# Use imaging to find the window when tumour blood vessels are working properly

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

## TL;DR

Low doses of anti-blood-vessel drugs briefly make tumour vessels work better, which helps immune cells and other drugs get in. Scans can find that window for each patient.

## Summary

Vascular normalisation after low-dose anti-angiogenic therapy is transient and dose-dependent, and DCE-MRI or perfusion CT can measure it patient by patient. Current anti-angiogenic and checkpoint combinations use fixed high doses and fixed schedules, so many patients are likely dosed outside their own normalisation window. Imaging-guided scheduling is a trial design intervention with existing drugs.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Timing checkpoint or cytotoxic administration to an imaging-defined perfusion peak increases intratumoural drug delivery and T-cell infiltration compared with fixed scheduling.
- Rationale: Normalisation is well documented in human rectal and glioblastoma studies where perfusion improvement correlated with outcome. Scheduling is free, and imaging endpoints read out in days rather than months.
- Proposed test: A randomised imaging-guided versus fixed-schedule window trial with intratumoural drug concentration or CD8 density as the primary endpoint in an accessible tumour.
- Maturity: early-clinical
- Actor: clinic

## Sources

- Bottleneck evidence (Cold tumours and the immunosuppressive microenvironment): Haslam & Prasad, Estimation of the percentage of US patients eligible for and responding to checkpoint inhibitors (JAMA Netw Open 2019): https://doi.org/10.1001/jamanetworkopen.2019.2535

## Connected records

- pairings: [PD-1 blockade + VEGF inhibition](https://onco.cc/pairings/io-plus-vegf/)
- technologies: [Anti-angiogenic therapy](https://onco.cc/technologies/antiangiogenic/), [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [MRI](https://onco.cc/technologies/mri/), [PET (positron emission tomography)](https://onco.cc/technologies/pet/)
- drugs: [Bevacizumab](https://onco.cc/drugs/bevacizumab/), [Lenvatinib](https://onco.cc/drugs/lenvatinib/)
- pathways: [VEGF angiogenesis](https://onco.cc/pathways/vegf-angiogenesis/)
- bottlenecks: [Cold tumours and the immunosuppressive microenvironment](https://onco.cc/bottlenecks/b-tme-immunosuppression/), [Wrong doses](https://onco.cc/bottlenecks/b-dose-optimisation/)
- key papers: [Estimation of the Percentage of US Patients With Cancer Who Are Eligible for and Respond to Checkpoint Inhibitor Immunotherapy Drugs](https://onco.cc/key-papers/paper-haslam-jama-netw-open/)

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