Comparison of different breast planning techniques and algorithms for radiation therapy treatment

This work aims at investigating the impact of treating breast cancer using different radiation therapy (RT) techniques – forwardly-planned intensity-modulated, f-IMRT, inversely-planned IMRT and dynamic conformal arc (DCART) RT – and their effects on the whole-breast irradiation and in the undesirable irradiation of the surrounding healthy tissues. Two algorithms of iPlan BrainLAB treatment planning system were compared: Pencil Beam Convolution (PBC) and commercial Monte Carlo (iMC). Seven left-sided breast patients submitted to breast-conserving surgery were enrolled in the study. For each patient, four RT techniques – f-IMRT, IMRT using 2-fields and 5-fields (IMRT2 and IMRT5, respectively) and DCART – were applied. The dose distributions in the planned target volume (PTV) and the dose to the organs at risk (OAR) were compared analyzing dose–volume histograms; further statistical analysis was performed using IBM SPSS v20 software. For PBC, all techniques provided adequate coverage of the PTV. However, statistically significant dose differences were observed between the techniques, in the PTV, OAR and also in the pattern of dose distribution spreading into normal tissues. IMRT5 and DCART spread low doses into greater volumes of normal tissue, right breast, right lung and heart than tangential techniques. However, IMRT5 plans improved distributions for the PTV, exhibiting better conformity and homogeneity in target and reduced high dose percentages in ipsilateral OAR. DCART did not present advantages over any of the techniques investigated. Differences were also found comparing the calculation algorithms: PBC estimated higher doses for the PTV, ipsilateral lung and heart than the iMC algorithm predicted.

Arquimedes : o matemático dos volumes!

[...], na matemática, quando se fala de volumes, é inevitável falar de Arquimedes. Nasceu em Siracusa, uma colónia grega situada na Sicília, em 287 a.C., e foi educado em Alexandria, no Egito. É considerado o maior matemático, físico e inventor do mundo antigo. Distinguiu-se também na Astronomia, por influência de seu pai que era astrónomo, e na Mecânica. Chegou a descrever um método para determinar o centro de gravidade dos corpos geométricos, tendo esboçado os princípios da alavanca. [...].

Modeling of the lung impedance using a fractional order ladder network with constant phase elements

The self similar branching arrangement of the airways makes the respiratory system an ideal candidate for the application of fractional calculus theory. The fractal geometry is typically characterized by a recurrent structure. This study investigates the identification of a model for the respiratory tree by means of its electrical equivalent based on intrinsic morphology. Measurements were obtained from seven volunteers, in terms of their respiratory impedance by means of its complex representation for frequencies below 5 Hz. A parametric modeling is then applied to the complex valued data points. Since at low-frequency range the inertance is negligible, each airway branch is modeled by using gamma cell resistance and capacitance, the latter having a fractional-order constant phase element (CPE), which is identified from measurements. In addition, the complex impedance is also approximated by means of a model consisting of a lumped series resistance and a lumped fractional-order capacitance. The results reveal that both models characterize the data well, whereas the averaged CPE values are supraunitary and subunitary for the ladder network and the lumped model, respectively.

Budget impact from the incorporation of positron emission tomography – computed tomography for staging lung cancers

OBJECTIVE To estimate the budget impact from the incorporation of positron emission tomography (PET) in mediastinal and distant staging of non-small cell lung cancer.METHODS The estimates were calculated by the epidemiological method for years 2014 to 2018. Nation-wide data were used about the incidence; data on distribution of the disease´s prevalence and on the technologies’ accuracy were from the literature; data regarding involved costs were taken from a micro-costing study and from Brazilian Unified Health System (SUS) database. Two strategies for using PET were analyzed: the offer to all newly-diagnosed patients, and the restricted offer to the ones who had negative results in previous computed tomography (CT) exams. Univariate and extreme scenarios sensitivity analyses were conducted to evaluate the influence from sources of uncertainties in the parameters used.RESULTS The incorporation of PET-CT in SUS would imply the need for additional resources of 158.1 BRL (98.2 USD) million for the restricted offer and 202.7 BRL (125.9 USD) million for the inclusive offer in five years, with a difference of 44.6 BRL (27.7 USD) million between the two offer strategies within that period. In absolute terms, the total budget impact from its incorporation in SUS, in five years, would be 555 BRL (345 USD) and 600 BRL (372.8 USD) million, respectively. The costs from the PET-CT procedure were the most influential parameter in the results. In the most optimistic scenario, the additional budget impact would be reduced to 86.9 BRL (54 USD) and 103.8 BRL (64.5 USD) million, considering PET-CT for negative CT and PET-CT for all, respectively.CONCLUSIONS The incorporation of PET in the clinical staging of non-small cell lung cancer seems to be financially feasible considering the high budget of the Brazilian Ministry of Health. The potential reduction in the number of unnecessary surgeries may cause the available resources to be more efficiently allocated.

Repercussões da estase pulmonar sobre os volumes, capacidades e débitos ventilatórios

Revista Portuguesa de Cardiologia, 1994, 13(10): 763-768.

Volumes e débitos expiratórios forçados em mulheres entre os 60 e os 68 anos - contribuição para o estudo dos parâmetros de referência portugueses

Via Pneumológica 1991; IV: 119-129

Evaluation of lung function abnormalities prevalence in poultry workers

Introduction - Poultry workers can be at an increased risk of occupational respiratory diseases, like asthma, chronic obstructive pulmonary disease and extrinsic allergic alveolitis. Spirometry screening is fundamental to early diagnosis trough the identification of related ventilatory defects. Purpose - We aimed to assess the prevalence of lung function abnormalities in poultry workers.

Characterisation of adventitious lung sounds in people with dementia

Introduction: Lower Respiratory Tract Infections (LRTIs) are highly prevalent in institutionalised people with dementia, constituting an important cause of morbidity and mortality. Computerised auscultation of Adventitious Lung Sounds (ALS) has shown to be objective and reliable to assess and monitor respiratory diseases, however its application in people with dementia is unknown. Aim: This study characterised ALS (crackles and wheezes) in institutionalised people with dementia. Methods: An exploratory descriptive study, including 6 long-term care institutions was conducted. The sample included a dementia group (DG) of 30 people with dementia and a match healthy group (HG) of 30 elderly people. Socio-demographic and anthropometric data, cognition, type and severity of dementia, cardio-respiratory parameters, balance, mobility and activities and participation were collected. Lung sounds were recorded with a digital stethoscope following Computerised Respiratory Sound Analysis (CORSA) guidelines. Crackles’ location, number (N), frequency (F), two-cycle duration (2CD), initial deflection width (IDW) and largest deflection width (LDW) and wheezes’ number (N), ratio (R) and frequency (F) were analysed per breathing phase. Statistical analyses were performed using PASW Statistics(v.19). Results: There were no significant differences between the two groups in relation to the mean N of crackles during inspiration and expiration in both trachea and thorax. DG trachea crackles had significant higher F during inspiration and lower IDW, 2CD and LDW during expiration when compared with HG. At the thorax, the LDW during inspiration was also significantly lower in the DG. A significant higher N of inspiratory wheezes was found in the HG. Both groups had a low ratio of high frequency wheezes. Conclusion: Computerised analyses of ALS informed on the respiratory system and function of people with dementia and elderly people. Hence, this could be the step towards prevention, early diagnosis and continuous monitoring of respiratory diseases in people with cognitive impairment.

Inapparent lung involvement in patients with the subacute juvenile type of paracoccidioidomycosis

Three patients with the diagnosis of subacute juvenile paracoccidioidomycosis who, at the time of their first visit, had no signs or symptoms of lung involvement, were studied. Initially the diagnosis was confirmed by the observation of P. brasiliensis in biopsy material obtained from clinically involved lymphadenopathies. The lung X-rays done in all patients, did not reveal pathologic changes, although it was possible to observe and isolate the fungus from sputum samples obtained from the three patients. This fact reinforces the pulmonary genesis of the mycosis and proofs the existence of a pulmonary primary infection, even in patients with the juvenile manifestations, in whom the lung component is obscured by the predominant lymph node involvement.

Cryptococcus gattii fungemia: report of a case with lung and brain lesions mimicking radiological features of malignancy

A 64-year-old apparently immunocompetent white man developed lung and brain lesions of disseminated cryptococcosis. The radiologic features mimicked those of lung cancer metastatic to the central nervous system. C. gattii was recovered from cultures of bronchoalveolar lavage fluid, brain biopsy, and blood. The same fungus was recovered from pulmonary and brain specimens at autopsy. Serum and cerebrospinal fluid cryptococcal antigen tests were diagnostic in our case and should be included in the diagnostic evaluation of unexplained pulmonary and cerebral lesions. A literature search showed few reports of fungemia by this species of Cryptococcus, contrasting to C. neoformans.

Watermelon Stomach, Hemorrhagic Pericarditis, Small Cell Carcinoma of the Lung and Synchronous Squamous Cell Carcinoma of the Tongue Base

Based on a case of gastric antral vascular ectasia (watermelon stomach) that was associated with hemorrhagic pericarditis, small cell lung carcinoma with mediastinal lymph node metastases and a synchronous squamous cell carcinoma of the base of the tongue, the authors made a review of the clinical, endoscopic and histopathological aspects of this type of gastropathy, and its association with other diseases, and of the results of its endoscopic therapy. The causes of hemorrhagic pericarditis are considered, emphasizing the necessity to know if the effusion has a malignant etiology. To the best of our knowledge the association of watermelon stomach to small cell lung carcinoma and squamous cell carcinoma of the base of the tongue has not yet been described. Extensive metastases to mediastal lymph nodes are common to small cell lung carcinoma.