Session Item

Patients with high-grade sarcoma of the extremities are treated with either pre-or postoperative radiation therapy. In Aarhus, Denmark, postoperative radiotherapy has been the standard practice delivering doses between 60 -66 Gy to the tumour bed. Few studies have investigated the long-term morbidities in these patients. Moreover, there is no consensus on what constitute organs at risk (OAR) in an extremity or how they should be delineated. This abstract describes the initial results from a large retrospective study investigating the correlation between the dose to a set of defined OAR in extremities and the development of late effects such as pain or impaired function of the irradiated extremity. 

This is a retrospective cohort study of patients treated with postoperative radiation therapy from 2009 to 2014. Patients were followed for at least five years. A comprehensive delineation was made for each patient, including the adjacent joint, muscle compartment, skin, bone, and neurovascular bundle. The Spearman correlation coefficient (rho) was used to evaluate the association between the mean dose to the structures and imparted function and pain development. The degree of pain was categorized into no pain; mild pain, no need for analgesics; moderate pain with occasional analgesics; and more severe pain with regular analgesic use. The functionality was categorized into no movement restriction, mild movement restrictions, moderate restriction affecting everyday life, severe restriction.

A total of 65 patients who underwent radical surgery and postoperative radiation therapy for an extremity sarcoma were evaluated. The pain was evaluated prospectively in 45 of these patients, and 27 patients (60%) developed some degrees of pain. Most of these patients were treated with a tumour located at the thigh (17/27). For tumours located close to the hip joint,  the higher the mean dose to the circumference of the extremity (structure cropped with 1 cm to the body outline), the more chronic pain in the lower extremity was experienced  (rho = 0.77 p< 0.001). This was not true for the upper extremities. Regardless of location, there was no association between the development of pain and the dose to the nearby joints (rho=0.18, p=0.26). The functionality was not affected with a higher dose to the circumference. However, the ability to walk was associated with the mean dose to the muscles for lower limb tumours close to the hip (rho 0.45, p=0.051). There was no association between the degree of fibrosis and functionality of the extremity.

The degree of chronic pain among sarcoma patients treated with postoperative radiation therapy is associated with the mean dose to the circumference of the lower extremities.