In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture). There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species,Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

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Purpose: This study aims to evaluate the results of intensity modulated radiotherapy quality assurance (IMRT QA) obtained with the MatriXX Evolution system and compare them to those previously obtained with, in order to implement this new technology in clinical routine, turning it more practical and still reliable. Materials and methods: Three moments are being compared: (i) an “Old Standard”, when the IMRT QA was performed with a polymethylmethacrylate slabs phantom, ionization chamber and radiographic film in the coronal plane; (ii) “Transition”, when the use of MatriXX system was initiated, but still in conjunction with a film simultaneously and (iii) “New Standard”, with MatriXX alone. The measurements were performed in linear accelerators with step‐and‐shoot technique. OmniPro‐I'mRT software was used to obtain the measured dose distributions (MatriXX and digitized film) and to compare them to calculated dose distributions ‐ by two treatment planning systems, Helax TMS and Oncentra MasterPlan. The percentage of points that meet the criteria of 3% dose difference and 3mm distance to agreement using the gamma function (γ) was evaluated, denoted here as γ≤1. Results: The IMRT QA with the “Old Standard” (141 patients) provides 2.1%±1.6% average dose difference and 95%±5% of γ≤1. During the “Transition” (48 patients), the average dose difference was 2.6%±1.4%, and the γ≤1 were 98%±2% with MatriXX and 99%±1% with films. Finally, with the “New Standard” (116 patients) a 2.2%±1.8% average dose difference and 98%±2% of γ≤1 where obtained. Conclusions: The results indicate a learning curve along this whole experience, as well as equivalence between film and MatriXX measured dose distributions, despite the distinct resolutions. IMRT QA performed with MatriXX Evolution system can properly substitute the ionization chamber and film pattern, reducing the time spent to execute these processes in clinical routine.

Purpose: Evaluate an Institutional sample of prostate IMRT results, constructing a Population based Dose Volume Histogram (DVHp) to compare with literature and use it as an internal benchmark for plan approval and quality assurance. Finally, seek for relations between dosimetric plan results with anatomic variables to create predictive parameters. Method and Materials: Retrospective analysis of 40 patients that received the following treatment: IMRT with 5 beams (60Gy to the prostate and 54Gy to the seminal vesicles SV) + 3DCRT boost with 3 beams (20Gy to the prostate), 10mm isotropical PTV margins. Technical details: Step‐and‐Shoot, 18MV beam energy, Siemens KonRad treatment planning system, 10mm MLC leaf width. Structures analyzed: bladder, rectum, femur heads, penile bulb, PTV80Gy (prostate+ margin), PTV54Gy (prostate +SV +margin). Main DVH points for each structure were used to build the DVHp. Results: For Bladder, the V80Gy was 11±7%. The V75Gy, V70Gy, V65Gy, were, respectively, 17±11%, 21±14%, 23±16% for bladder and 13±3%, 18±4%, 22±5% for rectum and its V60Gy was 28±6%. The Dmax, was 86±1Gy for bladder, 85±1Gy for rectum, and 50±4Gy for femur. For penile bulb, the average dose was 44±9Gy. For targets, the D95%, Average Dose, Dmin and Dmax were, respectively 79.4±0.6Gy, 83.9±0.8Gy, 71±4Gy and 88±1Gy for the PTV80Gy and 64±6Gy, 80±2Gy, 53±5Gy and 88±1Gy for PTV54Gy (which includes the PTV80Gy). The rectum doses have weak correlation with its volume (r=−0.29±0.02), but a moderate to strong correlation with its PTV overlap (r=0.71±0.05) ‐ more than 20% Rectum‐PTV overlap means 66% chance of violating the V75Gy<15% constraint. The bladder doses have a moderate correlation with its volume (r=−0.62±0.04) and a strong correlation with its PTV overlap (r=0.80±0.01). Conclusion: In general, the DVHp meets literature recommendations regarding prescription and dose limits. This analysis allows evaluating future plans based on Institutional acceptance criteria, more detailed and restrictive than literature.