These two books cover the most significant recent advances in oncological molecular imaging, from methods and preclinical research to clinical practice. The first book is divided into two sections. The first section focuses on standardized and emerging technologies, as well as probe designs for various imaging modalities, including advanced X-ray imaging, CT, MRI, SPECT, total body PET, ultrasound, optical imaging, optoacoustic imaging, and probes for these modalities. The section also covers artificial intelligence in radiomics. The second section focuses on preclinical applications, including advanced microscopy in animal imaging. The second book presents various clinical applications of molecular imaging and related imaging features. The first section of the second book discusses the crucial, emerging role of molecular imaging in planning and monitoring oncological therapies and future challenges and prospects in multimodality imaging. The second section discusses radiotherapy approaches (photon therapy, particle therapy, and internal therapy) and theranostics. Given its scope, this handbook will benefit anyone interested in the revolution in diagnostic and therapeutic oncology brought about by molecular imaging. A third section of the second book will venture a view of future challenges.