In patients with HER-2 positive breast cancer on pertuzumab/trastuzumab with newly developed asymptomatic brain metastases only, do you wait 3 weeks after administration of the targeted therapy to deliver SRS?

In a recently published study from Italy, Ippolito et al., PMID 35053467 a total of 10 patients with 32 HER2+ breast cancer brain metastases were treated with concurrent fSRT (27 Gy in 3 fractions) and Pertuzumab. Necrosis was reported in only 1 of the 32 treated lesions. The study is small but the ...

We don’t hold for herceptin and pertuzumab for SRS but do hold for T-DM1 as it has increased risk of radionecrosis.

Salvestrini et al., PMID 37437610

Several retrospective studies have shown the good tolerance of concomitant radiotherapy with trastuzumab and pertuzumab either in loco-regional or distant metastatic disease. However, given the underlying mechanism of action, the use of antibody-drug conjugates of trastuzumab (trastuzumab emtansine,...