Molecular imaging of tumor microenviroment: foreword.

In the last decade it has become increasingly clear that tumor microenvironment plays a key role in tumor formation, growth and progression. The complex network of interactions between tumor cells, resident stromal cells and recruited host cells along with the abnormal local physiologic conditions render tumor microenvironment quite different from normal stroma. Several excellent review articles have been published on imaging of hypoxia, angiogenesis, and other specific aspects of tumor microenvironment. The major aim of this issue of the Quarterly Journal of Nuclear Medicine and Molecular Imaging is to provide a unitary glance of the dynamic scenario surrounding cancer cells through the lenses of imaging technologies.