MRI pre-treatment tumour volume in maxillary complex squamous cell carcinoma treated with surgical resection

Preoperative imaging in third molar surgery - A prospective comparison of X-ray-based and radiation-free magnetic resonance orthopantomography

This study aimed to compare preoperative data relevant to third molar surgery based on radiographic orthopantomography (OPG) and orthopantomogram-like MR images (MR-OPG), using five different MR protocols. X-ray-based OPG and OPG-like MRI reconstructions from DESS, SPACE-STIR, SPACE-SPAIR, T1-VIBE-Dixon, and UTE sequences were acquired in 11 patients undergoing third molar surgery, using a 15-channel mandibular coil. Qualitative (image quality, susceptibility to artifacts, positional relationship, contact/non-contact of the inferior alveolar nerve (IAN), relationship to maxillary sinus, IAN continuity, root morphology) and quantitative (tooth length, retromolar distance, distance to the IAN, and distance to the mandible margin) parameters of the maxillary and mandibular third molars were assessed regarding inter-reader agreement and quantitative discrepancies by three calibrated readers. Radiation-free MR-OPGs generated within clinically tolerable acquisition times, which exhibited high image quality and low susceptibility to artifacts, showed no significant differences compared with X-ray-based OPGs regarding the assessment of quantitative parameters. UTE MR-OPGs provided radiographic-like images and were best suited for assessing qualitative preoperative data (positional relationship, nerve contact/non-contact, and dental root morphology) relevant to third molar surgery. For continuous and focal nerve imaging, DESS MR-OPG was superior. MR-OPGs could represent a shift towards indication-specific and modality-oriented perioperative imaging in high-risk oral and maxillofacial surgery.

Radiooncological View on Therapy Outcome after Multidisciplinary Treatment of Sinonasal Tumors

Simple Summary

Tumors of the nasal cavity and paranasal sinus are rare. Most are discovered at a locally advanced stage and require multimodal treatment consisting of surgery and radiotherapy with concomitant chemotherapy. Tumor localization between the eyes and near the brain makes treatment planning difficult due to the necessary consideration of both critical normal tissue with high protection priority and the curative aim of the best radiotherapy dose deposit. Thus, it is noteworthy how tumor volumes impact the five-year survival outcome. Therefore, we investigated initial tumor volumes before any therapy. Patients with larger mean initial tumor volumes of more than 75 cm³ had worse outcomes. There was no additional benefit of upfront surgery. Especially for patients with large tumor burdens of the nasal cavity or paranasal sinus, an interdisciplinary case discussion with the patient is essential in the process of shared decision-making.

Abstract

Purpose: We report the outcome of a mono-institutional retrospective study of sinonasal carcinoma with the primary focus on GTV (gross tumor volume) and the effect of radiotherapy. Methods: 53 patients with sinonasal carcinoma and that of the nasal cavity, paranasal sinus or both except lymphoma were included. All patients were treated between 1999 and 2017. For tumor volume delineation, all pre-therapeutic images were fused to the planning CT (computed tomography). Results: The median follow-up was 17 months [0.3–60], the median age 60 years, 35 males and 18 females were included. Squamous cell carcinoma (SCC) (60.4%) was the predominant histology, followed by adenocarcinoma (15.1%). The mean composite OS (overall survival) time was 33.3 ± 3.5 months. There was no significant difference in the 5 y composite OS between tumor localization or radiotherapy setting. The simultaneous integrated boost concept showed a trend towards improving five-year composite OS compared to the sequential boost concept. The only factor with a significant impact on the 5 y composite OS rate was the pre-therapeutic GTV (cutoff 75 cm³; p = 0.033). The GTV ≥ 100 cm³ has no effect on the 5 y composite OS rate for SCC. Conclusions: The pre-therapeutic GTV is a prognostic factor for five-year composite OS for the entire group of patients with sinonasal tumors, influencing the outcome after completion of all treatment strategies. The GTV seems to not influence five-year composite OS in SCC. For this rare tumor entity, an intensive, multidisciplinary discussion is essential to finding the best treatment option for the patient.

Clinical anatomy of the maxillary sinus: application to sinus floor augmentation

The anatomy of the maxillary sinus, especially its vascular anatomy, and its relationships with the teeth and alveolar processes have been well documented. The development of cone-beam computed tomography has resulted in dentists being more familiar with maxillary sinus floor augmentation procedures. This paper aims to revisit the classic anatomy of the maxillary sinus and review the newly published literature in order to help dentists diagnose in more detail and perform safer surgery of the maxillary sinus.

Three-Dimensional Volume Imaging to Increase the Accuracy of Surgical Management in a Case of Recurrent Chordoma of the Clivus

Patient: Male, 53

Final Diagnosis: Clivus chordoma

Symptoms: Pain the eye

Medication: —

Clinical Procedure: —

Specialty: Radiology

Early detection of pulp necrosis and dental vitality after traumatic dental injuries in children and adolescents by 3-Tesla magnetic resonance imaging

OBJECTIVES

More than 50% of all children suffer a traumatic dental injury (TDI) during childhood. In many cases, dentists apply root canal treatment (RCT), which is performed on an average of 7-10 days after replantation. Our aim was to evaluate whether RCT is necessary in many cases, and whether revitalization of affected teeth is possible and measurable by visualization using 3T magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Seven healthy children with TDI were treated by repositioning of the affected teeth and reduction of alveolar process fractures followed by splinting. Two weeks after initial treatment, splints were removed. After 6 weeks, all children received 3-Tesla (3T), three-dimensional, high-resolution MRI with a 20-channel standard head and neck coil. The mean age of the children (male/female = 5:2) was 10.8 years (range, 8-17 years). In addition, all children received conventional dental examination for tooth vitality and dental sensitivity to cold and tenderness on percussion.

RESULTS

3T MRI provided excellent images that allowed fine discrimination between dental pulp and adjacent tooth. Using four in-house optimized, non-contrast-enhanced sequences, including panoramic reconstruction, the assessment and analysis of the dental pulp was sufficiently feasible. We could demonstrate reperfusion and thus vitality of the affected teeth in 11 sites. In one child, MRI was able to detect nonreperfusion after TDI of the affected tooth. MRI results were confirmed by clinical examination in all cases. As a consequence of this expectant management and proof of reperfusion and tooth vitality by 3T MRI, only one child had to be treated by RCT.

CONCLUSION

3T MRI is a very promising tool for visualization and detection in the field of dental and oromaxillofacial diseases. By using new 3T MRI sequences in children with TDI, we could demonstrate that RCT are not necessary in every case, and thus could prevent unnecessary treatment of children in the future. Larger studies should follow to confirm the potential benefit in clinical practice.

Evaluation of four different optimized magnetic-resonance-imaging sequences for visualization of dental and maxillo-mandibular structures at 3 T

OBJECTIVES

The purpose of this study was to evaluate four in-house optimized, non-contrast enhanced sequences for MRI-investigation of maxillo-mandibular and dental structures by use of 3 T.

METHODS

12 volunteers with different dental status were examined by using a 3 T MRI with a 20-channel standard head-and-neck coil. All images performed were evaluated by using 3D-techniques, with different slice-thicknesses, in 3D T1- and T2-weighted sequences, as well as by using new techniques of image depictions. In addition phantom measurements were performed to estimate the extent of image artefacts caused by retainers and metal implants.

RESULTS

Mean age of the participants was 33 years (range, 25.5-62.75 years), and the sex ratio was 5 females to 7 males. We identified different techniques to improve osseous and dental structures, despite problems caused by dental implants, tooth crowns or braces.

CONCLUSION

The sequences evaluated offered excellent visualization in 2D and 3D of osseous and dental structures. Anatomical, osseous and dental structures were described at their ROI, in relation to patients with dental and head and neck pathologies. The ability to detect and distinguish pathological processes as soon as possible in 3D with excellent image quality avoiding ionizing radiation remains a challenging domain.

Imaging angiogenesis: perspectives and opportunities in tumour research - a method display

The growth of solid tumours necessitates angiogenesis. The aim of this paper is the presentation and evaluation of different ex vivo methods for analysing tumour angiogenesis. Oral squamous cell carcinomas (SCC) were induced in mice by subcutaneous injection of tumour cells in the groin region and processed for histology and microvascular corrosion casting. Vascularization was analysed light microscopically using CD31 immunochemistry. Corrosion casts were analysed by scanning electron microscopy (SEM), micro computed tomography (μCT) and synchrotron radiation-based micro computed tomography (SRμCT). Immunochemistry allows for a simple and authentic detection and stereological quantification of the SCC vascularization. μCT imaging of the corrosion casts gives a high-quality overview over the three-dimensional (3D) microvascular architecture. SEM and SRμCT allow a high-definition display of the vessel morphology, providing magnificent detail recognition down to the capillary level enabling imaging of different forms of tumour angiogenesis, e.g., sprouting and intussusceptive angiogenesis. Immunochemistry and SEM are regarded as suitable for most of the morphometrical and morphological assessments because of the simple procedure and the high explanatory power, especially in combination with each other. High resolution SRμCT helps answering specialized questions, however, requires sophisticated data processing for visualization and is of limited availability.