Diagnosis and treatment of cancer has continually improved over the past few decades. This is due to several reasons, including better treatment regimes. Decisions regarding treatments have resulted in more personalized and individual treatment options and the medical decisions relating to treatment options are usually informed through the availability of high-quality clinical information. Such information seeks to give the physician and surgeon an accurate indication of the primary cancer, whether it has spread, and if it has spread, to what extent. Treatment regimes have become more elaborate, with a move away from overly invasive surgical procedures. Less invasive surgery demands accurate information on the progress of the cancer, and this information often includes the analysis of lymph nodes, particularly sentinel nodes. Histological analysis of the sentinel nodes is well documented in the literature for the management of cancer. When a sentinel node has cancer cells present, it usually results in the surgeon removing all the nodes in that region; conversely, when the sentinel node is negative, the nodes are spared. Such sparing minimizes surgical trauma and also postsurgical complications, such as edema and paresthesia. Different ways to detect, localize, and biopsy or excise sentinel nodes for histological purposes have been adopted into clinical practice. Ultrasound, "blue dye," and various nuclear medicine techniques are prominent in their individual or combined ability to fulfill this exploratory diagnostic role. The options in nuclear medicine imaging (planar imaging, single photon emission computed tomography, and single photon emission computed tomography-computed tomography) all have values in sentinel node detection and localization. With a particular focus on breast cancer, this article examines the role and value of nuclear medicine in the detection and localization of sentinel nodes.
After reading this article, the participant should be able to:
- Discuss the impact of cancer, particularly breast cancer, and the primary method for staging cancer.
- Explain the changes in approach to surgical management of cancer and the value of histological analysis of the sentinel node in cancer management, focusing on breast cancer.
- Identify major technological advances in nuclear medicine imaging, such as the introduction of the gamma camera, single photon emission computed tomography (SPECT), and single photon emission computed tomography-computed tomography (SPECT-CT).
- Evaluate the benefits and limitations of planar imaging and SPECT in sentinel node localization.
- Discuss the value of SPECT-CT in sentinel node imaging.
- Define typical radiation doses for SPECT, low-resolution computed tomography (CT) with SPECT, diagnostic quality CT with SPECT, and plain film radiography.