Search

The purpose of this paper is to evaluate the impact of adding combined 18F-PET/CT to MRI for T and N staging of the oral and oropharyngeal cancer and calculation of the gross tumor volume (GTV) having histopathology as reference standard.PET/CT and MRI were performed in 66 patients with suspected oral and oropharyngeal cancer (41 primary tumors/25 recurrent tumors) and nodal disease (114 nodes). Statistical analysis included the McNemar test, sensitivity, specificity for the diagnostic modalities as well as regression analysis, and Bland-Altman graphs for calculated tumor volumes.There was no statistically significant difference between the two modalities compared to pathological findings regarding detection of disease (Por =0.72). The sensitivity/specificity for tumor detection were 100/80% and 96.72/60% for MRI and PET/CT, respectively. The sensitivity/specificity for nodal metastases were 88.46/75% and 83.81/73.91% for MRI and PET/CT, respectively. In 18% of cases, the MRI-based T staging resulted in an overestimation of the pathologic tumor stage. The corresponding rate for PET/CT was 22%. Regarding the treated necks, both modalities showed 100% sensitivity for detection of the recurrent lesions. In necks with histologically N0 staging, MRI and PET/CT gave 22% and 26% false positive findings, respectively. The mean tumor volume in the pathologic specimen was 16.6 +/- 18.6 ml, the mean volume derived by the MR imaging was 17.6 +/- 19.1 ml while the estimated by PET/CT volume was 18.8 +/- 18.1 ml (Por =0.007 between the three methods). The Bland-Altman analysis showed a better agreement between PET/CT and MRI.The diagnostic performance of FDG-PET/CT in the local staging of oral cancer is not superior to MRI.

To examine the feasibility of deriving quantitative microcirculatory parameters and to investigate the relationship between vascular and metabolic characteristics of head and neck tumours in vivo, using dynamic contrast-enhanced (DCE) MRI and fluorodeoxyglucose (FDG) PET imaging.Twenty-seven patients with primary squamous cell carcinoma (SCCA) underwent DCE-MRI and combined PET/CT imaging. DCE-MRI data were post-processed by using commercially available software. Transfer constant (K (trans)), extravascular extracellular blood volume (v (e)), transfer constant from the extracellular extravascular space to plasma (k (ep)) and iAUC (initial area under the signal intensity-time curve) were calculated. 3D static PET data were acquired and standardised uptake values (SUV) calculated.All microcirculatory parameters in tumours were higher than in normal muscle tissue (P ≤ 0.0019). Significant correlations were shown between k (ep) and K (trans) (ρ = 0.77), v (e) and k (ep) (ρ = -0.7), and iAUC and v (e) (ρ = 0.53). Significant correlations were observed for SUV(mean) and v (e) as well as iAUC (ρ = 0.42 and ρ = 0.66, respectively). SUV(max) was significantly correlated with iAUC (ρ = 0.69).The demonstrated relationships between vascular and metabolic characteristics of primary SCCA imply a complex interaction between vascular delivery characteristics and tumour metabolism. The lack of correlation between SUV and K (trans)/k (ep) suggests that both diagnostic techniques may provide complementary information.

Background and Objectives This preliminary report describes a new laser-assisted treatment option for the emerging complication of bisphosphonate related osteonecrosis (BON) of the jaw. Materials and Methods In eight tumour patients (three women, five men) ten bony lesions in the maxilla and mandible in the course of intravenous bisphosphonate therapy were treated with a variable square pulsed (VSP) Er:YAG laser. For the treatment, the Er:YAG laser was applied with a pulse energy of 1,000 mJ, a pulse duration of 300 microseconds, and a frequency of 12 Hz (energy density 157 J/cm2). The spot size was 0.9 mm and the handpiece was kept at a distance of about 10 mm from the bone surface. The diseased bone was ablated exclusively with the Er:YAG laser by subsequently sweeping the bone surface in a well directed scanning mode. Results The surgical procedure and postoperative wound healing were without any complications and a complete soft tissue recovering was achieved within 4 weeks. During follow-up examinations over 12 months soft tissue conditions were stable. The pulsed laser ablation caused a characteristic microstructured and craggy bone surface without a condensation or a smear layer on the laser rims. Conclusion The bone ablation technique using a VSP Er:YAG laser yielded promising clinical results without impairment of wound healing. A further analyse of the chemical, physical and pharmacological aspects of laser assisted treatment of BON lesions is necessary to get a safe and reliable treatment protocol for bisphosphonate-related osteonecrosis of the jaw. Lasers Surg. Med. 41:26–30, 2009. © 2008 Wiley-Liss, Inc.

Objectives: We sought to evaluate the routine clinical use of perfusion computed tomography in the detection and differentiation of primary and recurrent oropharynx and oral cavity tumors as well as of nodal disease. Materials and Methods: A total of 77 patients with primary cancer as well as suspected recurrent disease and lymph nodes were evaluated. A dynamic acquisition (4 X 6-mm slices) of the largest axial tumor surface was performed and the tumor blood flow (BF), blood volume (BV), and mean transit time (MTT) were calculated by using a modified deconvolution-based analysis taking into account the extravasation of the contrast agent for permeability surface area product imaging (PS). Tumor volume was calculated and region of interest analysis was performed on the pathologic and normal tissue. Results: The mean BF, BV, and PS values in the primary tumors (77.48 mL/min/100 g tissue; 5.29 mL/min; 13.33 mL/min/100 g tissue, respectively) were highly significantly different (P < 0.01) than those obtained in the normal structures. Mean MTT values (9.01 seconds) also were significantly lowered in the tumors compared with normal tissue (P < 0.05). There was no statistical difference in the perfusion values between the primary and the recurrent tumors. Recurrent disease could be differentiated on the basis of BF (P < 0.05) from tissue changes after chemo-radiation-treatment (mean BF: 69.71 versus 45.31 mL/min/100 g tissue, respectively). Differentiation of the lymph nodes was not possible by means of perfusion values. Tumor volume did not significantly correlate with any perfusion parameter. Conclusions: Perfusion CT of oropharyngeal and oral cavity cancer in clinical routine is feasible and helps outlining the malignant tissue as well as differentiating recurrent disease from nonspecific post-therapeutic changes.