Radiation therapy is the most widely used local therapy for the
treatment of KS. Most irradiated lesions regress with treatment,
but regrowth, often in 4-6 months, is common. Radiation
therapy provides effective palliation of
cosmetically disturbing lesions or localized bulky symptomatic disease
at any site.
Electron beam therapy, which has limited penetration beyond the dermis,
is effective for superficial lesions and generally provides good
cosmetic results. Initially, raised lesions flatten, lesion size may
decrease, and a violaceous lesion generally changes to a tan-brown,
hyperpigmented spot. Genital KS associated with pain, difficulty with
urination, or psychologic discomfort may be well palliated with electron
beam therapy without significant toxicity.
Conventional beam irradiation is a good choice for deep or bulky
lesions. No standard dosing
schedule for radiation can be recommended. Responses have been seen with
dosing schedules ranging from single doses of 800 cGy to fractionated
schemes with total doses exceeding 4,000 cGy.The optimal
radiation schedule and dose are defined by the goals of therapy. A
randomized, prospective trial of three radiation doses and schedules (40
Gy in 20 fractions, 20 Gy in fractionated doses, or a single 8 Gy dose)
observed a greater time to treatment failure and the least residual
cutaneous pigmentation for lesions treated with 40 Gy.
Radiation therapy is effective in treating oral cavity lesions, but
because of the significant risk of radiation-induced mucositis, this
therapy should be reserved for symptomatic disease. To minimize the
morbidity of oral cavity irradiation, patients should be aggressively
pretreated for local fungal and herpetic infections, and prescribed use
of an antibacterial mouthwash.
Edema secondary to lymphatic obstruction may be palliated with
radiation, but the benefit is often short-lived and may be complicated
by brawny induration, fibrosis, or ulceration, particularly in
previously irradiated fields. With the exception of patients with very
limited survival expectations, radiation therapy for symptomatic
visceral KS is not recommended.
Radiation therapy for AIDS-related Kaposi's Sarcoma.
Radiat Oncol Biol Phys. 1990
Department of Radiation Oncology, University of
California, San Francisco 94143.
Between March 1982 and October 1987, 375 fields in
187 patients with AIDS-related Kaposi's Sarcoma were treated in the
Department of Radiation Oncology at the University of California in
San Francisco (UCSF). Field sizes ranging from 2 x 2 cm to total
skin received doses of 8 Gy in a single fraction to 15-40 Gy in 5-10
fractions. Seventy-four percent of the patients have died.
Response to treatment was
achieved in over 90% of treated fields, with a median time to
progression of 21 months and an actuarial freedom from relapse at 6
months of 69% (97 patients alive). There was no difference in
outcome regardless of the fractionation regimen used. Severe
reactions were noted in 17% of treated fields, but this incidence
was significantly lower when a single fraction of 8 Gy was used (p
less than 0.001). Radiation therapy plays an important palliative
role in this devastating disease. This review supports the use of a
single 8 Gy fraction for all Kaposi's Sarcoma lesions of the skin.
Further data regarding single fraction therapy for lesions of other
sites are needed.
A randomized prospective trial of radiation therapy
for AIDS-associated Kaposi's
The optimal dose of radiation in the treatment of AIDS-associated Kaposi's
sarcoma has been controversial based on previous nonrandomized
Seventy-one cutaneous AIDS-associated Kaposi's
sarcoma lesions were randomly assigned to 1 of 3 radiation dose
regimens-8 Gy in 1 fraction, 20 Gy in 10 fraction. and 40 Gy in 20
fractions. Lesions were measured prior to and following treatment.
Complete resolution of palpable tumor was considered a complete
response, regardless of residual purple pigmentation. Reduction in
palpable tumor to less than 50% of pretreatment area was considered an
objective response. Less than 50% reduction in tumor size was considered
Complete response was higher
with 40 Gy (83%) and 20 Gy (79%) than with 8 Gy (50%). Absence of
residual purple pigmentation was greater (p =
.005) with 40 Gy (43%) than with 20 Gy (8%) or 8 Gy (8%). Lesion failure
was lower (p =
.03) with 40 Gy (52%) than with 20 Gy (67%) or 8 Gy (88%). Median time
to failure was 43 weeks with 40 Gy, 26 weeks with 20 Gy, and 13 weeks
with 8 Gy (p =
Fractionated radiotherapy to higher total doses resulted in improved
response and control of
sarcoma. This dose-dependence should be considered in determining the
optimal radiotherapeutic regimen for individual patients treated for