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The aim of this study was to compare lateral photon–electron (LPE), helical tomotherapy (HT), and volumetric-modulated arc therapy (VMAT) plans for total scalp irradiation. We selected a single adult model case and compared the dosimetric results for the three plans. All plans mainly used 6-MV photon beams, and the prescription dose was 60 Gy in 30 fractions. First, we compared the LPE, HT and VMAT plans, with all plans including a 1-cm bolus. We also compared HT plans with and without the bolus. The conformity indices for LPE, HT and VMAT were 1.73, 1.35 and 1.49, respectively. The HT plan showed the best conformity and the LPE plan showed the worst. However, the plans had similar homogeneity indexes. The dose to the hippocampus was the highest in the VMAT plan, with a mean of 6.7 Gy, compared with 3.5 Gy in the LPE plan and 4.8 Gy in the HT plan. The doses to the optical structures were all within the clinically acceptable range. The beam-on time and monitor units were highest in the HT plan. The HT plans with and without a bolus showed similar target coverage and organ-at-risk (OAR) sparing. The HT plan showed the best target coverage and conformity, with low doses to the brain and hippocampus. This plan also had the advantage of not necessarily requiring a bolus. Although the VMAT plan showed better conformity than the LPE plan and acceptable OAR sparing, the dose to the hippocampus should be considered when high doses are prescribed.

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The present study examined the effect of MAO inhibitors, deprenyl and harmaline, on the membrane permeability transition in brain mitochondria. Deprenyl, harmaline, and antioxidant enzymes (SOD and catalase) attenuated alteration of the swelling, membrane potential, cytochrome c release, and Ca2+ transport in mitochondria treated with dopamine. In contrast, deprenyl and harmaline did not reduce the peroxynitrite-induced change in membrane permeability. Deprenyl and harmaline inhibited the decrease in thioredoxin reductase activity and the thiol oxidation in mitochondria treated with dopamine but did not decrease the effect of peroxynitrite. Deprenyl and harmaline significantly decreased the formation of melanin from dopamine. The results suggest that deprenyl and harmaline may protect brain mitochondria against the toxic action of dopamine oxidation by the maintenance of thioredoxin reductase activity, inhibition of thiol oxidation, and inhibition of dopamine oxidation product formation. In contrast, MAO inhibitors may not defend brain mitochondria against damaging action of peroxynitrite.

PurposeTo evaluate the prognostic value of metabolic tumor volume (MTV) and maximum standardized uptake value (SUVmax) on initial positron emission tomography-computed tomography (PET-CT) and investigate the clinical value of SUVmax for early detection of locoregional recurrent disease after postoperative radiotherapy in patients with locally advanced head and neck squamous cell carcinoma (HNSCC).Materials and MethodsA total of 100 patients with locally advanced HNSCC received primary tumor excision and neck dissection followed by adjuvant radiotherapy with or without chemotherapy. The MTV and SUVmax were measured from primary sites and neck nodes. The prognostic value of MTV and SUVmax were assessed using initial staging PET/CT (study A). Follow-up PET/CT scan available after postoperative concurrent chemoradiotherapy or radiotherapy were evaluated for the SUVmax value and correlated with locoregional recurrence (study B). A receiver operating characteristic (ROC) curve analysis was used to define a threshold value of SUVmax with the highest accuracy for recurrent disease assessment.ResultsHigh MTV (>41 mL) is negative prognostic factor for disease free survival (p = 0.041). Postradiation SUVmax was significantly correlated with locoregional recurrence (hazard ratio, 1.812; 95% confidence interval, 1.361 to 2.413; p < 0.001). A cut-off value of 5.38 from follow-up PET/CT was identified as having maximal accuracy for detecting locoregional recurrence by ROC analysis.ConclusionMTV at staging work-up was significantly associated with disease free survival. The SUVmax value from follow-up PET/CT showed high diagnostic accuracy for the detection of locoregional recurrence in postoperatively irradiated HNSCC.

The present study examined the effects of ambroxol and erdosteine, bronchial expectorants, on the cytokine synthesis, granule enzyme release, and free radical production in rat alveolar macrophages activated by lipopolysaccharide. Ambroxol and erdosteine significantly decreased the production of tumour necrosis factors-a, interleukin-1b, and interleukin-6 in alveolar macrophages activated by lipopolysaccharide. These drugs significantly reduced the production of superoxide anion, hydrogen peroxide, and nitric oxide and the release of acid phosphatase and lysozyme in lipopolysaccharide-activated macrophages. Ambroxol and erdosteine showed no scavenging effect on superoxide anion and hydrogen peroxide, whereas both drugs effectively decomposed nitric oxide. The results show that ambroxol and erdosteine may inhibit the responses, including cytokine synthesis and free radical production, in rat alveolar macrophages activated by lipopolysaccharide. Unlike the production of reactive oxygen species, the inhibitory effect of ambroxol and erdosteine on the production of nitric oxide in lipopolysaccharide-activated alveolar macrophages may be accomplished by a scavenging action on the species and inhibition of the respiratory burst.