In what scenario could brachytherapy be favored over CABG for recurrent ISR lesions with two layers of stent refractory to cutting balloon or laser, provided the patient is a good surgical candidate?

This is a very interesting question that is nuanced by the specific situation. Knowing the specific anatomy is important. Whether this is single- or multivessel disease, and whether it is focal or diffuse, will influence the decision, as will patient preference.

I approach this using the information below:

Guidelines:

The ACC/AHA/SCAI 2021 Guideline for Coronary Artery Revascularization provides the following recommendations for recurrent ISR:

• Class I (LOE A): DES implantation for ISR when anatomic factors are appropriate and the patient can comply with DAPT.
• Class IIa (LOE C-EO): CABG can be useful over repeat PCI in patients with symptomatic recurrent diffuse ISR with an indication for revascularization to reduce recurrent events.
• Class IIb ...