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.

Primary Outcome Measures

1. Incidence of acute wound healing complications
   * Secondary operations required for wound treatment (debridement, secondary closure procedures such as rotationplasty, free flaps or skin grafts); * Readmission to hospital for wound care; * Invasive procedures required for wound care (drainage of hematoma, seroma or infected wound collection); * Deep wound packing required at any time (deep packing defined as packing deep to dermis in an area of dehisced wound) to an area of the wound measuring at least 2 cm in length; * Prolonged dressing changes, including packing of the wound for greater than six weeks from wound breakdown; * Repeat surgery for revision of a split thickness skin graft or requirement for wet dressings for longer than four weeks. (It is permissible for a patient to protect a totally epithelialized skin graft with a dry dressing without declaring a major wound complication) * Use of vacuum-assisted closure (VAC)

Secondary Outcome Measures

1. Acute Radiation Toxicity
   Acute radiation skin toxicity will be documented according to the Radiotherapy Oncology Group (RTOG) Acute Radiation Morbidity Scoring Criteria.
2. Late Radiation Toxicity- RTOG Late Radiation Morbidity
   Late radiation morbidity to skin, subcutaneous tissue, bone and joints will be documented according to the RTOG/EORTC Late Radiation Morbidity Scoring Scheme.
3. Late Radiation Toxicity- Common Toxicity Criteria
   Late radiation morbidity to skin, subcutaneous tissue, bone and joints will be documented according to the Common Toxicity Criteria v4.0
4. Late Radiation Toxicity- Limb Edema
   Peripheral limb edema will be documented according to the Late Limb Edema Scoring Criteria.
5. Limb Function
   Limb function will be documented according to the Musculoskeletal Tumor Society Rating Scale.
6. Patient function
   Patient function will be documented according to the patient completed Toronto Extremity Salvage Score (TESS)
7. Overall Survival
   Overall patient survival in months during the study period
8. Local recurrence-free survival
   Patient survival without a local recurrence in months during the study period.
9. Metastasis-free survival
   Patient survival without systemic metastases in months during the study period.