Lung · Organ at risk

Skin

Educational Summary
OAR

Dose constraints

Lung SBRT

ScheduleConstraintSource
30–34 Gy / 1 fx
Peripheral
Max dose 26 GyTROG SAFRON II
D10 cc <23 GyRTOG 0915
54 Gy / 3 fx
Peripheral
Max dose 33 GyUK SABR consensus 2022
D10 cc <30 GyUK SABR consensus 2022
50 Gy / 5 fx
Central
Max dose 32 GyRTOG 0813
D10 cc <30 GyRTOG 0813

Quoted from eviQ 3389 and eviQ 4018, checked 2026-09-22. Full table with references →

Anatomy

The outer surface of the body. For planning, “skin” is usually a thin shell just inside the external (body) contour rather than the anatomic skin layers.

Function in the body

The skin is the body's protective outer layer; it also helps control temperature and carries the sense of touch.

Why it matters

Skin dose matters most for peripheral SBRT targets near the chest wall or the surface of the liver, especially when few beam angles are used or beams enter through the same area. Endpoints include skin ulceration.

How to contour

Skin is built as a shell just inside the body outline, not drawn by hand:

  • Timmerman 2022 (Tables 8–11, written for its SBRT dose tables): the outer 0.5 cm of the body surface anywhere within the whole-body contour.
  • The EPTN 2018 atlas: the body contour as the outer border and the body contour cropped by 5 mm as the inner border, created automatically and then checked.

Both describe a 5 mm shell; other sources may use a different depth, so check the source behind your limit.

Review articleSource Verified
A Story of Hypofractionation and the Table on the Wall
Timmerman R · UT Southwestern Medical Center · 2022

An editorial history of the UT Southwestern SABR constraint tables — often called the “Timmerman tables” — covering how they were developed and revised, and their relationship to AAPM TG-101 and NRG/RTOG protocols. Tables 2–11 separate serial tissues (listed with a volume, a volume max and a max point dose) from parallel tissues (listed with a critical volume and a critical-volume dose max). In Tables 2–7 a footnote defines “point” as ≤0.035 cm³; Tables 8–11 add a contouring-instructions column for each structure.

View Source Details

Further reading

Related concepts

Maximum Dose
D0.03cc / Near-Max Dose
Dose-Volume Histogram