Practical integration of [18F]-FDG-PET and PET-CT in the planning of radiotherapy for non-small cell lung cancer (NSCLC): the technical basis, ICRU-target volumes, problems, perspectives.

The value of positron emission tomography using [18F]-fluoro-deoxy-glucose (FDG-PET) for pretherapeutic evaluation of patients with non-small cell lung cancer (NSCLC) is beyond doubt. Due to the increasing availability of PET and PET-CT scanners the method is now widely available, and its technical integration has become possible for radiotherapy planning systems. Due to the depiction of malignant tissue with high diagnostic accuracy, the use of FDG-PET in radiotherapy planning of NSCLC is very promising. However, by uncritical application, PET could impair rather than improve the prognosis of patients. Therefore, in the present paper we give an overview of technical factors influencing PET and PET-CT data, and their consequences for radiotherapy planning. We further review the relevant literature concerning the diagnostic value of FDG-PET and on the integration of FDG-PET data in RT planning for NSCLC. We point out the possible impact in gross tumor volume (GTV) definition and describe methods of target volume contouring of the primary tumor, as well as concepts for the integration of diagnostic information on lymph node involvement into the clinical target volume (CTV), and the possible implications of PET data on the definition of the planning target volume (PTV). Finally, we give an idea of the possible future use of tracers other than [18F]-FDG in lung cancer.     

The clinical importance of atrial fibrillation-flutter induced by electric transesophageal stimulation of the heart

A study was made of the clinical importance of atrial fibrillation-flutter (AFF) induced by using different modes of left atrium stimulation via the esophagus. Ninety-eight patients were entered into the study including 40 patients with a history of AFF paroxysms, 24 with risk factors of AFF development, and 27 practically normal persons. The stimulation modes applied permitted reproducing stable paroxysms of AFF in 85 percent of the patients with a history of arrhythmias and in none of the normal persons. As for the patients with risk factors, stable paroxysms of AFF could be induced in 33 percent of the cases. The specificity and sensitivity of transesophageal electrophysiologic stimulation (TEES) with the modes applied were 100 and 82 percent, respectively. The investigations have demonstrated that TEES appeared most effective when applied in the mode of an even increase of the frequency of the set pace up to 300 imp/min.     

Brain metastases in patients under 50?years of age: retrospective analysis

Several previous publications suggested that younger patients with brain metastases have longer survival than older patients. However, detailed studies of younger patient groups are scarce. Therefore, a multi-institutional analysis of younger patients with brain metastases was performed (defined as adults with age <50?years). Prognostic factors for survival were examined by uni- and multivariate analyses and compared to those obtained in patients with age ??50?years. Multivariate analysis of 106 patients (median age 44?years, range 23?C49?years) revealed three independent prognostic factors for survival: performance status, extracranial metastases and primary tumor control. Survival was significantly better in patients treated after the year 2000 (median 9.4?months) as compared to those treated before the year 2000 (median 5.1?months, p?=?0.04). This improvement appeared to be related to an increased use of surgery or radiosurgery (SRS) and decreasing numbers of patients with uncontrolled primary tumor. Irrespective of management approach, survival beyond 5?years was uncommon (actuarial rate 6?%; 17?% in patients treated with upfront surgery or SRS). In conclusion, more intense multidisciplinary approaches aiming at control both in the brain, extracranial metastatic sites, and primary tumor site might have contributed to gradual survival improvements in recent years. Nevertheless, further efforts are necessary to improve long-term survival.     

Textural features of hypoxia PET predict survival in head and neck cancer during chemoradiotherapy

European Journal of Nuclear Medicine and Molecular Imaging - The aim of this study was to investigate whether textural features of tumour hypoxia, assessed with serial [18F]fluoromisonidazole...