Journal of Community Nursing - page 17

JCN
2013,Vol 27, No 4
17
SKIN CARE
layer and destruction of cells at the
skin’s surface (Trueman et al, 2011).
Acute radiation damage is most
prominent in tissues containing
rapidly proliferating cells, such
as the epithelial surfaces of
the skin and alimentary tract.
Radiobiological damage affects the
regeneration of the skin through
the process of repair, redistribution,
repopulation and reoxygenation.
Damaged cells are replaced by cells
moving from the resting phase into
the active cycle (repopulation).
However, when the rate of
repopulation of basal cells cannot
match the rate of cell destruction
by treatment, skin damage occurs,
resulting in an acute radiation skin
reaction (Stone et al, 2003).
The goal of radiation is to find
a balance between providing a
sufficiently high dose of radiation
that will destroy or inactivate
cancer cells, while causing
minimal damage to surrounding
normal tissues. This is becoming
increasingly achievable due to
ongoing advances in delivery
techniques and state-of-the-art
equipment (Symonds et al, 2012).
One common misconception
is that radiotherapy-induced skin
reactions are ‘burns’. However,
this implies accidental occurrence,
whereas skin reactions are a
known side-effect of radiotherapy.
Acute radiotherapy-induced
skin reactions differ from burns
in terms of mechanism, extent,
duration and trajectory (
Table 1
). An
understanding of these differences
is pivotal in implementing the
correct interventions (Byrne et al,
2010; Trueman et al, 2011).
Similarly, the degree of severity
of skin reactions is influenced
by several intrinsic and extrinsic
factors, including (Ryan et al, 2007;
Ginot et al, 2010):
Dose
Size of treatment field and area
being treated
Age
Nutritional status
Smoking and alcohol intake
Comorbidities
Ethnic origin
(Noble-Adams, 1999). The skin
becomes red, may have a rash-like
appearance and can feel warm, tight
and itchy.
As the cumulative dose of
radiation increases, the degree of
erythema will range from faint
to brisk redness. Pigmentation
changes are caused by the migration
of melanin to the superficial layers
of the epidermis. In darker/black
skin, the treatment field will appear
darker during the erythematous
stages before progressing through
the other stages of dry and moist
desquamation. Hair follicles,
sweat and sebaceous glands in the
treatment field will also be affected
to differing degrees.
Dry desquamation
As the skin becomes more damaged
through ongoing radiation
exposure, it tries to compensate
by increasing mitotic activity and
migration of new cells to replace the
damaged ones.
The skin will start to get dry
around 3–4 weeks after treatment
starts. Flaking and scaling of the
skin occurs due to the decreasing
ability of the basal layer to replace
surface layers, shedding of the
epidermis, and reduced skin
lubrication from damage to the
sweat and sebaceous glands.
When new cell proliferation
occurs before desquamation, the
resulting imbalance between cell
production and cell loss results in
dry desquamation (
Figure 2
).
Moist desquamation
As radiotherapy continues, cell
proliferation reduces so that the
Concurrent treatments such
as chemotherapy.
The Radiotherapy skin
reaction cycle
Erythema
Basal cells start to be affected and
destroyed following the first dose
(fraction) of radiotherapy. During
the first 24 hours, a transient
erythema may occur due to the
reactive dilatation of capillaries and
vascular permeability. However,
visible skin changes in the
treatment field are usually not seen
until approximately 10–14 days after
the first fraction, corresponding
with the time it takes for the initial
damaged basal cells to migrate to
the surface of the skin, causing
erythema (
Figure 1
).
Radiotherapy triggers an
inflammatory response caused
by the release of histamine-like
substances and accompanied
by erythrocyte extravasation
and capillary dilation, exhibited
as various degrees of erythema
Table 1:
Difference between radiotherapy skin reaction and burn injury (Trueman et al, 2011)
Radiotherapy skin reaction
Burn injury
Cause
Absorption of energy from ionising
radiation affects the process
of regeneration
Trauma, e.g. fire, hot liquids, hot
objects, freezing objects, corrosive
chemicals, electric current, ultraviolet
(UV) light, etc
Time to reaction
Delayed — days
Immediate — minutes
Skin layers affected Epidermal layers only
Potentially all layers, from epidermis
down to muscle, tendon and bone
(superficial to full-thickness)
Sequence of damage
Damaged basal cells migrate
upwards
toward the surface of the skin
Damage occurs
downwards
through
layers of skin in relation to burn depth
Figure 1.
Example of skin showing erythema.
1...,7,8,9,10,11,12,13,14,15,16 18,19,20,21,22,23,24,25,26,27,...116