The key operative objective for surgical oncologists is almost alwayscomplete resection of tumour. Involved surgical resection margins havebeen demonstrated to be a predictor of local recurrence, and in manystudies reduced disease specific survival, across nearly every operablecancer type. In the case of oral and oropharyngeal cancer involvedresection margins are associated with an approximate doubling of riskof local recurrence.Over the last decade and a half we have made substantial advances inreducing rates of involved surgical margins. The most important advancehas been the advent of Hospital PACS radiology systems that haveallowed surgeons to examine re-formatted images in 3 planes of spaceand view multiple imaging modalities with fusion where necessary. Thishas allowed a complete understanding of the tumour anatomy whichcan then be translated into the operating theatre. Each subsite presentsunique problems which will be discussed. Anatomical planning hasreduced involved margin rates 6% which compares favourably with theliterature. This appears to be associated with improved local control.Local recurrence remains the predominant form of recurrence followingtreatment of sinonasal cancer. Following open surgery and adjuvantradiotherapy the pattern of local recurrence is largely predictable.Relapse occurs at posterior and superior locations; specifically theinfratemporal fossa, petrous apex, middle cranial fossa and clivus, aswell as the orbital apex. This has led us to the utilisation of a previouslydescribed approach to maxillectomy that allows direct visualization ofthe posterior separation. It also facilitates through defect central skullbase resection. The rationale, technical aspects, and our experience withthis approach in 36 patients will be described