Background: The purpose of the present retrospective study was to
determine the correlation between radiation therapy and the risk of
postradiation fracture following combined therapy for the treatment of
soft-tissue sarcomas of the lower extremity.
Methods: Three hundred and sixty-four patients with lower extremity
sarcomas that had been treated with combined external beam radiation therapy
and limb-salvage surgery were evaluated on the basis of a combined chart and
data-base review. For the purposes of analysis, high-dose radiation was
defined as 60 or 66 Gy and low-dose radiation was defined as 50 Gy. The timing
of irradiation was defined as preoperative, postoperative, or preoperative
followed by a postoperative boost. Univariate and multivariate analyses were
used to determine which factors were associated with fracture risk.
Results: Twenty-seven fractures occurred in twenty-three patients.
Twenty-four fractures occurred in twenty patients who had been managed with
high-dose radiation. Seventeen of these patients had received postoperative
radiation (with fifteen patients receiving 66 Gy and two receiving 60 Gy), and
three had received preoperative radiation with a postoperative boost (total
dose, 66 Gy). Three fractures occurred in three patients who had received
preoperative, low-dose radiation (50 Gy). Of the twenty-three patients who
sustained a pathologic fracture, eighteen were female and five were male. The
crude median time to fracture was forty-three months. Most fractures occurred
in the femoral shaft (thirteen) or the femoral neck (eight). High-dose
radiation was associated with a greater risk of fracture when compared with
low-dose radiation (p = 0.007).
Conclusions: Women more than fifty-five years of age who are managed
with removal of a thigh sarcoma combined with radiation therapy have a higher
risk of pathologic fracture. The frequency of pathologic fractures associated
with higher doses (60 or 66 Gy) of radiation is significantly higher than that
associated with lower doses (50 Gy).
Level of Evidence: Therapeutic Level III. See
Instructions to Authors for a complete description of levels of evidence.