Preclinical Validation of the Located Hyperthermia Using Gold Macro-Rods and Ultrasound as an Effective Treatment for Solid Tumors.

Hyperthermia, the procedure of raising the temperature of a part of or the whole body above normal for a defined period of time, is applied alone or as an adjunctive with various established cancer treatment modalities such as radiotherapy and chemotherapy. In this study used a method for inducing hyperthermia in solid tumors with a combination of gold macro rod (GR) and ultrasound, the feasibility of this technique was described only with computational models and in vitro. The Ehrlich tumor, derived from a mouse adenocarcinoma, has been used to investigate the bio-heat transfer and the effect of gold rods irradiated with ultrasound. The in vivo measurements demonstrated that the technique inhibited more 80% of the tumor growth in both experimental models tested. These results not only confirm the bio heat transfer to tissue as predicted by analytical calculation and in vitro measurements, but are also proved to be a potential alternative to kill cancer cells.

Neuronal Correlation Parameter and the Idea of Thermodynamic Entropy of an N-Body Gravitationally Bounded System.

Understanding how the brain encodes information and performs computation requires statistical and functional analysis. Given the complexity of the human brain, simple methods that facilitate the interpretation of statistical correlations among different brain regions can be very useful. In this report we introduce a numerical correlation measure that may serve the interpretation of correlational neuronal data, and may assist in the evaluation of different brain states. The description of the dynamical brain system, through a global numerical measure may indicate the presence of an action principle which may facilitate a application of physics principles in the study of the human brain and cognition.

Gold Rods Irradiated with Ultrasound for Combination of Hyperthermia and Cancer Chemotherapy.

PURPOSE: The aim of this study was to analyze feasibility (in vitro and in vivo) the use of hyperthermia produced by gold rods irradiated with ultrasound and their combination with chemotherapy with doxorubicin. MATERIALS AND METHODS: initially was determined the cell viability and Hsp70 levels after treatment by gold rods irradiated with ultrasound (GR+U) in cell culture. The pretreatment with GR+U combined with doxorubicin (DOX) was evaluated from IC50, caspase-3 expression and mechanisms of cell death by electron microscopy. For evaluate the in vivo effects was used solid Ehrlich carcinoma (SEC) Tumor. The animals received three treatments with the combination of GR+U+DOX over 16 days. RESULTS: The cell viability was completely inhibited after 40 min of treatment with GR+U and significant increases the expression of HSP70 was only observed after 10 min of treatment. GR+U+DOX presented significant reduction of IC50 representing 50.7%, 76.5% 45.2% and 46.6% for cell lines K562, NCI-H292, Hep-2 and MCF-7 respectively. GR+U+DOX presented significant reduction of IC50 representing 50.7%, 76.5% 45.2% and 46.6% for cell lines K562, NCI-H292, Hep-2 and MCF-7 respectively. The caspase-3 level and ultraestructural analysis showed that treatment with GR+U+DOX enhances induction of apoptosis. Pretreatment with GR+U combined with doxorubicin (1 mg) showed 87% inhibition against SEC. and no showed cardiotoxic effect. CONCLUSIONS: The combined treatment of GR+U and DOX exhibit synergistic characteristics observed by increasing the efficiency of doxorubicin.

Analytic considerations and axiomatic approaches to the concept cell death and cell survival functions in biology and cancer treatment.

This study contains a discussion on the connection between current mathematical and biological modeling systems in response to the main research need for the development of a new mathematical theory for study of cell survival after medical treatment and cell biological behavior in general. This is a discussion of suggested future research directions and relations with interdisciplinary science. In an effort to establish the foundations for a possible framework that may be adopted to study and analyze the process of cell survival during treatment, we investigate the organic connection among an axiomatic system foundation, a predator-prey rate equation, and information theoretic signal processing. A new set theoretic approach is also introduced through the definition of cell survival units or cell survival units indicating the use of "proper classes" according to the Zermelo-Fraenkel set theory and the axiom of choice, as the mathematics appropriate for the development of biological theory of cell survival.

The effect of the shape and size of gold seeds irradiated with ultrasound on the bio-heat transfer in tissue.

The aim of this report is to propose a new methodology to treat prostate cancer with macro-rod-shaped gold seeds irradiated with ultrasound and develop a new computational method for temperature and thermal dose control of hyperthermia therapy induced by the proposed procedure. A computer code representation, based on the bio-heat diffusion equation, was developed to calculate the heat deposition and temperature elevation patterns in a gold rod and in the tissue surrounding it as a result of different therapy durations and ultrasound power simulations. The numerical results computed provide quantitative information on the interaction between high-energy ultrasound, gold seeds and biological tissues and can replicate the pattern observed in experimental studies. The effect of differences in shapes and sizes of gold rod targets irradiated with ultrasound is calculated and the heat enhancement and the bio-heat transfer in tissue are analyzed.

Consistency of vendor-specified activity values for ¹9²Ir brachytherapy sources.

A long-term comparison was done between the manufacturer-stated ¹9²Ir activity and the measured ¹9²Ir activities determined with a well-type ionization chamber. Sources for a Nucletron Micro Selectron high-dose-rate (HDR) unit were used for this purpose. The radioactive sources reference activities were determined using a PTW well-type ionization chamber traceable to the National Institute of Standards and Technology Primary Calibration Laboratory. The measurements were taken in a period of 56 months with 17 different radioactive sources. The manufacturer stated activities were taken from the source calibration certificate provided by the manufacturer. These values were compared with the measured activities. The results have shown that both the percentage deviation of the monthly control measurements with the well-type chamber and the ratio between the measured activities to the manufacturer-stated value lie within ± 2.5%. These results were compared with similar published data and with uncertainty level (3% of the mean and 5% maximum deviation from mean) for brachytherapy sources calibration recommended by the AAPM. It was concluded that a threshold level of ±2.5% can be used as a suitable quality assurance indicator to spot problems in our department. The typical ±5% uncertainty as provided by the manufacturers may be tightened to ±3% to be more in line with published AAPM reports.

Study of a spherical phantom for Gamma knife dosimetry.

Four 16 cm diameter spherical phantoms were modeled in this study: a homogenous water phantom, and three water phantoms with 1 cm thick shell each made of different materials (PMMA, Plastic WaterTM and polystyrene). The PENELOPE Monte Carlo code was utilized to simulate photon beams from the Leksell Gamma Knife (LGK) unit and to determine absorbed dose to water (Dw) from a single 18 mm beam delivered to each phantom. A score spherical volume of 0.007 cm3 was used to simulate the dimensions of the sensitive volume of the Exradin A-16 ionization chamber, in the center of the phantom. In conclusion, the PMMA shell filled with water required a small correction for the determination of the absorbed dose, while remaining within the statistical uncertainty of the calculations (+/- 0.71). Plastic WaterTM and polystyrene shells can be used without correction. There is a potential advantage to measuring the 4 mm helmet output using these spherical water phantoms.

Photodynamic therapy for anal cancer.

Invasive anal cancers are generally successfully treated by combined chemotherapy with radiation therapy (XRT). For those patients who locally fail this intervention many are salvaged by surgery which generally results in permanent colostomy. We examined the treatment and outcome of Photofrin based photodynamic therapy (PDT) in a cohort of patients with anal cancer who failed locally despite chemo-radiation (N=6) and two patients with positive margins of resection after excision of small T(1) squamous cell anal cancers who refused further surgery or chemo-radiation. PDT consisted of outpatient infusion of Photofrin at 1.2mg/kg followed 48 h later by outpatient illumination. Red light (630 nm) illumination was delivered by a 5 cm diffusing fiber, treating transphincterally at 300 J/cm followed by microlens illumination at 200 J/cm(2) to the perianal tumor bed with 2 cm margin. All patients completed PDT without incident and all have maintained local control of disease in the anal region for the length of follow up (18-48 months). PDT may serve as a new means to salvage local failures and perhaps could be employed as a primary treatment modality in select patients with early stage of disease.

Nutrition and orthomolecular supplementation in lung cancer patients.

This article reviews updates and provides some data related to nutritional and orthomolecular supplementation in oncology patients with an emphasis on lung cancer, a commonly diagnosed tumor with significant nutritional disturbances. Cancer and its treatment play a significant role in nutritional imbalance which likely has negative impact on the patient both in terms of quality and quantity of life. Nutritional supplementation may correct these imbalances with significant clinical benefit both physiologically and psychologically. This review will help assist in providing clinically useful data to assess the cancer patient's nutritional status and to guide nutritional intervention to assist these patients' recovery.

Enhanced response of the fricke solution doped with hematoporphyrin under X-rays irradiation

The vials filled with Fricke solutions were doped with increasing concentrations of Photogem®, used in photodynamic therapy. These vials were then irradiated with low-energy X-rays with doses ranging from 5 to 20 Gy. The conventional Fricke solution was also irradiated with the same doses. The concentration of ferric ions for the Fricke and doped-Fricke irradiated solutions were measured in a spectrophotometer at 220 to 340 nm. The results showed that there was an enhancement in the response of the doped-Fricke solution, which was proportional to the concentration of the photosensitizer. The use of such procedure for studying the radiosensitizing property of photosensitizers based on the production of free radicals is also discussed.

Tubos de ensaio foram preenchidos com a solução Fricke dopada com Fotogem® em concentrações crescentes; essa hemotoporfirina é utilizada na terapia fotodinâmica. Esses tubos foram irradiados com doses de 5 a 20 Gy. A solução Fricke convencional também foi irradiada com as mesmas doses. As concentrações de íons férricos nas soluções Fricke convencional e dopadas irradiadas foram medidas num espectrofotômetro com comprimento de onda entre 220 e 340 nm. Os resultados mostraram que quando comparado o Fricke convencional com o Fricke dopado irradiado, as amostras dopadas demonstraram um aumento na resposta da dose absorvida que é proporcional a concentração do Photogem® na solução Fricke. Concluímos que esse procedimento pode ser utilizado para propósitos de dosimetria na terapia com radiossensibilizadores.

The use of fricke dosimetry for low energy x-rays

Neste trabalho, o dosímetro Fricke foi utilizado para verificação dos rendimentos de quatro qualidades de radiação produzidas por um aparelho de raios-X Pantak de 160 kV com potenciais entre 30 e 100 kV. Para tanto, foram utilizadas as qualidades de radiação recomendadas pela "Deutsh Internationale Normung" DIN 6809. As medidas foram realizadas em simuladores de plexiglas. Os resultados obtidos demonstraram que o dosímetro Fricke pode ser utilizado não apenas para a dosimetria desses equipamentos, mas também, para a manutenção do fator de calibração de sistemas de medidas para baixas energias.