A new strategy that combines two types of PET scans can guide personalised radiotherapy for head and neck cancers, according to new research published in The Journal of Nuclear Medicine.

Moving beyond the "one-size-fits-all approach," this research shows that treatment can be biologically tailor27 in a clinically feasible way with the potential to improve patient outcomes.

Conventional radiotherapy prescribes the same dose for nearly all patients based on the type of their tumour and standard tissue anatomy.

Advances in PET imaging, however, allow physicians to create biologic maps that show the unique characteristics of a tumour and can be utilised to develop a personalised treatment plan.

"This study shows a new way to personalise radiotherapy using two different PET tracers in the same patient. In a novel approach, we combined PET imaging of tumour oxygen levels, which influence radiation resistance, with PET imaging of tumour cell density, and used this information to calculate how much radiation dose is needed in different tumour regions,"  said Marta Lazzeroni, PhD, associate professor of Medical Radiation Physics at Stockholm University in Sweden.

Researchers explored a biologically guided treatment strategy for head and neck squamous cell carcinoma (HNSCC), using ¹⁸F-FDG PET to estimate relative cell density and ¹⁸F-FMISO PET to quantify hypoxia-related radioresistance.

Twenty-eight patients received both scans, and cellular information was analysed to create individual tumour profiles.

These biologic maps informed personalised treatment plans, with escalated doses designed for regions of the tumours with unfavourable characteristics.

Planned dose distributions achieved greater than 90 percent predicted tumour control probability based on radiobiological modelling in all cases, a significant increase from the approximately 60 percent tumour control probability reported in previous literature.

All treatment plans met standard clinical feasibility criteria to protect healthy organs and tissues, demonstrating the overall feasibility of the personalised strategy.

"The results from this proof-of-concept study highlight how molecular imaging can play an active role in guiding treatment decisions, not just diagnosing disease,"  stated Lazzeroni.

"In the future, PET imaging could become a key tool for designing truly personalised radiotherapy treatments and for adapting therapy as tumours change over time."

Source: Society of Nuclear Medicine and Molecular Imaging