Development of a treatment technique for the AeroForm™ tissue expander breast implant system–a single department experience

Purpose Air tissue expander systems offer breast cancer patients a number of advantages but present an unusual challenge when treating patients post mastectomy with external beam radiation therapy The primary aim of this study was to describe the planning protocol developed for external beam locoregional radiation therapy RT in post mastectomy patients with in situ air expanders and to quantify the effect of the AeroForm trade AirXpanders reg Palo Alto California implant on target volumes and treatment factors Secondary aims included an evaluation of clinical outcomes including acute side effects Methods and materials This is a single institution review of eight female patients treated between March and August All patients received a prescription of cGy in treatments delivered five times per week Specific density overrides were applied to critical structures in order to achieve the most accurate dose distribution Acute side effects were assessed at weeks two four and six during radiation therapy and followed up at week six after the final treatment Results A three dimensional D conformal radiation therapy CRT tangential wedged pair technique with additional contouring and density overrides applied to critical structures is suitable for patients with breast air tissue expanders mm ndash mm of bolus over the entire chest wall throughout treatment enhances treatment delivery accuracy to the superficial skin layers without increasing early acute skin reactions Conclusion It is feasible to plan radiation therapy in patients with air tissue expanders requiring chest wall with or without nodes irradiation using an appropriate planning technique and density overrides to critical structures The addition of bolus to the entire chest wall increases dose distribution accuracy Early clinical results show that this treatment method is reproducible has acceptable early toxicity and results in similar acute toxicity to those seen in patients without air expanders Our air expander protocol will continue to be adapted as additional prospective data is collected