Association of Pelvic Lymph Nodes Inclusion with Late Side Effects in Prostate Cancer Patients Undergoing Curative Radiotherapy

Objective: Curative radiotherapy is one of the two leading definitive treatment options for prostate cancer, along with surgery.The inclusion of pelvic lymph nodes in curative radiotherapy for prostate cancer is controversial.In our study, we aimed to investigate the association of pelvic lymph node irradiation with late gastrointestinal system (GIS) and genitourinary system (GUS) side effects in intermediate and high-risk prostate cancer patients who underwent curative radiotherapy.Materials and Methods: Patients who underwent curative radiotherapy for intermediate and high-risk prostate cancer between 2015 and 2022 were evaluated retrospectively.GIS and GUS side effects were graded according to the Radiation Therapy Oncology Group scale.Patients were divided into 2 groups: those who received treatment of the pelvic lymph node (group 1) and those who received treatment of the prostate and seminal vesicle (group 2).We analyzed whether there was a difference in late GIS and GUS side effects between the groups.The independent samples t-test was used to compare late side effects between the groups.A p-value of p<0.05 was considered statistically significant.Results: Seventy-one patients treated for intermediate and high-risk prostate cancer were analyzed.Thirty seven patients received a radiotherapy regimen in group 1, and 34 patients received a radiotherapy regimen in group 2. Intermediate risk patients received radiotherapy in group 2, and high-risk patients received radiotherapy in the group 1 regimen.The mean age of the patients was 70 years and the mean follow-up period was 39 months.All patients received hormone therapy.Late GUS and GIS side effect rates were found to be extremely low.There was no statistically significant difference between the groups in terms of side effect rates. Conclusion:In localized prostate cancer, including pelvic lymph nodes in the treatment area does not increase long-term GIS and GUS side effects.