Contribution of Molecular Imaging in Radiation Oncology

Over the past few years, a tremendous progress has been made in the field of oncology pertaining to advanced treatment planning, cancer imaging and treatment techniques. The limitation of conventional imaging in radiation oncology prompted the development of molecular imaging; which allows identifying or describing living biological process at cellular and molecular level and is especially addressed to reveal abnormalities in cells and molecules which cause the cancer. The techniques used include radiotracer imaging like PET scan & SPECT, MRI & MR spectroscopy, optical imaging, ultrasonography, and others. The early detection of cancer cells by molecular imaging and prompt treatment leads to better outcomes, which can potentially be assessed in early stage thorough molecular imaging. Different pathways, where this technique can be acted are cell metabolism & proliferation, hypoxia, apoptosis, angiogenesis. In the last decade, diagnostic methods involving molecular imaging have made advancement in the field of diagnosis and staging, target definition and response assessment of cancer. The most common used imaging technique is 18-FDG PET-CT scan, which has immense value in cancers of lung, breast, prostate, lymphoma and many more with increased sensitivity and specificity. Advancement in the understanding of the pathophysiology of cancer has led to developments of multimodality treatment concepts comprising surgery, radiotherapy, chemotherapy and molecularly targeted anti-cancer agents. It can be concluded, combined use of molecular imaging with these treatment modalities can prove to be a boon for cancer management.