Prostate Specific Antigen (PSA) as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT) in Combination with Additional External Beam Radiation Therapy (EBRT) for High Risk Prostate Cancer

Abstract

High-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT) is a common treatment option for locally advanced prostate cancer (PCa). Seventy-nine male patients (median age 71 years, range 50 to 79) with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval) with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA) value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index), Gleason score, D’Amico risk classification for PCa, digital rectal examination (DRE), PSA value after one/three/five year(s) follow-up (FU), time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis (p = 0.009), PSA on date of first HDR-BT (p = 0.033), and PSA on date of first follow-up after one year (p = 0.025) have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities.

Advances in Biomarkers for PCa Diagnostics and Prognostics—A Way towards Personalized Medicine

“…This Special Issue also covered studies on seminal plasma biomarkers [ 35 ], improved PET contrast between osteolytic and osteoblastic bone metastatic lesions with fasting [ 36 ] and the impact of the blood collection tube and storage time on CTC-mRNA (AR-V7) analysis [ 37 ]. Two clinical studies on different biomarkers for prostate brachytherapy [ 38 , 39 ] complete the large number of publications.…”

“…The last two studies of this Special issue present data on patients receiving prostate brachytherapy [ 38 , 39 ]. In the sixth study from Germany by PD Ecke et al [ 38 ] PSA, PSA density and other clinical data were evaluated before and after brachytherapy with external beam radiation in 79 high-risk PCa patients treated between 2009 and 2016.…”

“…The last two studies of this Special issue present data on patients receiving prostate brachytherapy [ 38 , 39 ]. In the sixth study from Germany by PD Ecke et al [ 38 ] PSA, PSA density and other clinical data were evaluated before and after brachytherapy with external beam radiation in 79 high-risk PCa patients treated between 2009 and 2016. PSA density and PSA at time of diagnosis ( p = 0.009 and 0.033), and PSA on date of first follow-up after one year ( p = 0.025) were significant predictors for local recurrence during follow-up [ 38 ].…”

“…In the sixth study from Germany by PD Ecke et al [ 38 ] PSA, PSA density and other clinical data were evaluated before and after brachytherapy with external beam radiation in 79 high-risk PCa patients treated between 2009 and 2016. PSA density and PSA at time of diagnosis ( p = 0.009 and 0.033), and PSA on date of first follow-up after one year ( p = 0.025) were significant predictors for local recurrence during follow-up [ 38 ]. The authors further concluded that their specific radiation therapy for high-risk PCa resulted in high biochemical control rates with minimal side-effects [ 38 ].…”

“…PSA density and PSA at time of diagnosis ( p = 0.009 and 0.033), and PSA on date of first follow-up after one year ( p = 0.025) were significant predictors for local recurrence during follow-up [ 38 ]. The authors further concluded that their specific radiation therapy for high-risk PCa resulted in high biochemical control rates with minimal side-effects [ 38 ].…”