|Ahead of print
Perineum and penile invasion of recurrent prostate carcinoma shown by Ga-68 PSMA PET/CT
Zehra Pinar Koc1, Pınar Pelin Özcan1, Vehbi Erçolak2
1 Department of Nuclear Medicine, Medical Faculty, Mersin University, Mersin, Turkey
2 Department of Oncology, Medical Faculty, Mersin University, Mersin, Turkey
|Date of Submission||23-Jul-2019|
|Date of Decision||04-Jan-2020|
|Date of Acceptance||24-Mar-2020|
|Date of Web Publication||05-Aug-2020|
Zehra Pinar Koc,
Department of Nuclear Medicine, Medical Faculty, Mersin University, Mersin
Source of Support: None, Conflict of Interest: None
Imaging of prostate cancer has recently had new modalities. Ga-68 Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography/Computed Tomography (PET/CT) has gained important diagnostic role in the management of the patients with prostate cancer. Patients with progressively elevated serum prostate specific antigen (PSA) level may be evaluated by Ga-68 PSMA PET/CT imaging. This case report presents a seventy five year old man with diagnosis of prostate cancer and progressive serum PSA increase. Local recurrence of the tumor as well as spread to the penis, perineum and skeleton was determined by Ga-68 PSMA imaging. This case illustrates that Ga-68 PSMA imaging may show unexpected sites of disease spread.
Keywords: PSA, PSMA, recurrence
| » Introduction|| |
Gallium-68 (Ga-68) prostate specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomograohy (CT) is the recent imaging modality in the imaging of prostate carcinoma metastasis and the primary tumor as well. The diagnostic power of this imaging modality is determined in the primary tumor, recurrent tumor and metastases detection. Although literature information regarding this modality is limited because it is a newly introduced modality there are some recent reports about this modality. Previous studies included histopathologic verification of the exact activity accumulation correlated with the tumor tissue in the primary tumor detection.
| » Case Report|| |
A 75-year-old man with the diagnosis of prostate carcinoma with significant prostate specific antigen (PSA) elevation was attended to the hospital and PET/CT was planned for the response evaluation. The imaging was performed 60 minutes after intravenous administration of 4 mCi (148 MBq) Gallium-68 (Ga-68) PSMA in craniocaudal direction in 3D acquisition mode; 1 min for per bed position with non-diagnostic CT scan performed for the attenuation correction. The imaging revealed increased activity accumulation in the severe metastatic lesions all over the bone skeleton and recurrent prostate carcinoma in the prostate bed as well as perineum and penile tissue [Figure 1]. The patient died 3 months after the Ga-68 PSMA imaging.
|Figure 1: The positron emission tomography, fusion transaxial and multiple intensity projection images of the patient with new growing and progressive metastatic lesions in the perineumum and bone in the six months follow up demonstrated in the Figure 1a, b and 2 a, b and 3 respectively |
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| » Discussion|| |
The current imaging consideration of the prostate cancer staging includes bone scintigrapy in selected patients as well as magnetic resonance (MR) imaging in the evaluation of the local tumor dissemination. Ga-68 PSMA imaging is a new method in the staging of the prostate carcinoma. Although this imaging is newly introduced, it has the potential to be a single imaging modality in selected patients. The Ga-68 PSMA imaging has superiority of demonstrating the bone and soft tissue dissemination as well as primary tumor. The gold standard methodology is ultrasound (US) guided fine needle aspiration biopsy in regional dissemination. Additionally, multiparametric MR imaging might improve the US guided biopsy according to previous reports. Previously choline PET was introduced in the detection of primary tumor in prostate, however, this method was hampered due to false positive results in benign lesions. Ga-68 PSMA PET-CT has the highest accuracy in the detection of primary tumor, however, has only the sensitivity of 50% in the determination of extension of the tumor through the capsule, except seminal vesicle invasion, which has 86% accuracy. In contrary with these results, this case showed the extra-capsular involvement with a discrete detection contrast.
In another study including Ga-68 PSMA PET-CT in 39 patients showed high sensitivity as well as correlated results with biochemical recurrence for PSA levels above 1.0 ng/mL. Since approximately 30% of the patients experience biological unfavorable disease after radical prostatectomy, the patients have chance to be programmed for salvage radiotherapy in the disease course. The discrimination of the recurrence site has the major importance in the designation of the treatment concept. Ga-68 PSMA PET-CT has advantage and superiority over other imaging modalities in the recurrence detection in the low PSA levels. A previous report decided the PSA cut-off level of 0.83 ng/mL in their series for detection of recurrent tumor in Ga-68 PSMA PET-CT study.
The Ga-68 PSMA PET-CT is newly introduced methodology in the field of prostate cancer imaging. Thus, a significant impact of this imaging modality is probable in the future. The most important advantage of this method over other modalities is the high imaging contrast in the lesions. Biochemical recurrent tumors without significant site in conventional imaging methods might be clearly shown by the means of this modality. Previous reports show interesting recurrent sites in periprostatic tissues including epididymis demonstrated by Ga-68 PSMA imaging. Another recent study pointed the possible role of robotic surgery by Ga-68 PSMA guidance. Another case report has demonstrated penile metastasis of prostate carcinoma as shown by Ga-68 PSMA PET/CT. This case shows that the Ga-68 PSMA imaging might show the unexpected sites of disease spread, and the prognostic significance of this finding should be interpreted in the future series.
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Conflicts of interest
There are no conflicts of interest.
| » References|| |
Fendler WP, Schmidt DF, Wenter V, Thierfelder KM, Zach C, Stief C, et al
. 68Ga-PSMA PET/CT detects the location and extent of primary prostate cancer. J Nucl Med 2016;57:1720-5.
Sonn GA, Chang E, Natarajan S, Margolis DJ, Macairan M, Lieu P, et al
. Value of targeted prostate biopsy using magnetic resonance-ultrasound fusion in men with prior negative biopsy and elevated prostate-specific antigen. Eur Urol 2014;65:809-15.
Hartenbach M, Hartenbach S, Bechtloff W, Danz B, Kraft K, Klemenz B, et al
. Combined PET/MRI improves diagnostic accuracy in patients with prostate cancer: A prospective diagnostic trial. Clin Cancer Res 2014;20:3244-53.
Henkenberens C, Derlin T, Bengel FM, Ross TL, Wester HJ, Hueper K, et al
. Patterns of relapse as determined by 68Ga-PSMA ligand PET/CT after radical prostatectomy: Importance for tailoring and individualizing treatment. Strahlenther Onkol 2018;194:303-10.
Leyh-Bannurah SR, Gazdovich S, Budäus L, Zaffuto L, Zaffuto E, Dell'Oglio P, et al
. Population-based external validation of the updated 2012 Partin tables in contemporary North American prostate cancer patients. Prostate 2017;77:105-13.
Henkenberens C, von Klot CA, Ross TL, Bengel FM, Wester HJ, Merseburger AS, et al
. (68) Ga-PSMA ligand PET/CT-based radiotherapy in locally recurrent and recurrent oligometastatic prostate cancer: Early efficacy after primary therapy. Strahlenther Onkol 2016;192:431-9.
Ceci F, Uprimmy C, Nilica B, Geraldo L, Kendler D, Kroiss A, et al
. (68) Ga-PSMA PET/CT for restaging recurrent prostate cancer: which factors are associated with PET/CT detection rate? Eur J Nucl Med Mol Imaging 2015;42:1284-94.
Polverari G, Ceci F, Graziani T, Cozzarini C, Castellucci P, Fanti S. A rare case of epididymal metastasis after radical prostatectomy detected by 68Ga-PSMA PET/CT. Clin Genitourin Cancer 2017;15:e525-e7.
Kumar R, Mittal BR, Bhattacharya A, Vadi SK, Singh H, Bal A, et al
. Positron emission tomography/computed tomography guided percutaneous biopsies of Ga-68 avid lesions using an automated robotic arm. Diagn Interv Imaging 2020;101:157-67.
Kamaleshwaran KK, Balasundararaj BKP, Jose R, Shinto AS. Penile metastasis from prostate cancer presenting as malignant priapism detected using gallium-68 prostate-specific membrane antigen positron emission tomography/computed tomography. Indian J Nucl Med 2018;33:57-8.
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