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Ultraviolet photoelectron spectroscopy (UPS) has been applied to the investigation of the electronic structure of oligothiophenes with 4–8 thiophene rings. In a series of α-linked oligomers (αn with n being the number of rings), a systematic evolution of the π band is observed. Several peaks which correspond to the π band are observed in the region of 0.7–3 eV below the Fermi level (EF), and the bandwidth becomes broader with increasing n. The nonbonding π band is observed at 3.5 eV below EF and its energy is almost independent of the number of thiophene units. UPS spectra of α7 and α8 are fairly similar to the spectra of polythiophene, showing that these oligomers are good model compounds of the polymer. The ionization threshold energy of α7 and polythiophene was observed to be 5.3 eV. The effect of irregularity on the π-electron system was also studied by using oligomers which contain a β linkage or a vinylene group at the middle of the molecule. The UPS spectra showed that the β linkages significantly affect the electronic structure of polythiophene, while the vinylene group does not. In order to analyze the UPS spectra and to investigate the electronic structures of oligomers, the orbital energies and the geometries of these oligomers are calculated by the semiempirical MNDO-SCF-MO (modified neglect of diatomic overlap self-consistent-field molecular orbital) method. Theoretically simulated spectra of these oligothiophenes derived from the obtained orbital energies by Gaussian broadening are compared with the observed ones. The agreement between the observed and calculated spectra is very good, particularly in the π region. It is shown from the optimized geometry that (1) αn ’s have planar structure and π electrons are delocalized, (2) the oligomer with β linkages has nonplanar structure leading to limited delocalization of π electrons, and (3) the oligomers... [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical effectiveness of pretreatment [18F] fluoro-2-deoxy-D-glucose-positron emission tomography for head-and-neck squamous cell carcinoma patients with nodal metastasis treated with chemoradiotherapy. Methods and Materials: Between March 2002 and December 2006, 178 patients with head-and-neck squamous cell carcinoma and nodal metastasis underwent fluoro-2-deoxy-D-glucose positron emission tomography before chemoradiotherapy. Fluoro-2-deoxy-D-glucose uptake by both the primary lesion and the neck node was measured using the standard uptake value (SUV). The overall survival, disease-free survival, local control, nodal progression-free survival, and distant metastasis-free survival rates were calculated, and several prognostic factors were evaluated. Results: The patients with a nodal SUV≥6.00 had a significantly lower 3-year disease-free survival rate than those with a lower SUV (44% vs. 69%, p=.004). On multivariate analysis, a high SUV of nodal disease also proved to be a significantly unfavorable factor for disease-free survival (p=.04, 95% confidence interval [CI], 1.02-3.23), nodal progression-free survival (p=.05; 95% CI, 1.00-4.15), and distant metastasis-free survival (p=.016; 95% CI, 1.25-8.92). Among the patients with a greater nodal SUV (≥6.00), those treated with planned neck dissection had better nodal progression-free survival than those in the observation group (p=.04, hazard ratio, 2.36; 95% CI, 1.00-5.85). Conclusion: Among head-and-neck squamous cell carcinoma patients treated with chemoradiotherapy, the pretreatment SUV of nodal disease was one of the strongest prognostic factors and also provided important information for the selection of patients suitable for planned neck dissection. [ABSTRACT FROM AUTHOR]

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The purpose of this study was to compare radiation treatment plans (RTPs) that used intensity-modulated radiation therapy (IMRT) with helical tomotherapy (HT) or three-dimensional conformal radiation therapy (3D-CRT) for nasal natural killer/Tcell lymphoma (NNKTL). We created RTPs that used IMRT with HT or 3D-CRT for eight NNKTL patients previously treated at our institution and conducted a pilot comparison between the two modalities using the parameters of the target coverage and homogeneity for the planning target volume (PTV) and the maximum and mean doses for organs at risk (OARs). The clinical target volume (CTV) included the gross tumour volume with an additional margin of 1.5 cm and the nasopharynx, palates and nasal cavity; the PTV with the CTV plus a 2 mm margin received a total dose of 50 Gy. IMRT achieved significantly better PTV coverage, with more than 99% of the PTV receiving 90% and 95% of the prescribed dose, whereas 3D-CRT could not provide adequate coverage of the PTV, with 89.1±2.6% and 84.5±2.7% of the PTV receiving 90% and 95% of the prescribed dose, respectively (both p ,0.0001). The homogeneity index was 0.29±0.06 for IMRT and 0.046±0.022 for 3D-CRT, which was statistically significant (p<0.0001). IMRT tended to provide equivalent or slightly better OAR avoidance than 3DCRT. In conclusion, 3D-CRT could not provide adequate coverage of the PTV because the PTV was close to many OARs. IMRT should be used for NNKTL because a lack of optimal RTPs could cause local failure. [ABSTRACT FROM AUTHOR]

Copyright of Acta Chirurgica Iugoslavica is the property of Association of Yugoslav Surgeons and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to investigate the therapeutic results of arterial injection therapy via the superficial temporal artery for 134 cases of stages III and IV (M0) oral cavity cancer retrospectively, and to clarify the prognostic factors. We administered intra-arterial chemoradiotherapy by continuous infusion of carboplatin in 65 cases from January 1993 to July 2002. Systemic chemotherapy was performed on 26 cases at the same time. We administered intra-arterial chemoradiotherapy by cisplatin with sodium thiosulphate in 69 cases from October 2002 to December 2006. Systemic chemotherapy was performed on 48 cases at the same time. The 3-year local control rate was 68.6% (T2-3: 77.9%; T4: 51.3%), and the 3-year survival rate was 53.9% (stage III: 62.9%; stage IV: 45.3%). Regarding the results of multivariate analysis of survival rates, age (<65), selective intra-arterial infusion, and the use of cisplatin as an agent for intra-arterial infusion were significant factors. The therapeutic results of intra-arterial chemoradiotherapy via the superficial temporal artery were not inferior to the results of surgery. In particular, the results of arterial injection therapy by cisplatin with sodium thiosulphate were excellent, so we believe that it will be a new therapy for advanced oral cavity cancer. [ABSTRACT FROM AUTHOR]