Page 316 Guide to Pain Management in Low-Resource Settings

304 Lutz Moser

requires frequently increasing doses of analgesics. Skel- to fi nd the answers. Th e clinical trials included patients
etal pain is thought to be induced by a combination of with painful bone metastases of any primary sites,
mechanical and biochemical factors that result in acti- mainly in the prostate, breast, and lung. Th e radiation
vation of pain receptors in local nerves. Increased blood doses of the most common schedules are single frac-
fl ow to the metastatic lesions promotes an infl ammato- tionation treatments with 8 Gy, shorter duration treat-
ry response, with release of cytokines by both the tumor ments with four times 5 Gy or fi ve times 4 Gy, or more
cells and the surrounding tissue. Radiotherapy is an ef- protracted regimens such as 10 times 3 Gy or 20 times
fective tool used to control pain due to bone metastasis. 2 Gy. Fractions with single doses of 4 Gy and 5 Gy are
Although a complete response will be achieved in only applied three to four times a week, 3 and 2 Gy fractions
30% of cases, a partial response results in a suffi cient most often fi ve times a week, up to the total doses of 30
reduction of additional pain medication. Further goals Gy and 40 Gy. Th e maximum relief of pain may be ex-
of treatment are preservation of mobility and function, pected after 1 month.
maintenance of skeletal integrity, and preservation of Th e degree and duration of pain relief do not de-
quality of life. pend on the fractionation schedules applied. No signifi -
Th e global response to radiotherapy of bone metas- cant diff erences in terms of pain relief and analgesic use
tasis in reducing pain is about 80%. About 3 out of 10 were found with single fractions, shorter duration treat-
people (30%) will have no pain within a month of ra- ments, or more protracted regimens. However, the re-
diotherapy treatment. For at least another 4 out of 10 treatment rate and pathological fracture rates are higher
(40%) people, the treatment reduces the pain by half. after single-fraction radiotherapy because a relevant re-
Th e patient’s subjective experience confi rms the ef- calcifi cation of osteolytic bone metastases following ir-
fectiveness of radiotherapy in reducing pain caused by radiation is related to more protracted schedules.
bone metastases and in improving quality of life. About
6 to 12 weeks after treatment, the bone repairs itself Is re-irradiation possible?
and becomes stronger.
Local palliative effi ciency can be expressed as the A second course of palliative radiotherapy of the aff ect-
time to pain progression, the rate of pathological frac- ed bone is possible and helpful if the fi rst course does
tures, and the requirement of local retreatment. De- not work well or if the pain is initially relieved, but in-
pending on the reported time periods for evaluation creases again some weeks or months later. Th e decision
and how the results were assessed, the documented for retreatment has to take into account any sensitive
duration of pain relief is more than 6 months in at least structures in the irradiated volume, for example the spi-
50% of patients, and the fi rst increase in pain score can nal cord or kidneys. Th e indication has to be confi rmed
be expected after 1 year in 40% of patients. by a radio-oncologist.
Th e reported incidence of pathological fractures fol-
lowing palliative radiotherapy of bone metastases is low, What are the side eff ects for
varying between 1% and 10%. Recalcifi cation of osteo-
external palliative radiotherapy?
lytic bone metastases after 6 months, defi ned as a rise of
density in the region of interest of more than 20%, was Palliative radiotherapy has few side eff ects. Acute toxic-
found in 25–58% of patients. ity is mild, rarely requiring further supportive care. Ir-
Studies show that hemibody or wide-fi eld irradia- respective of the fractionation schedule chosen, the in-
tion gives nearly all patients some pain relief. It can re- cidence of grade 2 or greater acute and late toxicity is
lieve pain completely in up to half of the people treated low, with a rate of approximately 10–15% (acute) and
and can help to stop new painful areas developing. 4% (late), respectively. Pronounced tiredness and listless
are the most common general side eff ects, but recovery
What fractionation schedules are occurs within a few weeks after treatment. Most specifi c
applied for pain control? side eff ects of external palliative radiotherapy depend
on the location of treatment. While radiotherapy of the
Confl icting opinions on low-dose, short-course radio- bones of the extremities might aff ect the skin locally
therapy versus prolonged or higher-dose schedules led with a light reversible erythema, a predominance of gas-
to many scientifi c publications and randomized trials trointestinal adverse eff ects such as emesis and diarrhea