Intra-operative electron beam radiotherapy for newly dignosed and recurrent malignant gliomas: feasibility and lon-term outcomes

INTRODUCTION: Intra-operative electron beam radiotherapy (IOERT) is an alternative to dose escalation for the treatment of central nervous system tumors. The objective of this study was to describe the feasibility and long-term outcomes of IOERT in the treatment of primary and recurrent gliomas. MATERIALS AND METHODS: From January 1992 through December 2002, all patients treated with IOERT at the Hospital San Francisco de Asis, Madrid/Spain were retrospectively reviewed. The selection criteria included patients with superficial tumors, KPS >70 % and lesions <6 cm. Irradiation was administered in one section. The prescribed dose considered the amount of post-resection residual tumor, previous radiotherapy and the tolerance level of brain structures exposed to IOERT. RESULTS: There were 17 patients (53 %) with newly diagnosed malignant brain gliomas and 15 patients with recurrent tumors. The delivered dose varied from 8 to 20 Gy (median 12.5 Gy) for primary and from 8 to 16 Gy (median 10 Gy) for recurrent tumors. The median overall survival for the entire cohort was 13 months (14 and 10.4 months for the primary and recurrent, respectively). Three patients presented with radionecrosis, one patient with osteomyelitis at the craniotomy bone flap, one with intracerebral hemorrhage, and another patient experienced a pulmonary embolism. CONCLUSIONS: IOERT is a feasible technique and can be viewed as a tool in the treatment of newly diagnosed or recurrent brain gliomas (AU)

Radiosurgery and whole brain therapy in the treatment of brainstem metastases

PURPOSE: The incidence of brainstem metastasis (BSM) accounts for 1-3% of brain metastases (BM). They are often associated with multiple BM and produce significant neurological symptoms. We retrospectively analyse the results of treatment with stereotactic radiosurgery (SRS). METHODS AND MATERIAL: We included the medical records of 28 patients aged 52.86+/-11.29 years; 17 (60.7%) were women. The most frequent primary tumours were breast (n=11), lung (n=9) and melanoma (n=4). A total of 30 BSM were treated with radiosurgery (SRS) with a linear accelerator (Linac Scalpel, University of Florida). The 3D planning was with image fusion. RESULTS: The mean time from the diagnosis of the primary tumour to the BM was 3+/-3.35 years; 5 cases were diagnosed simultaneously. Twenty-seven patients (96.4%) received whole brain radiotherapy, 19 before SRS and 8 after. The most usual dose was 30 Gy. Three patients underwent another SRS for other BM. The medium volume of BSM was 1.86+/-2.31 cc. The mean prescribed dose was 1114.33+/-315.6 cGy. The tumour volume did not change significantly with SRS but there was neurological improvement in 13 patients (41.9%). Twenty-four patients (85.7%) died, 22 (78.5%) due to the primary tumour: 12 cases (42.8%) due to progression of BM, 1 case due to progression of BSM and 10 due to local tumour progression or extra-cerebral metastases. Mean survival from diagnosis of BM was 22.8+/-32.4 months and from SRS of BSM, 16.8+/-31.56 months (1 month to 13.54 years). CONCLUSION: The combined treatment of SRS and whole brain radiotherapy treatment is effective in the control of BSM (only one patient died due to progression of BSM), improving the neurological symptoms in 41.9% of patients; therefore an early diagnosis and treatment is important. Many patients die due to causes other than the BSM (AU)

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Experimental determination of the convolution kernel for the study of the spatial response of a detector.

One of the most important parameters in the characterization of a detector is its spatial convolution kernel. This kernel contains all of the information about the influence that the detector size has on the measured beam profile. In this paper we present an experimental method for the determination of the spatial convolution kernel for commonly used detectors that are employed in the x-ray profile measurement: film + densitometer, diode, and ionization minichamber. Our work is based on first assuming a step function pattern on a photographic film is known and is a perfect step function. The kernel of the densitometer system was then derived from the deconvolution of the scanned profile to the step function. Next a film was exposed to a penumbra area of an x-ray beam from a linac. The film was scanned using the same densitometer. The "real profile" that emerges from a linear accelerator was derived by the deconvolution of the scanned profile using the now known kernel of the film densitometer. Under the same irradiation condition the x-ray profile was measured with other detectors and with this information we obtained the convolution kernels for these detectors by solving numerically their basic convolution integrals. The results show that the Gaussian convolution kernel is the most consistent with the measurements. The best numerical values for the FWHM of the kernels are 1.1 mm, 2.2 mm, and 5.4 mm for densitometer, diode, and minichamber, respectively.

[Transesophageal Doppler color echocardiography in the evaluation of patients after percutaneous mitral valvuloplasty]. / Eco Doppler color transesofágico en la valoración de los pacientes tras valvuloplastia mitral percutánea.

To determine the value of transesophageal ultrasound in the assessment of patients after percutaneous mitral valvuloplasty, 42 patients were studied by transthoracic (TTE) and transesophageal (TEE) two-dimensional and color Doppler echocardiography. All of them were studied as out-patients and without complications. We describe the technique, planes of examination and the advantages that this new acoustic window offers in patients after balloon valvuloplasty regarding to: detection of thrombus in the left atrium (LA), visualization of spontaneous echo contrast in the LA, evaluation of mitral regurgitation (MR), detection of small atrial septal defects (ASD) and evaluation of the stage of the commissures of the mitral valve. We detected thrombus by TEE, in 5/42 vs 1/42 by TTE approach. Spontaneous echo contrast was found in 35/42 by TEE and none by TTE. Small ASDs were visualized in 10/42 patients vs 2/42 by TTE. No differences were found in the evaluation of MR and mitral valve commissures either by TEE or TTE. We conclude that transesophageal echocardiography is a well-tolerated technique in outpatients which complements and improves the information obtained by the transthoracic approach in patients after balloon mitral valvuloplasty.

[Transesophageal echocardiographic diagnosis of a left atrial myxoma]. / Diagnóstico por ecocardiografía transesofágica de un mixoma auricular izquierdo.

We report the case of a 65 year old woman with a left atrial myxoma. The only clinical manifestation were two transient ischemic attacks of cerebral origin. The diagnosis was established by transesophageal echocardiography because of poor definition of the transtoracic approach. We comment the clinical and diagnostic features of this type of tumors, with emphasize in the value of transesophageal echocardiography.

[Coronary transluminal angioplasty and determination of the intracoronary gradient with a new monorail system]. / Angioplastía transluminal coronaria y determinación del gradiente intracoronario con un nuevo sistema "monorail".

STUDY OBJECTIVE: To evaluate the results obtained in coronary angioplasty using the new very low profile monorail catheter. DESIGN: A retrospective study to define the causes and frequency of successful and unsuccessful coronary angioplasty on proximal and distal lesions located in the three coronary vessels. SETTING: Patients referred to the Hemodynamic Unit for coronary angioplasty. PATIENTS: Coronary angioplasty was performed in 106 patients with cardiac ischemic disease (stable angina, unstable angina and myocardial infarction after thrombolytic therapy). INTERVENTIONS: To perform coronary angioplasty using a monorail system, including dilatation of vessels (angioplasty) and to measure the intracoronary gradient. RESULTS: A high success rate was achieved (92%) independent of vessel dilated or of the position of the stenosis. There was a lower success rate in complex lesions. CONCLUSION: In this study, this newly modified system for coronary angioplasty with balloon catheter and monorail pressure catheter gave a very high performance.

[Pulmonary mechanics and small airways in patent ductus arteriosus and interventricular communication, in relation to pulmonary arterial flow and pressure]. / La mecánica pulmonary y la vía aérea menor en la persistencia del canal arterial y la comunicación interventricular, en relación al flujo y a la presión arterial pulmonar.

Eighteen patients with ventricular septal defect or patent ductus arteriosus were studied to investigate the effects of an increase of pulmonary hypertension. In general group II showed similar results as previously reported in patients with atrial septal defect without pulmonary hypertension. In group I, we found an increased frequency of functional abnormalities in the small airways. We do not have a definitive explanation for the origin of these differences.

[Respiratory function in extrinsic allergic alveolitis caused by pigeons. Clinical, pathological and functional correlation]. / La función respiratoria en la alveolitis alérgica extrínseca por palomas. Correlación clínica, patológica y funcional.

Lung function tests (LFT) were performed in 71 patients with proven extrinsic allergic alveolitis due to pigeons (EAA-P), and they were correlated with lung biopsy (LB) findings. Lung function studies were analyzed to evaluate the clinical course of these patients treated with corticosteroids. Restrictive pulmonary function impairment was found in all cases (vital capacity 38 +/- 4%), residual volume was increased in 9 out of 14 patients (64%) (RV = 0.51 +/- 0.06 L.) and bronchial obstruction was a feature in 11/14 patients (78%) (MMEF = 53 +/- 4%). In all cases a low Pa02 was observed (44 +/- 2 mmHg) and in six an increase in PaC02 was detected. The vital capacity did not correlate with the degree of inflammation or fibrosis observed by LB. A significant negative correlation was found between Pa02 and the degree of inflammation (r = 0.68, p X 0.05) as well as with fibrosis + inflammation degrees (r = -0.63, p less than 0.05). In general, initial LFT and clinical improvement occur simultaneously. Lung function tests support the diagnosis of EAA-P, but are not capable of separating inflammation from lung fibrosis.