Biochemical Recurrence of Prostate Cancer Presenting as Solitary Testicular Metastasis on 68Ga-Labeled Prostate-Specific Membrane Antigen Ligand Positron Emission Tomography/Computed Tomography

Testicular metastasis in prostate cancer: A rare case of testicular metastasis diagnosed with 68Ga-PSMA and review of the literature

Objective:

Testicular metastasis in prostate cancer is a rare entity. We aimed to report the case where this rare condition was diagnosed with Gallium prostate-specific membrane antigen–positron emission tomography/computed tomography (68Ga-PSMA-PET/CT).

Subjects/patients and methods:

A 68-year-old male with a prostate adenocarcinoma presented with testicular metastasis. The patient was diagnosed with 68Ga-PSMA-PET/CT, and bilateral inguinal orchiectomy was performed. Herein, our case is presented, and a short review of the literature is carried out.

Conclusion:

68Ga-PSMA-PET/CT is an effective imaging method for detecting rare metastases.

Level of evidence:

4

PET imaging in testicular tumours

PURPOSE OF REVIEW

Testicular cancer is rare, but its incidence is expected to rise. [18F] fluorodeoxyglucose ([18F]FDG) PET/computed tomography (CT) added role in testicular cancer management has been defined in a set of specific clinical settings. The current review focuses on recent advances in the employment of PET/CT in testicular cancer patients.

RECENT FINDINGS

[18F]FDG PET/CT is not recommended for initial staging or for suspected testicular tumours. PET/CT role in testicular cancer management is mainly for the assessment of seminoma residual masses after therapy (>3 cm). Although [18F]FDG PET/CT has a very high negative predictive value, its positive predictive value varies across studies: appropriate PET/CT scheduling after therapy and a careful history are mandatory for accurate interpretation. Interim PET/CT could prove valuable to spare subsequent chemotherapy cycles in patients already in remission, reducing related toxicity. The role of [18F]FDG in nonseminoma tumours is hampered by the low sensitivity in teratoma.

SUMMARY

[18F]FDG PET/CT is currently used for the assessment of seminoma residual masses (>3 cm) after therapy. A negative PET could also spare unnecessary further chemotherapy cycles in responding patients, reducing toxicity. Although rare, testicular secondary lesions can be detected with non[18F]FDG tracers when PET/CT is performed for other primary tumours.

Isolated Testicular Metastasis Diagnosed More than a Decade and a Half Post Primary Treatment for Prostate Cancer

Prostate cancer is the most common visceral malignancy among men. It rarely metastasizes to the testicles. We herein present the case of a male patient who underwent a radical prostatectomy for a grade group 3 Gleason score 7 (4 + 3) prostate adenocarcinoma followed by adjuvant radiation therapy and continuous androgen deprivation therapy after his first biochemical recurrence. Despite optimal management, prostate-specific antigen (PSA) levels rose back up, upon which a PET/CT ⁶⁸Gallium scan demonstrated an isolated left testicular lesion that turned out to be of prostatic origin following orchiectomy. Testicular metastases from prostate cancer are of unknown prognosis, and the current treatment modality favors an orchiectomy.