Validation of functional imaging as a biomarker for radiation treatment response

Abstract

Major advances in radiotherapy techniques, increasing knowledge of tumour biology and the ability to translate these advances into new therapeutic approaches are important goals towards more individualized cancer treatment. With the development of non-invasive functional and molecular imaging techniques such as positron emission tomography (PET)-CT scanning and MRI, there is now a need to evaluate potential new biomarkers for tumour response prediction, for treatment individualization is not only based on morphological criteria but also on biological tumour characteristics. The goal of individualization of radiotherapy is to improve treatment outcome and potentially reduce chronic treatment toxicity. This review gives an overview of the molecular and functional imaging modalities of tumour hypoxia and tumour cell metabolism, proliferation and perfusion as predictive biomarkers for radiation treatment response in head and neck tumours and in lung tumours. The current status of knowledge on integration of PET/CT/MRI into treatment management and bioimage-guided adaptive radiotherapy are discussed.

Physiological gas exchange mapping of hyperpolarized 129Xe using spiral‐IDEAL and MOXE in a model of regional radiation‐induced lung injury

“…However, if detected early, acute RP may be treatable. Interfraction changes to the treatment plan or administration of anti‐inflammatory pharmaceuticals may minimize the development of RILI, without sacrificing RT efficacy . Early management of RP may also mitigate late stage, permanent fibrotic remodeling months/years following RT, culminating in radiation fibrosis (RF) .…”

“…Interfraction changes to the treatment plan or administration of anti-inflammatory pharmaceuticals may minimize the development of RILI, without sacrificing RT efficacy. [12][13][14][15] Early management of RP may also mitigate late stage, permanent fibrotic remodeling months/ years following RT, culminating in radiation fibrosis (RF). 10,16 The development and severity of RILI depend on the delivered dose, volume of tissue irradiated, and pre-existing pulmonary dysfunction prior to RT, among various other factors, making prediction difficult.…”

Overexpression of Receptor Tyrosine Kinase EphB4 Triggers Tumor Growth and Hypoxia in A375 Melanoma Xenografts: Insights from Multitracer Small Animal Imaging Experiments

“…Moreover, using [ 18 F]FMISO we demonstrated increased hypoxia in A375-EphB4 tumor xenografts in comparison to mock tumors. [ 18 F]FMISO is taken up by cells and its cellular trapping depends on the intracellular oxygen concentration [ 74 , 75 ]. In particular, by in vivo PET imaging it became evident that EphB4 overexpression increased hypoxia especially in ‘smaller’ tumors (sum of A375-pIRES and A375-EphB4 tumor volumes < 1582.3 mm 3 ) which were normally not yet hypoxic.…”

Recent advances in radiation oncology

“…There are two methods of achieving dose painting to biologic image-defined regions within a target: dose painting by contours and dose painting by numbers [ 134 , 135 ]. The first prescribes the dose within biological image-defined contours of the target, while the second prescribes dose to voxels throughout the target as a function of signal intensity of the corresponding voxel in a biologic image.…”