The lateral and longitudinal distributions of absorbed dose of broad and narrow light ion beams in water are investigated. An analytical algorithm based on the generalized Fermi-Eyges theory is developed and used to calculate the effects of multiple scattering and range straggling on the dose distribution of light ion beams in water. A first-order Gaussian multiple scattering and energy loss straggling approach is generally sufficiently accurate for describing the lateral and longitudinal spread of the Bragg peak and the associated energy deposition distribution of therapeutic light ion beams at ranges of clinical interest. Nuclear reactions are not taken into account in this study. The analytical algorithm given in the present study allows an accurate description of the radial spread and the range straggling of light ions traversing matter. A verification of this approach by comparing with experimental data, Monte Carlo methods and other analytical techniques will be presented in a forthcoming paper.

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Evaluation of the early response in NSCLC patients showed that it is feasible to determine a threshold value for effective radiosensitivity corresponding to good response. It also showed that a threshold value for the fraction of negative αeff could also be correlated with poor response. The proposed method, therefore, has potential to identify candidates for more aggressive strategies to increase the rate of local control and also avoid exposing to unnecessary aggressive therapies the majority of patients responding to standard treatment.

A non-linear conversion function between uptake and oxygen partial pressure for F-FMISO-PET could be applied toF-HX4 images to delineate hypoxic sub-volumes of similar size, shape, and relative location as based directly on the uptake. In order to apply the model for e.g., dose-painting, new parameters need to be derived for the accurate calculation of dose-modifying factors for this tracer.

Non-linear conversion of tracer uptake to pO in NSCLC imaged with HX4-PET allows a quantitative determination of the dose-boost needed to achieve a high probability of local control.

The poor OS predictive power of the quantities determined from repeated FDG-PET-CT images indicates that the third week of treatment might not be suitable for treatment response assessment. Comparatively, the second week during the treatment appears to be a better time window.

Purpose: To be able to experiment with various topics in advanced radiation therapy planning using a stand‐alone Windows‐based software. Method and Materials: Product code for IMRT planning was merged with research code for adaptive radiation therapy and dose computations. An architecture and graphical user interface tailor‐made for representing adaptive treatments was designed. Code for proton dose computation and treatment planning was developed and integrated into the system. Results: A software package that executes on a standard PC or advanced laptop has been developed. The system is capable of IMRT treatment planning using dose‐volume based functions, EUD, Poisson‐LQ and LKB biological models, both as objectives and hard constraints. Pencil beam and heterogeneity corrected collapsed cone dose computations can be used. The system can optimize every relevant combination of pencil beam weights, SMLC segments, gantry, couch and collimator angles. It is possible to perform intensity modulated proton therapy planning. Models for tumor repopulation and repair are included and irregularities in the fractionation scheme can be compensated for by allowing the dose to vary between fractions during optimization. The system exhibits a comprehensive GUI and functionality for simulation and evaluation of adaptive/IGRT treatments with algorithms for deformable dose accumulation based on information from portal imaging and 3D imaging modalities such as onboard CT scanners. Errors due to patient setup and organ motion can be counteracted and compensated for by couch shift and on‐ and offline IMRT replanning. Conclusion: A software environment suitable for studying various advanced topics in modern radiation therapy has been developed. The system has proven useful in research and development in IMRT optimization, biological models, proton therapy and adaptive radiation therapy. Conflict of Interest: The authors are employees and stock owners of the submitting company.