Enrico Martin

295 Summary in Chapter 5 , we asked respondents questions regarding postoperative morbidity and the use of functional reconstructions in MPNST. In total, 174 surgeons filled out the survey. Surgeons reported high rates of neuropathic pain (40.9%) and motor deficits (36.7%) postoperatively without differences between surgical subspecialties. Functional reconstructions for either motor or sensory deficits were however more commonly considered by plastic surgeons and other hand surgeons. Nevertheless, relative contraindications for their use did not differ between surgical subspecialties. Many surgeons were hesitant to perform reconstructions whenever radiotherapy would be administered. Overall, surgeons agreed on an average life expectancy of 3 years before functional reconstructions should be considered. This shows that any surgeon acknowledges the extent of postoperative morbidity, yet surgical oncologists and neurosurgeons, who operate most patients, should incorporate a reconstructive surgeon early on. Chapter 11 Function Loss in MPNST The extent of postoperative morbidity has never been investigated on a large scale in MPNSTs before. This was in part the reason to start the MONACO study, an international collaboration of 10 Dutch cancer centers and the Mayo Clinic to retrospectively collect data on oncological and functional outcomes in MPNST patients. This study focused on the prevalence of postoperative motor deficits and sensory deficits of critical areas: the hand, foot sole, and buttocks. Also, the use and outcomes of functional reconstructions were assessed. We included 756 patients, of which 658 were surgically resected. Serious motor deficits (≤M3) were present in 27.2% after resection and 24.3% of patients had loss of sensation in the hands, feet or buttocks. Only 4.0% had a functional reconstruction. NF1 patients, symptomatic, large and deep-seated tumors, tumors arising from a plexus or extremities were at an increased risk for functional deficits. Peripheral nerve surgeons were involved in the minority of MPNST cases arising from major nerves. Functional reconstructions that were performed resulted in good outcomes regardless of the use of multimodal therapy. Unsatisfactory functional outcomes were mainly caused by oncological failure resulting in the need for re-resections. This study shows there is room for improvement of functional outcomes if functional reconstructions were to be considered more often. A