Zoledronate reduces radiation-induced bone collagen degradation in radiation therapy

Study Type: Therapy
OE Level of Evidence: 2
Journal Level of Evidence: N/A
40 patients with skeletal metastasis who were scheduled to undergo local radiotherapy were included in this study. The purpose of the study was to determine the effect of zoledronate, a bisphosphonate, in collagen breakdown and bone loss secondary to radiation therapy. Patients were randomized Please login to view the rest of this report. Please login to view the rest of this report.
Funding: Not Reported
Conflicts: None disclosed
Why was this study needed now?
Therapeutic irradiation is associated with a reduction in bone mineral density that can increase the risk of pathological fractures. The reduction in bone mineral density is thought to occur immediately after the initiation of radiation therapy via degradation of the organic extracellular bone matrix. An optimal treatment for the reduction in bone mineral density as a result of radiotherapy has not yet been determined. The present study aims to evaluate the impact of zoledronic acid on bone density via examination of the urinary levels of hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) excretion.
What was the principal research question?
For patients over the age of 18 with skeletal metastases, how does zoledronic acid affect the excretion of hydroxylysylpyridinoline and lysylpyridinoline during radiotherapy treatment?
Population: 40 patients above the age of 18 with a histologically confirmed malignancy and a minimum of one radiograph confirmed skeletal metastasis were included in the study. Patients were also expected to survive for at least one year post enrollment, had a glomerular filtration rate of >30ml/min, and a serum calcium level > 2.0 and < 3.0mmol/l. Radiation was provided to patients on a case to case basic depending on their specific tumor, malignancy grade, and treatment goal. 4mg of zoledronic acid (Zometa, Novartis Pharma GmbH, Germany) was provided to all patients as a single dose every 4 weeks and infused over a period of 5 minutes. (M=21/F=19; mean age=63 [46-84]).
Intervention: Group B: The initial dose of zoledronic was provided in the morning prior to the first cycle of radiotherapy (n=20)
Comparison: Group A: The initial dose of zoledronic acid was provided after the last cycle of radiotherapy (n=20)
Outcomes: The outcome of concern was the amount of urinary levels of HP and LP.
Methods: RCT: Prospective: Single-centered
Time: Urine samples were taken at three times (T0=immediately before the first therapy session; T1=2 weeks after the start of the first therapy session; T2=at the end of the last therapy session)
What were the important findings?
What should I remember most?
How will this affect the care of my patients?
The authors responsible for this critical appraisal and ACE Report indicate no potential conflicts of interest relating to the content in the original publication.