BackgroundStudies report the need for improved pain management in the radiation oncology setting. Many patients with well controlled background pain experience breakthrough pain in cancer (BTPc) that can interrupt their treatment schedule with a potentially negative impact on outcomes. BTPc can be unpredictable and predictable; both types of pain can be managed with fast-acting analgesics, but predictable pain lends itself to anticipatory management.MethodsFive consecutive cases are described in which fentanyl pectin nasal spray (FPNS) was used to manage BTPc, with an emphasis on the anticipatory management of predictable pain in cancer patients receiving radiotherapy.ResultsPatients (four men, one woman), age range 32–84 years, were diagnosed with various cancers. All patients were receiving opioid treatment for chronic pain, and experienced predictable pain with radiotherapy which included pain associated with lying on a treatment table for a sustained time during an average of 29 radiotherapy treatments; pain associated with radiation simulation and radiotherapy; pain associated with odynophagia related to increasing mucositis during treatment, resulting in decreased nutritional intake; pain associated with the customized immobilization mask for head and neck cancer patients; and pain associated with defecation. Some patients also reported pain awakening them randomly at night (eg, sleep interruption). All patients attained lower pain intensity scores (2/10 to 3/10), reduced from approximately 7/10, when they were treated with FPNS 20 minutes before a predictable pain event. No patient experienced any pain-related interruptions to their course of radiotherapy. The average number of radiotherapy sessions was 29 per patient, excluding one short-course treatment for one patient.ConclusionFPNS offers a good solution to the management of BTPc because its fast onset of action makes it very suitable for the anticipatory treatment of predictable pain, which is likely to minimize interruptions to the radiotherapy schedule.