First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

iThemba Laboratory for Accelerator Based Science (iThemba LABS) is a multi-disciplinary accelerator facility. One of its main activities is the operation of a separated-sector cyclotron with a K-value of 200, which provides beams of various ion species. These beams are used for fundamental nuclear physics research in the intermediate energy region, radioisotope production, and medical physics applications. Due to the requirements of nuclear physics for new ion species and higher energies, the decision was made to install a copy of the so-called Grenoble test source (GTS) at iThemba LABS. In this paper, we will report on the experimental setup and the first results obtained with the GTS2 at iThemba LABS.

[Pleural drainage]

A chest tube is used to drain the contents of the pleural space to reconstitute the physiologic pressures within the pleural space and to allow the lungs to fully expand. Indications for chest tube placement include pneumothorax, hemothorax, pleural effusion, pleural empyema, and major thoracic surgery. The most appropriate site for chest tube placement is the 4th or 5th intercostal space in the mid- or anterior- axillary line. Attention to technique in placing the chest tube is vital to avoid complications from the procedure. Applying the step-by-step technique presented, placement of a chest tube is a quick and safe procedure. Complications - frequently occurring when the tube is inserted with a steel trocar - include hemothorax, dislocation, lung lacerations, and injury to organs in the thoracic or abdominal cavity.

Recurrent pleural effusion: who benefits from a tunneled pleural catheter?

Recurrent malignant pleural effusion (MPE) is a common concomitant phenomenon of malignant disease, which can worsen the patient's quality of life and lead to significant morbidity. Tunneled indwelling pleural catheters (TIPC) offer new modalities in patients with recurrent MPE and impaired dilatability of the lung. We report on our experience with 100 consecutive patients suffering from recurrent benign (n = 12) and malignant pleural effusion (n = 88) who were treated with TIPC. The catheter was placed during a VATS procedure or under local anesthesia in an open technique. The median residence time of the TIPC was 70 days; spontaneous pleurodesis was achieved in 29 patients. The rate of complications was low: pleura empyema (n = 4), accidental dislodgement (n = 2), malfunction of the drainage (n = 3). In conclusion, TIPC is a useful method for the palliative treatment of patients with recurrent malignant or nonmalignant pleural effusions and 3 groups of patients seem to benefit most: a) patients with the intraoperative finding of a trapped lung in diagnostic VATS procedure; b) patients after a history of repeated pleuracenteses or previously failed attempts at pleurodesis; c) patients in a reduced condition with a limited lifespan due to underlying disease.

[Treatment of pleural empyema]

Pleural empyema remains a frequently encountered clinical problem and is responsible for significant morbidity and mortality worldwide. Its diagnosis may be difficult; delays in diagnosis and treatment may contribute to morbidity, complications, and mortality. The management of parapneumonic effusion and empyema depends on timely, stage-dependent therapy and the underlying etiology. Thoracentesis and antibiotics remain the cornerstones of treatment in stage I disease. In the early fibrinopurulent phase (stage II) thoracoscopic methods should be considered. As treatment strategy for this stage, fibrinopurulent pleural empyema entails thorough debridement of multiloculated collections from the pleural cavity by video-assisted thoracic surgery. After evacuation of multilocular effusions and the removal of fibrin deposits with drainage by two intercostal chest tubes, irrigation treatment helps to achieve clarity of the pleural discharge. Open thoracotomy and decortication are reserved for organized, multiloculated empyema with lung entrapment (stage III disease). Early drain removal may lead to rapid symptomatic recovery and complete resolution.

[Treatment of pneumothorax]

Pneumothorax is defined as air in the pleural space, i.e. between the lung and the chest wall. Primary pneumothoraces (PSP) arise in otherwise healthy people without any lung disease. Secondary pneumothoraces (SSP) arise in subjects with underlying lung disease. Observation alone is recommended only in patients with small primary or secondary pneumothoraces of less than 1 cm depth or isolated apical pneumothoraces in asymptomatic patients. In symptomatic patients observation alone is inappropriate and active intervention is required. Although simple aspiration may be an option for first-line treatment in clinically stable patients with PSP, intercostal tube drainage is strongly recommended in all primary and secondary pneumothoraces requiring intervention. There are two objectives in the surgical management of pneumothorax. The first widely accepted objective is resection of blebs or the suture of apical perforations to treat the underlying defect. The second objective is to create a pleural symphysis to prevent recurrence. While video-assisted thoracic surgery may be the preferred surgical procedure for young, fit people with complicated or recurrent primary pneumothoraces, it is less reliable in cases of secondary pneumothorax. For the latter, open thoracotomy and repair is still the recommended approach.

Quantitative analysis of lung and tumour mobility: comparison of two time-resolved MRI sequences

The purpose of this study was to describe the use of parallel imaging technique (PAT) using dynamic MRI in lung and tumour mobility during the breathing cycle. 20 patients with stage I non-small cell lung carcinoma were investigated using two dynamic gradient echo sequences with PAT (TrueFISP (fast imaging with steady precession), and fast low angle shot (FLASH). Craniocaudal distance from the apex to the diaphragm of the thorax and tumour mobility during the breathing cycle were measured. Signal-to-noise ratio (SNR) of the tumour was determined. In spite of the different temporal resolutions both trueFISP and FLASH sequence proved to be adequate to continuously measure lung motion and tumour mobility. SNR of the tumour was significantly higher using the trueFISP sequence than FLASH sequence (20.7+/-3.6 vs 5.8+/-2.3, p<0.01). Mobility of the tumour bearing hemithorax was significantly lower compared with the non-tumour bearing hemithorax (p<0.05). Dynamic MRI using PAT allows for continuous quantitative documentation of tumour mobility and lung motion. Because of the higher SNR, trueFISP sequence provides a better delineation of intrapulmonary lesions with a sufficient temporal resolution.

[Pleural empyema: surgical treatment]

Pleural empyema runs in three stages, if untreated. Because it produces uncharacteristic signs, specific diagnosis and adequate treatment is often delayed. The treatment should be early, according to the stage and adapted to the given situation. Expenditure and morbidity of treatment are the higher the longer it is delayed. In the exudative stage 1, drainage--if necessary combined with antibiotic administration--is likely to be successful. In the fibrinous-purulent stage 3, often not clearly demarked from the other stages, video-assisted thoracoscopy (VATS) in its various forms provides the best therapeutic prerequisite. It makes it possible to open all cavities and free pleural layers from the, usually fibrinous or fibrosing, contents. Furthermore, VATS allows targeted drainage placement as essential precondition of effective irrigation. The definitive stage 3 of organization requires the technically demanding empyema excision or decortication.

MRT des Bronchialkarzinoms

Compared to computed tomography (CT), magnetic resonance imaging (MRI) only plays a minor role for the imaging of lung cancer. Among the reasons are technical limitations, such as longer acquisition times or inferior spatial resolution, as well as unfavourable tissue characteristics which cause a low signal-to-noise ratio of the lung parenchyma. However, MRI is a valuable tool for staging lung cancer and may in some cases even be considered the method of choice. The following review illustrates the role of MRI for the diagnosis of lung cancer using current MR-techniques. In particular, the potential of MRI for TNM-staging, new technical developments (e. g. parallel MRI), and the application of functional MRI of the chest are described.

[Brain metastases in renal cell carcinoma. Results of treatment and prognosis]

Brain metastases develop as a late manifestation of renal cell cancer (RCC) and pose an increasing challenge to urologists as a result of the more frequent prolonged survival of patients with advanced RCC. Therapeutic options, including surgical resection and radiotherapy, were analyzed retrospectively to assess survival and to identify factors influencing prognosis in a group of 90 patients treated either by brain metastasectomy (n = 64) or radiotherapy (n = 26). The analysis confirmed that the overall median survival was a disappointing 461 days and the 1-year survival rate was 31% for patients treated by surgical resection and 310 days and 15% respectively for patients treated by radiotherapy. However, a subgroup of patients who, benefitted significantly from aggressive treatment of metastases could be defined. The following favorable prognostic factors showed a trend toward improved survival: (1) metachronous appearance of brain metastases more than 1 year after nephrectomy (P < 0.0001), (2) good patient performance (Karnofsky > 70) (P < 0.0002), (3) patient's age under 50 years (P < 0.05), (4) solitary lesions (P < 0.05), (5) minimal or no neurological deficit (P < 0.05), and (6) the absence of/or minimal extracranial metastases (P < 0.05). No influence of lesion size and localization (infratentorial vs supratentorial) on survival was detected. Surgical treatment of recurrent brain tumors (n = 17) yielded and additional median survival advantage of 8 months as compared to untreated patients (n = 16). Our results suggest that, especially in patients with good prognostic criteria, a radical metastasectomy plus vigorous surgery of local recurrences and, if required, subsequent systemic immuno- or chemoimmunotherapy should be performed. In patients with poor prognosis, stereotactic radiosurgery is recommended for palliation and survival prolongation.