Imaging and resectability issues of sinonasal tumors

Sinonasal malignancy: ESMO-EURACAN Clinical Practice Guideline for diagnosis, treatment and follow-up

•The CPG provides key recommendations and algorithms for managing SMs, excluding mucosal melanoma and soft-tissue sarcomas. •The guideline covers diagnosis, staging, risk assessment, treatment and disease monitoring. •Technological advancements in treatment with RT are discussed with a special focus on particle therapy. •Surgical indications for open and transnasal endoscopic surgery are provided. •Neoadjuvant chemotherapy in high-grade, locally advanced SMs helps to select subjects for conservative treatments.

Diagnostic Accuracy of MRI for Orbital and Intracranial Invasion of Sinonasal Malignancies: A Systematic Review and Meta-Analysis

Background/Objectives: In this study, we review the diagnostic accuracy of magnetic resonance imaging (MRI) in detecting orbital and intracranial invasion of sinonasal malignancies (SNMs) using histopathological and surgical evidence as the reference standard. Methods: A systematic search of studies in English was conducted in MEDLINE and Embase, limited to articles published since 1990. We included studies using preoperative MRI to detect the intracranial and orbital invasion of SNMs, with histological or surgical confirmation as the reference standard, and reported patient numbers in each class as required to assess diagnostic accuracy. The outcome measures were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Heterogeneity was assessed with the Higgins inconsistency test (I2). Results: Seven original articles with 546 subjects were included in the review, with six included in the meta-analysis. The pooled overall accuracy for orbital invasion was higher at 0.88 (95% CI, 0.75-0.94) than that for intracranial invasion at 0.80 (95% CI, 0.76-0.83). The meta-analytic estimates and their 95% confidence intervals were as follows for intracranial/orbital invasion: sensitivity 0.77 (0.69-0.83)/0.71 (0.40-0.90); specificity 0.79 (0.74-0.83)/0.91 (0.78-0.97); PPV 0.76 (0.64-0.85)/0.78 (0.61-0.88); and NPV 0.82 (0.72-0.89)/0.90 (0.63-0.98). Substantial heterogeneity was observed in the Higgins inconsistency test (I2) for orbital invasion (84%, 83%, and 93% for sensitivity, specificity, and NPV, respectively). Conclusions: MRI yielded moderate-to-high diagnostic accuracy for intracranial and orbital invasion, despite some limitations leading to false diagnoses. Loss of the hypointense zone on postcontrast MRI was found to predict dural invasion. Infiltration of the extraconal fat beyond the periorbita was found to be an MRI feature of orbital invasion.

Unilateral Sinus Disease: What Is, and Is Not Odontogenic Sinusitis?

The differential diagnosis of unilateral sinus disease (USD) is broad, and while concerning etiologies like sinonasal neoplasia, invasive fungal sinusitis, and cerebrospinal fluid rhinorrhea should always be considered, most cases are due to noninvasive inflammatory or infectious conditions. To diagnose USD appropriately, clinicians must integrate the clinical history and examination, nasal endoscopy, computed tomography (CT), and possibly MRI. Odontogenic sinusitis (ODS) is the most common cause of unilateral maxillary sinus opacification on CT, with 45% to 75% of such cases being odontogenic in nature. This study provides USD diagnostic considerations and reinforces the diagnostic approach to ODS.

Imaging of Skull Base and Orbital Invasion in Sinonasal Cancer: Correlation with Histopathology

Simple Summary

Pretreatment assessment of local extension in sinonasal cancer is essential for prognostic evaluation and surgical planning. It essentially relies on CT and MRI imaging whose performance is not accurately described in the scientific literature. The aim of this study was to assess the diagnostic performance of CT and MRI for the diagnosis of skull base and orbital invasion in sinonasal cancer by comparing imaging findings to histopathological data. A total of 176 patients were included. Objective data about the diagnostic value of pretreatment imaging in patients with sinonasal cancer were obtained: they suggest that pretreatment assessment of orbital invasion is difficult, even with the combination of CT and MRI.

Abstract

Background: Pretreatment assessment of local extension in sinonasal cancer is essential for prognostic evaluation and surgical planning. The aim of this study was to assess the diagnostic performance of two common imaging techniques (CT and MRI) for the diagnosis of skull base and orbital invasion by comparing imaging findings to histopathological data. Methods: This was a retrospective two-center study including patients with sinonasal cancer involving the skull base and/or the orbit operated on between 2000 and 2019. Patients were included only if pre-operative CT and/or MRI, operative and histopathologic reports were available. A double prospective blinded imaging review was conducted according to predefined radiological parameters. Radiologic tumor extension was compared to histopathological reports, which were considered the gold standard. The predictive positive value (PPV) for the diagnosis of skull base/orbital invasion was calculated for each parameter. Results: A total of 176 patients were included. Ethmoidal intestinal-type adenocarcinoma was the most common type of cancer (41%). The PPV for major modification of the bony skull base was 78% on the CT scan, and 89% on MRI. MRI signs of dural invasion with the highest PPVs were: contact angle over 45° between tumor and dura (86%), irregular deformation of dura adjacent to tumor (87%) and nodular dural enhancement over 2 mm in thickness (87%). Signs of orbital invasion had low PPVs (<50%). Conclusions: This retrospective study provides objective data about the diagnostic value of pretreatment imaging in patients with sinonasal cancer.

Pathological Features of Brain Metastases

Metastases are the most common intracranial tumors in adults. Lung cancer, melanoma, renal cell carcinoma, and breast cancer are the most common primary tumors that metastasize to the brain. Improved detection of small metastases by MRI, and improved systemic therapy for primary tumors, resulted in increased incidence of brain metastasis. Advances in neuroanesthesia and neurosurgery have significantly improved the safety of surgical resection of brain metastases. Surgical approach and active management have become applicable for many patients. Subsequently, brain metastases diagnosis no longer equals palliative treatment. Moreover, the demand for diagnosing brain masses has increased with its associated challenges.

Skull base reconstruction with pedicled nasoseptal flap: Technique, indications, and limitations

Endoscopic skull base surgery allows extensive tumor resection but results in large defects requiring robust dural repair. The vascularized nasal septal flap pedicled on the posterior nasal septal artery is known to have an excellent success rate for dural defect coverage. Detailed step-by-step descriptions of the harvest and placement of this flap are scarce. Using a sketch, images, and a video, we describe a detailed method for endoscopically harvesting and placing a nasoseptal flap (NSF). We also describe the indications and the decision process leading to the use of NSF.

A review of nasal, paranasal, and skull base tumors invading the orbit

Tumors that invade the orbit are uncommon. The majority are meningiomas arising from the sphenoid ridge (66%). Others are bone and cartilage tumors arising from the surrounding bones of the orbit, pituitary adenomas, and epithelial tumors arising from the paranasal sinuses and nasal cavity. Meningiomas occur more often in women, whereas epithelial tumors have a predilection for men. Meningiomas and epithelial tumors typically present in the sixth decade of life, whereas bone tumors tend to affect individuals in their third decade of life. Patients often present with a combination of ophthalmological and otorhinolaryngological symptoms, including proptosis, pain, decreased visual acuity, restrictions in motility of the eye, epistaxis, and nasal obstruction. Sarcomas and benign bone and cartilage tumors arise from surrounding structures, whereas carcinomas usually arise from the paranasal sinuses. Surgery is the mainstay of treatment. Depending on the aggressiveness and histology of the tumor, surgery may be combined with radiation and chemotherapy. The prognosis is generally poor, but varies depending on histology and cell origin, size of the tumor, and degree of invasion. Meningiomas and benign bone tumors have the best prognoses. Sinonasal undifferentiated carcinomas, small-cell neuroendocrine carcinomas, osteosarcomas, and rhabdomyosarcomas have poorer prognoses.

Imaging of endoscopic approaches to the anterior and central skull base

Sinonasal endoscopy for treatment of benign sinonasal diseases is a well-established procedure. Recent advances in endoscope technology have substantially expanded its application with many institutions now offering resection of skull base lesions and sinonasal malignancies via the endoscopic approach. Its minimally invasive nature leads to faster recovery time, better cosmetic results, and fewer complications. Unfortunately, not all lesions involving the sinonasal region and skull base are accessible to sinonasal endoscopy. In addition, many of these disease processes are not directly visible on clinical examination. Therefore, the surgeon relies upon imaging to (1) determine the extent and possible nature of the disease; (2) provide guidance for surgical planning purposes, in particular, if a lesion is accessible to endoscopic surgery or if an open surgical approach is indicated. The radiologist, on the other hand, needs to be familiar with the technical limitations and contraindications of sinonasal endoscopy to provide a meaningful radiology report to the surgeon. The relative and absolute contraindications to endoscopic surgery can be categorised into technical factors, extent of a lesion, tumour vascularity, and anatomical variations and are discussed in this review article.

Multiparametric MRI findings of sinonasal rhabdomyosarcoma in adults with comparison to carcinoma

PURPOSE

To identify magnetic resonance imaging (MRI) features of sinonasal rhabdomyosarcoma in adults, including diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI features as compared with carcinomas.

MATERIALS AND METHODS

Sixty-four patients were included in this study, including 12 sinonasal rhabdomyosarcomas and 52 sinonasal carcinomas. MRI was completed in all 64 patients with a 3T MR scanner. Conventional MR (nonenhanced and static contrast-enhanced) imaging features, DCE-MRI parameters, and the apparent diffusion coefficients (ADCs) were analyzed by two authors independently (X.Y.W. and Y.Z.W.).

RESULTS

Compared with gray matter, sinonasal rhabdomyosarcomas appeared isointense on T₁ -weighted images in 11 cases (91.7%, 11 of 12), and hyperintense on T₂ -weighted images in 9 patients (75%, 9 of 12). After contrast, sinonasal rhabdomyosarcomas showed inhomogeneous enhancement in 10 cases (83.3%, 10 of 12). Skull involvement was found in eight patients (66.7%) with rhabdomyosarcomas. On T₂ -weighted images, sinonasal carcinomas demonstrated isointense in 31 cases (59.6%, 31/52), hyperintense in 14 (26.9%, 14/52), and hypointense in 7 (13.5%, 7/52). Skull involvement was detected in 14 cases (14/52, 26.9%). There were significant differences in T₂ signal intensity (P = 0.005) and skull involvement (P = 0.016) between sinonasal rhabdomyosarcoma and carcinomas. There was a marginal difference in time to peak enhancement (P = 0.061), while no difference in time to maximum enhancement (P = 0.403), maximum contrast index (P = 0.368), and time-intensity curve types (P = 0.138) between rhabdomyosarcoma and carcinomas. The ADCs of sinonasal rhabdomyosarcoma were significantly lower than those of sinonasal carcinomas (P < 0.001).

CONCLUSION

A multiparametric approach using conventional MRI with added ADCs had the potential to improve the diagnostic accuracy of sinonasal rhabdomyosarcoma in adults. Evidence level: 4 J. Magn. Reson. Imaging 2017;45:998-1004.

Imaging in Endoscopic Cranial Skull Base and Pituitary Surgery

Endoscopic endonasal approaches have widely accepted techniques for managing benign and malignant processes along the entire ventral skull base with similar or better results compared with open procedures, but with lower rates of complication. Managing pathology affecting the skull base can be challenging because of complex anatomy and the proximity of critical neurovascular structures. Postoperative imaging can be challenging, because of surgical alterations of normal anatomy and the now common use of complex reconstruction techniques. Understanding the normal imaging appearance of skull base reconstruction is important for accurate postoperative interpretation and delineation between normal reconstructive tissue and recurrent neoplasm.

Minimally invasive surgery of the anterior skull base: transorbital approaches

Minimally invasive approaches are becoming increasingly popular to access the anterior skull base. With interdisciplinary cooperation, in particular endonasal endoscopic approaches have seen an impressive expansion of indications over the past decades. The more recently described transorbital approaches represent minimally invasive alternatives with a differing spectrum of access corridors. The purpose of the present paper is to discuss transorbital approaches to the anterior skull base in the light of the current literature. The transorbital approaches allow excellent exposure of areas that are difficult to reach like the anterior and posterior wall of the frontal sinus; working angles may be more favorable and the paranasal sinus system can be preserved while exposing the skull base. Because of their minimal morbidity and the cosmetically excellent results, the transorbital approaches represent an important addition to established endonasal endoscopic and open approaches to the anterior skull base. Their execution requires an interdisciplinary team approach.

Improved performance in differentiating benign from malignant sinonasal tumors using diffusion-weighted combined with dynamic contrast-enhanced magnetic resonance imaging

Background:

Differentiating benign from malignant sinonsal lesions is essential for treatment planning as well as determining the patient's prognosis, but the differentiation is often difficult in clinical practice. The study aimed to determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can improve the performance in differentiating benign from malignant sinonasal tumors.

Methods:

This retrospective study included 197 consecutive patients with sinonasal tumors (116 malignant tumors and 81 benign tumors). All patients underwent both DW and DCE-MRI in a 3-T magnetic resonance scanner. Two different settings of b values (0,700 and 0,1000 s/mm²) and two different strategies of region of interest (ROI) including whole slice (WS) and partial slice (PS) were used to calculate apparent diffusion coefficients (ADCs). A DW parameter with WS ADCs_b0,1000 and two DCE-MRI parameters (time intensity curve [TIC] and time to peak enhancement [Tpeak]) were finally combined to use in differentiating the benign from the malignant tumors in this study.

Results:

The mean ADCs of malignant sinonasal tumors (WS ADCs_b0,1000 = 1.084 × 10⁻³ mm²/s) were significantly lower than those of benign tumors (WS ADCs_b0,1000 = 1.617 × 10⁻³ mm²/s, P < 0.001). The accuracy using WS ADCs_b0,1000 alone was 83.7% in differentiating the benign from the malignant tumors (85.3% sensitivity, 81.2% specificity, 86.4% positive predictive value [PPV], and 79.5% negative predictive value [NPV]). The accuracy using DCE with Tpeak and TIC alone was 72.1% (69.1% sensitivity, 74.1% specificity, 77.5% PPV, and 65.1% NPV). Using DW-MRI parameter was superior than using DCE parameters in differentiation between benign and malignant sinonasal tumors (P < 0.001). The accuracy was 87.3% (90.5% sensitivity, 82.7% specificity, 88.2% PPV, and 85.9% NPV) using DW-MRI combined with DCE-MRI, which was superior than that using DCE-MRI alone or using DW-MRI alone (both P < 0.001) in differentiating the benign from the malignant tumors.

Conclusions:

Diffusion-weighted combined with DCE-MRI can improve imaging performance in differentiating benign from malignant sinonasal tumors, which has the potential to improve diagnostic accuracy and to provide added value in the management for these tumors.