LETTER TO EDITOR
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|Year : 2011 | Volume
| Issue : 4 | Page : 513--514
Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma
S Basu, BP Tiwari
Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Hospital Annexe, Jerbai Wadia Road, Parel, Mumbai, India
Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Hospital Annexe, Jerbai Wadia Road, Parel, Mumbai
|How to cite this article:|
Basu S, Tiwari B P. Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma.Indian J Cancer 2011;48:513-514
|How to cite this URL:|
Basu S, Tiwari B P. Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma. Indian J Cancer [serial online] 2011 [cited 2021 Jan 27 ];48:513-514
Available from: https://www.indianjcancer.com/text.asp?2011/48/4/513/92247
We appreciate the interest of Dr. James in our research  and the concerns he has on this very important subject. We agree with some of the points but want to elaborate related concepts that are evolving at this point, for better understanding.
Very rightly, as the author states, the disease evaluation of prostate carcinoma occurs in three clinical settings and we strongly believe the role of FDG-PET should be assessed in these three settings separately. This has been a persistent flaw in the initial studies published in this domain and requires to be straightened out through systematic examination and debate. On several occasions in clinical practice, we have observed FDG-PET becoming negative much earlier than bone scans, particularly in the context of orchidectomy and hormonal therapy, hence can be considered superior to conventional skeletal scintigraphy in demonstrating therapeutic response early in the course of therapy (at times, in fact, the uptake in the responding bone scan lesions can increase due to sclerosis and 'flare' of osseous lesions). Hence, as stated in our discussion, the history of previous therapy is essential while comparing the two modalities for correct comparison of the two techniques.
Thus, for a head-to-head comparison of the two techniques such understanding becomes pivotal to obviate misinterpretation. Our study demonstrates and emphasizes the need for such patient stratification, whenever one undertakes such endeavor in prostate carcinoma. This is substantiated by the superior performance of FDG-PET in the "untreated" group. While all lesions could not be verified for obvious ethical and practical reasons, the correlative results were taken into account wherever feasible for characterizing a lesion as metastatic. Furthermore, one must recognize the potential of FDG-PET in detecting disease very early during the course of disease when it is confined to the bone marrow, is a major advantage. , We must realize that red marrow is the initial sites for development skeletal metastasis and FDG-PET is clearly superior to bone scan in this area. These factors have led to some interesting observations that have been reported in the recent literature ,, with respect to disease detection, prognosis and overall survival.
We agree with the view that the performance of FDG-PET is limited in detecting soft-tissue metastases, particularly in the prostatic bed and in local and regional disease, which is further hampered by the high urinary bladder FDG activity. Hence, newer and novel PET agents have been investigated like 18 F- or 11 C-acetate, and 18 F- or 11C-choline for this purpose; however, more comparative data are needed for definitive conclusion about their precise clinical utility. Also, these agents are not widely available in our country for routine clinical use at this time. About metastases at distant sites, an FDG-PET-CT (which has now almost completely replaced PET-alone modality across the world) would likely to be preferable compared to diagnostic CT alone, because of the advantage of providing whole body status (both skeletal and soft tissue disease) at a significantly lower whole body radiation dose to the patient. Also, baseline scan forms the basis for monitoring therapy once a treatment is instituted. Moreover, the potential of FDG PET-CT for disease prognosis, early treatment monitoring and overall outcome prediction are some of the factors that require to be considered. ,,
Overall, we feel that imaging and the choice of PET tracer (when multiple tracers are available in a center) should be tailored to the specific phases of the disease in a patient-specific manner with the definitive clinical question in mind for a particular indivdual. We strongly believe that better appreciation of the underlying theoretical concepts would further enhance the role and reliability of this powerful imaging modality and would bring about changes in the existing consensus guidelines relating to this important malignancy in the near future.
|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 Cancer 2010;47:385-90.|
|2||Basu S, Torigian D, Alavi A. Evolving Concept of Imaging Bone Marrow Metastasis in the 21st Century: Critical Role of FDG-PET. Eur J Nucl Med Mol Imaging 2008;35:465-71.|
|3||Basu S, Alavi A. "Bone Marrow" and not "Bone" is the primary site of skeletal metastasis: Critical Role of FDG-PET in this setting. J Clin Oncol 2007;25:1297.|
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