Pain, PSA flare, and bone scan response in a patient with metastatic castration-resistant prostate cancer treated with radium-223, a case report

Abstract

Background: Radium-223 has been shown to improve overall survival in men with metastatic castration-resistant prostate cancer with symptomatic bone metastases. The bone scan response to radium-223 has only been described in one single center trial of 14 patients, none of whom achieved the outstanding bone scan response presented in the current case.

Case presentation: In this case report, we describe a 75 year-old white man with extensively pre-treated metastatic castration-resistant prostate cancer and symptomatic bone metastases who experienced a flare in pain and prostate-specific antigen, followed by dramatic clinical (pain), biochemical (prostate-specific antigen), and imaging (bone scan) response.

Conclusion: The flare phenomena and bone scan response we observed have not previously been described with radium-223. This case suggests that the degree and duration of bone scan response may be predictive of overall survival benefit.

Figure 1

PSA trend and response to radium-223. The trend in the patient’s PSA over the course of his disease is shown, and the PSA response to radium-223 is highlighted. PSA flared after the first dose of radium-223, peaking at 996 ng/mL 3 weeks after the initiation of therapy. PSA then steadily improved and nadired at 554 ng/mL about 1 month after the 6th dose of radium-223. After completion of radium-223, PSA remained stable at about 600 ng/mL for about 7 months before increasing again.

Figure 2

Radionuclide bone scan trend and response to radium-223. A. June 2008, metastatic prostate cancer diagnosis. B. May 2010, disease progression on combined androgen blockade. C. May 2011, disease progression following sipuleucel-T immunotherapy. D. December 2011, disease progression just prior to docetaxel chemotherapy. E. June 2013, widespread disease progression associated with severe diffuse bone pain on enzalutamide (“pre-radium-223”). F. February 2014, dramatic bone scan response two months after completing six treatments of radium-223 (“post-radium-223”).

Figure 3

Alkaline phosphatase trend and response to radium-223. The trend in the patient’s alkaline phosphatase over the course of his disease is shown, and the alkaline phosphatase response to radium-223 is highlighted. Alkaline phosphatase was 564 U/L at the time of initiation of radium-223 and steadily improved throughout the course of radium-223. Alkaline phosphatase nadired at 144 U/L about 1 month after the 6th dose of radium-223 and then trended up again.

Figure 4

Diffuse sclerosis, resulting from the patient’s high osseous tumor burden and associated high radium-223 uptake. Diffuse osseous sclerosis on CT imaging of the spine (A), bilateral ilia (B), and bilateral femoral heads (B) is shown. This sclerosis occurred because of the patient’s high volume of bony metastatic disease and consequential high radium-223 uptake. We believe that this combination of high osseous tumor burden and high radium-223 uptake, resulting in diffuse sclerosis, contributed to our patient’s transfusion dependence, which has persisted in the absence of continued radium-223 therapy or systemic disease progression.