Intraoperative Near-Infrared Fluorescence Guided Surgery Using Indocyanine Green (ICG) for the Resection of Sarcomas May Reduce the Positive Margin Rate: An Extended Case Series

Contemporary surgical management of pediatric non-rhabdomyosarcoma soft tissue sarcoma

Non-rhabdomyosarcoma soft tissue sarcoma (STS) comprises most STS in pediatric patients. It is a diverse set of over 30 histologic subtypes. Treatment is based on risk group determined by tumor size, grade, and the presence of metastases. Surgical resection is a cornerstone of therapy, as tumors are often resistant to chemotherapy or radiation. While patients with isolated tumors less than 5 cm may undergo upfront resection, strong consideration should be given to neoadjuvant chemoradiotherapy to ensure negative margins at surgical resection and optimal outcomes. Sentinel lymph node biopsy is strongly recommended for clear cell and epithelioid sarcomas. The most common metastatic site is the lung, and metastases should be resected at the end of therapy, when feasible. Unfortunately, many high-risk patients progress on therapy, and alternative strategies including earlier metastatic control require investigation.

Intraoperative near-infrared fluorescence guided surgery using indocyanine green (ICG) may aid the surgical removal of benign bone and soft tissue tumours

BACKGROUND

Benign bone and soft tissue tumours encompass a broad, heterogenous range of tumours with varying clinical characteristics. These are often managed surgically with either curettage or marginal excision, but unfortunately have high rates of local recurrence. Indocyanine green (ICG) is a fluorescent dye which can be used to identify solid malignancies intraoperatively but its use is not yet established in benign bone and soft tissue tumours. This study aims to assess whether these tumours fluoresce when administered with ICG pre-operatively and whether this helps surgeons to identify tumour intra-operatively.

PATIENTS AND METHODS

Patients with locally aggressive benign bone and soft tissue tumours were administered with 25-75 mg of ICG preoperatively at the induction of anaesthesia. Fluorescence was imaged intraoperatively using the Stryker SPY-PHI camera.

RESULTS

Of the 12 patients included, 11 tumours fluoresced. The surgeons felt the fluorescence guided the procedure in 7 out of the 11 cases which fluoresced. It was felt to be particularly useful in the curettage of bone tumours, in which curettage could be repeated until the absence of fluorescence on imaging. After 12 months, no patients had local recurrence of the tumour. There were no adverse events recorded in this study and surgeons found the technology acceptable.

CONCLUSIONS

The use of ICG for fluorescence guided surgery is a promising technology to improve outcomes of surgery for benign bone and soft tissue tumours. Further, longer term, study with a control arm is needed to identify whether it results in a reduction in the local recurrence rate.

eTFC-01: a dual-labeled chelate-bridged tracer for SSTR2-positive tumors

BACKGROUND

Integrating radioactive and optical imaging techniques can facilitate the prognosis and surgical guidance for cancer patients. Using a single dual-labeled tracer ensures consistency in both imaging modalities. However, developing such molecule is challenging due to the need to preserve the biochemical properties of the tracer while introducing bulky labeling moieties. In our study, we designed a trifunctional chelate that facilitates the coupling of the targeting vector and fluorescent dye at opposite sites to avoid undesired steric hindrance effects. The synthesis of the trifunctional chelate N3-Py-DOTAGA-(tBu)3 (7) involved a five-step synthetic route, followed by conjugation to the linear peptidyl-resin 8 through solid-phase synthesis. After deprotection and cyclization, the near-infrared fluorescent dye sulfo-Cy.5 was introduced using copper free click chemistry, resulting in eTFC-01. Subsequently, eTFC-01 was labeled with [111In]InCl3. In vitro assessments of eTFC-01 binding, uptake, and internalization were conducted in SSTR2-transfected U2OS cells. Ex-vivo biodistribution and fluorescence imaging were performed in H69-tumor bearing mice.

RESULTS

eTFC-01 demonstrated a two-fold higher IC50 value for SSTR2 compared to the gold standard DOTA-TATE. Labeling of eTFC-01 with [111In]InCl3 gave a high radiochemical yield and purity. The uptake of [111In]In-eTFC-01 in U2OS.SSTR2 cells was two-fold lower than the uptake of [111In]In-DOTA-TATE, consistent with the binding affinity. Tumor uptake in H69-xenografted mice was lower for [111In]In-eTFC-01 at all-time points compared to [111In]In-DOTA-TATE. Prolonged blood circulation led to increased accumulation of [111In]In-eTFC-01 in highly vascularized tissues, such as lungs, skin, and heart. Fluorescence measurements in different organs correlated with the radioactive signal distribution.

CONCLUSION

The successful synthesis and coupling of the trifunctional chelate to the peptide and fluorescent dye support the potential of this synthetic approach to generate dual labeled tracers. While promising in vitro, the in vivo results obtained with [111In]In-eTFC-01 suggest the need for adjustments to enhance tracer distribution.

Surgical Margins in Musculoskeletal Sarcoma

» Negative margin resection of musculoskeletal sarcomas is associated with reduced risk of local recurrence.» There is limited evidence to support an absolute margin width of soft tissue or bone that correlates with reduced risk of local recurrence.» Factors intrinsic to the tumor, including histologic subtype, grade, growth pattern and neurovascular involvement impact margin status and local recurrence, and should be considered when evaluating a patient's individual risk after positive margins.» Appropriate use of adjuvant therapy, critical analysis of preoperative advanced cross-sectional imaging, and the involvement of a multidisciplinary team are essential to obtain negative margins when resecting sarcomas.

What is the diagnostic accuracy of fluorescence-guided surgery for margin assessment in appendicular bone and soft tissue tumors? - A systematic review of clinical studies

BACKGROUND

Fluorescence-guided surgery (FGS) is a novel technique to successfully assess surgical margins intraoperatively. Investigation and adoption of this technique in orthopaedic oncology remains limited.

METHODS

The PRISMA guidelines were followed for this manuscript. Our study was registered on PROSPERO (380520). Studies describing the use of FGS for resection of bone and soft tissue sarcomas (STS) on humans were included. Diagnostic performance metrics (sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV] and accuracy) and margin positivity rate were the outcomes assessed.

RESULTS

Critical appraisal using the Joanna Brigs Institute checklists showed significant concerns for study quality. Sensitivity of FGS ranged from 22.2 % to 100 % in three of the four studies assessing his metrics; one study in appendicular tumors in the pediatric population reported 0 % sensitivity in the three cases included. Specificity ranged from 9.38 % to 100 %. PPV ranged from 14.6 % to 70 % while NPV was between 53.3 % and 100 %. The diagnostic accuracy ranged from 21.62 % to 92.31 %. Margin positivity rate ranged from 2 % to 50 %, with six of the seven studies reporting values between 20 % and 50 %.

CONCLUSIONS

FSG is a feasible technique to assess tumor margins in bone and STS. Reported performance metrics and margin positivity rates vary widely between studies due to low study quality and high heterogeneity in dying protocols.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Emerging innovations and advancements in the treatment of extremity and truncal soft tissue sarcomas

In this special edition update on soft tissue sarcomas (STS), we cover classifications, emerging technologies, prognostic tools, radiation schemas, and treatment disparities in extremity and truncal STS. We discuss the importance of enhancing local control and reducing complications, including the role of innovative imaging, surgical guidance, and hypofractionated radiation. We review advancements in systemic and immunotherapeutic treatments and introduce disparities seen in this vulnerable population that must be considered to improve overall patient care.

Anaesthetic implications of intra-operative Indocyanine Green use in pediatric surgery

INTRODUCTION

The use of Indocyanine Green (ICG) dye for fluorescent guided surgery is increasing in children. In many cases, ICG is injected intravenously peri-operatively and is known to falsely alter peripheral oxygenation readings because of interference with the measured red/infrared absorbance ratio of pulsatile blood.

METHODS

The study occurred at a single centre tertiary children's hospital. ICG was delivered peri-operatively. SpO2 was monitored real-time in all patients. Blood pressure, heart rate, expired carbon dioxide and electrocardiographic data were collected from anaesthetic records. Data is median (interquartile range) RESULTS: Twenty-five patients(13 F;12 M) age 60(77)months and weight 17(18.7)kg were included between 01/April/2021 and 31/Nov/2022. Fifteen patients received 0.5(0.38) mg/kg ICG at induction of anesthesia with ΔSpO2 of 6(2) %. Median time to ΔSpO2 fall was 25(6) s with recovery taking 74(68) s. Time to recovery and ΔSpO2 were proportional to ICG dose/kg with r2 of 0.7993 and 0.597 and p of 0.0008 and 0.001 respectively on linear regression. Five patients had intralesional ICG and one had an enteral dose with no effect on SpO2. Eight patients had a total of 20 intraoperative bolus doses of ICG with no effect on SpO2 in 11. In 9, time to SpO2 fall was 26(12) s with ΔSpO2 of 4(1) % and recovery at 24(50) s. No corrective anaesthetic manoeuvres were required.

CONCLUSION

Understanding the timings of the transient artefactual fall and recovery in SpO2 following ICG injection is essential for safe anesthesia. This is the first study to evaluate this effect in children prospectively.

Fluorescence lifetime of injected indocyanine green as a universal marker of solid tumours in patients

The surgical resection of solid tumours can be enhanced by fluorescence-guided imaging. However, variable tumour uptake and incomplete clearance of fluorescent dyes reduces the accuracy of distinguishing tumour from normal tissue via conventional fluorescence intensity-based imaging. Here we show that, after systemic injection of the near-infrared dye indocyanine green in patients with various types of solid tumour, the fluorescence lifetime (FLT) of tumour tissue is longer than the FLT of non-cancerous tissue. This tumour-specific shift in FLT can be used to distinguish tumours from normal tissue with an accuracy of over 97% across tumour types, and can be visualized at the cellular level using microscopy and in larger specimens through wide-field imaging. Unlike fluorescence intensity, which depends on imaging-system parameters, tissue depth and the amount of dye taken up by tumours, FLT is a photophysical property that is largely independent of these factors. FLT imaging with indocyanine green may improve the accuracy of cancer surgeries.

Robotic Function-Preserving Resection of Gastric Gastrointestinal Stromal Tumor

INTRODUCTION

Gastric gastrointestinal stromal tumors (GISTs) located at the gastroesophageal junction (GEJ), lesser curvature, posterior gastric wall, or antrum present challenges for gastric function preservation. The aim of this study was to evaluate safety and effectiveness of robot-assisted resection of gastric GIST in challenging anatomic locations.

METHODS

This was a single-center case series of robotic gastric GIST resections in challenging anatomic locations performed from 2019 to 2021. GEJ GISTs are defined as tumors within 5 cm of the GEJ. Location of the tumor and distance from the GEJ were determined from the endoscopy report and/or cross-sectional imaging and operative findings.

RESULTS

There were 25 consecutive patients who underwent a robot-assisted partial gastrectomy for a gastric GIST in challenging anatomic locations. Tumors were located at the GEJ (n = 12), lesser curvature (n = 7), posterior gastric wall (n = 4), fundus (n = 3), greater curvature (n = 3), and antrum (n = 2). Median distance of tumor from GEJ was 2.5 cm. Both GEJ and pylorus were successfully preserved in all patients regardless of tumor location. Median operative time was 190 min with a median estimated blood loss of 20 mL and no conversion to open approach. Median hospital stay was 3 d with solid diet intake starting 2 d after surgery. Two (8 %) patients had Grade III or higher postoperative complications. Median tumor size upon resection was 3.9 cm. Negative margins were obtained in 96.3%. There was no evidence of recurrent disease with a median follow-up of 11.3 mo.

CONCLUSIONS

We demonstrate the safety and feasibility of using the robotic approach to facilitate function preservation gastrectomy in challenging anatomic locations without compromising oncologic resection.

Near-infrared (NIR) imaging with indocyanine green (ICG) may assist in intraoperative decision making and improving surgical margin in bone and soft tissue tumor surgery

BACKGROUND AND OBJECTIVES

Negative surgical margins are significant in improving patient outcomes. However, surgeons can only rely on visual and tactile information to identify tumor margins intraoperatively. We hypothesized that intraoperative fluorescence imaging with indocyanine green (ICG) could serve as an assistive technology to evaluate surgical margins and guide surgery in bone and soft tissue tumor surgery.

METHODS

Seventy patients with bone and soft tissue tumors were enrolled in this prospective, non-randomized, single-arm feasibility study. All patients received intravenous indocyanine green (0.5 mg/kg) before surgery. Near-infrared (NIR) imaging was performed on in situ tumors, wounds, and ex vivo specimens.

RESULTS

60/70 tumors were fluorescent at NIR imaging. The final surgical margins were positive in 2/55 cases, including 1/40 of the sarcomas. Surgical decisions were changed in 19 cases by NIR imaging, and in 7/19 cases final pathology demonstrated margins were improved. Fluorescence analysis showed that the tumor-to-background ratio (TBR) of primary malignant tumors was higher than that of benign, borderline, metastatic, and tumors ≥5 cm in size had higher TBR than those <5 cm.

CONCLUSIONS

ICG fluorescence imaging may be a beneficial technique to assist in surgical decision making and improving surgical margins in bone and soft tissue tumor surgery.

What Is the Significance of Indeterminate Pulmonary Nodules in High-Grade Soft Tissue Sarcomas? A Retrospective Cohort Study

BACKGROUND

Sarcomas are rare, aggressive cancers which frequently metastasise to the lungs. Following diagnosis, patients typically undergo staging by means of a CT scan of their chest. This often identifies indeterminate pulmonary nodules (IPNs), but the significance of these in high-grade soft tissue sarcoma (STS) is unclear. Identifying whether these are benign or malignant is important for clinical decision making. This study analyses the clinical relevance of IPNs in high-grade STS.

METHODS

All patients treated at our centre for high-grade soft tissue sarcoma between 2010 and 2020 were identified from a prospective database. CT scans and their reports were reviewed, and survival data were collected from patient records.

RESULTS

389 suitable patients were identified; 34.4% had IPNs on their CT staging scan and 20.1% progressed into lung metastases. Progression was more likely with IPNs ≥ 5 mm in diameter (p = 0.006), multiple IPNs (p = 0.013) or bilateral IPNs (p = 0.022), as well as in patients with primaries ≥ 5 cm (p = 0.014), grade 3 primaries (p = 0.009) or primaries arising deep to the fascia (p = 0.041). The median time to progression was 143 days. IPNs at diagnosis were associated with an increased risk of developing lung metastases and decreased OS in patients with grade 3 STS (p = 0.0019 and p = 0.0016, respectively); this was not observed in grade 2 patients.

CONCLUSIONS

IPNs at diagnosis are associated with significantly worse OS in patients with grade 3 STS. It is crucial to consider the primary tumour as well as the IPNs when considering the risk of progression. Surveillance CT scans should be carried out within 6 months.

Early results of minimally invasive fluorescent guided pediatric oncology surgery with delivery of indocyanine green during induction of anesthesia

BACKGROUND

Indocyanine green (ICG) fluoresces in the near infra-red (NIR) spectrum. It is widely used in adult oncological surgery for identification of tumor margins and lymph node sampling. However, deliver of ICG in almost all studies is 24 h or more prior to surgery. This is the first study in children to assess its feasibility in minimally invasive surgery (MIS) for oncological disease following ICG injection during induction of anesthesia.

METHODS

This was an open label, prospective, single center, feasibility study recruiting consecutive patients eligible for MIS tumor resection or metastectomy. ICG was injected intravenously at induction of anesthesia. Patient demographics, intraoperative appearances, post-operative histopathology, and surgeon Likert ratings were collected.

RESULTS

Fourteen patients were included. Five had lung metastases (Wilms, Osteosarcoma (2), Hodgkin's, melanoma) and 9 had other tumors (neuroblastoma, inflammatory myofibroblastic tumor, ganglioneuroma, phaeochromocytoma, adrenal tumor). Lung metastases were easily identifiable, and all had negative margins. Tumors containing viable disease fluoresced and were completely resected, whilst benign and heavily treated tumors were afluorescent. There were no adverse events relating to ICG or issues with background fluorescence.

CONCLUSION

Based on this small sample, injection of ICG during induction of anesthesia is safe and effective in showing tumor margins in patients who have had little or no neoadjuvant chemotherapy as well as in metastectomy in Wilms and osteosarcoma. Further studies are needed to confirm these preliminary results.

Application of Indocyanine Green Fluorescence Imaging in Assisting Biopsy of Musculoskeletal Tumors

(1) Background: Biopsies are the gold standard for the diagnosis of musculoskeletal tumors. In this study, we aimed to explore whether indocyanine green near-infrared fluorescence imaging can assist in the biopsy of bone and soft tissue tumors and improve the success rate of biopsy. (2) Method: We recruited patients with clinically considered bone and soft tissue tumors and planned biopsies. In the test group, indocyanine green (0.3 mg/kg) was injected. After identifying the lesion, a near-infrared fluorescence camera system was used to verify the ex vivo specimens of the biopsy in real time. If the biopsy specimens were not developed, we assumed that we failed to acquire lesions, so the needle track and needle position were adjusted for the supplementary biopsy, and then real-time imaging was performed again. Finally, we conducted a pathological examination. In the control group, normal biopsy was performed. (3) Results: The total diagnosis rate of musculoskeletal tumors in the test group was 94.92% (56/59) and that in the control group was 82.36% (42/51). In the test group, 14 cases were not developed, as seen from real-time fluorescence in the core biopsy, and then underwent the supplementary biopsy after changing the puncture direction and the location of the needle channel immediately, of which 7 cases showed new fluorescence. (4) Conclusions: Using the near-infrared fluorescence real-time development technique to assist the biopsy of musculoskeletal tumors may improve the accuracy of core biopsy and help to avoid missed diagnoses, especially for some selected tumors.

Evaluation of the Effect of Photodynamic Therapy on CAM-Grown Sarcomas

Resection margin adequacy plays a critical role in the local control of sarcomas. Fluorescence-guided surgery has increased complete resection rates and local recurrence-free survival in several oncological disciplines. The purpose of this study was to determine whether sarcomas exhibit sufficient tumor fluorescence (photodynamic diagnosis (PDD)) after administration of 5-aminolevulinic acid (5-ALA) and whether photodynamic therapy (PDT) has an impact on tumor vitality in vivo. Sixteen primary cell cultures were derived from patient samples of 12 different sarcoma subtypes and transplanted onto the chorio-allantoic membrane (CAM) of chick embryos to generate 3-dimensional cell-derived xenografts (CDXs). After treatment with 5-ALA, the CDXs were incubated for another 4 h. Subsequently accumulated protoporphyrin IX (PPIX) was excited by blue light and the intensity of tumor fluorescence was analyzed. A subset of CDXs was exposed to red light and morphological changes of both CAMs and tumors were documented. Twenty-four hours after PDT, the tumors were excised and examined histologically. High rates of cell-derived engraftments on the CAM were achieved in all sarcoma subtypes and an intense PPIX fluorescence was observed. PDT of CDXs resulted in a disruption of tumor-feeding vessels and 52.4% of CDXs presented as regressive after PDT treatment, whereas control CDXs remained vital in all cases. Therefore, 5-ALA mediated PDD and PDT appear to be promising tools in defining sarcoma resection margins (PDD) and adjuvant treatment of the tumor bed (PDT).

Immunohistochemical Evaluation of Candidate Biomarkers for Fluorescence-Guided Surgery of Myxofibrosarcoma Using an Objective Scoring Method

INTRODUCTION

Myxofibrosarcoma (MFS) is the most common soft-tissue sarcoma subtype in elderly patients. Local recurrence (LR) remains a major concern as the lack of intraoperative guidance and an infiltrative growth pattern with long, slender tails hamper surgeons' ability to achieve adequate resection margins for MFS. Fluorescence-guided surgery (FGS) could overcome this concern by delineating tumor tissue during surgery. One of the most important steps to successful FGS is to define a tumor-specific biomarker that is highly overexpressed in tumor tissue while low or absent in adjacent healthy tissue. The aim of this study is to evaluate the expression of eight previously selected promising biomarkers for FGS in MFS tissue samples with adjacent healthy tissue using immunohistochemistry (IHC).

METHODS

The following eight biomarkers were stained in seventeen paraffin-embedded MFS samples: tumor endothelial marker-1 (TEM-1, also known as endosialin/CD248), vascular endothelial growth factor receptor-1 (VEGFR-1, also known as Flt-1), vascular endothelial growth factor receptor-2 (VEGFR-2, also known as Flk1), vascular endothelial growth factor-A (VEGF-A), epidermal growth factor receptor (EGFR), insulin-like growth factor-1 receptor (IGF-1R), platelet derived growth factor receptor-α (PDGFR-α), and cluster of differentiation 40 (CD40, also known as TNFRSF5). A pathologist specializing in sarcoma annotated the margin between the tumor and adjacent healthy tissue in each MFS tissue sample. Subsequently, we used an objective IHC scoring method to assess and compare the difference in staining intensity between the tumor and adjacent healthy tissue, which is crucial for the use of FGS.

RESULTS

TEM-1, VEGF-A, and PDGFR-α stained all MFS tumors, while the other biomarkers did not show expression in all MFS tumors. Ultimately, TEM-1 was identified as the most suitable biomarker for FGS in MFS based on higher tumor-to-background (TBR) staining intensity compared to VEGF-A and PDGFR-α, regardless of preoperative therapy.

CONCLUSION

TEM-1-targeted FGS tracers should be further investigated to optimize MFS treatment.

The significance of margins in pediatric Non-Rhabdomyosarcoma soft tissue sarcomas: Consensus on surgical margin definition harmonization from the INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT)

BACKGROUND

Margin status following surgery in children, adolescents, and young adults with soft tissue sarcomas is controversial and has been defined differently by various specialties, with definitions changing over time and by cooperative group. The International Soft Tissue Sarcoma Consortium (INSTRuCT) is a collaboration of the Children's Oncology Group (COG) Soft Tissue Sarcoma Committee, European pediatric Soft Tissue sarcoma Study Group (EpSSG), and the European Cooperative Weichteilsarkom Studiengruppe (CWS) devoted to improving patient outcomes by pooling and mining cooperative group clinical trial data.

METHODS

The INSTRuCT non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) working group aimed to develop international harmonized recommendations regarding surgical margin assessment and definitions in children and adolescents with soft tissue tumors.

RESULTS AND CONCLUSION

This review addresses accepted principles and areas of controversy, including the perspectives of surgeons, pathologists, radiation oncologists, and pediatric oncologists, to develop a framework for building common guidelines for future research.

Intraoperative Evaluation of Soft Tissue Sarcoma Surgical Margins with Indocyanine Green Fluorescence Imaging

Soft tissue sarcomas (STS) are rare malignant tumors often associated with poor outcomes and high local recurrence rates. Current tools for intraoperative and definitive margin assessment include intraoperative frozen section and permanent pathology, respectively. Indocyanine green dye (ICG) is a historically safe fluorophore dye that has demonstrated efficacy for intraoperative margin assessment in the surgical management of both breast and gastrointestinal cancers. The utility of ICG in the surgical management of sarcoma surgery has primarily been studied in pre-clinical mouse models and warrants further investigation as a potential adjunct to achieving negative margins. This study is a prospective, non-randomized clinical study conducted on patients with confirmed or suspected STS. Patients younger than 18 years, with a prior adverse reaction to iodine or fluorescein, or with renal disease were excluded from the study. Intravenous ICG was infused approximately three hours prior to surgery at a dosage of 2.0-2.5 mg/kg, and following tumor resection, the excised tumor and tumor bed were imaged for fluorescence intensity. When scanning the tumor bed, a threshold of 77% calibrated to the region of maximum intensity in the resected tumor was defined as a positive ICG margin, according to published protocols from the breast cancer literature. ICG results were then compared with the surgeon's clinical impression of margin status and permanent pathology results. Out of 26 subjects recruited for the original study, 18 soft tissue sarcomas (STS) were included for analysis. Three subjects were excluded for having bone sarcomas, and five subjects were excluded due to final pathology, which was ultimately inconsistent with sarcoma. The average age of patients was 64.1 years old (range: 28-83), with an average ICG dose of 201.8 mg. In 56% (10/18) of patients, ICG margins were consistent with the permanent pathology margins, with 89% specificity. The use of ICG as an intraoperative adjunct to obtaining negative margins in soft tissue sarcoma surgery is promising. However, studies with larger sample sizes are warranted to further delineate the accuracy, optimal dosage, timing, and types of sarcoma in which this diagnostic tool may be most useful.

Biomarkers of disease recurrence in stage I testicular germ cell tumours

Stage I testicular cancer is a disease restricted to the testicle. After orchiectomy, patients are considered to be without disease; however, the tumour is prone to relapse in ~4-50% of patients. Current predictive markers of relapse, which are tumour size and invasion to rete testis (in seminoma) or lymphovascular invasion (in non-seminoma), have limited clinical utility and are unable to correctly predict relapse in a substantial proportion of patients. Adjuvant therapeutic strategies based on available biomarkers can lead to overtreatment of 50-85% of patients. Discovery and implementation of novel biomarkers into treatment decision making will help to reduce the burden of adjuvant treatments and improve patient selection for adjuvant therapy.

Synthesis and In Vivo Evaluation of a Site-specifically Labeled Radioimmunoconjugate for Dual-Modal (PET/NIRF) Imaging of MT1-MMP in Sarcomas

Bone sarcomas are devastating primary bone cancers that mostly affect children, young adults, and the elderly. These aggressive tumors are associated with poor survival, and surgery remains the mainstay of treatment. Surgical planning is increasingly informed by positron emission tomography (PET), and tumor margin identification during surgery is aided by near-infrared fluorescence (NIRF) imaging, yet these investigations are confounded by probes that lack specificity for sarcoma biomarkers. We report the development of a dual-modal (PET/NIRF) immunoconjugate ([⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW) that targets MT1-MMP, a matrix metalloproteinase overexpressed in high-grade sarcomas. [⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW was synthesized via site-specific chemoenzymatic glycan modification, characterized, and isolated in high specific activity and radiochemical purity. Saturation binding and immunoreactivity assays indicated only minor perturbation of binding properties. A novel mouse model of dedifferentiated chondrosarcoma based on intrafemoral inoculation of HT1080 WT or KO cells (high and low MT1-MMP expression, respectively) was used to evaluate target binding and biodistribution. Fluorescence and Cerenkov luminescence images of [⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW showed preferential uptake in HT1080 WT tumors. Ex vivo gamma counting revealed that uptake in MT1-MMP-positive tumors was significantly higher than that in control groups. Taken together, [⁸⁹Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW is a promising dual-modal sarcoma imaging agent for pre-operative surgical planning and intraoperative surgical guidance.

Prognostic value of p16, p53, and pcna in sarcoma and an evaluation of immune infiltration

Background

p16, p53, and proliferating cell nuclear antigen (pcna) genes play significant roles in many chromatin modifications and have been found to be highly expressed in a variety of tumor tissues. Therefore, they have been used as target genes for some tumor therapies. However, the differential expressions of the p16, p53, and pcna genes in human sarcomas and their effects on prognosis have not been widely reported.

Methods

The Oncomine dataset was used to analyze the transcription levels of p16, p53, and pcna genes, and the gene expression profile interactive analysis (GEPIA) dataset was used to analyze the differential expressions of p16, p53, and pcna. The expression levels of p16, p53, and pcna were further analyzed by Western Blotting. GEPIA and Kaplan–Meier analyses were used to analyze the prognostic value of p16, p53, and pcna. Furthermore, p16, p53, and pcna gene mutations and their association with overall survival (OS) and disease-free survival (DFS) were analyzed using cBioPortal datasets. In addition, genes co-expressed with p16, p53, and pcna were analyzed using Oncomine. The DAVID dataset was used to analyze the functional enrichment of p16, p53, pcna, and their co-expressed genes by Gene Ontology (GO) and Metascape were used to construct a network map. Finally, the immune cell infiltration of p16, p53, and pcna in patients with sarcoma was reported by Tumor Immune Estimation Resource (TIMER).

Results

p16, p53, and pcna were up-regulated in human sarcoma tissues and almost all sarcoma cell lines. Western Blotting showed that the expression of p16, p53, and pcna was elevated in osteosarcoma cell lines. The expression of pcna was correlated with OS, the expression of p16, p53, and pcna was correlated with relapse-free survival, and the genetic mutation of p16 was negatively correlated with OS and DFS. We also found that p16, p53, and pcna genes were positively/negatively correlated with immune cell infiltration in sarcoma.

Conclusions

The results of this study showed that p16, p53, and pcna can significantly affect the survival and immune status of sarcoma patients. Therefore, p16, p53, and pcna could be used as potential biomarkers of prognosis and immune infiltration in human sarcoma and provide a possible therapeutic target for sarcoma.

Intraoperative Near-Infrared Fluorescence Imaging with Indocyanine Green for Identification of Gastrointestinal Stromal Tumors (GISTs), a Feasibility Study

Simple Summary

Surgical resection plays a pivotal role in the treatment of GIST patients. The current study aims to explore the use of near-infrared fluorescence imaging to optimize the intraoperative tumor identification of GISTs. For this purpose, the potential and limitations of the widely used, and non-specific, tracer indocyanine green were assessed in a multicenter study including 10 patients. Our results show that GISTs typically have similar fluorescence intensity to the surrounding tissue, within several minutes after the intravenous administration of indocyanine green. These findings justify future research into specific fluorescent tracers for GISTs, and set a reference for future intraoperative imaging trials.

Abstract

Background: Optimal intraoperative tumor identification of gastrointestinal stromal tumors (GISTs) is important for the quality of surgical resections. This study aims to assess the potential of near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) to improve intraoperative tumor identification. Methods: Ten GIST patients, planned to undergo resection, were included. During surgery, 10 mg of ICG was intravenously administered, and NIRF imaging was performed at 5, 10, and 15 min after the injection. The tumor fluorescence intensity was visually assessed, and tumor-to-background ratios (TBRs) were calculated for exophytic lesions. Results: Eleven GIST lesions were imaged. The fluorescence intensity of the tumor was visually synchronous and similar to the background in five lesions. In one lesion, the tumor fluorescence was more intense than in the surrounding tissue. Almost no fluorescence was observed in both the tumor and healthy peritoneal tissue in two patients with GIST lesions adjacent to the liver. In three GISTs without exophytic growth, no fluorescence of the tumor was observed. The median TBRs at 5, 10, and 15 min were 1.0 (0.4–1.2), 1.0 (0.5–1.9), and 0.9 (0.7–1.2), respectively. Conclusion: GISTs typically show similar fluorescence intensity to the surrounding tissue in NIRF imaging after intraoperative ICG administration. Therefore, intraoperatively administered ICG is currently not applicable for adequate tumor identification, and further research should focus on the development of tumor-specific fluorescent tracers for GISTs.