Monitoring tumor response to therapy by means of 31p magnetic resonance spectroscopy a case of advanced prostatic cancer with metastatic chest wall tumor

Abstract

The response of advanced prostatic cancer with metastatic chest wall tumor to high-dose diethylstilbestrol diphosphate (DESP) therapy was monitored by in vivo 31P magnetic resonance spectroscopy (31P MRS) study. A eighty-three year old man with Stage D2 prostatic cancer had been treated with chlormadinone acetate and cyclophosphamide since 1984. He was admitted to our hospital with a chest wall tumor and anemia on May 9, 1992. The elavated PAP, PSA and γ-Sm levels were also observed. Needle biopsy of the tumor revealed poorly differentiated adenocarcinoma metastatic from the prostatic cancer. The patient received 500mg of DESP by DIV daily for 10 days, and the tumor was reduced by 54% clinically. The abnormal PAP, PSA and γ-Sm levels returned to almost normal range by three weeks afte the initiation of high-dose DESP therapy, and regression of the tumorwas confirmed by the MRI. After the first administration of DESP, the MR spectra of the chest wall tumor showed elavated peaks of phosphomonoesters and phosphodiesters. These substances are related to the membrane metabolism and theirincrease represents the membranous degeneration of tumor cells. The same changes continued consecuitively for three weeks, and corresponded with the regression of the tumor. In conclusion, these results suggest that in vivo 31P MRS of malignant tumors can be useful for evaluating early response to therapy prior to other clinical examinations. © 1994, THE JAPANESE UROLOGICAL ASSOCIATION. All rights reserved.