Session Item

Elective nodal radiation (ENI) is a standard component of treatment for patients undergoing definitive irradiation for many solid tumors, including: gynecologic, rectal, head & neck and bladder cancers.  With the development of technologies that allowed higher doses to be delivered to the prostate, some investigators became convinced this obviated the need to treat regional disease, despite the known pattern of spread and the policies adopted by urologist that there was a need to address nodal disease.  For example, AUA guidelines recommend a lymph node dissection be performed in patients with a risk of lymph node involvement exceeding 2%.  Essentially all the early phase III randomized trials establishing the role of ADT with external beam radiation (EBRT) included elective nodal irradiation (ENI) (e.g. RTOG 8531, 8610, 9202 and EORTC 22863, 22961).  The two largest phase III trials addressing ENI (neither powered for a survival endpoint) demonstrated that neoadjuvant hormonal therapy and ENI resulted in an improvement in progression free survival (PFS) (the primary endpoint) compared to irradiation limited to the prostate bed.  In addition, the majority of post hoc retrospective studies support ENI as does the pattern of failure following local treatment in high risk patients.  In the absence of level one evidence to the contrary, patients at high risk for pelvic lymph node involvement should receive prophylactic ENI.   With the completion of accrual to NRG/RTOG 0924 (n=2592, closed 7/2019) the impact of ENI on overall survival may finally be answered definitively, however, longer follow-up (5 to 10 years) is required.