Magnetic resonance imaging assessment of spinal cord and cauda equina motion in supine patients with spinal metastases planned for spine stereotactic body radiation therapy

PURPOSE

To assess motion of the spinal cord and cauda equina, which are critical neural tissues (CNT), which is important when evaluating the planning organ-at-risk margin required for stereotactic body radiation therapy.

METHODS AND MATERIALS

We analyzed CNT motion in 65 patients with spinal metastases (11 cervical, 39 thoracic, and 24 lumbar spinal segments) in the supine position using dynamic axial and sagittal magnetic resonance imaging (dMRI, 3T Verio, Siemens) over a 137-second interval. Motion was segregated according to physiologic cardiorespiratory oscillatory motion (characterized by the average root mean square deviation) and random bulk shifts associated with gross patient motion (characterized by the range). Displacement was evaluated in the anteroposterior (AP), lateral (LR), and superior-inferior (SI) directions by use of a correlation coefficient template matching algorithm, with quantification of random motion measure error over 3 separate trials. Statistical significance was defined according to P<.05.

RESULTS

In the AP, LR, and SI directions, significant oscillatory motion was observed in 39.2%, 35.1%, and 10.8% of spinal segments, respectively, and significant bulk motions in all cases. The median oscillatory CNT motions in the AP, LR, and SI directions were 0.16 mm, 0.17 mm, and 0.44 mm, respectively, and the maximal statistically significant oscillatory motions were 0.39 mm, 0.41 mm, and 0.77 mm, respectively. The median bulk displacements in the AP, LR, and SI directions were 0.51 mm, 0.59 mm, and 0.66 mm, and the maximal statistically significant displacements were 2.21 mm, 2.87 mm, and 3.90 mm, respectively. In the AP, LR, and SI directions, bulk displacements were greater than 1.5 mm in 5.4%, 9.0%, and 14.9% of spinal segments, respectively. No significant differences in axial motion were observed according to cord level or cauda equina.

CONCLUSIONS

Oscillatory CNT motion was observed to be relatively minor. Our results support the importance of controlling bulk patient motion and the practice of applying a planning organ-at-risk margin.

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.

Prophylactic dexamethasone effectively reduces the incidence of pain flare following spine stereotactic body radiotherapy (SBRT): a prospective observational study

PURPOSE

The purpose of this study was to determine the incidence of pain flare (PF) in patients receiving spine stereotactic body radiotherapy (SBRT) treated with prophylactic oral dexamethasone (DEX) 1 h before and for 4 days following SBRT.

METHODS

Forty-seven patients were accrued on this prospective observational study. The first cohort of 24 patients was treated with 4 mg, while a second cohort of 23 patients treated with 8 mg of DEX. The Brief Pain Inventory (BPI) was used to score pain and functional interference each day during SBRT and for 10 days following. Comparisons between the 4 and 8 mg cohorts, in addition to our previously reported steroid naïve patients post SBRT (n = 41), were also performed.

RESULTS

The total incidence of PF was 19 % (9/47). The incidence in the 4 and 8 mg cohorts was 25 % (6/24) and 13 % (3/23), respectively, and the difference was not statistically significant (p = 0.46). Comparing functional interference, the 4 mg cohort had better profile in walking ability (p < 0.005) and relationships with others (p < 0.035) compared to the 8 mg cohort. Compared to our previously reported steroid naïve cohort, prophylactic DEX significantly reduced the incidence of PF (68 vs. 19 %, p < 0.0001, respectively), patients had lower worst pain scores, and improved general activity interference outcome.

CONCLUSION

We recommend prophylactic DEX for patients treated with spine SBRT. Our current practice is based on the 4 mg protocol primarily due to the improved functional interference outcomes. A randomized trial is required to finalize the optimal regimen and schedule.

Risk of vertebral compression fracture specific to osteolytic renal cell carcinoma spinal metastases after stereotactic body radiotherapy: A multi-institutional study

PURPOSE

Determine the risk of vertebral compression fracture (VCF) following stereotactic body radiotherapy (SBRT), specific to osteolytic renal cell carcinoma (RCC) spinal metastases, and associated predictive factors.

METHODS

187 RCC osteolytic spinal tumor segments in 116 patients obtained from a multi-institutional pooled database were reviewed. Each segment was evaluated according to the Spinal Instability Neoplastic Score (SINS).

RESULTS

The median follow-up was 8.0 months. 34 VCF (34/187, 18%) were observed and median time to VCF was 2.4 months. VCF was observed in 43% (10/23), 24% (4/17) and 14% (20/147) of segments treated with 24Gy/fraction (fx), 20-23Gy/fx and ≤19Gy/fx, respectively. Multivariate analysis identified dose per fx (p=0.005), baseline VCF (p<0.001) and spinal misalignment (p=0.002) as predictors of VCF. Prior conventional radiotherapy (p=0.029) was found to be protective.

CONCLUSIONS

18% of osteolytic RCC spinal metastases fractured post-SBRT. The presence of a baseline fracture, spinal mal-alignment and treatment with ≥20Gy/fx predicted for VCF.

Spine stereotactic body radiotherapy for renal cell cancer spinal metastases: analysis of outcomes and risk of vertebral compression fracture

OBJECT

The aim of this study was to evaluate local control (LC) and the risk of vertebral compression fracture (VCF) after stereotactic body radiotherapy (SBRT) in patients with renal cell cancer spinal metastases.

METHODS

Prospectively collected data on 71 spinal segments treated with SBRT in 37 patients were reviewed. The median follow-up was 12.3 months (range 1.2-55.4 months). The LC rate was assessed based on each spinal segment treated and overall survival (OS) according to each patient treated. Sixty of 71 segments (85%) were radiation naive, 11 of 71 (15%) were previously irradiated, and 10 of 71 (14%) were treated with postoperative SBRT. The median SBRT total dose and number of fractions were 24 Gy and 2, respectively. The VCF analysis also included evaluation of the Spinal Instability Neoplastic Score criteria.

RESULTS

The 1-year OS and LC rates were 64% and 83%, respectively. Multivariate analysis identified oligometastatic disease (13 of 37 patients) as a positive prognostic factor (p = 0.018) for OS. Of 61 non-postoperative spinal segments treated, 10 (16%) developed VCFs; 3 of 10 were de novo VCFs and 7 of 10 occurred as progression of an existing VCF. The 1-year VCF-free probability rate was 82%. Multivariate analysis identified single-fraction SBRT and baseline VCF as significant predictors of SBRT-induced VCF (p = 0.028 and p = 0.012, respectively).

CONCLUSIONS

Spine SBRT yields high rates of local tumor control in patients with renal cell cancer. Baseline VCF and 18-24 Gy delivered in a single fraction were predictive of further collapse. Patients with oligometastatic disease may benefit most from such aggressive local therapy, given the prolonged survival observed.

Predictive factors for local control in primary and metastatic lung tumours after four to five fraction stereotactic ablative body radiotherapy: a single institution's comprehensive experience

AIMS

We report the outcomes of a large lung stereotactic ablative body radiotherapy (SABR) programme for primary non-small cell lung cancer (NSCLC) and pulmonary metastases. The primary study aim was to identify factors predictive for local control.

MATERIALS AND METHODS

In total, 311 pulmonary tumours in 254 patients were treated between 2008 and 2011 with SABR using 48-60 Gy in four to five fractions. Local, regional and distant failure data were collected prospectively, whereas other end points were collected retrospectively. Potential clinical and dosimetric predictors of local control were evaluated using univariate and multivariate analyses.

RESULTS

Of the 311 tumours, 240 were NSCLC and 71 were other histologies. The 2 year local control rate was 96% in stage I NSCLC, 76% in colorectal cancer (CRC) metastases and 91% in non-lung/non-CRC metastases. Predictors of better local control on multivariate analysis were non-CRC tumours and a larger proportion of the planning target volume (PTV) receiving ≥100% of the prescribed dose (higher PTV V100). Among the 45 CRC metastases, a higher PTV V100 and previous chemotherapy predicted for better local control.

CONCLUSIONS

Lung SABR of 48-60 Gy/four to five fractions resulted in high local control rates for all tumours except CRC metastases. Covering more of the PTV with the prescription dose (a higher PTV V100) also resulted in superior local control.

Surgical resection of epidural disease improves local control following postoperative spine stereotactic body radiotherapy

BACKGROUND

Spine stereotactic body radiotherapy (SBRT) is increasingly being applied to the postoperative spine metastases patient. Our aim was to identify clinical and dosimetric predictors of local control (LC) and survival.

METHODS

Eighty patients treated between October 2008 and February 2012 with postoperative SBRT were identified from our prospective database and retrospectively reviewed.

RESULTS

The median follow-up was 8.3 months. Thirty-five patients (44%) were treated with 18-26 Gy in 1 or 2 fractions, and 45 patients (56%) with 18-40 Gy in 3-5 fractions. Twenty-one local failures (26%) were observed, and the 1-year LC and overall survival (OS) rates were 84% and 64%, respectively. The most common site of failure was within the epidural space (15/21, 71%). Multivariate proportional hazards analysis identified systemic therapy post-SBRT as the only significant predictor of OS (P = .02) and treatment with 18-26 Gy/1 or 2 fractions (P = .02) and a postoperative epidural disease grade of 0 or 1 (0, no epidural disease; 1, epidural disease that compresses dura only, P = .003) as significant predictors of LC. Subset analysis for only those patients (n = 48/80) with high-grade preoperative epidural disease (cord deformed) indicated significantly greater LC rates when surgically downgraded to 0/1 vs 2 (P = .0009).

CONCLUSIONS

Postoperative SBRT with high total doses ranging from 18 to 26 Gy delivered in 1-2 fractions predicted superior LC, as did postoperative epidural grade.

Vertebral compression fracture after spine stereotactic body radiotherapy: a multi-institutional analysis with a focus on radiation dose and the spinal instability neoplastic score

PURPOSE

Vertebral compression fracture (VCF) is increasingly recognized as an adverse event after spine stereotactic body radiotherapy (SBRT). We report a multi-institutional study aimed at clarifying the risk and predictive factors associated with VCF.

PATIENTS AND METHODS

A total of 252 patients with 410 spinal segments treated with SBRT were included. The primary outcome was the development of VCF (a new VCF or progression of a baseline VCF). In addition to various patient-, treatment-, and tumor-specific factors, the Spinal Instability Neoplastic Scoring (SINS) system was applied to determine predictive value.

RESULTS

The median follow-up was 11.5 months (range, 0.03 to 113 months). The median and mean overall survival rates were 16 and 26 months, respectively. We observed 57 fractures (57 of 410, 14%), with 47% (27 of 57) new fractures and 53% (30 of 57) fracture progression. The median time to VCF was 2.46 months (range, 0.03 to 43.01 months), and 65% occurred within the first 4 months. The 1- and 2-year cumulative incidences of fracture were 12.35% and 13.49%, respectively. Multivariable analysis identified dose per fraction (greatest risk for ≥ 24 Gy v 20 to 23 Gy v ≤ 19 Gy), in addition to three of the six original SINS criteria: baseline VCF, lytic tumor, and spinal deformity, as significant predictors of VCF.

CONCLUSION

Caution must be observed when treating with ≥ 20 Gy/fraction, in particular, for patients with lytic tumor, spinal misalignment, and a baseline VCF. Frequent short-term follow-up is required, as nearly two thirds of all VCF occurred within the first 4 months. We also conclude that SINS may have utility in predicting patients at high risk of SBRT-induced VCF.

Management of Bartholin's gland carcinoma using high-dose-rate interstitial brachytherapy boost

PURPOSE

To describe the patterns of use, clinical outcomes, and dose-volume histogram parameters of high-dose-rate interstitial brachytherapy (HDR-ISBT) in the management of Bartholin's gland cancer.

METHODS AND MATERIALS

Five patients with Stage II-III Bartholin's gland carcinoma treated with CT-based HDR-ISBT boost were reviewed. Plans were generated using an inverse planning simulated annealing algorithm. Dose-volume histogram parameters were assessed. The total doses of HDR-ISBT and EBRT were converted to total equivalent dose in 2Gy (EQD2).

RESULTS

All 5 patients received HDR-ISBT as a boost (median dose, 30Gy) after EBRT (median dose, 45Gy). Three patients received postoperative irradiation for gross residual tumor or positive surgical margins and 2 patients were treated by primary chemoradiotherapy. The median V100, D90, and D100 for the CTV were 98.3%, 89Gy10, and 64Gy10 (EQD2), respectively. A complete response was observed in all patients. No local recurrence occurred. All patients remain alive and free of disease (median followup, 78 months; range, 8-93). Severe vaginal toxicities were observed, including vaginal necrosis that resolved with hyperbaric oxygen therapy.

CONCLUSIONS

HDR-ISBT boost after EBRT offers excellent long-term local control in patients with Bartholin's gland carcinoma. HDR-ISBT should be considered for positive surgical margins or residual tumor after surgery and for locally advanced malignancies treated by primary chemoradiotherapy.

Macroglossia due to Systemic Amyloidosis: Is There a Role for Radiotherapy?

Background

Macroglossia due to amyloid depositions can cause cosmetic problems and functional disability, and can lead to life-threatening airway obstruction. Management of macroglossia in systemic amyloidosis is controversial, and the role of surgery is unclear.

Case Description

We present a case of a 66-year-old woman affected by macroglossia due to light chain amyloidosis who presented with eating and breathing difficulties. Because of prior successful results of radiotherapy for localized amyloid disease, our patient was treated with external beam radiation therapy (20 Gy in 10 fractions). The treatment was well tolerated by the patient. However, her systemic amyloidosis progressed, with a subclinical increase in tongue width.

Conclusions

This is the first reported use of radiotherapy for amyloidosis of the tongue. There was no evidence of benefit using a total dose of 20 Gy. This therapeutic modality is not recommended for the routine management of macroglossia.

[Nutrition education in schools]

PURPOSE

School interventions aimed at developing nutrition knowledge are among the avenues to be considered to improve young Canadians' food habits. From a new toolkit targeting elementary school children in first and second grade, the report presents attitudes and behaviours of teachers having received and used the material.

METHODS

A total of 504 primary schools located in Quebec were solicited to participate in the study. A total of 214 teachers (42.5%) answered a self-administered questionnaire; 149 received the material and 63 used it.

RESULTS

Most of the respondents believed that schools should allocate more time for nutrition education. Those who have used the material identified the most popular themes as well as new themes to be developed. Limitations to the use of the material in class were related to lack of time.

CONCLUSIONS

Results support a clear interest from teachers toward transmitting nutrition information at school and the necessity to consider schools' specific constraints and needs to benefit from these education efforts.

Canadians' level of confidence in their sources of nutrition information

North Americans have a great interest in health and nutrition. However, because sources of nutrition information are vast, the quality of the information varies. We explored the potential benefit of segmenting the Canadian population by geographical location and age in determining the principal sources of nutrition information and level of confidence in these sources. A survey was posted on the Dietitians of Canada website: subjects indicated how frequently they used different healthy eating sources and their level of confidence in the various sources. A total of 870 questionnaires were retained. Magazines, books, the Internet, food labels, and brochures were the most frequently used sources of information. Analyses indicated differences between geographic areas in the use of the media (radio, newspaper, television), dietitians, and naturopaths as sources of nutrition information (p<0.05), and between seven age groups (<18 to 65+ years) in the use of the media (p<0.05). Respondents reported being very confident about nutrition information received from dietitians, physicians, books, the government, and nurses, with some differences occurring between geographic areas (p<0.05).