While radiation therapy (RT) has an integral role in the management of soft-tissue sarcoma, it has a limited role in that of bone sarcoma, with few exceptions (ie, Ewing sarcoma). In keeping with the rarity of these tumors, it has been demonstrated that patients treated at high-volume centers have significantly better survival and functional outcomes. 1–3 Accordingly, treatment should be delivered by a multidisciplinary team including orthopedic, medical, and radiation oncologists, as well as plastic and reconstructive surgeons, physical therapy specialists, and pathologists and radiologists with expertise in musculoskeletal sarcomas. 4 As the preceding articles in this supplement have addressed the major modalities in the treatment of sarcomas other than RT, this article will focus on how RT fits into the overall management mix, with a focus on soft-tissue sarcomas, where it figures most prominently.
BONE SARCOMAS: A LIMITED ROLE FOR RADIATION
The role of RT in the management of bone sarcomas is limited. Its primary application appears to be in Ewing sarcoma, for which curative treatment requires combined local and systemic therapy. For definitive therapy, limb-salvage surgery is preferable over amputation, but amputation may be an option for younger patients with lesions of the fibula, tibia, and foot. Based on the available data, postoperative RT is probably of benefit for all patients with Ewing sarcoma with close margins and/or those with a poor histologic response. 5 Further discussion of Ewing sarcoma management is beyond the scope of this article (see the second and fifth articles in this supplement).
For osteosarcoma, the current standard of care is surgical resection combined with neoadjuvant and adjuvant chemotherapy. RT had been used years ago, prior to the advent of effective chemotherapy regimens, but its use for osteosarcoma has now been relegated to a few select situations. These include lesions not amenable to surgical resection and reconstruction, cases in which the patient refuses surgery, cases where there are positive margins after resection, and cases where palliation is needed for symptomatic lesions.
SOFT-TISSUE SARCOMAS: RADIATION HAS A CLEAR ADJUVANT ROLE
The primary management of localized soft-tissue sarcomas is surgical resection to achieve a negative margin when feasible. Historically, local excision of soft-tissue sarcomas resulted in local failure rates of 50% to 70%, even when a margin of normal tissue around the tumor was excised. As a result, amputation became standard treatment. 6 In a landmark National Cancer Institute study 3 decades ago, patients were randomized to amputation or to limb-sparing surgery with the addition of RT. 7 Notably, disease-free and overall survival were not compromised by limb-sparing surgery plus RT, demonstrating that although lesser surgery in the absence of RT may be insufficient, limb-sparing surgery with RT was equal to amputation. Consequently, limb-sparing approaches have become the favored surgery for the majority of cases of soft-tissue sarcoma, as advocated in a consensus statement from the National Institutes of Health. 1
Indications vary by lesion grade
In general, adjuvant RT is recommended for all intermediate- and high-grade soft-tissue sarcoma lesions. A potential exception is a superficial tumor smaller than 5 cm with widely negative margins after resection. For low-grade lesions, re-excision is favored over adjuvant RT for positive or close margins, and RT is avoided in the setting of negative margins.