Malignant epidural spinal cord compression: the role of external beam radiotherapy

Stereotactic Body Radiation Therapy for Spinal Metastases: Benefits and Limitations

Progress in biological cancer characterization, targeted systemic therapies and multimodality treatment strategies have shifted the goals of radiotherapy for spinal metastases from short-term palliation to long-term symptom control and prevention of compilations. This article gives an overview of the spine stereotactic body radiotherapy (SBRT) methodology and clinical results of SBRT in cancer patients with painful vertebral metastases, metastatic spinal cord compression, oligometastatic disease and in a reirradiation situation. Outcomes after dose-intensified SBRT are compared with results of conventional radiotherapy and patient selection criteria will be discussed. Though rates of severe toxicity after spinal SBRT are low, strategies to minimize the risk of vertebral compression fracture, radiation induced myelopathy, plexopathy and myositis are summarized, to optimize the use of SBRT in multidisciplinary management of vertebral metastases.

From active shape model to active optical flow model: a shape-based approach to predicting voxel-level dose distributions in spine SBRT

Prediction of achievable dose distribution in spine stereotactic body radiation therapy (SBRT) can help in designing high-quality treatment plans to maximally protect spinal cords and to effectively control tumours. Dose distributions at spinal cords are primarily affected by the shapes of adjacent planning target volume (PTV) contours. In this work, we estimate such contour effects and predict dose distributions by exploring active optical flow model (AOFM) and active shape model (ASM). We first collect a sequence of dose sub-images and PTV contours near spinal cords from fifteen SBRT plans in the training dataset. The data collection is then classified into five groups according to the PTV locations in relation to spinal cords. In each group, we randomly choose a dose sub-image as the reference and register all other sub-images to the reference using an optical flow method. AOFM is then constructed by importing optical flow vectors and dose values into the principal component analysis (PCA). Similarly, we build ASM by using PCA on PTV contour points. The correlation between ASM and AOFM is estimated via a stepwise multiple regression model. When predicting dose distribution of a new case, the group is first determined based on the PTV contour. The prediction model of the selected group is used to estimate dose distributions by mapping the PTV contours from the ASM space to the AOFM space. This method was validated on fifteen SBRT plans in the testing dataset. Analysis of dose-volume histograms revealed that the important D2%, D5%, D10% and D0.1cc dosimetric parameters of spinal cords between the prediction and the clinical plans were 11.7 ± 1.7 Gy versus 11.8 ± 1.7 Gy (p = 0.95), 10.9 ± 1.7 Gy versus 11.1 ± 1.9 Gy (p = 0.8295), 10.2 ± 1.6 Gy versus 10.1 ± 1.7 (p = 0.9036) and 11.2 ± 2.0 Gy versus 11.1 ± 2.2 Gy (p = 0.5208), respectively. Here, the ‘cord’ is the spinal cord proper (not the thecal sac) extended 5 mm inferior and superior to the involved vertebral bodies, and the ‘PTV’ is the involved segment of the vertebral body expanded uniformly by 2 mm but excluding the spinal cord volume expanded by 2 mm (Ref. RTOG 0631). These results suggested that the AOFM-based approach is a promising tool for predicting accurate spinal cord dose in clinical practice. In this work, we demonstrated the feasibility of using AOFM and ASM models derived from previously treated patients to estimate the achievable dose distributions for new patients.

Comparison of Short-Course Radiotherapy Versus Long-Course Radiotherapy for Treatment of Metastatic Spinal Cord Compression: A Systematic Review and Meta-Analysis

In this study, we evaluate the efficacy of short-course radiotherapy (SCRT) versus long-course radiotherapy (LCRT) in the treatment of metastatic spinal cord compression (MSCC).PubMed, EMBASE, and Web of Science were searched up to April 2015. Relevant data were extracted based on inclusion and exclusion criteria. Methodological quality of randomized controlled trial (RCT) was evaluated using modified Jadad scale; non-RCT was evaluated using Newcastle-Ottawa Scale. Meta-analysis was performed using RevMan 5.3 software.Fourteen studies with 2239 patients were included. Results of meta-analysis showed that there were no significant differences between SCRT and long-course radiotherapy LCRT in 6-month overall survival rate (risk ratio [RR] = 0.97, 95% confidence interval [CI] 0.88, 1.07, P = 0.55), 1-year overall survival rate (RR = 0.94, 95% CI 0.85, 1.04, P = 0.22), motor function improvement (RR = 0.96, 95% CI 0.81, 1.13, P = 0.63), no change on motor function (RR = 0.98, 95% CI (0.88, 1.09), P = 0.74], and deterioration on motor function (RR = 0.96, 95% CI 0.71, 1.31, P = 0.78). Compared with SCRT, LCRT significantly increased 6-month local control rate (RR = 0.87, 95% CI 0.80, 0.95, P = 0.002), 1-year local control rate (RR = 0.83, 95% CI 0.71, 0.97, P = 0.02), and 2-year local control rate (RR = 0.83, 95% CI 0.79, 0.87, P < 0.00001).Both LCRT and SCRT provided similar survival rates and functional outcome, but LCRT showed better local control rates than SCRT. However, considering low cost and good patient's compliance, SCRT may be a better choice.

Interventions for the treatment of metastatic extradural spinal cord compression in adults

BACKGROUND

Metastatic extradural spinal cord compression (MESCC) is treated with radiotherapy, corticosteroids, and surgery, but there is uncertainty regarding their comparative effects. This is an updated version of the original Cochrane review published in theCochrane Database of Systematic Reviews (Issue 4, 2008).

OBJECTIVES

To determine the efficacy and safety of radiotherapy, surgery and corticosteroids in MESCC.

SEARCH METHODS

In March 2015, we updated previous searches (July 2008 and December 2013) of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, LILACS, CANCERLIT, clinical trials registries, conference proceedings, and references, without language restrictions. We also contacted experts for relevant published, unpublished and ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of radiotherapy, surgery and corticosteroids in adults with MESCC.

DATA COLLECTION AND ANALYSIS

Three authors independently screened and selected trials, assessed risk of bias, and extracted data. We sought clarifications from trial authors. Where possible, we pooled relative risks with their 95% confidence intervals, using a random effects model if heterogeneity was significant. We assessed overall evidence-quality using the GRADE approach.

MAIN RESULTS

This update includes seven trials involving 876 (723 evaluable) adult participants (19 to 87 years) in high-income countries. Most were free of the risk of bias. Different radiotherapy doses and schedulesTwo equivalence trials in people with MESCC and a poor prognosis evaluated different radiotherapy doses and schedules. In one, a single dose (8 Gray (Gy)) of radiotherapy (RT) was as effective as short-course RT (16 Gy in two fractions over one week) in enhancing ambulation in the short term (65% versus 69%; risk ratio (RR) was 0.93, (95% confidence interval (CI) 0.82 to 1.04); 303 participants; moderate quality evidence). The regimens were also equally effective in reducing analgesic and narcotic use (34% versus 40%; RR 0.85, 95% CI 0.62 to 1.16; 271 participants), and in maintaining urinary continence (90% versus 87%; RR 1.03, 95% CI 0.96 to 1.1; 303 participants) in the short term (moderate quality evidence). In the other trial, split-course RT (30 Gy in eight fractions over two weeks) was no different from short-course RT in enhancing ambulation (70% versus 68%; RR 1.02, 95% CI 0.9 to 1.15; 276 participants); reducing analgesic and narcotic use (49% versus 38%; RR 1.27, 95% CI 0.96 to 1.67; 262 participants); and in maintaining urinary continence (87% versus 90%; RR 0.97, 0.93 to 1.02; 275 participants) in the short term (moderate quality evidence). Median survival was similar with the three RT regimens (four months). Local tumour recurrence may be more common with single-dose compared to short-course RT (6% versus 3%; RR 2.21, 95% CI 0.69 to 7.01; 303 participants) and with short-course compared to split-course RT (4% versus 0%; RR 0.1, 95% CI 0.01 to 1.72; 276 participants), but these differences were not statistically significant (low quality evidence). Gastrointestinal adverse effects were infrequent with the three RT regimens (moderate quality evidence), and serious adverse events or post-radiotherapy myelopathy were not noted.We did not find trials comparing radiotherapy schedules in people with MESCC and a good prognosis. Surgery plus radiotherapy compared to radiotherapyLaminectomy plus RT offered no advantage over RT in one small trial with 29 participants (very low quality evidence). In another trial that was stopped early for apparent benefit, decompressive surgery plus RT resulted in better ambulatory rates (84% versus 57%; RR 1.48, 95% CI 1.16 to 1.90; 101 participants, low quality evidence). Narcotic use may also be lower, and bladder control may also be maintained longer than with than RT in selected patients (low quality evidence). Median survival was longer after surgery (126 days versus 100 days), but the proportions surviving at one month (94% versus 86%; RR 1.09, 95% CI 0.96 to 1.24; 101 participants) did not differ significantly (low quality evidence). Serious adverse events were not noted. Significant benefits with surgery occurred only in people younger than 65 years. High dose corticosteroids compared to moderate dose or no corticosteroidsData from three small trials suggest that high-dose steroids may not differ from moderate-dose or no corticosteroids in enhancing ambulation (60% versus 55%; RR 1.08, 95% CI 0.81 to 1.45; 3 RCTs, 105 participants); survival over two years (11% versus 10%; RR 1.11, 95% CI 0.24 to 5.05; 1 RCT, 57 participants); pain reduction (78% versus 91%; RR 0.86, 95% CI 0.62 to 1.20; 1 RCT, 25 participants); or urinary continence (63% versus 53%; RR 1.18, 95% CI 0.66 to 2.13; 1 RCT, 34 participants; low quality evidence). Serious adverse effects were more frequent with high-dose corticosteroids (17% versus 0%; RR 8.02, 95% CI 1.03 to 62.37; 2 RCTs, 77 participants; moderate quality evidence).None of the trials reported satisfaction with care or quality of life in participants.

AUTHORS' CONCLUSIONS

Based on current evidence, ambulant adults with MESCC with stable spines and predicted survival of less than six months will probably benefit as much from one dose of radiation (8 Gy) as from two doses (16 Gy) or eight doses (30 Gy). We are unsure if a single dose is as effective as two or more doses in preventing local tumour recurrence. Laminectomy preceding radiotherapy may offer no benefits over radiotherapy alone. Decompressive surgery followed by radiotherapy may benefit ambulant and non-ambulant adults younger than 65 years of age, with poor prognostic factors for radiotherapy, a single area of compression, paraplegia for less than 48 hours, and a predicted survival of more than six months. We are uncertain whether high doses of corticosteroids offer any benefits over moderate doses or indeed no corticosteroids; but high-dose steroids probably significantly increases the risk of serious adverse effects. Early detection; and treatment based on neurological status, age and estimated survival, are crucial with all treatment modalities. Most of the evidence was of low quality. High-quality evidence from more trials is needed to clarify current uncertainties, and some studies are in progress.

Stereotactic body radiotherapy: a new paradigm in the management of spinal metastases

Spine stereotactic body radiotherapy is based on delivering high biologically effective doses to spinal metastases, with the intent to maximize both tumor and pain control. The purpose of this review is to outline the technical details of spine stereotactic body radiotherapy, contrast clinical outcomes to low biologically effective dose conventional palliative radiotherapy, discuss the role of surgery in the era of spine stereotactic body radiotherapy, and summarize the major serious adverse events that patients would otherwise not be at risk of with conventional radiotherapy.

Use of single- versus multiple-fraction palliative radiation therapy for bone metastases: population-based analysis of 16,898 courses in a Canadian province

PURPOSE

There is abundant evidence that a single fraction (SF) of palliative radiation therapy (RT) for bone metastases is equivalent to more protracted and costly multiple fraction courses. Despite this, there is low utilization of SFRT internationally. We sought to determine the utilization of SFRT in a population-based, publicly funded health care system.

METHODS AND MATERIALS

All consecutive patients with bone metastases treated with RT during 2007 to 2011 in British Columbia (BC) were identified. Associations between utilization of SFRT and patient and provider characteristics were investigated.

RESULTS

A total of 16,898 courses of RT were delivered to 8601 patients. SFRT was prescribed 49% of the time. There were positive relationships among SFRT utilization and primary tumor group (P<.001; most commonly in prostate cancer), worse prognosis (P<.001), increasing physician experience (P<.001), site of metastases (P<.001; least for spine metastases), and area of training (P<.001; most commonly for oncologists trained in the United Kingdom). There was wide variation in the prescription of SFRT across 5 regional cancer centers, ranging from 25.5% to 73.4%, which persisted after controlling for other, potentially confounding factors (P<.001).

CONCLUSIONS

The large variability in SFRT utilization across BC Cancer Agency (BCCA) cancer centers suggests there is a strong cultural effect, where physicians' use of SFRT is influenced by their colleagues' practice. SFRT use in BC was similar to that in other Canadian and western European reports but strikingly higher than in the United States. Further work is needed to standardize SFRT prescribing practices internationally for this common indication for RT, with the potential for huge health system cost savings and substantial improvements in patients' quality of life.

Gradual Recovery from Nonambulatory Quadriparesis Caused by Metastatic Epidural Cervical Cord Compression in an Octogenarian Gallbladder Carcinoma Patient Treated with Image-Guided Three-Dimensional Conformal Radiotherapy Alone Using a Field-in-Field Technique

Radiotherapy for acute metastatic epidural spinal cord compression (MESCC) involves conventional techniques and dose fractionation schemes, as it needs to be initiated quickly. However, even with rapid intervention, few paraplegic patients regain ambulation. Here, we describe the case of a mid-octogenarian who presented with severe pain and nonambulatory quadriparesis attributable to MESCC at the fifth cervical vertebra, which developed 10 months after the diagnosis of undifferentiated carcinoma of the gallbladder. Image-guided three-dimensional conformal radiotherapy (IG-3DCRT) was started with 25 Gy in 5 fractions followed by a boost of 12 Gy in 3 fractions, for which a field-in-field (FIF) technique was used to optimize the dose distribution. Despite the fact that steroids were not administered, the patient reported significant pain reduction and showed improved motor function 3 and 4 weeks after the IG-3DCRT, respectively. Over the following 4 months, her neurological function gradually improved, and she was consequently able to eat and change clothes without assistance and to walk slowly for 10–20 m using a walker. She succumbed to progression of abdominal disease 8.5 months after the IG-3DCRT. This case demonstrates that image-guided FIF radiotherapy with a dose-escalated hypofractionated regimen can potentially improve functional outcome and local control.

Prevention and Treatment of Bone Metastases in Breast Cancer

In breast cancer patients, bone is the most common site of metastases. Medical therapies are the basic therapy to prevent distant metastases and recurrence and to cure them. Radiotherapy has a primary role in pain relief, recalcification and stabilization of the bone, as well as the reduction of the risk of complications (e.g., bone fractures, spinal cord compression). Bisphosphonates, as potent inhibitors of osteoclastic-mediated bone resorption are a well-established, standard-of-care treatment option to reduce the frequency, severity and time of onset of the skeletal related events in breast cancer patients with bone metastases. Moreover bisphosphonates prevent cancer treatment-induced bone loss. Recent data shows the anti-tumor activity of bisphosphonates, in particular, in postmenopausal women and in older premenopausal women with hormone-sensitive disease treated with ovarian suppression. Pain is the most frequent symptom reported in patients with bone metastases, and its prevention and treatment must be considered at any stage of the disease. The prevention and treatment of bone metastases in breast cancer must consider an integrated multidisciplinary approach.