Relationship between prostate volume reduction and neoadjuvant hormone therapy duration in prostate cancer radiotherapy

Abstract

Objective To study the relationship between changes in prostate volume and neoadjuvant hormone therapy (NHT) duration in prostate cancer radiotherapy. Methods Fifty patients with prostate cancer who received NHT were enrolled in the study continuously. The diameters along the x-, y-, and z-axes of the prostate were measured, and the volume of prostate was calculated weekly during radiotherapy. The relationship of prostate volume reduction with NHT duration, prostate volume before radiotherapy, and prostate cancer risk groups was analyzed during radiotherapy. Results The prostate volume in all patients decreased after radiotherapy. Patients with short NHT duration had larger changes in prostate volume and diameters than those with long NHT duration. Compared with those with a large prostate volume, patients with a normal prostate volume had larger changes in prostate volume and diameters long three axes after 7 weeks of radiotherapy, shorter NHT duration before radiotherapy, and lower risk of prostate cancer. In patients with low-and medium-risk prostate cancer, the prostate volumes were significantly reduced to 68.10% and 78.70%, respectively, of those before radiotherapy after no more than 4 months of NHT (P=0.002), but remained similar after more than 4 months of NHT. In patients with high-risk and more severe prostate cancer, the prostate volumes were significantly reduced to 76.59% and 85.46%, respectively, of those before radiotherapy after no more than 6 months of NHT (P=0.001), but remained similar after more than 6 months of NHT. Conclusions The changes in prostate volume and diameters along three axes during radiotherapy become smaller with longer NHT duration. Patients with low-or medium-risk prostate cancer have slight changes in prostate volume after more than 4 months of NHT, while patients with high-risk or locally advanced prostate cancer have slight changes in prostate volume after more than 6 months of NHT. Key words: Prostate neoplasms/radiotherapy; Prostate neoplasms/neoadjuvant hormone therapy; Prostate volume