New Technologies for Human Cancer Imaging

Abstract

Despite technical advances in many areas of diagnostic radiology, the detection and imaging of human cancer remains poor. A meaningful impact on cancer screening, staging, and treatment is unlikely to occur until the tumor-to-background ratio improves by three to four orders of magnitude (ie, 10 3 -to 10 4 -fold), which in turn will require proportional improvements in sensitivity and contrast agent targeting. This review analyzes the physics and chemistry of cancer imaging and highlights the fundamental principles underlying the detection of malignant cells within a background of normal cells. The use of various contrast agents and radiotracers for cancer imaging is reviewed, as are the current limitations of ultrasound, x-ray imaging, magnetic resonance imaging (MRI), single-photon emission computed tomography, positron emission tomography (PET), and optical imaging. Innovative technologies are emerging that hold great promise for patients, such as positron emission mammography of the breast and spectroscopy-enhanced colonoscopy for cancer screening, hyperpolarization MRI and time-of-flight PET for staging, and ion beam-induced PET scanning and near-infrared fluorescence-guided surgery for cancer treatment. This review explores these emerging technologies and considers their potential impact on clinical care. Finally, those cancers that are currently difficult to image and quantify, such as ovarian cancer and acute leukemia, are discussed. J Clin

H-ferritin–nanocaged doxorubicin nanoparticles specifically target and kill tumors with a single-dose injection

“…Mice with tumor sizes of 100 mm 3 are generally used to investigate drug effects. This is because solid tumors typically display Gompertzian kinetics (35), and they are typically found to be in a log phase of growth when at a size of 100 mm 3 , where the new tumor vessels are robustly developing and no necrosis in the interior of the tumor has appeared yet (36). The tumors in free Dox-, free HFn-, or PBS-treated groups grew rapidly, and the average volume of tumors reached >1,000 mm 3 on day 18 after tumor implantation (Fig.…”

Surgery with molecular fluorescence imaging using activatable cell-penetrating peptides decreases residual cancer and improves survival

“…From a molecular-imaging perspective, ACPPDs have several advantages over other targeted fluorescent probes previously described in the literature for use in a surgical system (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Molecular fluorescence-guided surgery demands that a given probe (a), works for a wide variety of tumor types (b), offers ample signal with low background (c), binds tightly to the tumor, and (d), is not affected by the physical trauma of surgery.…”

Targeting Liver Fibrosis

“…Molecular (targeted) imaging technology is based on a high-affinity ligand for a cell surface molecule that has been coupled to a radio-or MRI-imaging agent. 109 Ideally, fibrosis imaging constructs should be of small size, to allow penetration into the interstitial tissue, which is particularly relevant for imaging of fibrosis or fibrogenesis. In addition, the imaging construct should be nontoxic and have a desirable plasma half-life of 10-30 minutes, to be eliminated predominantly through the kidneys.…”