Radiolabelled somatostatin analogs for diagnosis and radio-guided surgery of neuroendocrine breast cancer undetectable with conventional imaging procedures

111 In-Pentetreotide-Guided Radiosurgery for Intraoperative Localization of Retroperitoneal Nodal Metastasis in a Patient With Ileal Neuroendocrine Tumor

ABSTRACT

64 Cu-DOTATATE PET/CT of a 44-year-old man with an ileal neuroendocrine tumor demonstrated the primary tumor, local nodal metastases, and a pericaval nodal metastasis. Localization of the pericaval node during surgery may be difficult, thus 4.4 mCi of 111 In-pentetreotide was administered before surgery to assist with localization and resection. At surgery, the pericaval nodal metastasis was readily detected by gamma probe, which could then be resected and pathologically proven to be a metastasis. This demonstrates the use of somatostatin receptor-targeted imaging for intraoperative localization of an otherwise difficult to surgically localize metastasis. Without intraoperative somatostatin receptor-targeted radiosurgery, disease may have been incompletely resected.

Interventional nuclear medicine: a focus on radioguided intervention and surgery

Within interventional nuclear medicine (iNM) a prominent role is allocated for the sub-discipline of radioguided surgery. Unique for this discipline is the fact that an increasing number of clinical indications (e.g. lymphatic mapping, local tumor demarcation and/or tumor receptor targeted applications) have been adopted into routine care. The clinical integration is further strengthened by technical innovations in chemistry and engineering that enhance the translational potential of radioguided procedures in iNM. Together, these features not only ensure ongoing expansion of iNM but also warrant a lasting clinical impact for the sub-discipline of radioguided surgery.

Recent advances in nuclear and hybrid detection modalities for image-guided surgery

Introduction: Radioguided surgery is an ever-evolving part of nuclear medicine. In fact, this nuclear medicine sub-discipline actively bridges non-invasive molecular imaging with surgical care. Next to relying on the availability of radio- and bimodal-tracers, the success of radioguided surgery is for a large part dependent on the imaging modalities and imaging concepts available for the surgical setting. With this review, we have aimed to provide a comprehensive update of the most recent advances in the field. Areas covered: We have made an attempt to cover all aspects of radioguided surgery: 1) the use of radioisotopes that emit γ, β⁺, and/or β^- radiation, 2) hardware developments ranging from probes to 2D cameras and even the use of advanced 3D interventional imaging solutions, and 3) multiplexing solutions such as dual-isotope detection or combined radionuclear and optical detection. Expert opinion: Technical refinements in the field of radioguided surgery should continue to focus on supporting its implementation in the increasingly complex minimally invasive surgical setting, e.g. by accommodating robot-assisted laparoscopic surgery. In addition, hybrid concepts that integrate the use of radioisotopes with other image-guided surgery modalities such as fluorescence or ultrasound are likely to expand in the future.

[Neuroendocrine neoplasms of the breast]

Neuroendocrine neoplasms (NEN) of the breast are specific tumor entities. According to the literature up to 5% of breast neoplasms are malignant epithelial neoplasms of the breast. They are defined by a neuroendocrine (NE) architecture and cytology combined with an expression of the neuroendocrine vesicle markers chromogranin A and/or synaptophysin. The diagnosis is supplemented by the receptor status and the proliferative activity. According to the World Health Organization (WHO) classification of 2012 the following groups of NEN are distinguished: (1) invasive breast carcinoma with NE differentiation, (2) well-differentiated neuroendocrine tumor (NET) and (3) poorly differentiated small cell carcinoma (NEC). This review article focuses on (1) the definition and basic principles of diagnostics, (2) the history, nomenclature and WHO classification from 2003 and 2012, (3) the frequency of breast NEN, (4) the hereditary background and functional activity, (5) the expression of receptors and (6) the possible clinical implications. In addition, the first results of a retrospective single center study (n = 465 patients with breast cancer over a time period of 4 years) on the frequency of NEN of the breast at the Breast Center of the University Hospital Düsseldorf are presented. In this study a frequency of 4.5% of NEN was found based on a diagnostic cut-off of > 50% Chromogranin A and/or synaptophysin positive tumor cells.

Neuroendocrine differentiation in breast cancer: established facts and unresolved problems

Neuroendocrine breast carcinoma (NEBC) diagnosis relies on (i) presence of morphologic neuroendocrine features, and (ii) neuroendocrine markers expressed in more than 50% of tumor cells. The World Health Organization classification describes 3 main histologic types: the solid, the small/oat cell, and the large cell variant. In addition, we have recently proposed a further categorization into 5 subgroups: the first 3 categories encompass solid lesions and include (i) solid cohesive carcinomas, (ii) alveolar carcinomas, and (iii) small cell carcinoma; the last subgroups include mucin-producing tumors which are (iv) solid papillary carcinomas and (v) cellular mucinous carcinomas. Chromogranin A and synaptophysin have been considered as the most sensitive and specific neuroendocrine markers in NEBC. At the molecular level, recent gene expression profiling studies have shown that NEBCs pertain to the luminal molecular type, being positive for hormone receptors and negative for HER2. Moreover, it has been demonstrated that mucinous and neuroendocrine carcinomas are transcriptionally distinct from conventional invasive ductal carcinomas. Following the above criteria, NEBCs constitute approximately 1% of all breast carcinomas. The clinical effect of neuroendocrine breast cancer is still a matter of debate; however, when compared with unselected breast cancers, NEBCs show a less aggressive clinical behavior.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.