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Ion transport and its regulation in the endolymphatic sac (ES) are reviewed on the basis of recent lines of evidence. The morphological and physiological findings demonstrate that epithelial cells in the intermediate portion of the ES are more functional in ion transport than those in the other portions. Several ion channels, ion transporters, ion exchangers, and so on have been reported to be present in epithelial cells of ES intermediate portion. An imaging study has shown that mitochondria-rich cells in the ES intermediate portion have a higher activity of Na, K-ATPase and a higher Na permeability than other type of cells, implying that molecules related to Na transport, such as epithelial sodium channel (ENaC), Na-K-2Cl cotransporter 2 (NKCC2) and thiazide-sensitive Na-Cl cotransporter (NCC), may be present in mitochondria-rich cells. Accumulated lines of evidence suggests that Na transport is most important in the ES, and that mitochondria-rich cells play crucial roles in Na transport in the ES. Several lines of evidence support the hypothesis that aldosterone may regulate Na transport in ES, resulting in endolymph volume regulation. The presence of molecules related to acid/base transport, such as H-ATPase, Na-H exchanger (NHE), pendrin (SLC26A4), Cl-HCO exchanger (SLC4A2), and carbonic anhydrase in ES epithelial cells, suggests that acid/base transport is another important one in the ES. Recent basic and clinical studies suggest that aldosterone may be involved in the effect of salt-reduced diet treatment in Meniere's disease. [ABSTRACT FROM AUTHOR]

Objective: This prospective study compared the value of pretreatment 4'-[methyl-11C]-thiothymidine (11C-4DST) volumetric parameters and those of 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG) in predicting the clinical outcome in patients with head and neck squamous cell carcinoma (HNSCC). Methods: Fifty patients with HNSCC underwent 11C-4DST PET/CT and 18F-FDG PET/CT prior to anticancer therapy. 18F-FDG metabolic tumor volume (18F-FDG MTV) and total lesion glycolysis (TLG) were calculated from 18F-FDG PET, and 11C-4DST MTV and total lesion proliferation (TLP) were calculated from 11C-4DST PET. All parameters were measured for the primary lesion and metastatic lymph nodes. Associations between clinical factors and PET/CT parameters and prognostic value were analyzed. Results: Receiver-operating characteristic analysis revealed that MTV, TLG, and TLP acquired from the primary lesion and metastatic lymph nodes were good parameters for predicting disease relapse and death. The area under the curves (AUCs) ranged from 0.63 to 0.71 for 18F-FDG PET/CT parameters. The AUCs of 11C-4DST PET/CT parameters were larger than those of 18F-FDG (range 0.72-0.81). Univariate analysis revealed that individuals with tumors showing a high value for any PET/CT parameter were at a significantly increased risk of relapse. Upon multivariate analysis, 18F-FDG MTV, 11C-4DST MTV and 11C-4DST TLP were significant independent factors for relapse-free survival (P = 0.04, P = 0.0001 and P = 0.0005, respectively). Conclusion: Pretreatment 11C-4DST PET/CT volume-based parameters can provide important prognostic information about patients with HNSCC. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the predictive potential of pre-treatment 3'-deoxy-3'-[18F]-fluorothymidine (FLT) uptake parameters for short-term outcome of primary head and neck squamous cell cancer (HNSCC) patients. Patients and Methods: A total of 32 patients undergoing pre-treatment FLT positron emission tomography/computed tomography (PET/CT) from May 2010 to May 2013 were evaluated. Semi-quantitative assessment was used to determine mean, peak and maximum standardized uptake values (SUVmean, SUVpeak and SUVmax), metabolic tumor volume (MTV) and total lesion proliferation (TLP). Clinicopathologic factors and PET/CT parameters were analyzed for their association with 2-year loco-regional control (LRC) and overall survival (OS). Results: The mean (± SD) SUVmean, SUVpeak, SUVmax, MTV and TLP were 5.97 ± 3.16, 6.71 ± 3.75, 10.05 ± 5.37, 7.31 ± 8.05 and 44.95 ± 52.82, respectively. In univariate analyses, N category was associated with OS (P = 0.037). Increased MTV ≥13 ml was associated with decreased LRC and OS (P < 0.0001). TLP ≥69.3 g was also linked with both LRC and OS (P = 0.009 and 0.015, respectively). Regarding SUVs, only the SUVpeak was associated with LRC and OS (P = 0.035 and 0.049, respectively). Conclusions: Pre-treatment MTV is the most useful parameter with FLT PET/CT. TLP and SUVpeak may also provide important prognostic information for patients with HNSCCs. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the predictive potential of pre-treatment 3′-deoxy-3′-[18F]-fluorothymidine (FLT) uptake parameters for short-term outcome of primary head and neck squamous cell cancer (HNSCC) patients. Patients and methods: A total of 32 patients undergoing pre-treatment FLT positron emission tomography/computed tomography (PET/CT) from May 2010 to May 2013 were evaluated. Semi-quantitative assessment was used to determine mean, peak and maximum standardized uptake values (SUV, SUV and SUV), metabolic tumor volume (MTV) and total lesion proliferation (TLP). Clinicopathologic factors and PET/CT parameters were analyzed for their association with 2-year loco-regional control (LRC) and overall survival (OS). Results: The mean (± SD) SUV, SUV, SUV MTV and TLP were 5.97 ± 3.16, 6.71 ± 3.75, 10.05 ± 5.37, 7.31 ± 8.05 and 44.95 ± 52.82, respectively. In univariate analyses, N category was associated with OS ( P = 0.037). Increased MTV ≥13 ml was associated with decreased LRC and OS ( P < 0.0001). TLP ≥69.3 g was also linked with both LRC and OS ( P = 0.009 and 0.015, respectively). Regarding SUVs, only the SUV was associated with LRC and OS ( P = 0.035 and 0.049, respectively). Conclusions: Pre-treatment MTV is the most useful parameter with FLT PET/CT. TLP and SUV may also provide important prognostic information for patients with HNSCCs. [ABSTRACT FROM AUTHOR]

Objective: This study compared change of (18)F-fluorothymidine (FLT) uptake with that of (18)F-fluorodeoxyglucose (FDG) in head and neck squamous cell cancer (HNSCC) patients during and after treatment and evaluated the utility for early monitoring of response to chemoradiotherapy. Methods: Thirty patients with newly diagnosed HNSCCs treated with concurrent chemoradiotherapy underwent FLT and FDG PET in pre-treatment (PET1), mid-treatment (PET2) and post-treatment (PET3) stages. The PET images were evaluated quantitatively using maximum standardized uptake values (SUVs). Ratios between SUVs at PET2 and PET3 were also calculated. Results: According to the SUVs, no significant differences were found with primary site location, cellular differentiation and T category in all PET scans. About a 78 % median decrease in FLT SUV was observed at the total dose (TD) of 30 Gy and no apparent change was observed thereafter. About a 40 % decrease in FDG SUV was observed at TD 30 Gy and significant decreases were then found at the 4- and 6-week time points after the therapy. FLT PET demonstrated no recurrence regions in patients with a PET3/PET2 ratio of <1.5. In comparison, FLT SUVs in PET3 with recurrence were increased more than three times. However, no significant difference was found between the values with recurrence and those with no recurrence in FDG PET. Conclusion: FLT PET signal change preceded FDG PET change and the increase of FLT uptake after the therapy can imply recurrence or a residual tumor. FLT PET seems promising for early evaluation of chemoradiation effects in HNSCCs. [ABSTRACT FROM AUTHOR]

Objective: This study compared change of F-fluorothymidine (FLT) uptake with that of F-fluorodeoxyglucose (FDG) in head and neck squamous cell cancer (HNSCC) patients during and after treatment and evaluated the utility for early monitoring of response to chemoradiotherapy. Methods: Thirty patients with newly diagnosed HNSCCs treated with concurrent chemoradiotherapy underwent FLT and FDG PET in pre-treatment (PET1), mid-treatment (PET2) and post-treatment (PET3) stages. The PET images were evaluated quantitatively using maximum standardized uptake values (SUVs). Ratios between SUVs at PET2 and PET3 were also calculated. Results: According to the SUVs, no significant differences were found with primary site location, cellular differentiation and T category in all PET scans. About a 78 % median decrease in FLT SUV was observed at the total dose (TD) of 30 Gy and no apparent change was observed thereafter. About a 40 % decrease in FDG SUV was observed at TD 30 Gy and significant decreases were then found at the 4- and 6-week time points after the therapy. FLT PET demonstrated no recurrence regions in patients with a PET3/PET2 ratio of <1.5. In comparison, FLT SUVs in PET3 with recurrence were increased more than three times. However, no significant difference was found between the values with recurrence and those with no recurrence in FDG PET. Conclusion: FLT PET signal change preceded FDG PET change and the increase of FLT uptake after the therapy can imply recurrence or a residual tumor. FLT PET seems promising for early evaluation of chemoradiation effects in HNSCCs. [ABSTRACT FROM AUTHOR]