Robust maximization of tumor control probability for radicality constrained dose painting by numbers of head and neck cancer

• Background and Purpose The aim of this study was to evaluate the potential and robustness to increase the tumor control probability (TCP) for robustly optimized dose painting plans compared to conventional homogeneous dose plans for head and neck cancers.Material and Methods We optimized a set of dose painting plans with a robust TCP maximizing objective under different mean dose constraints for the primary clinical target volume (CTVT). These plans were optimized with the robust mini-max algorithm together with dose-responses driven by standardized uptake values (SUV) from 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). The robustness in TCP was evaluated through sampling treatment scenarios with iso-center displacements. We also analyzed the impact on TCP predictions by considering dose-response uncertainties.Results The average increase in TCP with dose painting ranged between 3 to 20 percentage points (p.p.) which depended on the allowed integral CTVT dose. The median deviation in TCP increase was below 1p.p. for all sampled treatment scenarios versus the nominal plans. Patients with large tumors and large spread of SUV gained the greatest TCP increases. By considering dose-response uncertainties, a decrease of the TCP for a homogeneous dose yielded an increasing dose painting potential.Conclusions We have found that it is feasible to optimize FDG-PET driven dose painting plans that robustly increase the TCP compared to homogeneous dose treatments for head and neck cancers. The greatest potential TCP increases were found for patients with larger and more SUV heterogeneous tumors, which may give guidance for patient selection to further test the presented dose painting formalism.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Dose painting; Dose painting by numbers; Head and neck cancer; 18F-FDG PET/CT

Medicinsk radiofysik

Medical Radiophysics

Publikations- och innehållstyp

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