# Ultrasound-assisted blood test instead of a brain biopsy

Source: https://onco.cc/ideas/idea-bio2-sonobiopsy/  
OnCo record `idea-bio2-sonobiopsy` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Brain tumours release little DNA into blood because of the blood-brain barrier. Sonobiopsy briefly opens the barrier with focused ultrasound and microbubbles, raising circulating tumour DNA severalfold so a blood sample can replace repeat surgical biopsy for diagnosis and resistance monitoring in glioma and brain metastases.

## Summary

Focused ultrasound with microbubbles transiently opens the blood-brain barrier, and first-in-human sonobiopsy studies report severalfold increases in circulating tumour DNA and brain-derived proteins after sonication, without lasting damage. This could replace repeat surgical biopsy for molecular diagnosis, resistance monitoring and response assessment in glioma and brain metastases.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Focused ultrasound sonication before blood sampling raises the detection rate of tumour-specific mutations in plasma from under 20% to over 70% in glioma, with no grade 3 adverse events.
- Rationale: The barrier is the reason brain tumour liquid biopsy fails, and opening it is now a routine procedure in movement disorder and Alzheimer's trials. Diagnostic use requires only transient opening, which is a lower safety bar than drug delivery.
- Proposed test: A prospective study in patients undergoing planned resection: sonobiopsy plasma versus tissue as reference standard, reporting sensitivity, specificity and safety.
- Maturity: early-clinical
- Actor: engineering

## Sources

- Focused Ultrasound Foundation: https://www.fusfoundation.org

## Connected records

- cancers: [Glioma & glioblastoma](https://onco.cc/cancers/glioblastoma/)
- technologies: [Focused-ultrasound blood-brain barrier opening](https://onco.cc/technologies/bbb-focused-ultrasound/), [Liquid biopsy (ctDNA)](https://onco.cc/technologies/liquid-biopsy/), [MRD / molecular residual disease testing](https://onco.cc/technologies/mrd-testing/)
- companies: [Insightec](https://onco.cc/companies/insightec/)
- terms: [Blood-brain barrier (BBB)](https://onco.cc/terms/blood-brain-barrier/), [Circulating tumour DNA (ctDNA)](https://onco.cc/terms/ctdna/)
- bottlenecks: [The brain: barrier and sanctuary](https://onco.cc/bottlenecks/b-brain-delivery/), [Tumour heterogeneity and clonal evolution](https://onco.cc/bottlenecks/b-tumor-heterogeneity/)

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