior to enrollment who had failed on standard medication and had either failed or were two sick for catheter ablation. Most participants were men (90%), had high VT burden, and were heavily medicated.
SBRT Fails to Beat Standard for Metastatic Spine Pain
Stereotactic body radiotherapy (SBRT) was no better than standard radiation for palliation of painful spinal metastases, the phase III RTOG 0631 trial found.
For the primary endpoint of reduction in pain scores at 3 months, conventional external-beam radiotherapy (EBRT) eased pain at the treated site by 57.9% versus 40.3% with SBRT (P=0.99), according to findings presented by Samuel Ryu, MD, of Stony Brook University Medical Center in New York.
“Radiosurgery failed to improve the pain response from the patients’ perspective at 1, 3, and 6 months in patients with localized metastases,” said Ryu during the meeting’s plenary session. “This was due to a very low pain response rate from this radiosurgery group than the previously published clinical experience.”
NRG Oncology RTOG 0631 compared SBRT at 16 or 18 Gy in one fraction against conventional EBRT at 8 Gy in one fraction for the palliative treatment of patients with one to three painful spinal lesions — a score of at least 5 on the 10-point Numerical Rating Pain Scale.
In the 209 patients in the investigational arm, SBRT was delivered only to the involved spinal segment while in the 130 control patients, conventional EBRT was delivered to the involved spinal segment and one additional segment below and above. Baseline characteristics were mostly similar though the EBRT arm had significantly more patients with better performance status (90% vs 78% in the SBRT arm), as defined by a Zubrod score of 1 or less.
For the primary endpoint, patients in the SBRT arm had a mean baseline score of 6.06, which was reduced by 3.00 points at 3 months. In the EBRT arm, patients’ baseline score of 5.88 was reduced by 3.83 points.
Clinic Closures Tied to Worse Cervical Cancer Outcomes
Retrospective data found decreased rates of cervical cancer screening and increased rates of death from the disease in states that saw a net loss in their number of women’s health clinics.
From 2010 to 2013, nearly 100 of these clinics closed, largely due to regulations for Title X funding. In the subsequent 2 years, absolute rates of screening decreased by 5% in the 37 states that had clinics close versus 3% in the 13 states with no reduction in their number of clinics, reported Amar Srivastava, MD, MPH, also of Washington University School of Medicine.
“This study that we did actually starts to build into a story,” Srivastava said during a press conference. “We saw that in women living in states with clinic closures, there was a relative reduction in the number of women undergoing screening for cervical cancer; this led to a change in terms of the stage at diagnosis — a reduction in the number of early-stage diagnoses and a trend toward increases in late-stage diagnoses — which ultimately translated into an increase in the risk of death.”
Groups with significant declines in screening included uninsured (6.2%), Hispanic (5.3%), and unmarried (4.4%) women, as well as those ages 21 to 34 (4.8%). In this group of young women, early-stage cervical cancer diagnoses were significantly decreased in the states with clinic closures while showing a trend toward increased rates of later-stage diagnoses.
Srivastava’s team looked at data from the Surveillance, Epidemiology, and End Results database, and found a 36% relative increase in the risk for death for cervical cancer patients living in states with clinic closures (adjusted HR 1.36, P=0.04).
Robinson disclosed relationships with AstraZeneca, Elekta, EMD Serono, Merck, Radialogica, Varian, and ViewRay.
Ryu and Srivastava had no disclosures.