[Lutetium-177-PSMA radioligand therapy : Consensus within the framework of GKV-funded care between the university hospitals in Aachen, Bonn, Düsseldorf, Essen, and Cologne and the MDK Nordrhein]. / Lutetium-177-PSMA-Radioligandentherapie : Konsensus im Rahmen der GKV-finanzierten Versorgung zwischen den Hochschulkliniken in Aachen, Bonn, Düsseldorf, Essen und Köln und dem MDK Nordrhein.

In the last 3 years, Lutetium-177 prostate-specific membrane antigen radioligand therapy (Lu-177-PSMA-RLT) has received increasing attention in nuclear medicine as a new form of treatment for castration-resistant metastatic prostate cancer. This therapy combines the radionuclide Lutetium-177, which has been therapeutically used in nuclear medicine for many years, with a molecular target of the transmembrane prostate-specific membrane antigen expressed by prostate cancer cells. Since there are no prospective randomized studies on Lu-177-PSMA-RLT and the question of reimbursement has repeatedly been the subject of review by the MDK Nordrhein (Medischenische Dienst der Krankenversicherung), there was a desire because of the increasing number of patients being treated to clarify under which circumstances Lu-177-PSMA-RLT can be reimbursed by German statutory health insurance. The goals of this article are to help treating physicians understand how this new therapy option works, to integrate it in the overall therapy concept for castration-resistant metastatic prostate cancer, and, above all, to use Lu-177-PSMA-RLT-based on the current data-at the right place in the therapy sequence of castration-resistant metastatic prostate cancer.

Plasticity of plasticity? Changes in the pattern of perceptual correlates of reorganization after amputation.

We report a follow-up study on seven arm amputees in whom magnetic source imaging had originally revealed a strong correlation between the amount of cortical invasion of the deafferented cortex and the amount of pain evoked sensation mislocalized to the phantom limb. This re-examination was performed in order to corroborate the phenomenon of mislocalization. On follow-up examination for mislocalization 4 weeks later, a close correlation had remained between the original amount of cortical representational reorganization of the amputation zone (at the first examination) and the number of sites from where painful stimuli evoked sensations referred to the phantom limb, i.e. the amount of perceptual mislocalization, at the second examination. However, contrary to our expectation, the topography of referred sensation had completely changed in every patient. These results suggest that while the overall extent of reorganization is a rather stable phenomenon, the concomitant changes in the pattern of sensory processing are not. This may be due to the fact that alterations of sensory processing are not hardwired, but are rather mediated by an extensive and interconnected neural network with fluctuating synaptic strengths. This mechanism may be of importance for neurological rehabilitation.

Reorganizational and perceptional changes after amputation.

The demonstration of cortical representational shifts in adult animals subsequent to deafferentation from amputation or dorsal rhizotomy has spurred attempts to elucidate the perceptual correlates of reorganization. Because the hand is flanked by the face and the trunk on the cortical homunculus it has been suggested that cortical remapping in arm amputees leads to a mislocalization of sensations from these sites to the phantom arm in a systematic manner with modality specific one-to-one topographical correspondence. Therefore, we assessed shifts of representational zones by magnetic source imaging in eight arm-amputees and examined them for referred sensation by somaesthetic stimuli of different modalities at standardized sites. It was found that referred phantom sensations can be evoked from sites on the face and the trunk ipsilateral but also contralateral to the amputation and that the extent of physiological reorganization as revealed by magnetic source imaging strongly correlates with the number of sites, be it ipsi- or contralateral, from where painful stimuli evoke referred sensation. Thus, it seems that the extent of reorganization after amputation is closely related to nociceptive inputs. The mislocalization evoked from both sides of the body, suggesting involvement of bilateral pathways, demonstrates that the perceptual changes go beyond what can be explained by shifts in neighbouring cortical representational zones.

Cortical reorganization in human amputees and mislocalization of painful stimuli to the phantom limb.

In human arm amputees, a significant relationship was found between the amount of reorganization in the primary somato-sensory cortex, and the amount of body surface from which painful stimuli evoked sensations that were perceived to be emanating from the now missing extremity, i.e. the phantom limb. This mislocalization could be evoked almost equally from stimulation of either side of the body. Based on these findings obtained by magnetic source imaging and psychophysical testing in eight amputees, it is concluded that the extent of the generally known cortical reorganization contralateral to the amputation is an indicator of more widespread plastic changes in the brain involving bilateral pathways.