Stereotactic radiotherapy in the liver hilum. Basis for future studies

BACKGROUND

A basis for future trials with stereotactic body radiotherapy (SBRT) for tumors of the liver hilum should be established. Thus, dosage concepts, planning processes, and dose constraints as well as technical innovations are summarized in this contribution.

METHODS

On the background of our own data, the current literature was reviewed. The use of SBRT in the most common tumors of the liver hilum (pancreatic cancer and Klatskin tumors) was investigated. Dose constraints were calculated in 2 Gy standard fractionation doses.

RESULTS

A total of 8 pilot or phase I/II studies about SBRT in the liver hilum were identified. In recent years, the SBRT technique has developed very quickly from classical stereotactic body frame radiotherapy to IGRT techniques including gating and tracking systems. In the studies using classical body frame technique, patients experienced considerable toxicities (duodenal ulcer/perforation) as compared to tolerable side effects in IGRT studies (<10% grade 3 and 4 toxicities). Dose constraints for duodenum, liver, kidneys, colon, and spinal cord were derived from the investigated studies. Survival and local tumor control data are very heterogeneous: median survival in these patients with locally advanced pancreatic or Klatskin tumors ranges between 5 and 32 months. Excellent local tumor control rates of about 80% over 24 months were achieved using SBRT.

CONCLUSION

Despite a few negative results, SBRT seems to be a promising technique in the treatment of tumors of the liver hilum. Highest precision in diagnostics, positioning, and irradiation as well as strict dose constraints should be applied to keep target volumes as small as possible and side effects tolerable.

Severe infusion reactions to fabry enzyme replacement therapy: rechallenge after tracheostomy

A 34-year-old male patient with Fabry disease (OMIM 301500) commenced enzyme replacement therapy (ERT) with Agalsidase alfa, with positive clinical response. Infusion reactions, initially mild and easily managed, commenced during his 13th infusion, and continued over the next 3 years. Severity of reactions subsequently increased despite very slow infusion, extended prophylactic medication and attempted desensitisation, requiring regular intensive care unit (ICU) admissions. Facial oedema and flushing, throat tightness, headache and joint pain typically occurred 4-36 h after completion of most infusions, responding rapidly to subcutaneous adrenaline. Low titre specific IgG seroconversion was noted at 12 months, with subsequent reversion to negative after 5 years, despite persistence of infusion reactions. Specific IgE and skin testing was negative. Trial of ERT product switch to Agalsidase-beta resulted in no improvement in reactions. At 5 years, ERT was ceased in the face of recurrent ICU readmissions. In the face of progressive clinical deterioration, he underwent tracheostomy to allow recommencement of ERT. Two years later, he has clinically improved on regular attenuated dose Agalsidase-beta, administered by slow infusion in a local hospital setting.

Opioid-induced constipation in advanced illness: safety and efficacy of methylnaltrexone bromide

Constipation, one of the major side effects of opiates used in palliative care, can impair patients’ quality of life to a point where it prevents sufficient pain control. Methylnaltrexone is a novel μ-receptor antagonist, which does not pass the blood brain barrier. It is licensed to treat opiate induced constipation for patients with advanced diseases. This review article presents an overview of pharmacology and safety of its application, evidence of its efficacy and economic aspects of its use in clinical practice. Available data are limited but strongly suggest that methylnaltrexone causes laxation in less than 24 hours for at least half of those patients over the first two weeks of usage without impairing pain control or causing serious adverse effects. To avoid danger of gastrointestinal perforation it is contraindicated for patients at risk for that complication. More research is needed to evaluate its long-term efficacy and economic impact.

Parasympathetic but not sympathetic cardiac dysfunction at early stages of Parkinson's disease

BACKGROUND

Autonomic cardiovascular dysfunction is common in Parkinson's disease (PD). Imaging studies suggest loss of cardiac sympathetic nerves even in the absence of clinical signs of autonomic dysfunction. Aim of the study was to investigate the functional significance of autonomic cardiovascular denervation at early stages of PD.

METHODS

Seven PD patients (Hoehn and Yahr class 1 or 1.5) without clinical signs of autonomic dysfunction and seven age-matched healthy control subjects were studied. To evaluate the pre- and post-synaptic components of sympathetic innervation, dose-response curves of isoproterenol (no neuronal uptake) and epinephrine (neuronal uptake) on heart rate, contractility, cardiac output and systemic vascular resistance were determined echocardiographically. Additionally, measurements of baroreflex sensitivity and 24-h heart rate variability were done.

RESULTS

The chronotropic and inotropic responses during stimulation with isoproterenol and epinephrine were similar in PD patients and control subjects. Assessment of baroreflex sensitivity yielded no difference. Of the parameters of 24-h heart rate variability, only measures of high-frequency heart rate variation that more purely reflect parasympathetic activity were significantly depressed in PD patients as compared with control subjects.

CONCLUSIONS

The results of our study using direct determination of catecholamine-mediated chronotropic and contractile responses provide evidence against a functionally relevant sympathetic dysfunction. Possibly, sympathetic denervation is incomplete and the remaining fibers are sufficient for the maintenance of autonomic control. In contrast, the depression of several parameters of heart rate variability supports a significant change of parasympathetic activity at an early stage of PD with subclinical autonomic failure.

[Early symptoms and findings in optic nerve meningiomas]

PURPOSE OF THE STUDY

While evaluating radiotherapy results in patients with primary and secondary optic nerve sheath meningiomas (ONSM) treated between 1993 and 2002, a large amount of data about early signs and symptoms has been collected which might be helpful for establishing an early diagnosis.

METHODS

We have reviewed the charts of the patients available at the Centre of Ophthalmology, collecting especially pretreatment data.

RESULTS

112 patients, 4 with bilateral tumours, 83 % female were included. Mean age was 51.7 years. Visual acuity loss with relative afferent pupillary defect was the main symptom and sign in primary ONSM (38 patients). Median interval between first symptoms and diagnosis was 12 months. Optic discs were in approximately one half atrophic, the other half were swollen, and only rarely normal (3 cases only). Retinociliary shunt vessels were seen in 10 cases. Nerve fibre bundle defects were the major visual field finding (including constriction and central scotoma). Visual acuity was better than 0.5 (20 / 40) in 46 % and worse than 0.1 (20 / 200) in 30 %. In secondary ONSM, the interval to diagnosis was with a median of 6 months shorter than in primary ONSM. Approximately half of the optic discs were atrophic, only 6 % were swollen. Even here nerve fibre bundle defects were dominating, only 7 % had vertical hemianopic defect. Visual acuity was better than 0.5 (20 / 40) in 30 % and in worse than 0.1 (20 / 200) 22 %. 45 % had ocular motility disorders.

DISCUSSION

Vertical hemianopic defects were surprisingly rare. The high rate of nerve fibre bundle defects and the relatively high number of patients with good visual acuity might explain why this disorder is occasionally mistaken for glaucoma. A typical clinical appearance can be outlined: mainly mid-aged women, slowly progressing visual loss, frequently motility disorders, relative afferent pupillary defect, nerve fibre bundle defects and atrophic or--mainly in primary ONSM--swollen optic disc form the characteristic picture.

Chloride, gluconate, sulfate, and short-chain fatty acids affect calcium flux rates across the sheep forestomach epithelium

In ruminants, more than 50% of overall gastrointestinal Ca absorption can occur preintestinally, and the anions of orally applied Ca salts are thought to play an important role in stimulating ruminal Ca absorption. This assumption is based mainly on ion-exchange studies that have used gluconate as the control anion, which may bind Ca2+ ions and interfere with treatment effects. In the present study, we investigated the distinct effects of different anions on Ca absorption across the sheep rumen and on the concentration of free Ca2+ ions ([Ca2+]ion). We showed that gluconate, sulfate, and short-chain fatty acids (SCFA) remarkably reduced [Ca2+]ion in buffer solutions. Nevertheless, increasing the Cl or SCFA concentration by 60 mM stimulated net ruminal Ca absorption 5- to 7-fold, but these effects could be antagonized by gluconate. Therefore, ion-exchange experiments must be (re)evaluated very carefully, because changes in [Ca2+]ion in the presence of gluconate, sulfate, or SCFA not only might entail an underestimation of Ca flux rates, but also might have effects on other cellular pathways that are Ca2+ dependent. Concerning the optimal Ca supply for dairy cows, the present study suggests that CaCl2 formulations and Ca salts of the SCFA stimulate Ca absorption across the rumen wall and are beneficial in preventing or correcting a Ca deficiency.

Neurology of Fabry disease

BACKGROUND

Fabry disease has diverse neurological manifestations, many of which influence morbidity and quality of life.

AIMS

The aim of the study was to document the clinical and subclinical neurological manifestations in a cohort of Australian patients with Fabry disease, using multiple clinical tools and a multidisciplinary approach.

METHODS

Participants completed focused questionnaires and underwent clinical neurological examination, Neurocognitive testing using Mini Mental State Examination and Neuropsychiatry Unit Cognitive Screen, Quantitative Sensory Testing (QST), autonomic assessment using RR interval variation, intracranial magnetic resonance imaging (MRI) and audiology. In subsets of patients who had previously undergone QST and/or prospective serial quality-of-life assessments over the previous 5 years, results before and after enzyme replacement therapy were compared.

RESULTS

Twenty hemizygotes and two heterozygotes were recruited. The age (mean +/- standard deviation (SD)) of male participants was 40.4 +/- 11.9 years (range 20-62 years); the women were aged between 20 and 56 years. Increasing age was strongly associated with increasing neurological disability. Clinical peripheral neuropathy predominantly affected thermal sensation in all patients, with variable involvement of pinprick and light touch. QST confirmed these findings. Clinical cerebellar tests were commonly abnormal: this has not been previously reported in the absence of symptomatic cerebrovascular disease. There was hearing loss was in 90% of patients and no patient older than 44 years had normal hearing. MRI lesion prevalence increased with age. Despite neurological complications being common, formal cognitive testing was basically normal. QST thresholds for pain showed a significant change after enzyme replacement therapy.

CONCLUSIONS

Neurological complications in Fabry disease are common, complex and may be devastating. All patients studied had neurological involvement, with protean and diverse manifestations.

Anti-CD20 antibody in thrombotic thrombocytopenic purpura refractory to plasma exchange

Thrombotic thrombocytopenic purpura is a rare condition characterized by microangiopathic haemolytic anaemia, thrombocytopenia, altered neurology, renal impairment and fever. While plasma exchange has reduced mortality from more than 90% to between 10 and 30%, a proportion of cases fail to respond. Rituximab may be efficacious in the management of refractory cases of thrombotic thrombocytopenic purpura. We present two cases in which rituximab was used with successful outcomes. Treatment resulted in resolution of severe clinical and haematological abnormalities in both patients. There has been no relapse after 16 months follow up. Our experience supports the use of rituximab in difficult cases of TTP. Ongoing evaluation of its use is in progress at our institution.

The Kidney Disease: Improving Global Outcomes website: Comparison of guidelines as a tool for harmonization

Chronic kidney disease (CKD) is a worldwide public health problem with significant comorbidity and mortality. Improving quality of life and survival of CKD patients necessitates a large number of preventive and therapeutic interventions. To resolve these issues several organizations have developed guidelines, which are difficult to compare comprehensively. The Kidney Disease: Improving Global Outcomes website at http://kdigo.org compares five major guidelines. The section 'compare guidelines' covers 41 topics distributed over five major subjects: (1) general clinics; (2) hemodialysis (HD); (3) vascular access for HD; (4) peritoneal dialysis; and (5) chemistries. The tables compare guideline recommendations and the evidence levels on which they are based, with direct links to each of the guidelines. These data show that the different guideline groups tend to propose similar targets, but that nuances in the guideline statements, their rationale, and grading of evidence levels present some discrepancies, although most guidelines are based on the same literature. We conclude that there is an urgent need to harmonize existing guidelines, and for a global initiative to avoid the parallel development of conflicting guidelines on the same topics. The tables displayed on the website offer a basis for structuring this process, a procedure which has recently been initiated by a body composed of the five guideline development groups.