Radioguided Surgery

TO THE EDITOR: Within the framework of a valuable initiative, the supplement to the December issue of The Journal of Nuclear Medicine highlights some of the major contributions that nuclear medicine and molecular imaging have made to patient care over 60 years of publication. An additional area that deserves mention is radioguided surgery, which starts with the nuclear medicine procedure of tagging with a radioactive label (administered either systemically or locoregionally) a certain tissue or lesion to ease its identification by preoperative imaging and its subsequent resection by an intraoperative counting probe. There have been several thousand citations to articles published in The Journal of Nuclear Medicine regarding radioguided sentinel lymph node (SLN) biopsy, contributing to the recognition of this procedure as the standard of care for some cancers. After Cabañas introduced in the 1970s the SLN concept as an anatomic notion (1), in 1992 Morton renewed interest in the SLN approach using visual guidance with a blue dye to visualize lymphatic drainage from tumors, recognizing its variability from patient to patient (2). Nonetheless, it was the introduction of radioguidance in the mid-1990s that led to the current array of clinical applications of SLN surgery—as witnessed by the number of publications in this field, which have increased by more than 10-fold every 5 years between 1996 and 2005 versus 1991–1995.

As a fundamental aid for primary staging of solid epithelial cancers, radioguided SLN biopsy constitutes one of the best examples of how nuclear medicine interacts with and has a crucial impact on other medical specialties. In fact, this procedure constitutes the undisputed standard of care for initial treatment of cutaneous melanoma and breast cancer, and it is increasingly being recognized as the standard of care also for penile cancer, head and neck cancers, and some gynecologic cancers. Radioguided surgery, including robot-assisted procedures, is undergoing clinical validation in other malignancies, not only for SLN biopsy but also for radiotagged tumor resection.

Ranking of articles published in The Journal of Nuclear Medicine according to the number of citations in the international literature identifies the top 5 articles as milestone contributions to establish radioguided SLN biopsy as the standard of care, particularly for breast cancer and cutaneous melanoma (3–7). The next 5 most cited articles (8–12) deal with important components of radioguided SLN surgery that ensure optimal performance of the procedure, as well as technologic advances based on fruitful interactions of nuclear medicine with other medical specialties. In particular, they emphasize the crucial role of preoperative imaging within the whole procedure of radioguided surgery and the possibility for hybrid imaging with SPECT/CT to provide a road map for easier navigation during the surgical procedure, guided both by the γ-probe and by preoperative lymphatic mapping—especially in anatomically complex regions such as the head and neck or the abdomen. Other crucial factors driving further developments are the possibility of tagging lesions with radioactive seeds and the availability of dual-signature imaging agents for lymphatic mapping or tumor-seeking procedures using both radioguidance (by preoperative SPECT/CT or PET/CT imaging and intraoperative γ-probe counting) and fluorescence-based guidance with probes in close surgical environments, such as during laparoscopy with robot-assisted surgery.

• © 2021 by the Society of Nuclear Medicine and Molecular Imaging.