Neoadjuvant Radiotherapy for Soft Tissue Sarcoma
Volume 9- Issue 1
Sam Hajialiloo Sami1, Azra Izanloo2, Arefpoor Amir Mohamad3 and Mirkazemi Masoud*1
1Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, IR Iran
2Razavi Cancer Research Center, Razavi Hospital, Imam Reza International University, Mashhad, Iran
3Firrozgar Hospital, Iran University of Medical Sciences, Iran
Received: September 08, 2018; Published: September 18, 2018
*Corresponding author: Masoud Mirkazemi, Bone and Joint Reconstruction Research Centre, Shafa Orthopaedic Hospital, Iran University of Medical Sciences, Tehran, Iran
Soft Tissue Sarcoma (STS) is a rare neoplasm that accounts for 1% of all solid tumors in adults. In 2013, 11410 new cases were diagnosed in adults and children in the United States with 4,390 expected deaths [1]. In more than 50 to 60% of the cases, limbs are involved and it can have more than 50 histological subtypes
[2] . These tumors are invasive and their metastasis risk is high
[3] . Today, the treatment of sarcomas often includes a combination of surgery, radiotherapy and chemotherapy [3]. However, there are extensive disputes and challenges regarding the use of chemotherapy and radiotherapy in these patients. Some studies have adopted optional chemotherapy treatment as an adjunct to increase the chance of preserving a limb, but the use of this method has not had a significant effect on overall survival [4].
Other studies have suggested that in patients for whom the tumor cannot be removed completely by surgery, to increase the chance oftumor necrosis considering its high survival, a neoadjuvant chemotherapy treatment with hypofractionated radiotherapy or in some cases adjuvant chemotherapy, depending on the living cells, has been recommended. These methods have been able to improve patient complications and induce a pathologic response [4]. Various protocols have been proposed for radiotherapy of these patients. Radiation protocol is in form of external preoperative radiation therapy and postoperative external radiation therapy or brachy therapy. Each strategy is intended to obtain maximum local control by maintaining limb function [5,6].
In most centres, external radiation therapy is used postoperatively, as it does not require postponing surgery and eliminates the residual disease after surgery. In addition, the pathology sample and surgical margins will be at the disposal of the pathologist for detailed examination [7,8]. This method provides the best local control, but since target therapy is not specifically defined, the treatment should be administered with higher dose and greater volume, which leads to physical disability and reduced quality of life [9]. Other morbidities of this treatment includes complications of surgical ulcers and delayed problems such as subcutaneous tissue fibrosis, edema, joint dryness and bone damages like osteoarthritis and fractures [10-12].
For the above reasons, preoperative radiotherapy have received great amount of attention as a new therapeutic approach [13]. In this technique, since the volume of treatment is specified, the field size is contracted [14]. Contrary to postoperative radiotherapy, this technique does not damage the hematopoietic network and since the percentage of hypoxic cells in the tumor margin is lower, it requires a smaller dose of radiation therapy and is therefore associated with improved functional outcomes [15]. Overall, it has been shown that neoadjuvant radiotherapy has a high R0 resection rate for STS patients undergoing surgical resection, and negative surgical margin and pre-or post-operation of RT can improve the overall survival. However, further studies are needed to examine and determine its actual effects.