Image-Guided Drug Delivery with Single-Photon Emission Computed Tomography: A Review of Literature

Abstract

Tremendous resources are being invested all over the world for prevention, diagnosis, and treatment of various types of cancer. Successful cancer management depends on accurate diagnosis of the disease along with precise therapeutic protocol. The conventional systemic drug delivery approaches generally cannot completely remove the competent cancer cells without surpassing the toxicity limits to normal tissues. Therefore, development of efficient drug delivery systems holds prime importance in medicine and healthcare. Also, molecular imaging can play an increasingly important and revolutionizing role in disease management. Synergistic use of molecular imaging and targeted drug delivery approaches provides unique opportunities in a relatively new area called `image-guided drug delivery' (IGDD). Single-photon emission computed tomography (SPECT) is the most widely used nuclear imaging modality in clinical context and is increasingly being used to guide targeted therapeutics. The innovations in material science have fueled the development of efficient drug carriers based on, polymers, liposomes, micelles, dendrimers, microparticles, nanoparticles, etc. Efficient utilization of these drug carriers along with SPECT imaging technology have the potential to transform patient care by personalizing therapy to the individual patient, lessening the invasiveness of conventional treatment procedures and rapidly monitoring the therapeutic efficacy. SPECT-IGDD is not only effective for treatment of cancer but might also find utility in management of several other diseases. Herein, we provide a concise overview of the latest advances in SPECT-IGDD procedures and discuss the challenges and opportunities for advancement of the field.

Protein‐Nanoreactor‐Assisted Synthesis of Semiconductor Nanocrystals for Efficient Cancer Theranostics

“…SPECT/CT imaging might provide the anatomical imaging at a macroscopic level, and thus we further demonstrate the SPECT/CT imaging capacity of CuS‐NCs on the mice bearing 4T1 tumor at the dose of 1.0 mCi 99m Tc (Figure F–H). CuS‐NCs had remarkable radioactive signals at tumor during 2–12 h (Figure F,H), owing to their enhanced tumor accumulation and radioactive half‐life of 6.02 h. In particular, CuS‐NCs also generated the strongest radioactive signals at 6 h post‐injection (Figure G), indicating a clear tumor identification with high imaging contrast.…”

Radiolabeled inorganic nanoparticles for positron emission tomography imaging of cancer: an overview

“…Presently, the most prudent approach that provides quantitative information about the whole body biodistribution is by incorporating suitable radioisotopes in the nanoparticles — a process known as “radiolabeling”. 2, 6, 7 After administration of the radiolabeled nanoparticles in living subjects, their in vivo biodistribution can be non-invasively monitored by molecular imaging techniques such as single photon emission computed tomography (SPECT), 8 PET, 9 Cerenkov luminescence (CL), 10 Cerenkov resonance energy transfer (CRET), 11 etc., that are now been widely explored for cancer imaging in preclinical and/or clinical settings.…”

“…The third advantage lies in the ability of nanoparticles to combine both diagnostic and therapeutic capabilities onto the same nanoplatform, giving rise to the emerging concept of “image-guided drug delivery”. 8, 9 Additionally, different therapeutic agents (chemotherapeutic drugs as well as suitable therapeutic radioisotopes) can be incorporated in the same nanoplatform which might be a viable option toward multimodality targeted therapy for improved cancer management.…”

Formulation, characterization and tissue distribution of a novel pH-sensitive long-circulating liposome-based theranostic suitable for molecular imaging and drug delivery

“…1,2,29 The imaging function requires the labeling of theranostic carriers with radioactive or non-radioactive isotopes on the bilayer surface or through encapsulation. While some prefer the design that shields the imaging elements from the outer biological environment, others appreciate surface chelation for its versatility in the choice of radionuclides and its high labeling efficiency.…”