Indian Journal of Cancer Medknow Publications on behalf of Indian Cancer Society ISSN: 0019-509X EISSN: 1998-4774 Vol. 48, Num. 3, 2011, pp. 372-372

Indian Journal of Cancer, Vol. 48, No. 3, July-September, 2011, pp. 372

Letter to Editor

PET scan for prostate cancer

FV James

Section of Genito-urinary Oncology. Regional Cancer Centre, Trivandrum - 695 011, India
Correspondence Address: F V James, Section of Genito-urinary Oncology. Regional Cancer Centre, Trivandrum - 695 011, India, francisvjames@yahoo.co.uk

Code Number: cn1199

PMID: 21921345

DOI: 10.4103/0019-509X.84921

Sir,

It was interesting to read the symposium article titled "Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma" by Tiwari BP and colleagues from Radiation Medicine Centre, BARC Mumbai in Indian J Cancer. ^[1] It was elaborate and descriptive.

I wish to make the following comments. Patients with prostate cancer are evaluated for disease usually at three phases: At presentation, biochemical failure after local treatment and hormone refractory disease. Detecting site of metastasis is most important at biochemical failure after local treatment. Seltzer et al. found that PET was true positive in six of nine with CT-guided fine needle aspiration proved metastases in lymph nodes. ^[2] Haseman et al. reported that of the six patients with positive biopsies from prostatic bed (for biochemical failure after prostatectomy) who had PET scans, one was positive, five were negative. ^[3] Two of four patients with negative biopsies had negative positron emission tomography scans, two were positive. This indicates that PET is not sensitive or specific enough in local and regional disease. This is true for bone lesions as well, which is admitted by the authors. Hence, the probable use may be in detecting visceral disease, for which CT scan is good enough.

The positive uptake in FDG PET is taken as metastasis, without cytological verification. Some of them may be false positive. This makes the interpretation of the findings difficult.

I would like to point out the recommendations of a multidisciplinary consensus meeting of the Association of Urological Oncology of the German Cancer Society, which is based on good evidence. ^[4] "Contrast-enhanced computed tomography remains the standard imaging technique for monitoring of pulmonary, hepatic and lymph node metastases. Bone scintigraphy is still the most widely used imaging technique for the detection and follow-up of osseous lesions. For clinical trials it might be replaced by either PET-CT or MRI of the skeletal axis."

Hence, the conclusion should be that the value of FDG PET remains investigational in prostate cancer and not recommended routinely.

References

1.	Tiwari BP, Jangra S, Nair N, Tongaonkar HB, Basu S. Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma. Indian J Cancer2010;47:385-90.  Back to cited text no. 1  [PUBMED]
2.	Seltzer MA, Barbaric Z, Belldegrun A, Naitoh J, Dorey F, Phelps ME, et al. Comparison of helical computerized tomography, positron emission tomography and monoclonal antibody scans for evaluation of lymph node metastases in patients with prostate specific antigen relapse after treatment for localized prostate cancer. J Urol 1999;162:1322-8.  Back to cited text no. 2  [PUBMED]  [FULLTEXT]
3.	Haseman MK, Reed NL, Rosenthal SA. Monoclonal antibody imaging of occult prostate cancer in patients with elevated prostate-specific antigen. Positron emission tomography and biopsy correlation. Clin Nucl Med 1996;21:704-13.  Back to cited text no. 3  [PUBMED]  [FULLTEXT]
4.	Heidenreich A, Albers P, Classen J, Graefen M, Gschwend J, Kotzerke J, et al. Association of Urologic Oncology of the German Cancer Society. Imaging studies in metastatic urogenital cancer patients undergoing systemic therapy: Recommendations of a multidisciplinary consensus meeting of the Association of Urological Oncology of the German Cancer Society. Urol Int 2010;85:1-10.  Back to cited text no. 4  [PUBMED]  [FULLTEXT]

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