Preoperative vs Postoperative IMRT for Extremity/Truncal STS

Perioperative RT in addition to surgery is widely accepted as standard management for soft
tissue sarcoma (STS) of the extremity and trunk. However, controversy remains as to whether
RT should be delivered preoperatively or postoperatively. While both confer similar rates of
local control, preoperative RT leads to a decrease in late tissue morbidities such as
fibrosis, limb edema, joint stiffness and fracture as compared to postoperative RT. The
reasons for this are likely multifactorial, but are in part related to total dose delivered
(50 Gray (GY) preoperatively and 60-66 Gy postoperatively) and, based on a previous National
Cancer Institute (Canada) Phase III randomized controlled trial, the much larger volume
treated in the postoperative setting compared to that in the preoperative setting. The
optimal radiation dose used in the postoperative setting is unknown but has been developed
empirically and doses of 60-66 Gy are generally employed.However, investigators in
Norway/Sweden and France have found equivalent local control rates for patients with negative
surgical margins treated with 50 GY postoperativelyThe main concern with preoperative RT has
centered on the risk of an increased rate of delayed wound healing and major wound
complications. Although some studies suggest it may be possible to reduce the incidence of
acute wound healing complications associated with pre-operative radiation than previously
seen in the 2D RT era, this has yet to be tested in the phase III setting. IG-IMRT allows a
much higher degree of conformality and accurate delivery of dose to the tumour while sparing
surrounding normal tissue. This may allow similar rates of acute wound healing complications
for pre- and postoperative RT in the treatment of STS.

Inclusion Criteria:

1. Histologically proven soft tissue sarcoma of the extremity or trunk following review
by local reference pathologist.

2. Deemed appropriate for preoperative or postoperative radiotherapy and conservative
surgery following patient assessment by a radiation oncologist and surgical
oncologist.

3. Lesion is primary or locally recurrent. Patient may have undergone excisional biopsy
with positive margins at a referring hospital and are eligible following discussion
among the surgical oncologists and radiation oncologists that IMRT is an acceptable
treatment for that case.

4. Eastern Cooperative Oncology Group (ECOG) score 0-3

5. Patient is aged 18years or older.

6. Patient is able to provide informed consent

7. Patient is available for treatment and follow-up.

Exclusion Criteria:

1. Benign histology.

2. Prior malignancy within the previous five years or concurrent malignancy with the
exception of adequately treated basal cell carcinoma of the skin or carcinoma in-situ
of the cervix.

3. Prior radiotherapy to the target site

4. Planned chemotherapy for (neo)adjuvant treatment

5. Conservative surgery to the target site

6. Presence of regional nodal disease or unequivocal distant metastases.

7. Other major medical illness deemed to preclude safe administration of protocol
treatment or required follow-up.