External Beam Radiotherapy for Cancer in Children
Optimal treatment of children with cancer requires combined-modality
therapy incorporating chemotherapy, surgery, and radiotherapy. Chemotherapy alone
is not sufficient to cure most childhood solid tumors; either
Figure 69-3
The patient and anesthetic monitors are viewed on closed-circuit
television during an intraoperative radiation procedure. (From Mackenzie
RA, Southorn PA, Stensrud PE: Anesthesia at remote locations. In
Miller RD [ed]: Anesthesiology, 5th ed. Philadelphia, Churchill Livingstone, 2000,
p 2262.)
resection or radiation is needed for local tumor control.[192]
Children with radiosensitive malignant tumors typically require radiation therapy
for a number of sessions over a period of several weeks. Although the treatments
are painless, young children cannot be depended on to remain absolutely motionless
in the strange and frightening surroundings of radiation therapy rooms. Because
immobility
during treatment is mandatory, sedation/analgesia or general anesthesia is usually
necessary.[193]
Anesthetic regimens for external beam radiation in children should
provide brief periods of anesthesia at a depth that ensures immobility and minimal
time to recovery.[194]
Airway management should
be appropriate to whatever body position the patient requires for the radiation.
Because all personnel must leave the room during actual delivery of the radiation,
the anesthetic technique should facilitate remote monitoring for continuous assessment
of the patient.[194]
During the actual radiation
treatment period, the patient and anesthesia equipment are observed continuously
by closed-circuit television, and monitors are mirrored to the remote observation
site outside the treatment room.
Typically, patients require a series of treatments and hence a
series of anesthetic regimens. It is therefore desirable to avoid repeated invasive
procedures to the degree feasible[194]
and to keep
the anesthesia technique as simple as possible. The LMA has proved to be a simple
and safe airway device for use in children undergoing general anesthesia for external
beam irradiation.[195]
[196]
Intravenous propofol infusion has been used satisfactorily in these children.[197]
[198]
If the patient does not have an intracranial
mass lesion, intramuscular administration of ketamine has provided satisfactory conditions.
[199]
However, excessive salivation and postoperative
nausea and vomiting make ketamine a less desirable alternative. Given the frequent
need for repeated treatments over a period of days or weeks, intravenous access may
become difficult. Placement of a peripherally inserted central catheter may provide
ongoing intravenous access.[200]
[201]
