Increased prescription dose for large vessel intravascular brachytherapy

Catheter Cardiovasc Interv. 2023 Nov;102(6):1034-1039. doi: 10.1002/ccd.30852. Epub 2023 Oct 19.

Abstract

Background: Most randomized studies testing the effectiveness of IVBT were limited to vessels less than 4 mm diameter. In fact, it is now common to treat vessels larger than 4 mm. Accordingly, the authors instituted a prescription dose increase to 34 Gy at 2 mm from source center for vessels greater than 4.0 mm. The increase in prescription dose to 34 Gy at 2 mm from center is substantial, being 50% higher than the conventional maximum of 23 Gy.

Aim: To take a close look at group of patients treated to 34 Gy, and for whom follow-up angiograms are available.

Methods: Ten patients treated for ISR with a prescription dose of 34 Gy and for whom follow-up angiograms were available were studied. Beta-radiation brachytherapy was performed with a Novoste Beta-Cath System using a strontium-90 (beta) source (Best Vascular, Springfield, VA). Source lengths of 40 or 60 mm were used. A dose of 34 Gy was prescribed at 2 mm from the source center.

Results: Patients were re-catheterized from 2 to 21 months (median: 16 months) following IVBT, all for symptoms suggested of restenosis. All patients had some degree of ISR of the target vessel, but no IVBT-treated vascular segment showed angiographic signs of degeneration, dissection or aneurysm.

Conclusion: The authors' clinical impression, along with detailed review of the 10 cases, suggest that using a 34 Gy prescription dose at 2 mm from source center does not result in increased toxicity.

Keywords: brachytherapy; cardiac; coronary; dosimetry; radiation; restenosis.

MeSH terms

  • Brachytherapy* / adverse effects
  • Catheterization
  • Coronary Restenosis*
  • Humans
  • Stents
  • Treatment Outcome
  • Vascular Surgical Procedures