The Effect of Prostate Cancer Radiotherapy on Testosterone Level: A Systematic Review and Meta-analysis

Abstract

Introduction: In the current study, a systematic search and meta-analysis were performed to evaluate the effect of prostate cancer radiotherapy on testosterone levels of patients. Methods: To illuminate the effect of radiotherapy on the testosterone level of prostate cancer patients, a systematic search was conducted in accordance with the PRISMA guideline in electronic databases of Scopus, Embase, PubMed, Web of Science, and clinical trials up to December 2018 using relevant keywords. Based on a certain set of inclusion and exclusion criteria, 12 eligible studies that had data on the testosterone level following prostate cancer radiotherapy were included in the meta-analysis. Results: According to the various techniques of prostate cancer radiotherapy, the dose values scattered to the testicular tissues ranged from 0.31 to 10 Gy. Combining the findings from 12 studies, it was found that prostate cancer radiotherapy leads to a significant reduction in the testosterone level (Weighted Mean Difference [WMD]: -51.38 ng/dL, 95% CI: -75.86, -26.90, I2=0.0%, P<0.05). Furthermore, subgroup analysis by the patient number showed a significant reduction in the testosterone level at patient number < 50 (WMD: -80.32 ng/dL, 95% CI: -125.10, -35.55, I2= 0.0%) and 50 < patient number < 100 (WMD: -46.99 ng/dL, 95% CI: - 87.15, -6.82, I2= 0.0%). Subgroup analysis based on treatment technique type revealed a significant reduction in testosterone level after conventional radiotherapy (WMD: -56.67, 95% CI: -100.45,-12.88, I2= 34.3%) and IMRT/SBRT technique (WMD: -57.42, 95% CI: -99.39, -15.46, I2= 0.0%) in comparison with the proton therapy (WMD: 0.00, 95% CI: -80.24, 80.24). Conclusion: The findings showed a significant decrease in the testosterone level of prostate cancer patients after radiotherapy compared with pre-treatment levels.

The Long-Term Effect of Intensity Modulated Radiation Therapy for Prostate Cancer on Testosterone Levels

“…From daily fiducial image guidance, the testes-in-field mean dose was 3.50 Gy, whereas the testes-out-of-field scatter dose was 0.16 Gy for a complete IMRT course of 39 fractions. The authors concluded that incidental doses to the testes from prostate IMRT can be minimized by (1) opting to restrict the use of elective pelvic nodal fields, which would increase testicular dose to 1.72 Gy for 6 MV energies, (2) choosing photon energies less than 10 MV, and (3) using the smallest port sizes necessary for daily image guidance. 16 As such, each time IMRT needs to be performed, a computed tomography (CT) image is taken first to accurately locate the prostate for radiation.…”

“…Previous studies on external-beam radiation therapy (EBRT) have evaluated changes in serum testosterone levels in patients receiving EBRT for prostate cancer 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 and other pelvic malignancies. 10 , 11 NRG Oncology, a newly developed clinical trials network group consisting of the coordinated efforts of the National Surgical Adjuvant Breast and Bowel Project, the Radiation Therapy Oncology Group (RTOG), and the Gynecologic Oncology Group recently reported on the RTOG 9408 randomized clinical trial and found that a total dose of 68.4 Gy to the prostate was only associated with a median decrease in testosterone of 13.5% at 3 months after treatment.…”

Changes in sexual function and serum testosterone levels in patients with prostate cancer after image-guided proton therapy

“…[ 17 ] reported that secondary doses during prostate PT were ~10 −4 Sv Gy –1 at 50 cm from the beam isocenter and were an order of magnitude lower than during conventional IMRT. In addition, a systematic review and meta-analysis revealed a greater reduction in testosterone level after conventional radiotherapy and IMRT/SBRT than after PT [ 18 ].…”

Evaluation of set-up errors and estimation of set-up margin during external beam radiation therapy of prostate cancer using electronic portal imaging device (EPID)

“…1 There are several therapeutic modalities for this malignancy including radical prostatectomy, radiotherapy and hormonal therapy. [2][3][4] It has been proven that different therapeutic techniques of external beam radiotherapy (EBRT) can be applied as a standard modality for prostate cancer treatment. 5,6 The main goal of three-dimensional conformal radiation therapy (3DCRT), as an EBRT technique, is to deliver conformal dose distribution to the target volume while minimising radiation dose to surrounding normal tissues.…”