Lung Cancer.pdf

248 A.A. Vaporciyan, J.F. Kelly, and K.M.W. Pisters
or 4). This severe esophagitis can necessitate dietary modification, narcotic
analgesics, and, for patients who have lost more than 10% of their body
weight, feeding tube placement. Another factor that can influence acute
side effects in patients treated with chemoradiation is the daily radiation
dose—especially when patients receive greater than 2 Gy per day, as in the
case of hyperfractionated treatment delivering 1.2 to 1.5 Gy twice daily.
When chemotherapy is given concurrently with hyperfractionated radiation
therapy, approximately two thirds of patients experience severe
esophagitis. This excess toxicity explains why concurrent chemotherapy
and hyperfractionated radiation therapy is currently restricted to the protocol
setting.
Late Side Effects
Late or chronic complications of radiation therapy are defined as complications
occurring or persisting 90 days or later after the completion of
treatment. When radiation therapy is carefully planned and delivered
with respect to normal tissue tolerances, severe late complications are
not routinely seen. In addition to the previously mentioned dose guidelines
for the total volume of lung treated, the doses to the spinal cord,
heart, and esophagus must be considered (Table 13–1). When these dose
limits (based on 1.8–2.0 Gy per fraction) are respected, the risk of severe
complications, such as cardiomyopathy or myelitis, is less than 5% at 5
years after therapy. In contrast to acute side effects, long-term side effects
are more directly related to the dose per fraction or individual radiation
treatment than to the total radiation dose. The risk of more intense
late complications increases as the dose per fraction increases. In the
randomized, prospective intergroup trial comparing sequential chemotherapy
and radiation therapy versus concurrent chemotherapy and
once-daily radiation therapy versus concurrent chemotherapy and
twice-daily radiation therapy (Curran et al, 2000), the late complication
rate was about 17% in all 3 arms. This finding suggests that adding concurrent
chemotherapy to radiation therapy does not increase the rate of
late complications. The intergroup trial also found that the different
rates of acute esophagitis in the 3 arms did not translate into correspondingly
different rates of late esophageal stricture, indicating that
acute radiation-related complications do not predict for late complications.
Thoracic Surgery
In general, of the 3 modalities available for the treatment of patients with
lung cancer, surgery is associated with the highest incidences of treatment-related
morbidity (15%– 40%) and mortality (1%–12%). The occurrence
of surgery-related side effects and deaths is minimized through