Cerebral processing of histamine-induced itch using short-term alternating temperature modulation - an FMRI study.

Human neuroimaging studies on the physiology of itch have been hampered by the lack of reproducible "on-off" stimuli. Using a previously established biphasic temperature stimulus model, we investigated the cerebral activation pattern of itch processing in 12 healthy volunteers with functional magnetic resonance imaging. Itch was provoked on the right forearm with skin prick application of 1% histamine-dihydrochloride. Local temperature modulation allowed reproducible itch provocation above scratch threshold (defined as 33/100 on a visual analogue scale) during 25 degrees C, whereas itch declined below scratch threshold during the 32 degrees C stimulation period. No itch sensation was reported using 0.9% saline with temperature modulation. Itch sensation above scratch threshold was associated with increased activation of the thalamus, presupplementary motor area, anterior insular, inferior parietal, and dorsolateral prefrontal cortex, and decreased activation of the orbitofrontal, medial frontal, mid-cingulate, and primary motor cortex in comparison to saline. The biphasic temperature model allows rapid modulation of histamine-induced itch. The evoked itch sensation above scratch threshold is processed by a network of brain regions contributing to the encoding of sensory, emotional, attention-dependent, cognitive-evaluative and motivational aspects of itch

Variability in lymph node irradiation in patients with breast cancer-results from a multi-center survey in German-speaking countries.

Purpose Lymph node irradiation in breast cancer has gained complexity due to recently published studies and technical innovations which then led to changes in international guidelines. We sought to determine real-time variability in lymph node irradiation in clinical practice in German-speaking countries. Methods The Department of Radiation Oncology, Technical University of Munich (TUM), developed an online-based questionnaire focusing on the indication, target definition, and treatment technique of lymph node irradiation in patients with breast cancer. The invitation to participate in the survey was sent to members of the German Society of Radiation Oncology (DEGRO) by e-mail. The results of the survey were exported from the online platform into SPSS for a detailed analysis. Results In total, 100 physicians completed the questionnaire between 05/2019 and 06/2019. Despite the existence of several treatment and contouring guidelines, we observed large variability of lymph node irradiation: The guideline recommendation for internal mammary irradiation is not consistently implemented in clinical practice and irradiation of the axilla after positive SLNB (sentinel lymph node biopsy) or ALND (axillary lymph node dissection) is handled very differently. Furthermore, in most clinics, the ESTRO (European Society for Therapeutic Radiology and Oncology) contouring consensus is not used, and PTV (planning target volume) definitions and margins vary considerably. Conclusion Further clinical studies should be performed with a particular focus on radiotherapy for lymphatic drainage to support and amend the existing guidelines. These studies should establish a more standardized treatment of the lymph node regions in clinical practice. Quality assurance should enforce broad implementation of consensus recommendations