980 resultados para DOSE RADIOIODINE THERAPY


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For the general practitioner to be able to prescribe optimal therapy to his individual hypertensive patients, he needs accurate information on the therapeutic agents he is going to administer and practical treatment strategies. The information on drugs and drug combinations has to be applicable to the treatment of individual patients and not just patient study groups. A basic requirement is knowledge of the dose-response relationship for each compound in order to choose the optimal therapeutic dose. Contrary to general assumption, this key information is difficult to obtain and often not available to the physician for many years after marketing of a drug. As a consequence, excessive doses are often used. Furthermore, the physician needs comparative data on the various antihypertensive drugs that are applicable to the treatment of individual patients. In order to minimize potential side effects due to unnecessary combinations of compounds, the strategy of sequential monotherapy is proposed, with the goal of treating as many patients as possible with monotherapy at optimal doses. More drug trials of a crossover design and more individualized analyses of the results are badly needed to provide the physician with information that he can use in his daily practice. In this time of continuous intensive development of new antihypertensive agents, much could be gained in enhanced efficacy and reduced incidence of side effects by taking a closer look at the drugs already available and using them more appropriately in individual patients.

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ABSTRACT Background: Chronic obstructive pulmonary disease (COPD) is characterised by an abnormal inflammatory response mainly to cigarette smoke that flares up during exacerbations of the disease (ECOPD). Reduced activity of histone deacetylases (HDAC) contributes to enhanced inflammation in stable COPD. It was hypothesised that HDAC activity is further reduced during ECOPD and that theophylline, an HDAC activator, potentiates the antiinflammatory effect of steroids in these patients. A study was performed to investigate HDAC activity during ECOPD and the effects of theophylline on the anti-inflammatory effects of steroids in a randomised single-blind controlled study. Methods: 35 patients hospitalised with ECOPD and treated according to international guidelines (including systemic steroids) were randomised to receive or not to receive low-dose oral theophylline (100 mg twice daily). Before treatment and 3 months after discharge, HDAC and nuclear factor-kB (NF-kB) activity in sputum macrophages, the concentration of nitric oxide in exhaled air (eNO) and total antioxidant status (TAS), tumour necrosis factor a (TNFa), interleukin (IL)-6 and IL8 levels in sputum supernatants were measured. Results: Patients receiving standard therapy showed decreased NF-kB activity, eNO concentration and sputum levels of TNFa, IL6 and IL8, as well as increased TAS during recovery of ECOPD, but HDAC activity did not change. The addition of low-dose theophylline increased HDAC activity and further reduced IL8 and TNFa concentrations. Conclusions: During ECOPD, low-dose theophylline increases HDAC activity and improves the anti-inflammatory effects of steroids.

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90Y-labelled radiopharmaceuticals offer promising prospects for radionuclide therapies of tumours, e.g. radioimmunotherapies (RIT), (EANM, 2007), peptide receptor radiotherapies (PRRT), (Otte et al., 1998), and selective internal radiotherapies (SIRT), (Salem and Thurston, 2006). 90Y, an almost pure high-energy beta radiation emitter (Eβ,max = 2.28 MeV), is a favourable radionuclide for therapeutic purposes. However, when preparing and performing these therapies, high activities of 90Y (>1 GBq) are to be manipulated and technicians, physicians and nurses may receive high skin exposures to the hands. If radiation protection standards are low, the exposure of staff can exceed the annual skin dose limit of 500 mSv. Within a particular work package (WP4) of the ORAMED project, comprehensive measurements in nuclear medicine departments of several hospitals in 6 European countries were carried out. The study focussed on 90Y-labelled substances such as Zevalin® and DOTATOC to achieve a representative database on staff exposure. This paper summarises the most important results and conclusions for individual monitoring of skin exposure of staff.

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PURPOSE: Exercise improves insulin resistance and is a first line for the prevention and treatment of type 2 diabetes. The extent, however, to which these responses are dose dependent is not known. The purpose of this study was to examine whether exercise dose was associated with improvements in insulin sensitivity after 4 months of exercise training in previously sedentary adults. METHODS: Fifty-five healthy volunteers participated in a 16-wk supervised endurance exercise intervention with a pre/postintervention design. Insulin sensitivity was assessed by euglycemic hyperinsulinemic clamp, peak oxygen uptake by a graded exercise test, and body composition by dual-energy x-ray absorptiometry. The exercise intervention consisted of three to five sessions per week with a minimum of three sessions supervised. A ramped exercise prescription protocol was used to achieve 75% of peak HR for 45 min per session. Exercise dose, expressed as average kilocalories expended per week, was computed as the product of exercise intensity, duration and frequency. RESULTS: Improved insulin sensitivity was significantly related to exercise dose in a graded dose-response relationship. No evidence of threshold or maximal dose-response effect was observed. Age and gender did not influence this dose-response relationship. Exercise intensity was also significantly related to improvements in insulin sensitivity, whereas frequency was not. CONCLUSIONS: This study identifies a graded dose-response relationship between exercise dose and improvements in insulin sensitivity. The implication of this observation is of importance for the adaptation of exercise prescription in clinical situations.

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PURPOSE: In the radiopharmaceutical therapy approach to the fight against cancer, in particular when it comes to translating laboratory results to the clinical setting, modeling has served as an invaluable tool for guidance and for understanding the processes operating at the cellular level and how these relate to macroscopic observables. Tumor control probability (TCP) is the dosimetric end point quantity of choice which relates to experimental and clinical data: it requires knowledge of individual cellular absorbed doses since it depends on the assessment of the treatment's ability to kill each and every cell. Macroscopic tumors, seen in both clinical and experimental studies, contain too many cells to be modeled individually in Monte Carlo simulation; yet, in particular for low ratios of decays to cells, a cell-based model that does not smooth away statistical considerations associated with low activity is a necessity. The authors present here an adaptation of the simple sphere-based model from which cellular level dosimetry for macroscopic tumors and their end point quantities, such as TCP, may be extrapolated more reliably. METHODS: Ten homogenous spheres representing tumors of different sizes were constructed in GEANT4. The radionuclide 131I was randomly allowed to decay for each model size and for seven different ratios of number of decays to number of cells, N(r): 1000, 500, 200, 100, 50, 20, and 10 decays per cell. The deposited energy was collected in radial bins and divided by the bin mass to obtain the average bin absorbed dose. To simulate a cellular model, the number of cells present in each bin was calculated and an absorbed dose attributed to each cell equal to the bin average absorbed dose with a randomly determined adjustment based on a Gaussian probability distribution with a width equal to the statistical uncertainty consistent with the ratio of decays to cells, i.e., equal to Nr-1/2. From dose volume histograms the surviving fraction of cells, equivalent uniform dose (EUD), and TCP for the different scenarios were calculated. Comparably sized spherical models containing individual spherical cells (15 microm diameter) in hexagonal lattices were constructed, and Monte Carlo simulations were executed for all the same previous scenarios. The dosimetric quantities were calculated and compared to the adjusted simple sphere model results. The model was then applied to the Bortezomib-induced enzyme-targeted radiotherapy (BETR) strategy of targeting Epstein-Barr virus (EBV)-expressing cancers. RESULTS: The TCP values were comparable to within 2% between the adjusted simple sphere and full cellular models. Additionally, models were generated for a nonuniform distribution of activity, and results were compared between the adjusted spherical and cellular models with similar comparability. The TCP values from the experimental macroscopic tumor results were consistent with the experimental observations for BETR-treated 1 g EBV-expressing lymphoma tumors in mice. CONCLUSIONS: The adjusted spherical model presented here provides more accurate TCP values than simple spheres, on par with full cellular Monte Carlo simulations while maintaining the simplicity of the simple sphere model. This model provides a basis for complementing and understanding laboratory and clinical results pertaining to radiopharmaceutical therapy.

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Background: Preclinical data indicate activity of mammalian target of rapamycin inhibitors and synergistic activity together with radiotherapy in glioblastoma. The aim of this trial is to assess the therapeutic activity of temsirolimus (CCI-779), an intravenous mTOR inhibitor, in patients with newly diagnosed glioblastoma with unmethylated O6 methlyguanine-DNA-methlytransferase (MGMT)promoter. Methods: Patients (n=257) with newly diagnosed glioblastoma after open surgical biopsy or resection fulfilling basic eligibility criteria underwent a central MGMT promoter analysis using quantitative methylation specific PCR. Patients with glioblastoma harboring an unmethylated MGMT promoter (n=111) were randomized 1:1 between radiotherapy (60 Gy; 5 times 2 Gy per week) plus concomitant and six cycles of maintenance temozolomide or radiotherapy plus weekly temsirolimus at 25 mg flat dose to be continued until progression or undue toxicity. Primary endpoint was overall survival at 12 months (OS12). Sample size of the investigational treatment arm required 54 patients to assess adequacy of temsirolimus activity set at 80%. More than 38 patients alive at 12 months in the per protocol population was considered a positive signal. A control arm of 54 patients treated with the standard of care was implemented to evaluate the assumptions on OS12. Results: Between December 2009 and October 2012, 111 pts in 14 centers were randomized and treated. Median age was 55 and 58 years in the temsirolimus and standard arm, respectively. Most patients (95.5%) had a WHO performance status of 0 or 1. Both therapies were properly administered with a median of 13 cycles of maintenance temsirolimus. In the per protocolpopulation, exactly 38 patients treated with temsirolimus (out of 54 eligible) reached OS12. In the intention to treat population OS12 was 72.2% [95% CI (58.2, 82.2)] in the temozolomide arm and 69.6% [95% CI (55.8, 79.9) in the temsirolimus arm [HR=1.16 95% CI (0.77, 1.76), p=0.47]. Conclusions: The therapeutic activity of temsirolimus in patients with newly diagnosed glioblastoma with an unmethylated MGMT promoter is too low.

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Lymphatic vessels transport fluid, antigens, and immune cells to the lymph nodes to orchestrate adaptive immunity and maintain peripheral tolerance. Lymphangiogenesis has been associated with inflammation, cancer metastasis, autoimmunity, tolerance and transplant rejection, and thus, targeted lymphatic ablation is a potential therapeutic strategy for treating or preventing such events. Here we define conditions that lead to specific and local closure of the lymphatic vasculature using photodynamic therapy (PDT). Lymphatic-specific PDT was performed by irradiation of the photosensitizer verteporfin that effectively accumulates within collecting lymphatic vessels after local intradermal injection. We found that anti-lymphatic PDT induced necrosis of endothelial cells and pericytes, which preceded the functional occlusion of lymphatic collectors. This was specific to lymphatic vessels at low verteporfin dose, while higher doses also affected local blood vessels. In contrast, light dose (fluence) did not affect blood vessel perfusion, but did affect regeneration time of occluded lymphatic vessels. Lymphatic vessels eventually regenerated by recanalization of blocked collectors, with a characteristic hyperplasia of peri-lymphatic smooth muscle cells. The restoration of lymphatic function occurred with minimal remodeling of non-lymphatic tissue. Thus, anti-lymphatic PDT allows control of lymphatic ablation and regeneration by alteration of light fluence and photosensitizer dose.

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BACKGROUND: Over 50% of patients with head and neck squamous cell carcinoma (HNSCC) present with locoregionally advanced disease. Those at intermediate-to-high risk of recurrence after definitive therapy exhibit advanced disease based on tumour size or lymph node involvement, non-oropharynx primary sites, human papillomavirus (HPV)-negative oropharyngeal cancer, or HPV-positive oropharynx cancer with smoking history (>10-pack-years). Non-surgical approaches include concurrent chemoradiotherapy, induction chemotherapy followed by definitive radiotherapy or chemoradiotherapy, or radiotherapy alone. Following locoregional therapies (including surgical salvage of residual cervical nodes), no standard intervention exists. Overexpression of epidermal growth factor receptor (EGFR), an ErbB family member, is associated with poor prognosis in HNSCC. EGFR-targeted cetuximab is the only targeted therapy that impacts overall survival and is approved for HNSCC in the USA or Europe. However, resistance often occurs, and new approaches, such as targeting multiple ErbB family members, may be required. Afatinib, an irreversible ErbB family blocker, demonstrated antiproliferative activity in preclinical models and comparable clinical efficacy with cetuximab in a randomized phase II trial in recurrent or metastatic HNSCC. LUX-Head & Neck 2, a phase III study, will assess adjuvant afatinib versus placebo following chemoradiotherapy in primary unresected locoregionally advanced intermediate-to-high-risk HNSCC. METHODS/DESIGN: Patients with primary unresected locoregionally advanced HNSCC, in good clinical condition with unfavourable risk of recurrence, and no evidence of disease after chemoradiotherapy will be randomized 2:1 to oral once-daily afatinib (40 mg starting dose) or placebo. As HPV status will not be determined for eligibility, unfavourable risk is defined as non-oropharynx primary site or oropharynx cancer in patients with a smoking history (>10 pack-years). Treatment will continue for 18 months or until recurrence or unacceptable adverse events occur. The primary endpoint measure is duration of disease-free survival; secondary endpoint measures are disease-free survival rate at 2 years, overall survival, health-related quality of life and safety. DISCUSSION: Given the unmet need in the adjuvant treatment of intermediate-to-high-risk HNSCC patients, it is expected that LUX-Head & Neck 2 will provide new insights into treatment in this setting and might demonstrate the ability of afatinib to significantly improve disease-free survival, compared with placebo. TRIAL REGISTRATION: ClinicalTrials.gov NCT01345669.

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PURPOSE: To evaluate the rate of tumor recurrence within the irradiated volume after initial low-dose irradiation of limited-stage small-cell lung cancer (SCLC), to assess the tolerance of a sequential combination of low-dose chest irradiation followed by chemotherapy, and to confirm the responsiveness of limited-stage SCLC to low-dose irradiation. METHODS AND MATERIALS: In this pilot study, 26 patients with limited-stage SCLC were treated by first-line 20-Gy thoracic irradiation followed 3 weeks later by chemotherapy (cisplatin, doxorubicin, and etoposide for six cycles). RESULTS: We present our final results with a median follow-up of surviving patients of 7 years. The response rate to this low-dose irradiation was 83%, with an overall response rate to radiochemotherapy of 96% and a median survival of 21 months. No unexpected early or late toxicity was observed. The rate of initial isolated local failure was 8%, which compares favorably with other published series using higher doses of radiochemotherapy. CONCLUSION: An initial chest irradiation of 20 Gy before chemotherapy could be sufficient to reduce the risk of local failure during the time of survival of patients with limited-stage SCLC. Potential advantages of this treatment may be the prevention of resistance mechanisms to radiotherapy induced by preliminary chemotherapy and a reduced radiation-induced toxicity.

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BACKGROUND: Pegylated liposomal doxorubicin (PLD) and bevacizumab are active agents in the treatment of metastatic breast cancer (MBC). We carried out a multicenter, single-arm phase II trial to evaluate the toxicity and efficacy of PLD and bevacizumab as first-line treatment in MBC patients. METHODS: Bevacizumab (10 mg/kg) and PLD (20 mg/m(2)) were infused on days 1 and 15 of a 4-week cycle for a maximum of six cycles. Thereafter, bevacizumab monotherapy was continued at the same dose until progression or toxicity. The primary objective was safety and tolerability, and the secondary objective was to evaluate efficacy of the combination. RESULTS: Thirty-nine of 43 patients were assessable for the primary end point. Eighteen of 39 patients (46%, 95% confidence interval 30% to 63%) had a grade 3 toxicity. Sixteen (41%) had grade 3 palmar-plantar erythrodysesthesia, one had grade 3 mucositis, and one severe cardiotoxicity. Secondary end point of overall response rate among 43 assessable patients was 21%. CONCLUSIONS: In this nonrandomized single-arm trial, the combination of bimonthly PLD and bevacizumab in locally recurrent and MBC patients demonstrated higher than anticipated toxicity while exhibiting only modest activity. Based on these results, we would not consider this combination for further investigation in this setting.

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Since the early 1980s high dose chemotherapy with autologous hematopoietic stem cell support was adopted by many oncologists as a potentially curative option for solid tumors, supported by a strong rationale from laboratory studies and apparently convincing results of early phase II studies. As a result, the number and size of randomized trials comparing this approach with conventional chemotherapy initiated (and often abandoned before completion) to prove or disprove its value was largely insufficient. In fact, with the possible exception of breast carcinoma, the benefit of a greater escalation of dose of chemotherapy with stem cell support in solid tumors is still unsettled and many oncologists believe that this approach should cease. In this article, we critically review and comment on the data from studies of high dose chemotherapy so far reported in adult patients with small cell lung cancer, ovarian cancer, germ cell tumors and sarcomas.

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Over the past few years, the therapeutic potential of Treg has been highlighted in the field of autoimmune diseases and after allogeneic transplantation. The first hurdle for the therapeutic use of Treg is their insufficient numbers in non-manipulated individuals, in particular when facing strong immune activation and expanding effector cells, such as in response to an allograft. Here we review current approaches being explored for Treg expansion in the perspective of clinical therapeutic protocols. We describe different Treg subsets that could be suitable for clinical application, as well as discuss factors such as the required dose of Treg, their antigen-specificity and in vivo stability, that have to be considered for optimal Treg-based immunotherapy in transplantation. Since Treg may not be sufficient as stand-alone therapy for solid organ transplantation in humans, we draw attention to possible hurdles and combination therapy with immunomodulatory drugs that could possibly improve the in vivo efficacy of Treg.

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Background/Purpose: Patient-reported outcomes (PROs) in patients with rheumatoid arthritis (RA) are critical in evaluating RA treatment effects on function and health-related quality of life (HR-QoL). Significant improvement in PROs has been reported in RA studies of biologic agents, including etanercept (ETN), but most studies have been conducted in patients with established disease. In addition to assessing treatment effects in early RA, there is interest in therapeutic strategies that allow dose reduction or withdrawal of biologic therapy (biologic-free) after induction of response. The PRIZE trial is an ongoing, 3-period study to evaluate the efficacy of combined ETN and methotrexate (MTX) therapy in patients with early, moderate-to-severe RA and to assess whether efficacy (remission) can be maintained with ETN dose reduction or biologic-free (Period 2) or drug-free (Period 3). Herein we report PROs associated with ETN 50 mg QW plus MTX (ETN50/MTX) therapy administered for 52 wks in Period 1 (induction) of the PRIZE trial. Methods: In Period 1, MTX- and biologic-naı‥ve patients with early, active RA (symptom onset 12 mo from enrollment; DAS28 _3.2) received open-label ETN50/MTX for 52 wks. The starting dose of MTX was 10 mg QW; at the discretion of the investigator, titration was permitted up to a maximum of 25 mg QW to achieve remission. Corticosteroid boosts were administered to patients not achieving low disease state at wks 13 and 26, unless contraindicated or not tolerated. PROs were assessed using the Health Assessment Questionnaire (HAQ) total score; Patient Acceptable Symptom State (PASS); EuroQol-5 Dimensions (EQ-5D) total index; Short Form Health Survey (SF-36); Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue; Work Instability Scale for Rheumatoid Arthritis (RAWIS); and Work Productivity and Activity Impairment Questionnaire: Rheumatoid Arthritis (WPAI:RA). Results: A total of 306 patients received treatment in Period 1 (mITT population); 222 (73%) patients completed the period. The majority of patients were female (70%), with a mean age of 50 y, mean DAS28 of 6.0 (median, 6.0), and duration of disease symptoms from onset of 6.5 months (median, 6.3 mo). Significant and clinically meaningful improvements in PROs, including in HAQ, EQ-5D, SF-36, and FACIT-Fatigue, were demonstrated with ETN50/MTX therapy from baseline to the final on therapy visit (Table; P_0.0001). Similar improvements were observed in all dimensions of RA-WIS and WPAI:RA (Table; P_0.0001). Conclusion: Combination therapy with ETN50/MTX for 52 wks in patients with _12 mo of symptomatic, active RA resulted in significant, clinically important improvements in measures of physical function, including normal HAQ (66.6% of patients), HR-QoL, fatigue, and work productivity. These outcomes are consistent with those reported in prior studies in patients with more established disease.

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Currently, androgen deprivation therapy (ADT) has a well-defined role when administered together with radiotherapy (RT): neo-adjuvant and concurrent combination for intermediate risk-disease and adjuvant therapy for high risk disease. Evidence of this association was generated by randomized trials designed and led approximately 30 years ago; thus the question which arises is how relevant and portable are these data in our current clinical practice? In the present review, we examine the pitfalls of these published randomized controlled trials, their relevance to present daily clinics, where high-dose external beam RT or brachytherapy is applied, as well as the adoption of ADT in patients with concomitant cardiovascular disorders.