**Author details**

**Abbreviations**

164 Radiotherapy

AP anterior‐posterior CI confidence interval CR complete remission CS Calcaneodynia score

EC endothelial cells

Gy Gray

IL interleukin

KV kilovoltage

mA milliampere

mSv milliSievert MV megavoltage NC no change

NO nitric oxide

PR partial remission QOL quality of life

ROS reactive oxygen species SSD skin‐to‐source distance

VAS visual analogue scale

TGF‐*β*<sup>1</sup> transforming growth factor *β*<sup>1</sup>

Cu chemical element symbol for copper

iNOS inducible nitric oxide synthases

mRNA messenger ribonuclein acid

NF‐κB nuclear factor kappa B

LD‐EBRT low dose external beam radiotherapy

NSAID non‐steroidal anti‐inflammatory drug PBMC peripheral blood mononuclear cells

GCG‐BD German Cooperative Group on Radiotherapy for Benign

ICRP International Commission on Radiological Protection

Diseases

Robert Michael Hermann1, 2\*, Frank Bruns2 and Mirko Nitsche1, 3

