# In vitro assays as a tool to personalize treatment in central nervous system tumors: a systematic literature review

## TL;DR

This paper reviews how in vitro drug testing using patient-derived models could help personalize brain tumor treatments, especially for glioblastoma.

## Contribution

The study systematically evaluates the potential of in vitro assays to predict treatment outcomes in brain tumors, highlighting their promise over traditional molecular profiling.

## Key findings

- In vitro assays using patient-derived models reliably predict treatment outcomes for brain tumors.
- Molecular profiling has limited effectiveness in glioblastoma due to evolving tumor profiles.
- Only limited-quality evidence supports the use of in vitro assays in clinical settings.

## Abstract

Personalized therapy in neuro-oncology has traditionally relied on molecular profiling. However, clinical benefit has been scarce to date. Recently, in vitro drug sensitivity testing using patient-derived models—such as organoids and cell lines—has emerged as a promising strategy. We systematically reviewed evidence on the efficacy of in vitro drug screening in predicting treatment outcome for brain tumors, including but not limited to glioblastoma. PRISMA guidelines were followed. Fifteen studies were included, comprising 300 patients overall. Cohort studies built the largest group; only one randomized clinical trial was found. In vitro assays, using patient-derived stem cells, standardized assays ad the ChemoID, or tumor-derived organoids, were able to reliably predict treatment outcome. However, the overall quality of evidence was limited. These models may overcome limitations of molecular profiling, especially in glioblastoma, where driver mutations are often lacking and the molecular profile evolves at recurrence. Although initial results are promising, further validation is needed before clinical implementation.