Preoperative Image Fusion of Fluoro-2-Deoxy-d-Glucose???Positron Emission Tomography and Computed Tomography Data Sets in Oral Maxillofacial Carcinoma

Surfing the spectrum - what is on the horizon?

Diagnostic imaging techniques have evolved with technological advancements - but how far? The objective of this article was to explore the electromagnetic spectrum to find imaging techniques which may deliver diagnostic information of equal, or improved, standing to conventional radiographs and to explore any developments within radiography which may yield improved diagnostic data. A comprehensive literature search was performed using Medline, Web of Knowledge, Science Direct and PubMed Databases. Boolean Operators were used and key-terms included (not exclusively): terahertz, X-ray, ultraviolet, visible, infra-red, magnetic resonance, dental, diagnostic, caries and periodontal. Radiographic techniques are primarily used for diagnostic imaging in dentistry, and continued developments in X-ray imaging include: phase contrast, darkfield and spectral imaging. Other modalities have potential application, for example, terahertz, laser doppler and optical techniques, but require further development. In particular, infra-red imaging has regenerated interest with caries detection in vitro, due to improved quality and accessibility of cameras. Non-ionising imaging techniques, for example, infra-red, are becoming more commensurate with traditional radiographic techniques for caries detection. Nevertheless, X-rays continue to be the leading diagnostic image for dentists, with improved diagnostic potential for lower radiation dose becoming a reality.

Image fusion in preoperative planning

This article presents a comprehensive overview of generating a digital Patient-Specific Anatomic Reconstruction (PSAR) model of the craniofacial complex as the foundation for a more objective surgical planning platform. The technique explores fusing the patient's 3D radiograph with the corresponding high-precision 3D surface image within a biomechanical context. As taking 3D radiographs has been common practice for many years, this article describes various approaches to 3D surface imaging and the importance of achieving high-precision anatomical results to simulate surgical outcomes that can be measured and quantified. With the PSAR model readily available for facial assessment and virtual surgery, the advantages of this surgical planning technique are discussed.

Accuracy of 18F-FDG-PET/CT for staging of oral squamous cell carcinoma

BACKGROUND

This study prospectively assessed 2-[F18]-fluoro-2-deoxy-D-glucose-positron emission tomography (18F-FDG-PET)/CT (PET/CT) in oral squamous cell carcinoma.

METHODS

Twenty-three patients completed preoperative TNM staging (CT, MR, whole-body fusion imaging PET/CT). In patients who underwent surgical therapy (19 of 23), TNM staging based on PET/CT scan was compared with pTNM.

RESULTS

PET/CT correctly staged 16 of 19 primary tumors (accuracy 84.2%, sensitivity 84.2%, positive predictive value 100%) and correctly ruled out bone invasion in 3 patients with false-positive results according to CT and/or MR. PET/CT incorrectly identified neck involvement in 5 of 15 patients (3 false positives, 2 false negatives) who underwent neck dissection (accuracy 66.7%, specificity 76.9%, negative predictive value 83.3%). False-negative cases showed a nodal size not exceeding 10 mm. One patient with a bronchial synchronous primary tumor was identified.

CONCLUSION

PET/CT scan showed good accuracy in determining the extension and/or depth of invasion of the primary tumor. Nevertheless, PET/CT was not accurate to rule out nodal metastases.

F-18 FDG PET/CT Following Dental Extraction in a Patient With Head and Neck Cancer

A 48-year-old man with squamous-cell carcinoma of the left tonsillar fossa and cervical lymph node metastases was being staged before radiation and chemotherapy. The patient had periodontal disease, and extraction of 2 teeth was performed before therapy. A staging PET/CT was performed 1 week after extraction. This case demonstrates increased FDG uptake at the extraction sites, which could be potentially mistaken for metastatic lesions, especially without the fused PET/CT images.

Case Report: Fusion of positron emission tomography (PET) and computed tomography (CT) images for image-guided endoscopic navigation in maxillofacial surgery: Clinical application of a new technique

INTRODUCTION

Surgery based on computed tomography (CT) data is becoming increasingly important in the head and neck region. The technique for hardware fusion between positron emission tomography (PET) and computed tomography (CT) has only been established commercially in the last 4 years. The advantages over CT alone are obvious. The surgeon is simultaneously provided with a map of anatomical as well as of functional (metabolic) details. The fused images offer improved localization of malignant lesions and improved targeting of biopsy, especially for small lesions.

PURPOSE

A new technique for image-guided tumour localization for maxillofacial surgery based on PET/CT-image fusion is described.

PATIENT AND METHOD

A 78-year-old woman was admitted to this department with a tumour of the skull base. Three dimensional fusion of computed CT with positron PET images on a commercially available navigation system is described. After patient-to-image registration, a high-resolution endoscope was calibrated intraoperatively. Image-guided biopsy specimens were taken under direct visual control.

CONCLUSION

PET/CT-image fusion proved extremely helpful to navigate the endoscope to the target lesion and to identify the tumour.

Fusion image of positron emission tomography and computed tomography for the diagnosis of local recurrence of rectal cancer

BACKGROUND

The aim of this study was to evaluate the clinical and therapeutic value of digital fusion image (FI) of positron emission tomography (PET) using (18)F-fluorodeoxy glucose and computed tomography (CT) in patients who were suspected of having a local recurrence of rectal cancer.

METHODS

Forty-two patients (32 men and 10 women; mean age, 61.4 years, range, 40-79 years) with a suspicion of local recurrence after curative resection of rectal cancer were prospectively recruited and underwent (18)F-fluorodeoxy glucose-PET and CT. The FI was reconstructed with a commercially available digital software program, T-B Fusion. Wilcoxon signed rank test was used to compare FI with CT alone or PET alone.

RESULTS

FI yielded a correct diagnosis in 39 (93%) of 42 patients, whereas CT alone and PET alone did so in 33 (79%) and 37 (88%) patients, respectively. FI had better diagnostic accuracy than CT alone (P = .0138) and PET alone (P = .0156). Overall, FI altered patient management in 11 (26.2%) patients on the basis of additional information, including differentiation of the tumor from the postoperative scar in 6 patients, exact anatomical location in 3 patients, and both in 2 patients.

CONCLUSIONS

FI has a potential clinical value in the treatment of suspected local recurrence of rectal cancer.