Near-infrared fluorescence imaging of a solitary fibrous tumor of the pancreas using methylene blue

A Giant Malignant Solitary Fibrous Tumor of the Pancreas: A Case Report and Review of the Literature

We present a case report of a giant solitary fibrous tumor (SFT) with a review of the literature and discuss its biological features and diagnosis. A 43-year-old man presented to our emergency department with abdominal pain and distension with an evolution of two days. Contrast-enhanced computed tomography (CT) showed a large, well-circumscribed semisolid mass (12 cm x 10 cm x 12 cm) localized in the pancreatic head. The histological diagnosis obtained by endoscopic ultrasound-guided trans-duodenal tumor biopsy with fine-needle aspiration showed proliferating short spindle-shaped cells, suggesting a mesenchymal neoplasia of low grade. We proceeded to a Whipple surgical technique. The histopathological study of the resected tumor confirmed proliferating spindle-shaped cells in the tissue, and one mitotic figure was observed in 10 high-power fields (HPFs). Immunostaining was positive for CD34 and STAT-6. The histological diagnosis was a malignant pancreatic SFT. In the six months posterior to the surgical procedure, the patient has been free of recurrent disease. Preoperative diagnosis is difficult and requires comprehensive evidence including clinical, immunohistochemistry, and histological features. Since there are currently no recognized best practices, we advise total surgical excision and careful clinical monitoring.

Imaging, pathology, and diagnosis of solitary fibrous tumor of the pancreas: A case report and review of literature

BACKGROUND

A solitary fibrous tumor (SFT) is often located in the pleura, while SFT of the pancreas is extremely rare. Here, we report a case of SFT of the pancreas and discuss imaging, histopathology, and immunohistochemistry for accurate diagnosis and treatment.

CASE SUMMARY

A 54-year-old man presented to our hospital with pancreatic occupancy for over a month. There were no previous complaints of discomfort. His blood pressure was normal. Blood glucose, tumor markers, and enhanced computed tomography (CT) suggested a malignant tumor. Because the CT appearance of pancreatic cancer varies, we could not confirm the diagnosis; therefore, we performed endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB). Pathology and immunohistochemistry were consistent with SFT of the pancreas. The postoperative pathology and immunohistochemistry were consistent with the puncture results. The patient presented for a follow-up examination one month after discharge with no adverse effects.

CONCLUSION

Other diseases must be excluded in patients with a pancreatic mass that cannot be diagnosed. CT and pathological histology have diagnostic value for pancreatic tumors. Endoscopic puncture biopsy under ultrasound can help diagnose pancreatic masses that cannot be diagnosed preoperatively. Surgery is an effective treatment for SFT of the pancreas; however, long-term follow-up is strongly recommended because of the possibility of malignant transformation of the tumor.

Solitary Fibrous Tumor of the Pancreas: Analysis of 9 Cases With Literature Review

Solitary fibrous tumor (SFT) has been increasingly reported in various anatomic sites. However, it is still extremely rare in the pancreas. Herein, we present the first series of primary pancreatic SFTs. Nine cases of primary pancreatic SFTs were analyzed. The mean age was 60 years (36 to 76 y) with no sex predilection. Six tumors were in the head, 3 were in the tail. On imaging studies, tumors were described as a hypervascular mass, 2 revealed cystic areas, and 3 were favored to be neuroendocrine tumors. On biopsy, 2 cases were diagnosed as atypical spindle cell tumor; one was misdiagnosed as suspicious for sarcoma, and another case as metastatic renal cell carcinoma. Two were diagnosed as low-grade sarcoma and low-grade stromal tumor on frozen sections. Grossly, tumors were well-demarcated with a median size of 4 cm (0.9 to 15 cm). Microscopically, they were composed of ovoid to spindle tumor cells with no significant mitotic activity and were arranged in alternating hypercellular and hypocellular areas. Staghorn-like vessels and entrapped pancreatic parenchyma were also detected within all tumors. Tumor cells revealed diffuse/strong nuclear STAT6 expression in 7 of 8, CD34 in 7 of 9, and bcl-2 in 4 of 4 tested cases. One tested tumor harbored NAB2 - STAT6 fusion. Eight patients with available follow-up data were free of disease at a mean follow-up of 76 months (3 to 189 mo). SFT should be considered in the differential diagnoses of mesenchymal neoplasms of the pancreas. Immunohistochemical nuclear STAT6 expression is a characteristic feature of SFT. Primary pancreatic SFTs seem to have favorable biological behavior in our series.

Synthesis, Optical Properties, and In Vivo Biodistribution Performance of Polymethine Cyanine Fluorophores

Near-infrared (NIR) cyanine dyes showed enhanced properties for biomedical imaging. A systematic modification within the cyanine skeleton has been made through a facile design and synthetic route for optimal bioimaging. Herein, we report the synthesis of 11 NIR cyanine fluorophores and an investigation of their physicochemical properties, optical characteristics, photostability, and in vivo performance. All synthesized fluorophores absorb and emit within 610-817 nm in various solvents. These dyes also showed high molar extinction coefficients ranging from 27,000 to 270,000 cm-1 M-1, quantum yields 0.01 to 0.33, and molecular brightness 208-79,664 cm-1 M-1 in the tested solvents. Photostability data demonstrate that all tested fluorophores 28, 18, 20, 19, 25, and 24 are more photostable than the FDA-approved indocyanine green. In the biodistribution study, most compounds showed tissue-specific targeting to selectively accumulate in the adrenal glands, lymph nodes, or gallbladder while excreted to the hepatobiliary clearance route. Among the tested, compound 23 showed the best targetability to the bone marrow and lymph nodes. Since the safety of cyanine fluorophores is well established, rationally designed cyanine fluorophores established in the current study will expand an inventory of contrast agents for NIR imaging of not only normal tissues but also cancerous regions originating from these organs/tissues.

Pancreatic hamartoma: detection of harbouring NAB2-STAT6 fusion gene

AIM

Hamartomas in the pancreas are rare and are often histologically and morphologically similar to solitary fibrous tumours (SFTs). We examined the differences between hamartomas and SFTs at the molecular level.

METHODS AND RESULTS

Thirteen patients histopathologically diagnosed with pancreatic hamartoma were included in the study. We also performed STAT6 immunohistochemistry (IHC), which is used in the diagnosis of SFT. Furthermore, for the three cases in which RNA was extracted, reverse transcription polymerase chain reaction to search for NAB2-STAT6 fusions was used. Macroscopically, 13 patients had well-demarcated tumour lesions. Histologically, no islets of Langerhans were observed in the lesions, acinar tissue and ducts were unevenly distributed, and elastic fibres were not observed around the ducts by Elastica Van Gieson staining. One case contained a lipomatous hamartoma composed mainly of adipose tissue. Seven of the 13 cases demonstrated expression of STAT6 in the nuclei of intervening spindle cells. NAB2-STAT6 fusions were observed in two of the three cases in which RNA was extracted. These two cases also demonstrated STAT6 expression in spindle cells using STAT6 IHC. In one case of lipomatous hamartoma, we did not confirm NAB2-STAT6 fusion or STAT6 expression in STAT6 IHC.

CONCLUSION

Of the 13 patients histopathologically diagnosed with hamartoma, two demonstrated NAB2-STAT6 fusions, suggesting the existence of pancreatic hamartomas with molecular-level components identical to those of SFT.

Fluorescence Imaging Using Methylene Blue Sentinel Lymph Node Biopsy in Melanoma

Introduction

Fluorescence imaging of sentinel node biopsy in melanoma is a novel method. Both indocyanine green (ICG) and methylene blue (MB) have fluorescent properties. The aim of this study was to present, for the first time in a clinical series of patients, the possible usage of MB as a fluorescent dye for sentinel node biopsy during surgery for melanoma.

Material and methods

Twenty patients with skin melanoma, who were candidates for sentinel node biopsy were enrolled in our study. All patients underwent simultaneous use of standard nanocolloid and blue dye. Transcutaneous visualization of the sentinel node, visualization of lymphatic channels as well as sentinel node fluorescent visualization were all measured. We also performed calculations of Signal to Background ratios (SBR).

Results

In 15% (3/20) of patients, the fluorescent sentinel node was visible through the skin. The median SBR for the sentinel node visualization by fluorescence was 3.15 (range, 2.7–3.5). Lymphatic channels were visible in lymphatic tissue via fluorescence before visualization by the naked eye in 4 patients (20%). The median SBR ratio was 3.69 (range, 2.7–4.2). Sentinel nodes were visible by fluorescence in 13 cases (65%). The median SBR ratio was 2.49 (range, 1.5–5.7). No factors were found to be associated with fluorescent MB visualization of a sentinel node during biopsy.

Conclusion

This is the first clinical study presenting the usefulness of fluorescent sentinel node biopsy in melanoma patients using MB as a fluorophore. Further studies are necessary to provide methods for its’ clinical implementation.

Overview and Future Perspectives on Tumor-Targeted Positron Emission Tomography and Fluorescence Imaging of Pancreatic Cancer in the Era of Neoadjuvant Therapy

BACKGROUND

Despite recent advances in the multimodal treatment of pancreatic ductal adenocarcinoma (PDAC), overall survival remains poor with a 5-year cumulative survival of approximately 10%. Neoadjuvant (chemo- and/or radio-) therapy is increasingly incorporated in treatment strategies for patients with (borderline) resectable and locally advanced disease. Neoadjuvant therapy aims to improve radical resection rates by reducing tumor mass and (partial) encasement of important vascular structures, as well as eradicating occult micrometastases. Results from recent multicenter clinical trials evaluating this approach demonstrate prolonged survival and increased complete surgical resection rates (R0). Currently, tumor response to neoadjuvant therapy is monitored using computed tomography (CT) following the RECIST 1.1 criteria. Accurate assessment of neoadjuvant treatment response and tumor resectability is considered a major challenge, as current conventional imaging modalities provide limited accuracy and specificity for discrimination between necrosis, fibrosis, and remaining vital tumor tissue. As a consequence, resections with tumor-positive margins and subsequent early locoregional tumor recurrences are observed in a substantial number of patients following surgical resection with curative intent. Of these patients, up to 80% are diagnosed with recurrent disease after a median disease-free interval of merely 8 months. These numbers underline the urgent need to improve imaging modalities for more accurate assessment of therapy response and subsequent re-staging of disease, thereby aiming to optimize individual patient's treatment strategy. In cases of curative intent resection, additional intra-operative real-time guidance could aid surgeons during complex procedures and potentially reduce the rate of incomplete resections and early (locoregional) tumor recurrences. In recent years intraoperative imaging in cancer has made a shift towards tumor-specific molecular targeting. Several important molecular targets have been identified that show overexpression in PDAC, for example: CA19.9, CEA, EGFR, VEGFR/VEGF-A, uPA/uPAR, and various integrins. Tumor-targeted PET/CT combined with intraoperative fluorescence imaging, could provide valuable information for tumor detection and staging, therapy response evaluation with re-staging of disease and intraoperative guidance during surgical resection of PDAC.

METHODS

A literature search in the PubMed database and (inter)national trial registers was conducted, focusing on studies published over the last 15 years. Data and information of eligible articles regarding PET/CT as well as fluorescence imaging in PDAC were reviewed. Areas covered: This review covers the current strategies, obstacles, challenges, and developments in targeted tumor imaging, focusing on the feasibility and value of PET/CT and fluorescence imaging for integration in the work-up and treatment of PDAC. An overview is given of identified targets and their characteristics, as well as the available literature of conducted and ongoing clinical and preclinical trials evaluating PDAC-targeted nuclear and fluorescent tracers.

Versatile Types of Inorganic/Organic NIR-IIa/IIb Fluorophores: From Strategic Design toward Molecular Imaging and Theranostics

In vivo imaging in the second near-infrared window (NIR-II, 1000-1700 nm), which enables us to look deeply into living subjects, is producing marvelous opportunities for biomedical research and clinical applications. Very recently, there has been an upsurge of interdisciplinary studies focusing on developing versatile types of inorganic/organic fluorophores that can be used for noninvasive NIR-IIa/IIb imaging (NIR-IIa, 1300-1400 nm; NIR-IIb, 1500-1700 nm) with near-zero tissue autofluorescence and deeper tissue penetration. This review provides an overview of the reports published to date on the design, properties, molecular imaging, and theranostics of inorganic/organic NIR-IIa/IIb fluorophores. First, we summarize the design concepts of the up-to-date functional NIR-IIa/IIb biomaterials, in the order of single-walled carbon nanotubes (SWCNTs), quantum dots (QDs), rare-earth-doped nanoparticles (RENPs), and organic fluorophores (OFs). Then, these novel imaging modalities and versatile biomedical applications brought by these superior fluorescent properties are reviewed. Finally, challenges and perspectives for future clinical translation, aiming at boosting the clinical application progress of NIR-IIa and NIR-IIb imaging technology are highlighted.

Cytopathological characteristics of solitary fibrous tumour involving the pancreas by fine needle aspiration: Making an accurate preoperative diagnosis in an uncommon location

BACKGROUND

Solitary fibrous tumour (SFT) is a unique mesenchymal neoplasm with classic features on histology and is characterised by the NAB2-STAT6 gene fusion. There are rare reports of SFTs with pancreatic involvement and only two cases in the literature reporting its features by preoperative fine needle aspiration (FNA). Herein, we characterise the cytomorphological features of four SFTs involving the pancreas by FNA to establish a preoperative diagnostic approach.

METHODS

The anatomic pathology archives of two academic medical centres were searched to identify patients with a pancreatic FNA cytology specimen and a confirmed diagnosis of SFT by surgical resection. The clinical history, pathological diagnosis, cytomorphological findings, and results of immunohistochemistry (IHC) were reviewed.

RESULTS

Four SFTs were identified from four patients with a median age of 59 years. The morphological features were variable but most frequently showed a bland spindled-to-epithelioid proliferation in fragments and single cells with small, oval, elongated, and hypochromatic nuclei in a haphazard arrangement with or without dense collagen. One tumour presented with a concurrent metastasis and showed a pure epithelioid component with necrosis and enlarged, hyperchromatic nuclei with conspicuous nucleoli and scattered mitoses. IHC was necessary for all diagnoses which were confirmed by surgical resection.

CONCLUSIONS

SFTs with pancreatic involvement are rare, and non-specific features and tumour heterogeneity can pose a diagnostic challenge on FNA; however, IHC can be used to make a definitive diagnosis. As a result, FNA is a simple, safe, cost-effective, and accurate approach that can be used to diagnose SFT in the pancreas.

Clinically translatable formulation strategies for systemic administration of nerve-specific probes

Nerves are extremely difficult to identify and are often accidently damaged during surgery, leaving patients with lasting pain and numbness. Herein, a novel near-infrared (NIR) nerve-specific fluorophore, LGW01-08, was utilized for enhanced nerve identification using fluorescence guided surgery (FGS), formulated using clinical translatable strategies. Formulated LGW01-08 was examined for toxicology, pharmacokinetics (PK), and pharmacodynamics (PD) parameters in preparation for future clinical translation. Optimal LGW01-08 imaging doses were identified in each formulation resulting in a 10x difference between the toxicity to imaging dose window. Laparoscopic swine surgery completed using the da Vinci surgical robot (Intuitive Surgical) demonstrated the efficacy of formulated LGW01-08 for enhanced nerve identification. NIR fluorescence imaging enabled clear identification of nerves buried beneath ~3 mm of tissue that were unidentifiable by white light imaging. These studies provide a strong basis for future clinical translation of NIR nerve-specific fluorophores for utility during FGS to improve patient outcomes.

Malignant solitary fibrous tumor of the pancreas: a case report

Background

Solitary fibrous tumors (SFTs) are rare tumors, mostly derived from connective tissue mesenchymal cells that arise from the pleura. There are very few reports of primary pancreatic SFT. Preoperative diagnosis is difficult owing to the lack of distinctive radiological findings. We report a case of pancreatic SFT with particularly rare malignant findings.

Case presentation

A 60-year-old man was referred to the hospital because of a right upper quadrant mass and abnormal liver function test results. Contrast-enhanced computed tomography (CT) showed a well-defined enhanced tumor measuring approximately 8 cm in the pancreatic head. Magnetic resonance imaging (MRI) showed T1WI hypointensity, T2WI hyperintensity, and DWI hyperintensity. The main pancreatic duct and common bile duct were dilated owing to obstruction by the tumor. The following tumor markers were mildly elevated: carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), SPan-1, and DUPAN-2. The histological diagnosis obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was negative for pancreatic ductal carcinoma, malignant lymphoma and neuroendocrine tumor, suggesting the possibility of mesenchymal tumor, but the diagnosis was not confirmed. The patient was judged suitable for surgery and underwent subtotal stomach-preserving pancreatoduodenectomy with D2 lymph node dissection. On histopathological examination of the resected specimen, infiltrating spindle-shaped cells had proliferated, containing numerous mitotic figures, with necrotic findings inside the tumor. Immunostaining was positive for cluster of differentiation-34 (CD34), B cell CLL/lymphoma-2 (Bcl-2), and signal transducer and activator of transcription (STAT6). On the basis of these findings, a diagnosis of malignant pancreatic SFT was made. The patient remains free of recurrent disease after 12 months of follow-up without adjuvant therapy and he is being carefully followed up as an outpatient.

Conclusions

We experienced a case of malignant pancreatic head SFT. Immunohistochemical staining of the extracted specimens was useful for diagnosis.

Methylene Blue-Current Knowledge, Fluorescent Properties, and Its Future Use

Methylene blue is a fluorescent dye discovered in 1876 and has since been used in different scientific fields. Only recently has methylene blue been used for intraoperative fluorescent imaging. Here, the authors review the emerging role of methylene blue, not only as a dye used in clinical practice, but also as a fluorophore in a surgical setting. We discuss the promising potential of methylene blue together with the challenges and limitations among specific surgical techniques. A literature review of PubMed and Medline was conducted based on the historical, current and future usage of methylene blue within the field of medicine. We reviewed not only the current usage of methylene blue, but we also tried to grasp its' function as a fluorophore in five main domains. These domains include the near-infrared imaging visualization of ureters, parathyroid gland identification, pancreatic tumors imaging, detection of breast cancer tumor margins, as well as breast cancer sentinel node biopsy. Methylene blue is used in countless clinical procedures with a relatively low risk for patients. Usage of its fluorescent properties is still at an early stage and more pre-clinical, as well as clinical research, must be performed to fully understand its potentials and limitations.

Atypical/malignant solitary fibrous tumor of the pancreas with spleen vein invasion: Case report and literature review

INTRODUCTION

Solitary fibrous tumor (SFT) is an uncommon mesenchymal tumor that is most common in the pleura. However, according to previous studies, the SFT of the pancreas is extremely rare; only 20 cases have been reported so far. Here, we conduct a literature review and report the first case of atypical/malignant SFT of the pancreas with spleen vein invasion.

PATIENT CONCERNS

The patient is a 61-year-old Chinese male who presented with 1 week of upper abdominal pain. Abdominal magnetic resonance imaging showed a huge mass (>10 cm) at the distal end of the pancreas, and the mass obstructing the splenic vein.

DIAGNOSIS

Atypical/malignant SFT of the pancreas with splenic vein tumor thrombus.

INTERVENTIONS

The patient underwent laparoscopic distal pancreatectomy with splenectomy procedure to achieve a radical resection, and did not undergo chemotherapy or radiotherapy.

OUTCOMES

Abdominal computed tomography scans were performed at 1 and 4 months after resection, and no signs of recurrence or metastasis were found (. B).(Figure is included in full-text article.) CONCLUSION:: The clinical symptoms of atypical/malignant SFT of the pancreas with spleen vein invasion are not atypical, and imaging feature is lack of specificity. Preoperative diagnosis is difficult, and there is a potential for malignancy. However, due to the paucity of randomized control trials, there is no established, globally accepted treatment strategy, radiation therapy and chemotherapy regimens have not demonstrated global effectiveness, and no standardized treatments have been identified. Therefore, we recommend complete surgical resection and close clinical follow-up.

Fluorescence Image-Guided Surgery - a Perspective on Contrast Agent Development

In the past several decades, a number of novel fluorescence image-guided surgery (FGS) contrast agents have been under development, with many in clinical translation and undergoing clinical trials. In this review, we have identified and summarized the contrast agents currently undergoing clinical translation. In total, 39 novel FGS contrast agents are being studied in 85 clinical trials. Four FGS contrast agents are currently being studied in phase III clinical trials and are poised to reach FDA approval within the next two to three years. Among all novel FGS contrast agents, a wide variety of probe types, targeting mechanisms, and fluorescence properties exists. Clinically available FGS imaging systems have been developed for FDA approved FGS contrast agents, and thus further clinical development is required to yield FGS imaging systems tuned for the variety of contrast agents in the clinical pipeline. Additionally, study of current FGS contrast agents for additional disease types and development of anatomy specific contrast agents is required to provide surgeons FGS tools for all surgical specialties and associated comorbidities. The work reviewed here represents a significant effort from many groups and further development of this promising technology will have an enormous impact on surgical outcomes across all specialties.

Malignant solitary fibrous tumor of the pancreas with systemic metastasis: A case report and review of the literature

BACKGROUND

Pancreatic solitary fibrous tumor (SFT) is a rare neoplasm of intermediate biological potential. So far, only 22 cases have been reported since 1999. All the cases, except one, exhibited benign features. Here, we report the first case of malignant pancreatic SFT with typical Doege-Potter syndrome, along with the clinical and pathologic evidence of its systemic metastasis.

CASE SUMMARY

The patient was a 48-year-old man with a 1-year history of pancreatic and liver masses and refractory hypoglycemia. Increased uptake of the tracer fluorodeoxyglucose (FDG) was found in the liver and bones by fluorine-18 FDG positron emission tomography/computed tomography. After multidisciplinary discussion, a distal pancreatectomy procedure was performed, and histological examination showed a lesion composed of abundant heterogeneous spindle cells with localized necrosis. On immunohistochemistry evaluation, STAT6 was found to be diffusely expressed in the tumor. Based on the overall evidence, the patient was diagnosed with malignant pancreatic SFT with liver and bone metastases.

CONCLUSION

The diagnosis of malignant SFT requires comprehensive evidence including clinical, immunohistochemistry, and histological features. This case may be presented as a reference for diagnoses and management of malignant pancreatic SFTs with systemic metastasis.

A rare case of metastatic solitary fibrous tumor of the pancreas manifesting as a cystic neoplasm: a case report

Background

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor that typically arises from the pleura. Although it may appear in other organs, it rarely develops in the pancreas. We report herein a rare case of metastatic SFT of the pancreas originating from an intracranial tumor and subsequently identified as a cystic neoplasm of the pancreas.

Case presentation

A 58-year-old woman with a past medical history of brain tumor visited the hospital for further investigation of a cystic tumor in the pancreas tail. Abdominal imaging showed a heterogeneously enhancing mass that was initially suspected as a neuroendocrine neoplasm, solid pseudopapillary neoplasm, or mucinous cystic neoplasm of the pancreas. Distal pancreatectomy was performed without any intraoperative and postoperative complications. Pathological findings confirmed a diagnosis of malignant SFT of the pancreas with hyperproliferative potential. A histopathological review of her brain tumor revealed that the pancreatic tumor was derived from her brain lesion. The patient developed recurrent brain disease 4 years after the pancreatectomy, but no recurrence has been observed in the abdominal cavity.

Conclusions

SFT should be considered in the differential diagnosis of untypical hypervascular pancreatic mass, particularly in patients with a history of an intrathoracic or intracranial mesenchymal tumor. Immunohistochemical analysis is crucial in detecting this tumor entity. Hyperproliferative status indicates a malignant disease and requires careful postoperative observation.

Fluorescence Guidance in Surgical Oncology: Challenges, Opportunities, and Translation

Surgical resection continues to function as the primary treatment option for most solid tumors. However, the detection of cancerous tissue remains predominantly subjective and reliant on the expertise of the surgeon. Surgery that is guided by fluorescence imaging has shown clinical relevance as a new approach to detecting the primary tumor, tumor margins, and metastatic lymph nodes. It is a technique to reduce recurrence and increase the possibility of a curative resection. While significant progress has been made in developing this emerging technology as a tool to assist the surgeon, further improvements are still necessary. Refining imaging agents and tumor targeting strategies to be a precise and reliable surgical strategy is essential in order to translate this technology into patient care settings. This review seeks to provide a comprehensive update on the most recent progress of fluorescence-guided surgery and its translation into the clinic. By highlighting the current status and recent developments of fluorescence image-guided surgery in the field of surgical oncology, we aim to offer insight into the challenges and opportunities that require further investigation.

Methylene Blue-Based Near-Infrared Fluorescence Imaging for Breast Cancer Visualization in Resected Human Tissues

Breast-conserving surgery is facing the challenge of objective tumor margin identification intraoperatively. Near-infrared fluorescence imaging would be an ideal approach to visualize tumor margins during surgeries. In this preliminary study, the feasibility of methylene blue-based near-infrared fluorescence imaging technique for breast cancer detection was assessed in resected human breast specimens after breast cancer surgeries. Thirty patients with breast cancer scheduled for surgical treatment were enrolled, including 10 patients with preoperative chemotherapy and 20 patients without. Each of them received an injection of 1 mg/kg methylene blue intravenously 3 hours before the surgery. Then, a home-developed methylene blue-specific near-infrared fluorescence imaging system was employed to image the resected breast tissues and identify the tumor by the fluorescence contrast. Specimens were taken for pathological examinations as the reference. There were no severe adverse events attributable to methylene blue. Of 20 patients, who did not receive preoperative chemotherapy, 16 exhibited fluorescent contrast on their resected tissues (signal-to-background ratio: 1.94 ± 0.71). In contrast, tumors were identified in 3 of 10 specimens from patients who underwent preoperative chemotherapy (signal-to-background ratio: 1.63 ± 0.38). A total of 35 tissues were sampled from 30 specimens. Besides 30 tumor samples, 5 more suspicious samples with fluorescence signal were confirmed to be benign hemorrhagic tissues. Therefore, a sensitivity of 0.63 and a positive predictive value of 0.79 were achieved by the methylene blue fluorescence imaging strategy. Here, we demonstrate the feasibility of using methylene blue fluorescence imaging to identify breast cancer. Preoperative chemotherapy had an impact on imaging effect, which may reduce the detection rate. After all, methylene blue fluorescence imaging has great potential to be used into breast-conserving surgery for tumor-positive margins detection, but further clinical trial study is needed ( http://www.chictr.org.cn/ Clinical Trial Registry ID: ChiCTR1800015400, Near-infrared fluorescence imaging applied in breast cancer identification with methylene blue).

Indocyanine Green Perfusion Imaging-Guided Laparoscopic Pancreaticoduodenectomy: Potential Application in Retroperitoneal Margin Dissection

BACKGROUND

During laparoscopic pancreaticoduodenectomy (LPD), dissecting uncinate process from the superior mesenteric artery (SMA) will determine one of the important surgical margins (retroperitoneal margin) for predicting oncological outcomes and the quality of LPD. However, clear identification of the division line for retroperitoneal margin is not easy as the uncinate process of the pancreas is anatomically very close to SMA and intermingled with the nerve plexus and soft tissues around SMA. In this study, we present data regarding the potential usefulness of indocyanine green (ICG)-enhanced approach in obtaining retroperitoneal margin during LPD.

METHODS

From January to September 2017, medical records of patients who underwent LPD for periampullary pathological conditions were retrospectively reviewed. ICG (5 mg/2 cm³) was prepared and intravenously injected when dissecting uncinate process of the pancreas. Perioperative outcomes, including gender, age, diagnosis, body mass index, operation time, estimated blood loss, transfusion, presence of postoperative pancreatic fistulas (POPFs), and length of hospital stay, were evaluated.

RESULTS

During the study period, a total of 37 patients underwent LPD for periampullary pathological lesions. Among them, ICG-enhanced dissection of uncinate process of the pancreas was applied in 10 patients (27%). All patients were able to obtain margin-negative resection. There were no significant differences between the perioperative outcomes of patients who did and did not undergo ICG-enhanced approach.

DISCUSSION

ICG perfusion-based laparoscopic dissection of retroperitoneal margin is feasible and safe in LPD. This intraoperative visual difference can provide the surgeon with very helpful real-time visual information. Further study is mandatory.

The development of fluorescence guided surgery for pancreatic cancer: from bench to clinic

INTRODUCTION

Surgeons face major challenges in achieving curative R0 resection for pancreatic cancers. When the lesion is localized, they must appropriately visualize the tumor, determine appropriate resection margins, and ensure complete tumor clearance. Real-time surgical navigation using fluorescence-guidance has enhanced the ability of surgeons to see the tumor and has the potential to assist in achieving more oncologically complete resections. When there is metastatic disease, fluorescence enhancement can help detect these lesions and prevent unnecessary and futile surgeries. Areas covered: This article reviews different approaches for delivery of a fluorescence signal, their pre-clinical and clinical developments for fluorescence guided surgery, the advantages/challenges of each, and their potential for advancements in the future. Expert commentary: A variety of molecular imaging techniques are available for delivering tumor-specific fluorescence signals. Significant advancements have been made in the past 10 years due to the large body of literature on targeted therapies and this has translated into rapid developments of tumor-specific probes.

Indocyanine green loaded hyaluronan-derived nanoparticles for fluorescence-enhanced surgical imaging of pancreatic cancer

Pancreatic ductal adenocarcinoma is highly lethal and surgical resection is the only potential curative treatment for the disease. In this study, hyaluronic acid derived nanoparticles with physico-chemically entrapped indocyanine green, termed NanoICG, were utilized for intraoperative near infrared fluorescence detection of pancreatic cancer. NanoICG was not cytotoxic to healthy pancreatic epithelial cells and did not induce chemotaxis or phagocytosis, it accumulated significantly within the pancreas in an orthotopic pancreatic ductal adenocarcinoma model, and demonstrated contrast-enhancement for pancreatic lesions relative to non-diseased portions of the pancreas. Fluorescence microscopy showed higher fluorescence intensity in pancreatic lesions and splenic metastases due to NanoICG compared to ICG alone. The in vivo safety profile of NanoICG, including, biochemical, hematological, and pathological analysis of NanoICG-treated healthy mice, indicates negligible toxicity. These results suggest that NanoICG is a promising contrast agent for intraoperative detection of pancreatic tumors.

Optical molecular imaging for tumor detection and image-guided surgery

We have witnessed rapid development of fluorescence molecular imaging of solid tumors for cancer diagnosis and image-guided surgery in the past decade. Many biomarkers unique to cancer cells or tumor microenvironment, such as cell surface receptors, hypoxia, secreted proteases and extracellular acidosis have been characterized, and can be used to distinguish cancer from normal tissue. A variety of optical imaging probes have been developed to target these biomarkers to improve tumor contrast over the background tissue. Unlike conventional anatomical and molecular imaging technologies, fluorescent imaging method benefits from its safety, high-spatial resolution and real-time capability, and therefore, has become a highly adoptable imaging method for tumor detection and image-guided surgery in clinics. In this review, we summarize recent progress in 'always-ON' and stimuli-activatable fluorescent imaging probes, and discuss their potentials in tumor detection and image-guided surgery.

Photodynamic Therapy

Photodynamic therapy is a clinical technique for the treatment of cancers, microbial infections and other medical conditions by means of light-induced generation of reactive oxygen species using photosensitising drugs. The intrinsic fluorescence of many such drugs make them potential theranostic agents for simultaneous diagnosis and therapy. This chapter reviews the basic chemical and biological aspects of photodynamic therapy with an emphasis on its applications in theranostics. The roles of nanotechnology is highlighted, as well as emerging trends such as photoimmunotherapy, image-guided surgery and light- and singlet-oxygen dosimetry.

Fluorescence-Guided Surgery

Surgical resection of cancer remains an important treatment modality. Despite advances in preoperative imaging, surgery itself is primarily guided by the surgeon’s ability to locate pathology with conventional white light imaging. Fluorescence-guided surgery (FGS) can be used to define tumor location and margins during the procedure. Intraoperative visualization of tumors may not only allow more complete resections but also improve safety by avoiding unnecessary damage to normal tissue which can also reduce operative time and decrease the need for second-look surgeries. A number of new FGS imaging probes have recently been developed, complementing a small but useful number of existing probes. In this review, we describe current and new fluorescent probes that may assist FGS.

A case of a "wandering" mobile solitary fibrous tumor occurring in the pancreas

A 73-year-old male with a complaint of abdominal discomfort was examined by abdominal ultrasonography and found to have a hypoechoic mass in the upper abdomen. On abdominal computed tomography (CT), there was a 5-cm, hypervascular mass between the stomach and aorta. Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) showed a homogeneous mass with hypointensity on T1-weighted images, accompanied by stenosis of the main pancreatic duct of the pancreatic head. On endoscopic ultrasonography, the mass was depicted as a round homogeneous, hypervascular mass attached to the pancreatic head. Surprisingly, the mass was located on the right side of the aorta on the second CT. Histological examination of the resected specimen showed that the lesion was composed of spindle cells with cord-like arrangement, the features of which were compatible with a mobile solitary fibrous tumor.

Beyond the margins: real-time detection of cancer using targeted fluorophores

Over the past two decades, synergistic innovations in imaging technology have resulted in a revolution in which a range of biomedical applications are now benefiting from fluorescence imaging. Specifically, advances in fluorophore chemistry and imaging hardware, and the identification of targetable biomarkers have now positioned intraoperative fluorescence as a highly specific real-time detection modality for surgeons in oncology. In particular, the deeper tissue penetration and limited autofluorescence of near-infrared (NIR) fluorescence imaging improves the translational potential of this modality over visible-light fluorescence imaging. Rapid developments in fluorophores with improved characteristics, detection instrumentation, and targeting strategies led to the clinical testing in the early 2010s of the first targeted NIR fluorophores for intraoperative cancer detection. The foundations for the advances that underline this technology continue to be nurtured by the multidisciplinary collaboration of chemists, biologists, engineers, and clinicians. In this Review, we highlight the latest developments in NIR fluorophores, cancer-targeting strategies, and detection instrumentation for intraoperative cancer detection, and consider the unique challenges associated with their effective application in clinical settings.

Structure-Inherent Targeting of Near-Infrared Fluorophores for Image-Guided Surgery

Although various clinical imaging modalities have been developed to visualize internal body structures and detect abnormal tissues prior to surgical procedures, most medical imaging modalities do not provide disease-specific images in real-time. Optical imaging can provide the surgeon with real-time visualization of the surgical field for intraoperative image-guided surgery. Imaging in the near-infrared (NIR) window (650-900 nm), also known as the "therapeutic window" has high potential by offering low absorbance and scattering in tissues resulting in minimized background autofluorescence. Clinically, optical fluorescence imaging with the targeted contrast agents provides opportunities for significant advances in intraoperative image-guided surgery. There are only two clinically available NIR fluorophores, indocyanine green (ICG) and methylene blue (MB), that support the image-guided surgery. However, neither of them perform in vivo by providing optimum specificity and stability for targeted image guidance. Therefore, it is of paramount importance to develop targeted NIR fluorophores for unmet clinical needs. Using the right combination of an NIR fluorescence imaging system and a targeted fluorophore, the desired target tissues can be imaged to provide real-time fluorescence guidance without changing the field-of-view during surgery. Thus, in a clinical discipline, the development of NIR fluorophores for 'structure-inherent targeting' is an unmet need for early phase diagnostics with accurate targeting.

Validation of full-field optical coherence tomography in distinguishing malignant and benign tissue in resected pancreatic cancer specimens

Background

Pancreatic cancer is the fourth leading cause of cancer-related mortality in the United States. The minority of patients can undergo curative-intended surgical therapy due to progressive disease stage at time of diagnosis. Nonetheless, tumor involvement of surgical margins is seen in up to 70% of resections, being a strong negative prognostic factor. Real-time intraoperative imaging modalities may aid surgeons to obtain tumor-free resection margins. Full-field optical coherence tomography (FF-OCT) is a promising diagnostic tool using high-resolution white-light interference microscopy without tissue processing. Therefore, we composed an atlas of FF-OCT images of malignant and benign pancreatic tissue, and investigated the accuracy with which the pathologists could distinguish these.

Materials and methods

One hundred FF-OCT images were collected from specimens of 29 patients who underwent pancreatic resection for various indications between 2014 and 2016. One experienced gastrointestinal pathologist and one pathologist in training scored independently the FF-OCT images as malignant or benign blinded to the final pathology conclusion. Results were compared to those obtained with standard hematoxylin and eosin (H&E) slides.

Results

Overall, combined test characteristics of both pathologists showed a sensitivity of 72%, specificity of 74%, positive predictive value of 69%, negative predictive value of 79% and an overall accuracy of 73%. In the subset of pancreatic ductal adenocarcinoma patients, 97% of the FF-OCT images (n = 35) were interpreted as tumor by at least one pathologist. Moreover, normal pancreatic tissue was recognised in all cases by at least one pathologist. However, atrophy and fibrosis, serous cystadenoma and neuroendocrine tumors were more often wrongly scored, in 63%, 100% and 25% respectively.

Conclusion

FF-OCT could distinguish normal pancreatic tissue from pathologic pancreatic tissue in both processed as non-processed specimens using architectural features. The accuracy in pancreatic ductal adenocarcinoma is promising and warrants further evaluation using improved assessment criteria.

[Application of carbon nanoparticles as lymph node tracers in patients with cN0 lingual squamous cell carcinoma un-dergoing neck dissection]

OBJECTIVE

This study aimed to investigate the value of carbon nanoparticles as lymph node tracers in neck dissection for cN0 lingual squamous cell carcinoma patients.

METHODS

Ninety-six patients with cN0 lingual squamous cell carcinoma were recruited to undergo surgical treatment were randomly divided into two groups, namely, the carbon nanoparticle-labeled group (the experimental group, 50 cases) and the control group (46 cases). Carbon nanoparticle suspension was injected into the submucosal layer around the site of the primary tumor at three or four points (0.1 mL for each point) 12 h before surgery. Supraomohyoid neck dissection (SOHND, Levels Ⅰ to Ⅲ) or comprehensive neck dissection (CND, Levels Ⅰto Ⅴ) were performed based on the size and location of the primary tumor. All the lymph nodes were dissected and separated from the ex vivo surgical specimens for histopathological evaluation. The number, size, location, and pathological result of all the lymph nodes were compared between the two groups. Statistical analyses were conducted by SPSS 19.0 software.

RESULTS

A total of 1 137 lymph nodes were detected in 31 SOHND patients. The average number of lymph nodes detected in the experimental group was (43.79±19.23) /case, which was significantly higher than that in the control group [(30.82±8.77) /case] (P=0.019). Level Ⅲ covered the largest number of lymph nodes in the two groups. However, the number and proportion of lymph nodes found in Level Ⅱ of the experimental group were significantly higher than those of the control group (P=0.000). A total of 3 938 lymph nodes were detected in 65 CND patients. The average number of lymph nodes detected in the experimental group [(66.67±20.02) /case] was larger than that in the control group [(53.03±20.98) /case] (P=0.026). The difference in the lymph node location between the two groups was not statistically significant (P=0.354). In the two neck dissection methods, both the proportion of minute lymph nodes and the accuracy of the detected lymph nodes in the experimental group were significantly larger than those in the control groups (P=0.000). Compared with the control group, more metastases were proven by the carbon nanoparticle-labeled lymph nodes (P=0.000) in the experimental group.

CONCLUSIONS

Carbon nanoparticles as lymph node tracers in patients with cN0 lingual squamous cell carcinoma undergoing neck dissection can increase the number of detected lymph nodes, especially the minute nodes. Such nanoparticles can further ensure the thoroughness of neck dissection and the accuracy of clinicopathological stage.

Is there a role for near-infrared technology in laparoscopic resection of pancreatic neuroendocrine tumors? Results of the COLPAN "colour-and-resect the pancreas" study

BACKGROUND

The intraoperative identification of pancreatic neuroendocrine tumors (PanNETs) is of utmost importance to drive their laparoscopic resection. Near-infrared (NIR) surgery has emerged as a new technique for localizing tumors or neoplastic tissue. This study aimed to explore the results of the application of NIR in the laparoscopic resection of PanNETs.

METHODS

Per protocol we enrolled ten subjects undergoing laparoscopic pancreatic surgery for PanNET from March 2016 to October 2016. During surgery, the patients were injected with indocyanine green dye (ICG, 25 mg given in 5 boli of 5 mg each). The switch-activation of NIR was performed to identify PanNETs. An ex-post analysis of the images was realized using ImageJ Software® to calculate the fluorescence signal.

RESULTS

NIR imaging identified all ten PanNETs. Nine (90%) laparoscopic distal pancreatectomy with splenectomy and one (10%) laparoscopic enucleation were performed. The mean maximum tumor dimension was 2.4 cm (range 1-4 cm). Eight non-functioning PanNETs (80%) and two insulinomas (20%) were found at the final pathology. Nine out of ten (90%) PanNETs were detected after the second ICG bolus. The mean latency time was 80 s and the mean visibility time was 220 s. The peak of tumor visualization was reached 20 min after the last bolus. This finding was confirmed by the ex-post analysis of the fluorescence signal (mean signal-to-background ratio of 7.7, p = 0.001). NIR identified two additional lesions, which turned out to be normal lymph nodes at final pathology. A fluorescent signal was identified at the bed of the enucleation, and thus, a further exeresis was performed and final pathology revealed that is was residual neoplastic tissue.

CONCLUSIONS

This explorative study shows that NIR with ICG can have a role in laparoscopic pancreatic resection of PanNETs. Further studies are needed to assess the proper setting and role of this new and promising technology.

Pancreatic solitary fibrous tumor in a toddler managed by pancreaticoduodenectomy: a case report and review of the literature

Solitary fibrous tumor (SFT) of the pancreas is rare, with 15 adult cases reported in the English literature. We described a 14-month-old boy who presented with obstructive jaundice. Dominantly elevated serum CA19-9 was detected. Imaging studies revealed a well-circumscribed, solid mass in the pancreatic head. A pancreaticoduodenectomy (child procedure) was performed using Shen’s anastomosis technique. After resection of the tumor, liver function and serum tumor markers normalized and clinical signs receded. The boy was disease free after a follow-up of 12 months. Histological examination showed the tumor consisted of “patternless pattern” arranged spindle tumor cells and keloid-like hyalinized collagen. Immunohistochemical staining was positive for CD34 and vimentin. Mutation analysis of CTNNB1 was negative. To the best of our knowledge, our patient was the first case of pancreatic SFT in a pediatric population. SFT should be considered in differential diagnosis when confronted with a pancreatic tumor in children. Complete resection should be meticulously pursued.

Near infrared fluorescent imaging of brain tumor with IR780 dye incorporated phospholipid nanoparticles

Background

Near-IR fluorescence (NIRF) imaging is becoming a promising approach in preclinical tumor detection and clinical image-guided oncological surgery. While heptamethine cyanine dye IR780 has excellent tumor targeting and imaging potential, its hydrophobic property limits its clinical use. In this study, we developed nanoparticle formulations to facilitate the use of IR780 for fluorescent imaging of malignant brain tumor.

Methods

Self-assembled IR780-liposomes and IR780-phospholipid micelles were prepared and their NIRF properties were characterized. The intracellular accumulation of IR780-nanoparticles in glioma cells were determined using confocal microscopy. The in vivo brain tumor targeting and NIRF imaging capacity of IR780-nanoparticles were evaluated using U87MG glioma ectopic and orthotopic xenograft models and a spontaneous glioma mouse model driven by RAS/RTK activation.

Results

The loading of IR780 into liposomes or phospholipid micelles was efficient. The particle diameter of IR780-liposomes and IR780-phospholipid micelles were 95 and 26 nm, respectively. While stock solutions of each preparation were maintained at ready-to-use condition, the IR780-phospholipid micelles were more stable. In tissue culture cells, IR780-nanoparticles prepared by either method accumulated in mitochondria, however, in animals the IR780-phospholipid micelles showed enhanced intra-tumoral accumulation in U87MG ectopic tumors. Moreover, IR780-phospholipid micelles also showed preferred intracranial tumor accumulation and potent NIRF signal intensity in glioma orthotopic models at a real-time, non-invasive manner.

Conclusion

The IR780-phospholipid micelles demonstrated tumor-specific NIRF imaging capacity in glioma preclinical mouse models, providing great potential for clinical imaging and image-guided surgery of brain tumors.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-1115-2) contains supplementary material, which is available to authorized users.

Pancreatic solitary fibrous tumor causing ectopic adrenocorticotropic hormone syndrome

Solitary fibrous tumors occasionally present with hypoglycemia because of the excessive release of insulin-like growth factor II. We report the first case of pancreatic solitary fibrous tumor causing ectopic adrenocorticotropic hormone syndrome. An 82-year-old Japanese man presented with lower limb edema, uncontrolled hypertension, hypokalemia, and baseline hypercortisolism. Distal pancreatectomy was performed after the clinical diagnosis of a neuroendocrine tumor with ectopic secretion of adrenocorticotropic hormone. On histological examination, the tumor showed spindle cells in a fascicular arrangement. The diagnosis of the solitary fibrous tumor was confirmed by the identification of the NAB2-STAT6 fusion gene and positive immuno-histochemical staining for STAT6 and CD34. Using quantitative real-time polymerase chain reaction, mRNA that encoded proopiomelanocortin, precursor of adrenocorticotropic hormone, was detected. Proopiomelanocortin production through the demethylation of the promoter region Domain IV was detected. Pancreatic solitary fibrous tumors represent a new cause of ectopic adrenocorticotropic hormone syndrome.

Preclinical evaluation of near-infrared (NIR) fluorescently labeled cetuximab as a potential tool for fluorescence-guided surgery

The high rate of recurrence in patients with pancreatic ductal adenocarcinoma (PDAC) could be reduced by supporting the surgeons in discriminating healthy from diseased tissues with intraoperative fluorescence-guidance. Here, we studied the suitability of Cetuximab, a therapeutic monoclonal antibody targeting the human epidermal growth factor receptor (EGFR), near-infrared (NIR) fluorescently labeled as a new tool for fluorescence-guided surgery. Distribution and binding of systemically injected Cetuximab Alexa Fluor 647 conjugate (Cetux-Alexa-647) and the co-injected control human IgG Alexa Fluor 750 conjugate (hIgG-Alexa-750) was studied over 48 h by NIR fluorescence imaging in mice bearing human orthotopic AsPC-1 and MIA PaCa-2 PDAC tumors. Cetux-Alexa-647, but not the control hIgG-Alexa-750 fluorescence, was specifically detected in vivo in both primary pancreatic tumors with maximum fluorescence intensities at 24 h, and in metastases of AsPC-1 tumors as small as 1 mm. Lifetime analysis and NIR fluorescence microscopy of tumor sections confirmed the binding specificity of Cetux-Alexa-647 to PDAC cells. Comparable results were obtained with Cetuximab conjugated to Alexa Fluor 750 dye (Cetux-Alexa-750). Fluorescence-guided dissection, performed 24 h after injection of Cetuximab conjugated to IRDye 800CW (Cetux-800CW), enabled a real-time delineation of AsPC-1 tumor margins, and small metastases. Odyssey scans revealed that only the vital part of the tumor, but not the necrotic part was stained with Cetux-800CW. NIR fluorescently labeled Cetuximab may be a promising tool that can be applied for fluorescence-guided surgery to visualize tumor margins and metastatic sites in order to allow a precise surgical resection.

Image-guided tumor surgery: will there be a role for fluorescent nanoparticles?

Image-guided surgery (IGS) using fluorescent nanoparticles (NPs) has the potential to substantially impact patient treatment. The use of fluorescence imaging provides surgeons with real-time feedback on the location of diseased tissue using safe, low-cost imaging agents and instrumentation. Fluorescent NPs are likely to play a role as they are capable of taking advantage of the enhanced permeability and retention (EPR) effect and can be modified to avoid clearance, increase circulation time, and specifically target tumors. Clinical trials of IGS using the FDA-approved fluorophores indocyanine green and methylene blue have already shown preliminary successes, and incorporation of fluorescent NPs will likely improve detection by providing higher signal to background ratio and reducing false-positive rates through active targeting. Preclinical development of fluorescent NP formulations is advancing rapidly, with strategies ranging from passive targeting to active targeting of cell surface receptors, creating pH-responsive NPs, and increasing cell uptake through cleavable proteins. This collective effort could lead to clinical trials using fluorescent NPs in the near future. WIREs Nanomed Nanobiotechnol 2016, 8:498-511. doi: 10.1002/wnan.1381 For further resources related to this article, please visit the WIREs website.

Solitary fibrous tumor of the pancreas: Case report and review of the literature

Solitary fibrous tumor (SFT) is a mesenchymal tumor typically located in the pleura, but can also be found as an asymptomatic mass in other areas, including the liver, peritoneum, kidney and salivary glands. However, SFT rarely locates in the pancreas. We present such a case of pancreatic SFT, along with a review of all reported cases. A 55-year-old man was treated surgically for an asymptomatic pancreatic mass after a rigorous preoperative control. Histologic examination of the resected specimen showed characteristics of an SFT. As only 15 cases of pancreatic SFT have been reported so far, an attempt to compare the cases was considered intriguing. We found that patients with pancreatic SFT were mainly women (81.25%), with a median age of 54 years at the time of diagnosis and a median tumor size of 5.83 cm. Pancreatic SFTs were revealed incidentally in 50% of cases, and all of them showed an enhancement through arterial computed tomography. All tumors were positive for CD34, ten were positive for Bcl-2, and twelve were negative for S100. The diagnosis of this pancreatic tumor is established by a combination of clinical suspicion, imaging procedures and histological findings, and is confirmed by immunohistochemical staining. Although the behavior of SFTs is rather benign, close clinical follow-up is recommended due to a potentially malignant nature.

Malignant Solitary Fibrous Tumor of the Pancreas

Solitary fibrous tumor (SFT) arising in the pancreas is exceedingly rare, with only 11 cases reported in the English literature. All cases described thus far have exhibited benign histology. We report the first case of malignant SFT of the pancreas. The patient was a 52-year-old woman who presented with obstructive jaundice and a 15-cm pancreatic head mass. The mass showed areas with typical histologic features for SFT including small fibroblastlike cells arranged in the well-characterized "patternless pattern" of architecture, hemangiopericytomalike vessels, areas with dense collagen and infrequent mitoses (0-2 per 10 high-power fields [HPFs]). In addition, multiple areas with an overtly sarcomatous morphology were present, containing large spindle and epithelioid cells with nuclear pleomorphism, marked cellularity, up to17 mitoses per 10 HPFs, and necrosis. Immunohistochemical stains were positive for CD34 and B-cell CLL/lymphoma 2 (Bcl-2) in both benign and malignant components and showed strong, diffuse p53 and p16 staining in the malignant component. At last follow-up (40 months), the patient was alive and well without evidence of disease. However, given that the presence of a malignant component in extrapancreatic SFT has been associated with recurrence/metastasis and death, complete surgical resection and close long-term follow-up is required.

Near-infrared imaging of brain tumors using the Tumor Paint BLZ-100 to achieve near-complete resection of brain tumors

OBJECT

The intraoperative clear delineation between brain tumor and normal tissue in real time is required to ensure near-complete resection without damaging the nearby eloquent brain. Tumor Paint BLZ-100, a tumor ligand chlorotoxin (CTX) conjugated to indocyanine green (ICG), has shown potential to be a targeted contrast agent. There are many infrared imaging systems in use, but they are not optimized to the low concentration and amount of ICG. The authors present a novel proof-of-concept near-infrared (NIR) imaging system using a standard charge-coupled device (CCD) camera for visualizing low levels of ICG attached to the tumors. This system is small, inexpensive, and sensitive. The imaging system uses a narrow-band laser at 785 nm and a notch filter in front of the sensor at the band. The camera is a 2-CCD camera, which uses identical CCDs for both visible and NIR light.

METHODS

The NIR system is tested with serial dilution of BLZ-100 from 1 μM to 50 pM in 5% Intralipid solution while the excitation energy is varied from 5 to 40 mW/cm(2). The analog gain of the CCD was changed from 0, 6, and 12 dB to determine the signal-to-noise ratio. In addition to the Intralipid solution, BLZ-100 was injected 48 hours before euthanizing the mice that were implanted with the human glioma cell line. The brain was removed and imaged using the NIR imaging system.

RESULTS

The authors' results show that the NIR imaging system using a standard CCD is able to visualize the ICG down to 50 nM of concentration with a high signal-to-noise ratio. The preliminary experiment on human glioma implanted in mouse brains demonstrated that BLZ-100 has a high affinity for glioma compared with normal brain tissue. Additionally, the results show that NIR excitation is able to penetrate deeply and has a potential to visualize metastatic lesions that are separate from the main tumor.

CONCLUSIONS

The authors have seen that BLZ-100 has a very high affinity toward human gliomas. They also describe a small, cost-effective, and sensitive NIR system for visualizing brain tumors tagged using BLZ-100. The authors hope that the use of BLZ-100 along with NIR imaging will be useful to delineate the brain tumors in real time and assist surgeons in near-complete tumor removal to increase survival and reduce neurological deficits.

Primary mesenchymal tumors of the pancreas: single-center experience over 16 years

OBJECTIVE

Primary mesenchymal tumors of the pancreas are extremely rare and no comprehensive study of this class of tumors has been previously performed.

METHODS

Twenty cases of the primary mesenchymal tumors of the pancreas were selected and compared clinicopathologic variables with consecutively resected 500 pancreatic ductal adenocarcinomas.

RESULTS

Finally, 20 (0.3%) cases were confirmed as primary mesenchymal tumors. The 14 (70%) cases of benign/borderline tumors included 4 cases of fibromatoses, 2 cases of cavernous hemangiomas, 2 cases of schwannomas, 2 cases of solid and cystic hamartomas, 2 cases of solitary fibrous tumors, 1 case of inflammatory myofibroblastic tumor, and 1 case of angiomyolipoma. The 6 (30%) cases of sarcomas comprised 3 cases of undifferentiated/unclassified sarcomas, 1 case of leiomyosarcoma, 1 case of Ewing sarcoma/primitive neuroectodermal tumor, and 1 case of atypical lipomatous tumor/well-differentiated liposarcoma. When compared with the 500 ductal adenocarcinomas, the 3 surgically resected sarcomas were larger (mean, 5.8 cm vs 3.6 cm; P = 0.02); however, no difference in median survival time was observed between patients with sarcoma (23 months) and patients with ductal adenocarcinoma (16 months).

CONCLUSIONS

First, primary mesenchymal tumors of the pancreas are extremely rare. Second, several primary mesenchymal tumor types can be observed in the pancreas. Understanding these rare disease entities will help ensure their correct diagnosis.

Current and future intraoperative imaging strategies to increase radical resection rates in pancreatic cancer surgery

Prognosis of patients with pancreatic cancer is poor. Even the small minority that undergoes resection with curative intent has low 5-year survival rates. This may partly be explained by the high number of irradical resections, which results in local recurrence and impaired overall survival. Currently, ultrasonography is used during surgery for resectability assessment and frozen-section analysis is used for assessment of resection margins in order to decrease the number of irradical resections. The introduction of minimal invasive techniques in pancreatic surgery has deprived surgeons from direct tactile information. To improve intraoperative assessment of pancreatic tumor extension, enhanced or novel intraoperative imaging technologies accurately visualizing and delineating cancer cells are necessary. Emerging modalities are intraoperative near-infrared fluorescence imaging and freehand nuclear imaging using tumor-specific targeted contrast agents. In this review, we performed a meta-analysis of the literature on laparoscopic ultrasonography and we summarized and discussed current and future intraoperative imaging modalities and their potential for improved tumor demarcation during pancreatic surgery.

Real-time intraoperative detection of breast cancer using near-infrared fluorescence imaging and Methylene Blue

BACKGROUND

Despite recent developments in preoperative breast cancer imaging, intraoperative localization of tumor tissue can be challenging, resulting in tumor-positive resection margins during breast conserving surgery. Based on certain physicochemical similarities between Technetium((99m)Tc)-sestamibi (MIBI), an SPECT radiodiagnostic with a sensitivity of 83-90% to detect breast cancer preoperatively, and the near-infrared (NIR) fluorophore Methylene Blue (MB), we hypothesized that MB might detect breast cancer intraoperatively using NIR fluorescence imaging.

METHODS

Twenty-four patients with breast cancer, planned for surgical resection, were included. Patients were divided in 2 administration groups, which differed with respect to the timing of MB administration. N = 12 patients per group were administered 1.0 mg/kg MB intravenously either immediately or 3 h before surgery. The mini-FLARE imaging system was used to identify the NIR fluorescent signal during surgery and on post-resected specimens transferred to the pathology department. Results were confirmed by NIR fluorescence microscopy.

RESULTS

20/24 (83%) of breast tumors (carcinoma in N = 21 and ductal carcinoma in situ in N = 3) were identified in the resected specimen using NIR fluorescence imaging. Patients with non-detectable tumors were significantly older. No significant relation to receptor status or tumor grade was seen. Overall tumor-to-background ratio (TBR) was 2.4 ± 0.8. There was no significant difference between TBR and background signal between administration groups. In 2/4 patients with positive resection margins, breast cancer tissue identified in the wound bed during surgery would have changed surgical management. Histology confirmed the concordance of fluorescence signal and tumor tissue.

CONCLUSIONS

This feasibility study demonstrated an overall breast cancer identification rate using MB of 83%, with real-time intraoperative guidance having the potential to alter patient management.

Real-time fluorescence image-guided oncologic surgery

Medical imaging plays a critical role in cancer diagnosis and planning. Many of these patients rely on surgical intervention for curative outcomes. This requires a careful identification of the primary and microscopic tumors, and the complete removal of cancer. Although there have been efforts to adapt traditional-imaging modalities for intraoperative image guidance, they suffer from several constraints such as large hardware footprint, high-operation cost, and disruption of the surgical workflow. Because of the ease of image acquisition, relatively low-cost devices and intuitive operation, optical imaging methods have received tremendous interests for use in real-time image-guided surgery. To improve imaging depth under low interference by tissue autofluorescence, many of these applications utilize light in the near-infrared (NIR) wavelengths, which is invisible to human eyes. With the availability of a wide selection of tumor-avid contrast agents, advancements in imaging sensors, electronic and optical designs, surgeons are able to combine different attributes of NIR optical imaging techniques to improve treatment outcomes. The emergence of diverse commercial and experimental image guidance systems, which are in various stages of clinical translation, attests to the potential high impact of intraoperative optical imaging methods to improve speed of oncologic surgery with high accuracy and minimal margin positivity.

Image-guided cancer surgery using near-infrared fluorescence

Paradigm shifts in surgery arise when surgeons are empowered to perform surgery faster, better and less expensively than current standards. Optical imaging that exploits invisible near-infrared (NIR) fluorescent light (700-900 nm) has the potential to improve cancer surgery outcomes, minimize the time patients are under anaesthesia and lower health-care costs largely by way of its improved contrast and depth of tissue penetration relative to visible light. Accordingly, the past few years have witnessed an explosion of proof-of-concept clinical trials in the field. In this Review, we introduce the concept of NIR fluorescence imaging for cancer surgery, examine the clinical trial literature to date and outline the key issues pertaining to imaging system and contrast agent optimization. Although NIR seems to be superior to many traditional imaging techniques, its incorporation into routine care of patients with cancer depends on rigorous clinical trials and validation studies.

Near infrared fluorescence for image-guided surgery

Near infrared (NIR) image-guided surgery holds great promise for improved surgical outcomes. A number of NIR image-guided surgical systems are currently in preclinical and clinical development with a few approved for limited clinical use. In order to wield the full power of NIR image-guided surgery, clinically available tissue and disease specific NIR fluorophores with high signal to background ratio are necessary. In the current review, the status of NIR image-guided surgery is discussed along with the desired chemical and biological properties of NIR fluorophores. Lastly, tissue and disease targeting strategies for NIR fluorophores are reviewed.