Bone Scans May Be Useful In Early Diagnosis of Calciphylaxis

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MedicalResearch.com Interview with:
Daniela Kroshinsky, MD, MPH
Department of Dermatology
Massachusetts General Hospital, Boston 
 and
Suchismita Paul, MD
Medical student at Harvard Medical School, Boston, Massachusetts, at the time of the study now with Department of Medicine and Department of Dermatology and Cutaneous Surgery Jackson Memorial

Medical Research: What is the background for this study?

Response: Calciphylaxis is a life-threatening disease and the diagnosis is challenging with clinicians mostly relying on the clinical findings along with an assessment of risk factors. Tissue biopsy is often falsely negative, requiring multiple tissue biopsies, possibly propagating new lesion formation, and delaying treatment initiation. Therefore, a non-invasive tool would be of significant value for the diagnosis of calciphylaxis. The use of bone scans for the diagnosis of calciphylaxis has been reported in several case reports, yet its use remains controversial because of the reported low sensitivity and specificity. Only one previous study from 2002 reported that in fact the sensitivity is very high (97%), however, only 4 of 36 calciphylaxis patients were biopsy-confirmed and the specificity was not addressed.

We investigated the potential role of bone scintigraphy for the early diagnosis and treatment monitoring of calciphylaxis. We performed a retrospective case-control study involving 49 patients, 18 calciphylaxis cases (biopsy-confirmed in 14) and 31 controls with end-stage renal disease without calciphylaxis.

Medical Research: What are the main findings?

Response: In our study, bone scans were deemed to be positive for calciphylaxis based on increased heterogeneous radiotracer uptake within soft tissues, throughout the body with a predilection for areas corresponding to clinical findings. The sensitivity and specificity of bone scintigraphy for calciphylaxis is 89% and 97%, respectively. There was more intense uptake in areas corresponding to the earlier plaques and nodules rather than the later ulcerated stage. In most patients, there was no radiotracer uptake at ulceration sites corresponding to devitalized tissue. Hence, bone scans appear to be more useful in the early diagnosis of calciphylaxis. Finally, our data demonstrated an interval decrease in radiotracer uptake following sodium thiosulfate therapy, corresponding to a clinical response to treatment.

Medical Research: What should clinicians and patients take away from your report?

Response: The take away point is that our study confirms that bone scintigraphy is highly sensitive and specific for the diagnosis of calciphylaxis. It can be used for the early diagnosis of calciphylaxis and can also be used to monitor treatment response to sodium thiosulfate.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: This was a retrospective study with limited number of patients, however this was a pilot study and calciphylaxis is a rare disorder. Future prospective studies are needed for further validation. Future studies are also needed to address if bone scans can differentiate calciphylaxis-like skin lesions from calciphylaxis.

Citation:

Paul S, Rabito CA, Vedak P, Nigwekar SU, Kroshinsky D. The Role of Bone Scintigraphy in the Diagnosis of Calciphylaxis. JAMA Dermatol. Published online December 16, 2015. doi:10.1001/jamadermatol.2015.4591.

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More interviews with researchers from JAMA on MedicalResearch.com

 

Daniela Kroshinsky, MD, MPH, & Suchismita Paul, MD (2016). Bone Scans May Be Useful In Early Diagnosis of Calciphylaxis MedicalResearch.com

Last Updated on January 15, 2016 by Marie Benz MD FAAD