Aim: To illuminate the experience of an altered social context for patients with primary brain tumours living away from home while undergoing proton beam therapy. Design: A descriptive, qualitative cross-sectional interview study. Methods: Nineteen patients were interviewed between December 2015–August 2016, either during (N = 7) or before and after (N = 12) their proton beam therapy. A hermeneutical analysis was performed. Results: Participants made adjustments to achieve control and well-being during the treatment period. The analysis also revealed two interrelated patterns that helped participants adjust: being part of the family from a distance and seeking affinity. Conclusion: It is important that patients receiving treatment far from home find a way to remain a part of their family and find affinity in the altered social context. Health professionals can prepare patients for the treatment period and can implement interventions to promote well-being for both patients and their relatives. © 2020 The Authors.