Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Radiography in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology 2008 / The focus of this study is the professional communication practices of radiotherapists as clinical practitioners and as teachers of student/novice radiotherapists. The study was undertaken at a higher education institution and a radiation oncology department in South Africa and addressed the research question; what are the communication practices of radiotherapists in their professional practice and as higher education teachers. This work on professional communication was based on practice and discourse theory as relating to a local context of professional practice and education. Professional communication, seen in this sense, is a social practice which needs to be understood as operating within educational, work and social discursive practices of radiation therapy. A case study approach was chosen as the most appropriate research strategy for capturing the authentic communication practices of radiotherapists in clinical and educational practice. The professional communication practices of ten student and five qualified radiotherapists were investigated through typical teaching and learning interactions in a work integrated learning curriculum. The learning interactions were observed and video-taped in the classroom, tutorial, and demonstration room. Communication interactions were observed and audio taped in the clinical workplace. The research participants, using the video footage as part of their reflections, were interviewed about their communication practices. All interviews were audio taped and transcribed. Analysis of the data was by means of thematic analysis where the data was coded and categorised by means of pattern matching. The findings from the study showed that the communication practices of radiotherapists include: an ‘academic language’, through which academic content knowledge is expressed; a ‘professional language’ for negotiating the complex professional relationships within the clinical environment; and a language for patient care. Their students (novice radiotherapists) are required to master this professional language within their own ‘language of learning’ practice which includes the multilingual component of the workplace. A multilayered model of professional communication evolved and was developed within the analysis process. This model identifies three genres of professional communication: intra-, inter- and extraprofessional communication. Each of these genres was shown to have both formal and informal registers. Technical communication was further identified as a subset of intra- and interprofessional communication. These were further contextualised within the clinical radiotherapy workplace and the classroom (pedagogic) communication practice. The findings also identified multilingualism as a discursive practice within the professional communication of the radiotherapy classroom and workplace. In conclusion, it is argued that the professional communication of radiotherapists comprises a continuum of communication practices that has significance for both professional and pedagogic radiotherapy practice, and it is shown that communication practices play an important role in the establishment of professional identity and expertise and enable the novice radiotherapist to find their ‘professional voice’.