The development of radiolabeled small-molecule prostate-specific membrane antigen (PSMA) inhibitors has advanced molecular imaging in prostate cancer. The use of 177Lu-PSMA is especially beneficial because its therapeutic β-emission combined with γ-radiation enables precise treatment and comprehensive imaging in patients with prostate cancer. We present a case of a prostate cancer patient who developed lower extremity lymphedema and hydrocele secondary to prior radiotherapy. Posttherapy whole-body imaging following 177Lu-PSMA treatment revealed dermal backflow with a notable accumulation of soft tissue in the lower extremities and hydrocele.