CASES OF THE WEEK - “ROLE OF 99mTc PSMA (Prostate specific membrane antigen) WHOLE BODY AND SPECT-CT SCAN in PROSTATE CANCER WITH PSA OF 0.454 ng/ml” by Dr ShekharShikare, Consultant & HOD, Nuclear Medicine, & Dr Mohammed Istrabadi, Consultant, Urology/General Surgery, NMC Royal Hospital Sharjah

CASES OF THE WEEK - “ROLE OF 99mTc PSMA (Prostate specific membrane antigen) WHOLE BODY AND SPECT-CT SCAN in PROSTATE CANCER WITH PSA OF 0.454 ng/ml” by Dr ShekharShikare, Consultant & HOD, Nuclear Medicine, & Dr Mohammed Istrabadi, Consultant, Urology/General Surgery, NMC Royal Hospital Sharjah

ROLE OF 99mTc PSMA (Prostate specific membrane antigen) WHOLE BODY AND SPECT-CT SCAN in PROSTATE CANCER WITH PSA OF 0.454 ng/ml.

66 yrs old male. H/O Radicle prostectomy for cancer prostate- 4 years ago

HP - Adeno-carcinoma prostate invading directly into normal glandular elements of the prostate, peri-neural lymphatics & wall of the vascular channels ( tumor did not infiltrate the whole thickness of the capsule). Gleason score = 6

5.12.2015 7.5.2016 8.11.2017 27.12.2017

PSA (0.22-6.16) 0.987 1.173 2.340 (Casodex 50 mgm) 0.454 (on medication)

Ref for 99mTc PSMA WHOLE BODY AND SPECT-CT scan for prostate cancer evaluation in view of PSA of 0.454.

99mTc- PSMA whole body AND SPECT-CT scan showed

Abnormal PSMA tracer accumulation in left prostatic bed (Better appreciated in SPECT-CT FUSED images at 5 & 20 hours images).Rest of the whole body images were unremarkable.

PSMA  AVID SMALL TISSUE ABNORMALITY SEEN IN LEFT PROSTATIC BED,WHICH REPRESENT RECURRANCE OF THE DISEASE PROCESS.

What is PMSA

PSMA (Prostate Specific Membrane Antigen) is a membrane glycoprotein which is overexpressed manifold on prostate cancers. The expression increases with tumor aggressiveness, androgen independence, metastatic disease, and disease recurrence. PSMA is an excellent target for radionuclide imaging and therapy of prostate cancer for several reasons. It is mainly expressed in prostate cancer in all stages of the disease, up-regulated in androgen refractory or metastatic disease, expressed on the cell surface as an integral membrane protein, not released into the circulation, and It is mainly expressed in prostate cancer in all stages of the disease, up-regulated in androgen refractory or metastatic disease, expressed on the cell surface as an integral membrane protein, not released into the circulation, and internalized after antibody binding (receptor-mediated endocytosis)

99mTc PSMA SPECT/CT Imaging identifies tumor cells expressing PSMA antigen with excellent sensitivity & specificity, thereby detecting lesions remaining unidentified by conventional methods. (Asian J Androl. 2017 May-Jun; 19(3): 267–271.Published online 2016 Dec 13. doi: 10.4103/1008682X.192638. Evaluation of 99mTc-labeled PSMA-SPECT/CT imaging in prostate cancer patients who have undergone biochemical relapse.

Clinical Applications

  1. Diagnosing prostate cancer in patient with raised PSA.
  2. Staging Prostate Cancer, best for N&M Staging.
  3. Post Prostatectomy and radiotherapy for rising PSA.
  4. Response to radiation and chemotherapy in metastatic prostate cancer.

PMSA studies are able to determine the extent of prostate cancer and whether it has spread to the lymph nodes or other parts of the body and provided a higher detection rate than conventional imaging modalities and is helpful in clinical diagnosis and treatment.

Unique Cases 075b Unique Cases 075c

99mTc- PSMA whole body scan (19.2.2018)

Comment- PSMA  AVID SMALL TISSUE ABNORMALITY SEEN IN LEFT PROSTATIC BED, WHICH REPRESENT RECURRANCE OF THE DISEASE PROCESS.0