Pre-operative RadiothErapy for Soft Tissue SarcOmas

This will be a phase I/II study of hypofractionation delivering five fractions (one fraction delivered every 2nd day) of 7 Gy of external beam radiotherapy over 5 fractions (one and half week period) in patients with localized STSs who are planned to receive pre-operative radiotherapy. Patients will undergo surgery 4-6 weeks after completion of RT.

Pre-treatment evaluation will be according to standard practice:

History and Physical Exam

• height,
• weight
• history (diabetes, vascular disease)

Radiology

• MRI of primary site or
• CT if MRI not tolerated
• CT chest

Quality of Life

• Musculoskeletal Tumour Society Rating Scale
• Toronto Extremity Salvage Score (TESS)

Follow-up assessment will be done as follows:

History and Physical Exam

• Acute radiation toxicity
• During RT and 2 weeks after end of RT

Acute surgical toxicity - wound assessment

• At hospital discharge,
• 2 weeks post-surgery
• 1 month post-surgery
• 3 months post-surgery
• 6 months post-surgery

Late toxicity (skin, subcutaneous, bone, joint) & peripheral limb edema

• Every 6 months thereafter

Radiology

• Chest CT-scan
• Within 1 month pre-surgery
• Standard thereafter

MRI or CT scan of primary site

• Prior to surgery, as standard
• Every 3-6 months or as needed after surgery

Quality of life Questionnaires

• Toronto Extremity Salvage Score (TESS
• Musclo Tumor Rating Scale (MSTS)
• At months 1,3,6, 12, 18 and 24 after surgery.
• Yearly thereafter up to 5 years

Inclusion criteria

• Histologically proven STS of the extremities, above the knee, or trunk following review by our pathologist

• Lesions smaller than 15cm in largest dimension
• Deemed appropriate for preoperative radiotherapy and conservative surgery following patient assessment by a radiation oncologist and surgical oncologist
• Lesion is primary or locally recurrent. Patients who underwent unplanned non-oncological excision ("whoops" procedure) at a referring hospital are NOT eligible
• No previous radiation therapy
• ECOG 0-2 (or Karnofsky Performance Status ≥ 70) within 60 days prior to registration
• Resectable primary lesion with or without distant metastasis
• Age ≥ 18
• Patient must be able to provide study-specific informed consent prior to study entry
• Patient is available for treatment and follow-up

Exclusion criteria

• Patients who underwent unplanned non-oncological excision ("whoops" procedure) at a referring hospital

• Lesions below the knee
• Prior or concurrent invasive malignancy (except non-melanomatous skin cancer) or lymphomatous/hematogenous malignancy, unless continually disease free for a minimum of 5 years
• Regional lymph node involvement
• Previous irradiation to the area to be treated
• Other major medical illness deemed to preclude safe administration of protocol treatment or required follow-up