Radioguided Exploration Facilitates Surgical Cytoreduction of Neuroendocrine Tumors

Introduction: Radioguided exploration (RGS) can be an important tool to direct the cytoreduction of neuroendocrine tumors (NETs). The selection of the proper radiolabeled isotope, the dose, and the time interval between isotope injection and exploration are the major factors that lead to the successful use of this technique. Methods: Data on 43 patients who underwent RGS of their NET at our facility (Ochsner Medical Center-Kenner) was collected. These cases were reviewed to determine the optimal radiopharmaceutical, dose, and interval between injection and exploration. Results: The isotopes used were ⁹⁹technetium sulfur colloid in three patients, ¹²³I metaiodobenzylguanidine ( ¹²³I-MIBG) in six patients, and ¹¹¹In-pentreotide in 30 abdominal NET patients and in four patients undergoing neck and mediastinum explorations. In 29 of 30 ¹¹¹In-pentreotide-guided abdominal explorations (five of which were re-explorations, all successful), the gamma detector was determined to be "helpful". In the four neck and mediastinum explorations, the gamma probe was deemed "essential" for completing a quick, safe, and minimally invasive procedure. ¹²³I-MIBG injection, in contrast, was useful in only one patient. The optimal dose and interval between injection and exploration of ¹¹¹In-pentreotide were discovered to be 6 mCi injected 7 days prior to the planned exploration. Conclusion: Radioguided exploration is a useful tool to guide the cytoreduction of NETs. The correct choice of radiopharmaceutical, its dose, and the interval between injection and exploration are critical for obtaining optimal results.