First Experience of Intra-Operative Radiation Therapy (IORT) during Kyphoplasty in Patients Diagnosed with Spinal Metastasis in Iran

Research Article

Austin J Clin Case Rep. 2021; 8(4): 1208.

First Experience of Intra-Operative Radiation Therapy (IORT) during Kyphoplasty in Patients Diagnosed with Spinal Metastasis in Iran

Seddighi AS1, Nikouei A2, Seddighi A1*, Akbari ME3, Arjmand Y2, Ommi D4, Zali A5 and Hosseini M2

1Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

2GP Member of Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

3Cancer Research Center, Shohada Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

4Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

5Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

*Corresponding author: Afsoun Seddighi, Associate Prof of Neurosurgery. Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Received: April 22, 2021; Accepted: May 13, 2021; Published: May 20, 2021

Abstract

Object: Based on previous studies, 30 to 40% of cancer patients are diagnosed with bone metastasis. Median Overall Survival (OS) of patients who are diagnosed with spinal metastasis (vertebral structures) is about 7 to 9 months which with recent progresses in oncologic and radiotherapy treatment modalities, their prognosis is slightly developed. In this study, authors plan to evaluate the effects of Intra-operative Radiation Therapy (IORT) in patients who are candidate for Kyphoplasty procedure.

Methods: In this study, we have included patients who are diagnosed with spinal metastasis with radiological and histopathological confirmation. From July 2017 to December 2018, we have included 9 patients who fulfilled our predefined inclusion and exclusion criteria into our case-series study performed on Shohada Tajrish Hospital. Patients underwent radiotherapy during Kyphoplasty by our IORT device INTRABEAM (Carl Zeiss AG, Germany) as “Kypho-IORT’ procedure. We have evaluated these patients in post-operative period, as well as on 2 weeks, 1 month, 2 months and 6 months on post-operative period as our follow-up plan.

Results: In this study, 9 patients (5 males and 4 females) with mean age of 68 years with spinal metastasis from breast (4 cases), prostate (2 cases), lung (2 cases) and gastrointestinal tract (1 case), underwent Kypho-IORT for 15 vertebrae levels with individualized radiation dose and interval. In postoperative follow-up period, patients exhibit pain relief (in 78%) assessed by Visual Assessment Score (VAS) and improvement in their Quality of Life (QoL). No major complications including new neurological deficit, major cement leak and embolic disorders were encountered during the study; however, minor cement leak encountered in 4 cases, and 2 patients have expired during follow up period; however, other patients are still alive and under follow-up with mean OS of 10 months.

Conclusion: This study is the first experience of evaluation of IORT effects during Kyphoplasty in Iran, in patients diagnosed with spinal metastasis with poor prognosis, to improve their quality of life, local control rate and their OS. This study could be considered as one of the pioneers in continuing the evaluation of Kypho-IORT as a novel technique in these group of patients.

Keywords: Intra-operative radiation therapy; Kyphoplasty; Overall survival; Kypho-IORT

Introduction

In general, 30 to 40% of patients diagnosed with cancer, somehow develop bone metastasis in later stages [1]. Among these metastasis, more than half of them occur in spine, mostly in thoracic spine from T4 to T7 in 70% of the cases, followed by lumbar and cervical spine with 20 and 10% respectively [2]. Common complications of spinal metastasis include central axis pain, pathologic fractures and neurologic disorders secondary to spinal cord compression. Although the overall survival rate of these patients is reported to be from 7 to 9 months, application of optimal oncologic therapeutic procedures has improved the mentioned value in recent years [3]. Therefore, utilization of advanced therapeutic regiments for patients suffered from bony metastasis is essential to enhance their quality of life. In recent years, Oncologists have suggested employment of Radiotherapy (RT) adjacent to chemotherapy regiments for better bony metastasis control [4]. At first, External Beam Radiotherapy (EBRT) was one the most effective procedures in management of patients with spinal metastasis, ranging from 8 to 40 Gray (Gy), in 1 to 20 units, respectively [5]. Also, EBRT was reported to be effective in pain alleviation just few days following its application in enrolled patients [6].

However, due to medium 6-month period required for repeated calcium deposition in spinal column bones, patients were always faced fracture risk in mentioned interval; thus, surgical interventions such as vertebral augmentation is justified to preserve an adequate stability. Since justification of post-operative RT for prevention of early regrowth of malignant tissues, application of RT in 2nd to 4th postoperative period is suggested [7]. Existing evidence suggest promising reports of spine Stereotactic Body Radiotherapy (SBRT) with splitdose from 1 to 5 units to reduce treatment period, remarkable local control and pain control equivalent or even superior to EBRT [8].

Another technology for cancer control in the scope of RT is intraoperative radiotherapy (IORT) which consists of focused radiation to tumor bed intra-operatively. IORT is capable of delivering high amounts of radiation dosages to the tumor’s bed in a precise manner, sparing healthy tissue from excessive radiation [9]. Commonly, IORT is used coupled with other therapeutic modalities, such as various surgical techniques to achieve maximum tumor resection, EBRT and chemotherapy as a part of multidisciplinary approach [10]. Until now, no definite method is proven to increase their life expectancy and all of the studies and trials, exhibited variable results. Experts aim to control pain and maintain patient’s functionality in different aspects. Between among all suggested therapeutic approaches, RT remains the principal management approach in these patients. Authors aim to discuss their first experience of spinal IORT in Iran.

Materials and Methods

This study is a clinical trial with aim to evaluate the effect of addition of IORT technique to kyphoplasty procedure in patients diagnosed with spinal metastasis. Demographic data of patients collected and documented by observation and interview, as well as their underlying diseases. Also, intervention techniques through direct observation of operation field and radiation were documented. Patients with age range of 18 to 80 years with spinal metastasis which was confirmed by radiological and histopathological evaluations who were kyphoplasty candidates were included in the study. Our exclusion criteria were previous history of IORT to the same involved location, presence of primary bone tumors or neural tissue tumors of spine (extradural, intra-dural, extra-medullary and intra-medullary), presence of any local soft tissue infection or systemic infection leading to patient deterioration, presence of underlying anatomic disorder of spinal column which results in inability to maintain IORT applicators in desired place, previous history of spinal column fractures or osteoporosis in spinal column (defined as T-score less than -2.5), hazardous anesthesia induction and patient’s failure to give consent based on provisions of World Medical Association Declaration of Helsinki in 1964. After effective act of our defined inclusion and exclusion criteria, 9 patients who suffered from underlying cancer with spinal metastasis and candidate for kyphoplasty surgical procedure were enrolled to neurosurgical department of Shohada Tajrish hospital from July 2017 to December 2019. At admission, pain assessment was performed using Visual Assessment Score (VAS). Also, performance ability of these patients were evaluated and documented by Karnofsky Performance Score (KPS) and Oswestry Disability Index (ODI). Intervention consist of RT with INTRABEAM (Carl Zeiss AG, Germany) with needle applicator, with consult of radio-oncologists during kyphoplasty operation with both closed and open methods. Alongside mentioned factors, authors introduced complementary variables including sex, bone mineral density, patient’s chief complaint, tumor to surface distance, histopathological examination, metastasis number, vertebral body involvement, vertebral instability, lesion type (lytic or blastic), duration of underlying cancer, extra-vertebral involved viscera, duration of metastasis spread to vertebrae, kyphoplasty type (open or closed), anesthesia type, beam illumination type (one sided or two sided), radiation duration, total radiation dosage, American Society of Anesthesiologists (ASA) score, post-operative complications, post-intervention cancer progress, post-intervention vertebral deformity, focal neurologic deficit at 2nd post-operative month, depth dose measurement, dosage homogeneity and applicator distance to tumor’s core. Patients were scheduled to be evaluated at 2nd postoperative week, along with 1st, 2nd and 6th post-operative month for neurological assessment and investigation of possible complications and radiological surveys.

Results

Nine patients, including 5 males and 4 females, with mean age of 68 years with confirmed diagnosis of spinal metastasis entered in study. From these patients, 4 cases were found that their metastasis have spread from breast cancer, followed by 2 from prostate cancer, 2 from lung cancer and one patient from his gastrointestinal malignancy. Pre-operative details of our patients based on the included variables are summarized in Table 1.