Related Experiment Video
Updated: Jan 28, 2026

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Serum Testosterone 60 Months after Passive-Scatter Proton Therapy for Localized Prostate Cancer
R Charles Nichols1,2, Christopher G Morris1,2, Curtis Bryant1,2
1a Department of Radiation Oncology , University of Florida College of Medicine , Gainesville , Florida , USA.
Abstract:
Studies demonstrate a decline of ∼10% in serum testosterone (ST) level after X-ray radiotherapy for prostate cancer. We evaluated changes in ST for patients with low- and intermediate-risk prostate cancer receiving 70-82Gy(RBE) using passive-scatter proton therapy (PT). ST was checked at baseline (n = 358) and at 60+ months after PT (n = 166). The median baseline ST was 363.3 ng/dl (range, 82.0-974.0). The median ST 5 years after PT was 391.5 ng/dl (range, 108.0-1061.0). The difference was not statistically significant (p = 0.9341). Passive-scatter PT was not associated with testosterone suppression at 5 years, suggesting that protons may cause less out-of-field scatter radiation than X-rays.
Related Concept Videos
Cancer Therapies
However, cancer treatments can pose several challenges, as therapies used to kill cancer cells are generally also toxic to normal cells. Moreover, cancer cells mutate rapidly and can develop resistance to chemical agents or radiation therapy. Besides, all types of cancer cells may not respond to the same therapy. Some cancer cells respond to one...
Targeted Cancer Therapies
There are several types of targeted therapies against...
Testosterone: Functions and Regulation
Passive Filters
Low-Pass Filters
Low-pass filters are designed to transmit signals with frequencies lower than the cutoff frequency, ωc, and attenuate those above it. The cutoff...
Active versus Passive Immunity
Active Immunity
Active immunity refers to the resistance one develops...
Proton (¹H) NMR: Chemical Shift
Absorption signals of all the protium nuclei...

