A review on the transition from PDR to HDR brachytherapy (interventional radiotherapy) for treatment of head and neck cancer: Clinical and practical aspects

PURPOSE: To increase knowledge on clinical outcomes of pulsed-dose-rate (PDR) and high-dose-rate (HDR) brachytherapy (BT) (also referred to as Interventional Radiotherapy (IRT)) treatments for superficial head and neck cancer subsites (i.e., lip and nasal vestibule carcinoma) and to provide insight in the practical aspects of a transition from PDR to HDR BT. METHODS: A systematic literature review following the PRISMA guidelines was performed using PubMed and Embase to examine the clinical outcomes of PDR and HDR BT. Additional information on the practical aspects of a transition from PDR to HDR BT was obtained through interviews by means of a questionnaire, completed by five experienced brachytherapy centers. The topics addressed were “treatment”, “equipment and usage”, and “workflow and logistics”. RESULTS: Of 1095 records identified from two databases, eleven studies (four PDR, seven HDR) were included for the systematic review. Local control (LC) rates ranged from 91% to 100% (median 93%) and 86–100% (median 95%) for PDR and HDR studies, respectively. According to the information provided by the five institutions, significant practical differences between institutions included fractionation schedules, weekly treatment days, and hospitalization choices. CONCLUSION: Both PDR and HDR BT result in excellent LC with median above 93% for lip and nasal vestibule carcinomas. Therefore, a transition from PDR to HDR BT is not expected to influence local control. In terms of practical aspects, questionnaire results show that HDR provides more flexibility than PDR in terms of patient hospitalization and afterloader availability. The choice between PDR or HDR is mostly dependent on institutional resources.