Taunk NK, et al. – Analysts tried to correlate early (within 12 weeks) post–treatment perfusion MRI changes with long–term outcomes after treatment of lung cancer brain metastases with stereotactic radiosurgery (SRS). Findings suggested the effectiveness of post–treatment K^trans SD as an early post–treatment imaging biomarker to help predict long–term response of lung cancer brain metastases to SRS.

Methods

• They acquired pre- and post-treatment perfusion MRI scans in patients treated with SRS for intact non-small cell lung cancer brain metastases.
• They estimated time-dependent leakage (K trans), blood plasma volume (Vp), and extracellular extravascular volume (Ve) for each lesion.
• Furthermore, patients were followed longitudinally with serial MRI until death, progression, or intervention (whole brain radiation or surgery).

Results

• 53 lesions treated with SRS from 41 total patients, were incorporated.
• It was noted that median follow-up after treatment was 11 months.
• 85% was the actuarial local control at one year.
• Results revealed a significant difference (p=0.032) in post-treatment K trans SD between patients with progressive disease (mean=0.0317) and without progressive disease (mean=0.0219).
• For predicting progressive disease and no progressive disease, a post-treatment K trans SD cutoff value of 0.017 was highly sensitive (89%).
• There was no association between early post-treatment volume change and outcome (p=0.941).