Soft tissue sarcoma and radiation therapy advances, impact on toxicity

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Adjuvant radiotherapy for soft tissue sarcoma (STS) has evolved since the 1970s, with trials characterizing pre-operative and post-operative treatment toxicities.
• Technological advancements like intensity-modulated radiation therapy (IMRT) and image-guided radiotherapy (IGRT) have improved precision, reducing normal tissue irradiation and long-term toxicities.

Purpose of the Study:

• To review the evolving role and optimal application of radiotherapy in managing soft tissue sarcoma (STS).
• To compare the toxicity profiles of pre-operative versus post-operative radiotherapy for STS, particularly in extremity and retroperitoneal locations.
• To emphasize the importance of multidisciplinary care and clinical trial participation for STS patients.

Main Methods:

• Review of clinical trials and technological advancements in radiotherapy for STS.
• Comparison of toxicity outcomes between pre-operative and post-operative radiotherapy strategies.
• Discussion of current international phase III trials (PAZNTIS and STRASS) evaluating novel therapeutic combinations and radiotherapy timing.

Main Results:

• Modern IMRT-IGRT techniques significantly reduce acute and long-term radiation-related toxicities in extremity STS.
• Pre-operative IMRT-IGRT for extremity STS is associated with better target delineation and spares patients from chronic side effects like bone fracture, fibrosis, and joint stiffness.
• Post-operative radiotherapy for retroperitoneal STS carries a high risk of severe to fatal toxicities due to the proximity of radiosensitive organs to the surgical cavity.

Conclusions:

• Pre-operative radiotherapy, especially IMRT-IGRT, is the preferred approach for extremity STS due to a more favorable toxicity profile and preservation of limb function.
• For retroperitoneal STS, pre-operative radiotherapy is recommended over post-operative due to significantly reduced risks of severe complications.
• Multidisciplinary management at specialized centers and participation in ongoing clinical trials are crucial for optimizing STS treatment outcomes.