Biomedical Photonics (BMP - E-Journal)
Not a member yet
274 research outputs found
Sort by
Исследование влияния неравномерности нанесения на подложку радионуклида на распределение поглощенной дозы, создаваемой решеткой микроисточников
No full textThe impact of irregularity in radionuclide coating of scaffold on the distribution of absorbed dose produced by grid of microsources was analyzed. On engineering software MATHCAD the program for calculation of absorbed dose produced by grid of microsources was created. To verify this algorithm the calculation model for MCNP code was established and represented the area consisted of soft biological tissue or any other tissue in which the grid of microsources was incorporated. Using the developed system the value of possible systematic irregular coating of radioactivity on the microsource’s core was analyzed. The distribution of activity along the surface of microsource was simulated to create distribution of absorbed dose rate corresponding to experimental data on radiation injury. The obtained model of microsource with irregular distribution of activity was compared to conventional microsource with core coated regularly along the entire area of the silver stem by main dosimetry characteristics. The results showed that even for extremely irregular distribution of activity the distribution of dose rate produced by microsource in the tumor area was not substantially different from dose-rate field obtained for microsource with regularly coated activity. The differences in dose rates (up to 10%) in areas which were the nearest to the center of the grid were significantly lower than its decline from center to periphery of the grid. For spatial distribution of absorbed dose for specific configuration of microsource set and tracing of curves of equal level by selected cut-off the program SEEDPLAN was developed. The developed program represents precisely enough the spatial distribution of selected configuration set of microsources using results of calculation data for absorbed dose around the single microsource as basic data and may be used for optimal planning of brachytherapy with microsources.
Флуоресцентная цистоскопия у больных немышечно-инвазивным раком мочевого пузыря
Get PDFThe main challenge of treating non-muscle invasive bladder cancer is multifocal tumors. Current methods of diagnosis are failed to detect all superficial flat tumor lesions in bladder mucosa. The use of fluorescence imaging with 5-aminolevulinic acid (5-ALA) allows to improve the sensibility of routine cystoscopy, but low specificity decreases its diagnostic accuracy. The method of fluorescence imaging combined with local fluorescence spectroscopy developed in P.A. Herzen MCRI has been shown to increase the specificity from 71% to 84%. Thus, local fluorescence spectroscopy in visible fluorescence of 5-ALA-induced protoporphyrin allows to perform guided biopsy and decrease the rate of diagnostic mistakes. Основной проблемой лечения немышечно-инвазивного рака мочевого пузыря является мультицентричный рост опухоли. Современные методы диагностики не позволяют выявить все поверхностные плоские опухолевые очаги в слизистой мочевого пузыря. Применение визуализационной флуоресцентной диагностики с 5-аминолевулиновой кислотой (5-АЛК) позволяет повысить чувствительность рутинной цистоскопии, но невысокая специфичность метода снижает его диагностическую точность. В МНИОИ им. П.А. Герцена разработана методика, сочетающая флуоресцентную визуализацию с локальной флуоресцентной спектроскопией, что позволило повысить специфичность метода с 71% до 84%. Таким образом, применение локальной флуоресцентной спектроскопии в очагах визуально определяемой флуоресценции 5-АЛК-индуцированного протопорфирина IX позволяет выполнять прицельные биопсии и снизить число диагностических ошибок.
Фотодинамическая терапия эпителиальных злокачественных новообразований кожи
Get PDFThe results of photodynamic therapy (PDT) in patients with skin cancer are represented. The treatment was performed in 283 patients with basal cell skin cancer (BCSC) and also in 51 patients with squamous cell skin cancer (SCSC). For PDT the photosensitizer Photolon at dose of 1.1–1.6 mg/kg body weight was used. The light irradiation dose delivered to tumor was from 100 to 600 J/cm2 by one or several fields according to type and size of tumor lesion. After PDT for BCSC the complete regression of tumor lesions was in 96.8% of cases, partial regression – in 3.2%. For PDT of recurrent tumors the complete regression was observed in 76.4% of cases, partial regression – in 23.6%. After PDT in patients with primary SCSC the complete regression was achieved in 91.7% of patients and partial regression – in 8.3%. For treatment of recurrent SCCS the complete regression was observed only in 59.3% of cases, partial – in 33.3%, no response – in 7.4%. For follow-up period from 6 months to 5 years recurrent SCSC was diagnosed in 31.2% of patients. The results shows that the application of PDT allows to perform effective treatment of basal and squamous cell skin cancer for unfavorable localization of tumor and in case of limitations for surgical treatment and/or radiotherapy and the efficacy of treatment depends on stage of disease. clinical and morphological pattern of process and previous treatment modality.
Системная фотодинамическая терапия с фотосенсибилизатором фотолон в лечении онкологических больных с регионарными и отдаленными метастазами
Get PDF The results of photodynamic therapy (PDT) in 76 patients with tumors of different sites and with regional or distant metastases are represented. Sixty three patients were under combined or multimodal therapy, 13 patients had systemic PDT as monotherapy. The technique of PDT was as follows: the solution of photosensitizer photolon was administered intravenously at dose of 0.8–1.4 mg/ kg body weight. Laser blood irradiation was performed simultaneously (wavelength of 662 nm, output power of 20 mW, irradiation time of 50 min). Stabilization of the disease defined as the absence of new tumor foci was observed in 55% of treated patients: among them in 47% of patients with disseminated melanoma during 6–10 months after treatment, in 65% patients with breast cancer – for 3–6 years after treatment, and also in 100% of patients with cancer of other sites (colorectal, pancreatic, cervical, ovarian, lung and stomach cancer, retroperitoneal neuroblastoma) – for 10–12 months after treatment. According to ultrasound data the shrinkage of most of metastases up to its complete disappearance was observed. The authors consider that effects of systemic PDT are due to decrease of circulating tumor cells in blood and also due to beneficial impact of this modal of treatment on immune status of cancer patient. Intravenous PDT was shown to improve treatment results and quality of life in patients with metastases of malignant tumors. The approved technique is of considerable interest and requires further investigation of its efficiency including its combination with methods of combined and multimodal treatment.
Результаты комбинированного антиангиогенного воздействия на новообразованные сосуды роговицы. экспериментально-морфологическое исследование
Get PDFResults of comparative experimental and morphological study of activity on corneal neovascularization in rabbit’s eye of photodynamic therapy with Photosense and antiangiogenic therapy with Avastin (bevacizumab) alone, and in its combination are represented. The treatment was performed in regimens: 1) photodynamic therapy with Photosense (single intravenous injection in dose of 0.3 mg/kg 72 h prior to laser irradiation, power density of irradiation 500 mW/cm2, wavelength 675 nm); 2) drug antiangiogenic therapy with Avastin (single subconjuctival introduction at dose of 1.25 mg); 3) photodynamic therapy with Photosense (in described regimen) in combination with subconjuctival introduction of Avastin at dose of 1.25 mg immediately prior to irradiation. Combined photodynamic therapy with antiangiogenic therapy allows to obtain almost complete occlusion in all regions of corneal neovascular bed with shorter time interval comparing with those for monoregimens. In case of blood flow retention in great vessels courses of combined modality treatment may be repeated. The absence of side-effects on surrounding tissues and the recovery of optical characteristics of cornea may allow to use this upcoming method in clinical practice.
Фотодинамическая терапия базальноклеточного рака кожи ЛОР-органов
Get PDFResults of photodynamic therapy in 96 patients with primary and recurrent basal cell skin cancer of ENT-organs are represented. For photodynamic therapy the Russian-made photosensitizer Photoditazine at dose of 0.6–1.4 mg/kg was used. Parameters were selected taking into account type and extent of tumor and were as follows: output power – 0.1–3.0 W, power density – 0.1–1.3 W/cm2, light dose – 100–400 J/cm2. The studies showed high efficacy of treatment for primary and recurrent basal cell skin cancer of nose, ear and external auditory canal – from 87.5 to 94.7% of complete regression. Examples of efficacy of the method are represented in the article. High efficacy and good cosmetic effects allowed to make a conclusion about perspectivity of photodynamic therapy for recurrent basal cell skin cancer of ENT-organs. Приведены результаты лечения методом фотодинамической терапии 96 пациентов с первичным и рецидивным базальноклеточным раком кожи ЛОР-органов. Для проведения фотодинамической терапии применяли фотосенсибилизатор отечественного производства – фотодитазин – в дозе 0,6–1,4 мг/кг. Параметры облучения подбирались с учетом формы и распространенности опухолевого процесса и составляли: выходная мощность – 0,1–3,0 Вт, плотность мощности – 0,1–1,3 Вт/см2, доза света – 100–400 Дж/см2. Исследования показали высокую эффективность лечения первичного и рецидивного базальноклеточного рака кожи носа, ушной раковины и наружного слухового прохода – от 87,5 до 94,7% случаев полной регрессии. В статье приведены примеры, иллюстрирующие эффективность предложенной методики. Высокая эффективность и хорошие косметические результаты позволили сделать вывод о перспективности применения фотодинамической терапии в лечении базальноклеточного рака кожи ЛОР-органов.
Фотодинамическая терапия в лечении метастатического рака молочной железы
Get PDFResults of treatment for cutaneous metastasis of breast cancer with photjdynamic therapy are represented. The study included 46 patients, the total number of treated cutaneous metastases was 535. For photodynamic therapy photosensitizer photolon given intravenously at a dose of 0.9–1.6 mg/kg body weight 3 h before treatment session (wave length 661±1 nm, плотность мощности 0,11–0,56 J/cm2), мощность на выходе волокна 0,3–2,0 Wt, light dose 50–600 J/cm2. Complete regression of metastasis was obtained in 33.6% of cases, partial – in 39.4%, stabilization – in 22.6%, progression of disease was in 4.3% of cases. The results show the perspectiveness of photodynamic therapy for metastasis as one of the step of treatment. Приведены результаты лечения внутрикожных метастазов рака молочной железы методом фотодинамической терапии. Исследовано 46 пациенток, суммарное число пролеченных внутрикожных метастазов составило 535. Для проведения фотодинамической терапии использовали фотосенсибилизатор фотолон, который вводили пациенткам внутривенно в дозе 0,9–1,6 мг/кг массы тела за 3 ч до проведения сеанса облучения (длина волны 661±1 нм, плотность мощности 0,11–0,56 Дж/см2), мощность на выходе волокна 0,3–2,0 Вт, плотность энергии 50–600 Дж/см2. В результате лечения полная регрессия метастатических очагов была получена в 33,6% случаев, частичная – в 39,4%, стабилизация – в 22,6%, прогрессирование зарегистрировано в 4,3% случаев. Полученные результаты свидетельствуют о перспективности применения метода фотодинамической терапии для лечения метастатических очагов рака молочной железы как одного из этапов комбинированного лечения.
Оценка противоопухолевой эффективности применения диметилового эфира хлорина е6 при фотодинамической терапии
Get PDFResults of the study for anticancer efficacy of photodynamic therapy with chlorin e6 dimethyl ether for treatment of outbread rats with sarcoma M-1 are represented. The drug was given intravenously or intraperitonealy at a dose of 1.25 mg/kg body weight (light dose – 300 J/cm2) or 2,5 mg/kg body weight (light dose – 150 J/cm2). The spectrometry showed that maximal drug accumulation in tumor was in 2 h after intravenous injection or 3 h after intraperitoneal injection of photosensitizer, thus, sensitized tumors were irradiated according to these time intervals. Intraperitoneal injection of chlorin е6 dimethyl ether at a dose of 1.25 mg/kg body weight with treatment session in 3 h and light dose of 300 J/cm2 was the most effective (the complete response in animals – 86%).Приведены результаты изучения противоопухолевой эффективности фотодинамической терапии с диметиловым эфиром хлорина е6 при лечении беспородных крыс с саркомой М-1. Препарат вводили животным внутривенно и внутрибрюшинно в дозах 1,25 мг/ кг (световая доза облучения 300 Дж/см2) или 2,5 мг/кг (доза облучения 150 Дж/см2). Результаты спектрометрии показали, что максимальное накопление препарата в опухоли было достигнуто через 2 ч после внутривенного и через 3 ч после внутрибрюшинного введения фотосенсибилизатора, поэтому облучение сенсибилизированных опухолей проводили через указанные промежутки времени. Наибольшая эффективность фотодинамической терапии с диметиловым эфиром хлорина е6 была достигнута в режиме с внутрибрюшинным введением препарата в дозе 1,25 мг/кг и дальнейшим сеансом облучения через 3 ч, плотность энергии облуче- ния 300 Дж/см2 (процент полного излечения животных 86%).
Фотодинамическая терапия больных раком нижней губы
Get PDFResults of diagnosis and treatment in 32 patients with lower lip cancer using photodynamic therapy (PDT) with photosensitizer Photosense are represented. 15 patients had stage I of disease, in 12 – stage II and in 5 – stage III. Photosensitizer Photosense was administered at dose of 0.5 mg/kg body weight in 20 patients and at dose of 0.8 mg/kg – in 12 patients as single intravenous infusion. During the treatment the fluorescent diagnosis (FD) was performed. The average power of diagnostic laser irradiation was 2 mW, light dose on tissue surface was < 1 J/cm2. Power density of therapeutic laser irradiation accounted for 150–300 mW/cm2, light dose of one session was 200-300 J/cm2. First session of PDT was performed 24 h after drug injection, the interval between following sessions accounted for 24 h. The number of session varied from 3 to 5. The results of FD showed the increase of fluorescent intensity in the center of tumor from 14.9 up to 150.8 r.u. 24 h after drug injection, this parameter in the normal mucosa increased from 13,4 to 88,3 r.u. The side-effects of PDT with Photosense included pain syndrome, which was managed by non-opioid analgesics in all 10 patients. The signs of phototoxycity were observed in 9 patients. Two months after PDT 22 (68.7%) patients had complete regression of tumor lesion, the response in 8 (25%) patients was defined as partial, 2 (6.3%) patients had stabilization of tumor growth.