Embolization of Middle Meningeal Arteries for Symptomatic Subacute Subdural Hematoma in Patients with Cancer.

PURPOSE: The purpose of this study was to evaluate the technical and clinical success of middle meningeal artery (MMA) embolization performed for symptomatic subacute subdural hematoma (SDH) in patients with cancer. METHODS: This study retrospectively included 23 consecutive patients (12 men, 11 women; median age 61 years, interquartile range: 55.5-75.5) who underwent 34 MMA angiograms for symptomatic SDH in 2022 and 2023. Median SDH thickness was 10.5 mm (7-12). Median platelet count was 117 K/mcL (54.5-218). 10 patients (43.5%, 10/23) had hematologic malignancies, seven patients (30.4%, 7/23) had surgery. Fluoroscopy time (FT), reference dose (RD), and kerma area product (Kap) were analyzed. Adverse events and outcomes were recorded. RESULTS: The median imaging and clinical follow-up were 65 days (36.5-190.5) and 163 days (86-274), respectively. The technical success rate was 91.2% (31/34) as three MMA were not identified in two patients. Median procedure duration was 61 min (55.5-75.5). Median FT was 21.6 min (15.5-31.8); median RD was 158 mGy (96-256); and median Kap was 32.9 Gy.cm2 (20.4-45.1). No further intervention was needed. For 16 patients, SDH resolved after in median 59.5 days (50-90). For seven patients, SDH remained visible on the last imaging follow-up performed at 24 days in median (6.5-36.5). No predictive factor of failure was identified. The adverse event rate was 1/23 (4.3%). Eight patients (34.8%, 8/23) died during follow-up from progression of cancer. CONCLUSION: MMA embolization of symptomatic SDH in patients with cancer appears safe and is associated with improvement in clinical symptoms.

40 Gray in 5 Fractions for Salvage Reirradiation of Spine Lesions Previously Treated With Stereotactic Body Radiotherapy.

BACKGROUND AND PURPOSE: A retrospective single-center analysis of the safety and efficacy of reirradiation to 40 Gy in 5 fractions (reSBRT) in patients previously treated with stereotactic body radiotherapy to the spine was performed. METHODS: We identified 102 consecutive patients treated with reSBRT for 105 lesions between 3/2013 and 8/2021. Sixty-three patients (61.8%) were treated to the same vertebral level, and 39 (38.2%) to overlapping immediately adjacent levels. Local control was defined as the absence of progression within the treated target volume. The probability of local progression was estimated using a cumulative incidence curve. Death without local progression was considered a competing risk. RESULTS: Most patients had extensive metastatic disease (54.9%) and were treated to the thoracic spine (53.8%). The most common regimen in the first course of stereotactic body radiotherapy was 27 Gy in 3 fractions, and the median time to reSBRT was 16.4 months. At the time of simulation, 44% of lesions had advanced epidural disease. Accordingly, 80% had myelogram simulations. Both the vertebral body and posterior elements were treated in 86% of lesions. At a median follow-up time of 13.2 months, local failure occurred in 10 lesions (9.5%). The 6- and 12-month cumulative incidences of local failure were 4.8% and 6%, respectively. Seven patients developed radiation-related neuropathy, and 1 patient developed myelopathy. The vertebral compression fracture rate was 16.7%. CONCLUSION: In patients with extensive disease involvement, reSBRT of spine metastases with 40 Gy in 5 fractions seems to be safe and effective. Prospective trials are needed to determine the optimal dose and fractionation in this clinical scenario.

Dynamic Contrast Enhanced MR Perfusion and Diffusion-Weighted Imaging of Marrow-Replacing Disorders of the Spine: A Comprehensive Review.

Significant advancements in cancer treatment have led to improved survival rates for patients, particularly in the context of spinal metastases. However, early detection and monitoring of treatment response remain crucial for optimizing patient outcomes. Although conventional imaging methods such as bone scan, PET, MR imaging, and computed tomography are commonly used for diagnosing and monitoring treatment, they present challenges in differential diagnoses and treatment response monitoring. This review article provides a comprehensive overview of the principles, applications, and practical uses of dynamic contrast-enhanced MR imaging and diffusion-weighted imaging in the assessment and monitoring of marrow-replacing disorders of the spine.

Factors Affecting Diagnostic Yield of Lesional Bone Biopsy in Hematologic Malignancy Patients.

PURPOSE: To evaluate factors affecting the diagnostic yield (percent of biopsy samples leading to a pathologic diagnosis) of lesional bone biopsies in patients with hematologic malignancies. MATERIALS AND METHODS: This retrospective study included 206 lesional bone biopsies in 182 patients with a hematologic malignancy between January 2017 and December 2022. The parameters that were reviewed to evaluate diagnostic yield included biopsy device type (manual vs. electric-powered drill), number of biopsy cores acquired, core biopsy needle gauge, preliminary intra-procedural sample adequacy (touch preparation cytology determining if samples are adequate for final pathologic examination), lesion morphology on Computed Tomography (CT), and presence of crush artifact. RESULTS: Review of 206 lesional biopsies showed overall diagnostic yield to be 89.8% (185/206). The two statistically significant factors affecting diagnostic yield were biopsy device type and in-room adequacy. 41/42 samples obtained with the electric-powered drill and 144/164 samples obtained using a variety of manual needles were diagnostic (97.6% vs 87.8%, p = 0.03). Of the 192 samples that were assessed for sample adequacy intra-procedurally, 97/102 of the samples that were deemed adequate were diagnostic, and 77/90 of the samples where intra-procedural adequacy was not confirmed were diagnostic (95.1% vs 85.6%, p = 0.018). The remaining factors did not affect diagnostic yield. CONCLUSION: The use of an electric-powered drill bone biopsy device and intra-procedural confirmation of sample adequacy are associated with a higher diagnostic yield of lesional bone biopsies in patients with hematologic malignancies. The presence or absence of crush artifact did not significantly affect the diagnostic yield in these patients.

Spine MRI Identifies Clinically Relevant Findings in Patients With Cancer Presenting With Back Pain.

STUDY DESIGN: This is a retrospective, cross-sectional study. OBJECTIVE: The primary aim was to identify the diagnostic yield of spine magnetic resonance imaging (MRI) in detecting malignant pathology in cancer patients with back pain. We also sought to evaluate the role of MRI extent ( i.e. regional vs. total) in identifying malignant pathology. SUMMARY OF BACKGROUND DATA: No prior study has systematically investigated the yield of spine MRI in a large cohort of cancer patients. METHODS: Spine MRI reports from 2017 to 2021 for back pain (acute and nonspecified chronicity) in cancer patients were reviewed to identify clinically relevant findings: malignant (1) epidural, (2) leptomeningeal, (3) intramedullary, (4) osseous disease, and (5) fracture. Logistic regression was used to evaluate the association between MRI extent and the presence of cancer-related findings. For patients with multiple MRIs, short-interval scans (≤4 mo) were evaluated to assess the yield of repeat imaging. RESULTS: At least one cancer-related finding was identified on 52% of 5989 spine MRIs ordered for back pain and 57% of 1130 spine MRIs ordered specifically for acute back pain. The most common pathology was malignant osseous disease (2545; 43%). Across all five categories, most findings (77%-89%) were new/progressive. Odds of identifying a finding were significantly higher with total versus regional spine MRIs ( P <0.001). Although only 14 patients had a positive regional MRI followed shortly by a positive total spine MRI, most of these repeat total spine MRIs (78%) identified findings outside the scope of the initial regional scan. Twenty-one patients had both computed tomography and MRI within 30 days of each other; eight (38%) had compression fractures appreciated on MRI but not on computed tomography. CONCLUSIONS: Our findings suggest imaging the total spine in cancer patients with back pain given higher odds of identifying malignant pathology and instances of capturing otherwise not visualized disease. Further work is warranted to confirm these findings.

T1-Weighted, Dynamic Contrast-Enhanced MR Perfusion Imaging Can Differentiate between Treatment Success and Failure in Spine Metastases Undergoing Radiation Therapy.

BACKGROUND AND PURPOSE: Current imaging techniques have difficulty differentiating treatment success and failure in spinal metastases undergoing radiation therapy. This study investigated the correlation between changes in dynamic contrast-enhanced MR imaging perfusion parameters and clinical outcomes following radiation therapy for spinal metastases. We hypothesized that perfusion parameters will outperform traditional size measurements in discriminating treatment success and failure. MATERIALS AND METHODS: This retrospective study included 49 patients (mean age, 63 [SD, 13] years; 29 men) with metastatic lesions treated with radiation therapy who underwent dynamic contrast-enhanced MR imaging. The median time between radiation therapy and follow-up dynamic contrast-enhanced MR imaging was 62 days. We divided patients into 2 groups: clinical success (n = 38) and failure (n = 11). Failure was defined as PET recurrence (n = 5), biopsy-proved (n = 1) recurrence, or an increase in tumor size (n = 7), while their absence defined clinical success. A Mann-Whitney U test was performed to assess differences between groups. RESULTS: The reduction in plasma volume was greater in the success group than in the failure group (-57.3% versus +88.2%, respectively; P < .001). When we assessed the success of treatment, the sensitivity of plasma volume was 91% (10 of 11; 95% CI, 82%-97%) and the specificity was 87% (33 of 38; 95% CI, 73%-94%). The sensitivity of size measurements was 82% (9 of 11; 95% CI, 67%-90%) and the specificity was 47% (18 of 38; 95% CI, 37%-67%). CONCLUSIONS: The specificity of plasma volume was higher than that of conventional size measurements, suggesting that dynamic contrast-enhanced MR imaging is a powerful tool to discriminate between treatment success and failure.

Feasibility and Safety of Percutaneous CT-Guided Bone Biopsies in Patients with Cancer Using a Patient-Mounted Robotic System: A Retrospective Analysis of 40 Consecutive Biopsies.

This retrospective study evaluated the feasibility and safety of percutaneous computed tomography (CT)-guided bone biopsies in patients with cancer using a patient-mounted robotic system with steering capabilities. The study included 39 patients (17 women, 22 men; median age, 65.5 years; interquartile range [IQR], 54.8-71.0 years). Forty biopsies were performed in the pelvis, spine, ribs, shoulder, femur, and sternum. The technical success rate was 100%, and the median trajectory length was 55.9 mm (IQR, 47.1-73.6 mm). Intermediate checkpoints were used in 8 biopsies. Median time from the first to final scan was 21 minutes (IQR, 17-37 minutes). The overall procedure time was 30 minutes (IQR, 24-36 minutes). The median dose length product and effective dose were 536.6 mGy⋅cm (IQR, 396.2-837.7 mGy∗cm) and 7.1 mSv (IQR, 4.7-10.8 mSv), respectively. No adverse events occurred. The diagnostic yield for cancer was 72.5%. Percutaneous robotic-assisted bone biopsies demonstrated high technical success, adequate diagnostic yield, and favorable safety profile.

Dynamic Contrast-Enhanced MR Perfusion: Role in Diagnosis and Treatment Follow-Up in Patients with Vertebral Body Tumors.

Recent therapeutic advances have led to increased survival times for patients with metastatic disease. Key to survival is early diagnosis and subsequent treatment as well as early detection of treatment failure allowing for therapy modifications. Conventional MR imaging techniques of the spine can be at times suboptimal for identifying viable tumor, as structural changes and imaging characteristics may not differ pretreatment and posttreatment. Advanced imaging techniques such as DCE-MRI can allow earlier and more accurate noninvasive assessment of viable disease by characterizing physiologic changes and tumor microvasculature.

Delay of Aortic Arterial Input Function Time Improves Detection of Malignant Vertebral Body Lesions on Dynamic Contrast-Enhanced MRI Perfusion.

Dynamic contrast-enhanced MRI (DCE) is an emerging modality in the study of vertebral body malignancies. DCE-MRI analysis relies on a pharmacokinetic model, which assumes that contrast uptake is simultaneous in the feeding of arteries and tissues of interest. While true in the highly vascularized brain, the perfusion of the spine is delayed. This delay of contrast reaching vertebral body lesions can affect DCE-MRI analyses, leading to misdiagnosis for the presence of active malignancy in the bone marrow. To overcome the limitation of delayed contrast arrival to vertebral body lesions, we shifted the arterial input function (AIF) curve over a series of phases and recalculated the plasma volume values (Vp) for each phase shift. We hypothesized that shifting the AIF tracer curve would better reflect actual contrast perfusion, thereby improving the accuracy of Vp maps in metastases. We evaluated 18 biopsy-proven vertebral body metastases in which standard DCE-MRI analysis failed to demonstrate the expected increase in Vp. We manually delayed the AIF curve for multiple phases, defined as the scan-specific phase temporal resolution, and analyzed DCE-MRI parameters with the new AIF curves. All patients were found to require at least one phase-shift delay in the calculated AIF to better visualize metastatic spinal lesions and improve quantitation of Vp. Average normalized Vp values were 1.78 ± 1.88 for zero phase shifts (P0), 4.72 ± 4.31 for one phase shift (P1), and 5.59 ± 4.41 for two phase shifts (P2). Mann-Whitney U tests obtained p-values = 0.003 between P0 and P1, and 0.0004 between P0 and P2. This study demonstrates that image processing analysis for DCE-MRI in patients with spinal metastases requires a careful review of signal intensity curve, as well as a possible adjustment of the phase of aortic AIF to increase the accuracy of Vp.

Middle meningeal artery embolization using cone-beam computed tomography augmented guidance in patients with cancer.

PURPOSE: The purpose of this study was to evaluate the safety and efficacy of middle meningeal artery embolization (MMAE) performed under cone-beam computed tomography (CBCT) augmented guidance in patients with cancer. MATERIALS AND METHODS: Eleven patients with cancer (seven women, four men; median age, 75 years; age range: 42-87 years) who underwent 17 MMAEs under CBCT with a combination of particles and coils for chronic subdural hematoma (SDH) (n = 6), postoperative SDH (n = 3), or preoperative embolization of meningeal tumor (n = 2) from 2022 to 2023 were included. Technical success, fluoroscopy time (FT), reference dose (RD), kerma area product (KAP) were analyzed. Adverse events and outcomes were recorded. RESULTS: The technical success rate was 100% (17/17). Median MMAE procedure duration was 82 min (interquartile range [IQR]: 70, 95; range: 63-108 min). The median FT was 24 min (IQR: 15, 48; range: 21.5-37.5 min); the median RD was 364 mGy (IQR: 37, 684; range: 131.5-444.5 mGy); and the median KAP was 46.4 Gy.cm2 (9.6, 104.5; range: 30.2-56.6 Gy.cm2). No further interventions were needed. The adverse event rate was 9% (1/11), with one pseudoaneurysm at the puncture site in a patient with thrombocytopenia, which was treated by stenting. The median follow-up was 48 days (IQR; 14, 251; range: 18.5-91 days]. SDH reduced in 11 of 15 SDHs (73%) as evidenced by follow-up imaging, with a size reduction greater than 50% in 10/15 SDHs (67%) . CONCLUSION: MMAE under CBCT is a highly effective treatment option, but appropriate patient selection and careful consideration of potential risks and benefits is important for optimal patient outcomes.

Early Detection of Leptomeningeal Metastases Among Patients Undergoing Spinal Stereotactic Radiosurgery.

Purpose: The management of patients with advanced solid malignancies increasingly uses stereotactic body radiation therapy (SBRT). Advanced cancer patients are at risk for developing leptomeningeal metastasis (LM), a fatal complication of metastatic cancer. Cerebrospinal fluid (CSF) is routinely collected during computed tomography (CT) myelography for spinal SBRT planning, offering an opportunity for early LM detection by CSF cytology in the absence of radiographic LM or LM symptoms (subclinical LM). This study tested the hypothesis that early detection of tumor cells in CSF in patients undergoing spine SBRT portends a similarly poor prognosis compared with clinically overt LM. Methods and Materials: We retrospectively analyzed clinical records for 495 patients with metastatic solid tumors who underwent CT myelography for spinal SBRT planning at a single institution from 2014 to 2019. Results: Among patients planned for SBRT, 51 (10.3%) developed LM. Eight patients (1.6%) had subclinical LM. Median survival with LM was similar between patients with subclinical versus clinically evident LM (3.6 vs 3.0 months, P = .30). Patients harboring both parenchymal brain metastases and LM (29/51) demonstrated shorter survival than those with LM alone (2.4 vs 7.1 months, P = .02). Conclusions: LM remains a fatal complication of metastatic cancer. Subclinical LM detected by CSF cytology in spine SBRT patients has a similarly poor prognosis compared with standardly detected LM and warrants consideration of central nervous system-directed therapies. As aggressive local therapies are increasingly used for metastatic patients, more sensitive CSF evaluation may further identify patients with subclinical LM and should be evaluated prospectively.

Preoperative Embolization of Metastatic Spinal Cord Compression with n-Butyl Cyanoacrylate: Safety and Effectiveness in Limiting Blood Loss.

PURPOSE: To evaluate the safety and effectiveness of preoperative embolization with n-butyl cyanoacrylate (nBCA) performed for metastatic spinal cord compression (MSCC) in limiting blood loss (BL). MATERIALS AND METHODS: In this institutional review board-approved retrospective study, clinical records from 2017 to 2022 were reviewed. Twenty consecutive patients (11 men and 9 women; mean age, 65.8 years ± 10.0; range, 45-82 years) underwent 21 preoperative spine tumor embolizations with nBCA. Angiograms were used to calculate the percentage reduction in tumor vascularity, and relevant clinical data (levels studied and embolized, fluoroscopy time [FT], reference dose [RD], and Kerma area product [KAP]) and operative data (BL and operative time [OT]) were analyzed. Adverse events and outcomes were recorded. RESULTS: A median of 2 levels were embolized per procedure (range, 1-5) but 4.9 were studied (range, 1-10). After embolization, tumor blush was reduced by a median of 87.3% (range, 50%-90%). The mean FT was 41 minutes ± 15.4 (range, 16-67 minutes), the mean RD was 1,977.1 mGy ± 1,794.3 (range, 450.2-6,319 mGy), and the mean KAP was 180.5 Gy·cm2 ± 166.2 (range, 30.4-504 Gy·cm2). The adverse event rate was 1 (4.7%) of the 21 embolizations because a weakness of lower extremities related to swelling was observed. Surgery was performed at a mean of 1.4 days ± 1 (range, 1-5 days) after embolization. The mean surgical estimated BL was 432.5 mL ± 328.5 (range, 25-1,100 mL), and the mean OT was 210.1 minutes ± 97.4 (range, 57-489 minutes). CONCLUSIONS: Preoperative embolization of tumors resected for MSCC with nBCA is a safe procedure allowing for performance of surgery with acceptable BL.

Responder Analysis of Pain Relief After Surgery for the Treatment of Spinal Metastatic Tumors.

BACKGROUND: Central tendency analysis studies demonstrate that surgery provides pain relief in spinal metastatic tumors. However, they preclude patient-specific probability of treatment outcome. OBJECTIVE: To use responder analysis to study the variability of pain improvement. METHODS: In this single-center, retrospective analysis, 174 patients were studied. Logistic regression modeling was used to associate preoperative characteristics with rating the Brief Pain Inventory (BPI) worst pain item 0 to 4. Linear regression modeling was used to associate preoperative characteristics with minimal clinically important improvement (MCI) in physical functioning defined by a 1-point decrease in the BPI Interference Construct score from preoperative baseline to 6 months postoperatively. RESULTS: Patient-level analysis revealed that 60% of patients experienced an improvement in pain. At least half experienced a decrease in pain resulting in MCI in physical functioning. Cutpoint analysis revealed that 48% were responders. Increasing scores on the preoperative pain intensity BPI items, the MD Anderson Symptom Inventory (MDASI) Core Symptom Severity Construct, the MDASI Spine Tumor-Specific Construct, the presence of preoperative neurologic deficits, and postoperative complications were associated with lower probability of treatment success while increasing severity in all BPI pain items, and MDASI constructs were associated with increased probability of MCI in physical function. Significant mortality and loss to follow-up intrinsic to this patient population limit the strength of these data. CONCLUSION: Although patients with milder preoperative symptoms are likely to achieve better pain relief after surgery, patients with worse preoperative symptom also benefit from surgery with adequate pain relief with an improvement in physical function.

Phase 3 Multi-Center, Prospective, Randomized Trial Comparing Single-Dose 24 Gy Radiation Therapy to a 3-Fraction SBRT Regimen in the Treatment of Oligometastatic Cancer.

PURPOSE: This prospective phase 3 randomized trial was designed to test whether ultra high single-dose radiation therapy (24 Gy SDRT) improves local control of oligometastatic lesions compared to a standard hypofractionated stereotactic body radiation therapy regimen (3 × 9 Gy SBRT). The secondary endpoint was to assess the associated toxicity and the impact of ablation on clinical patterns of metastatic progression. METHODS AND MATERIALS: Between November 2010 and September 2015, 117 patients with 154 oligometastatic lesions (≤5/patient) were randomized in a 1:1 ratio to receive 24 Gy SDRT or 3 × 9 Gy SBRT. Local control within the irradiated field and the state of metastatic spread were assessed by periodic whole-body positron emission tomography/computed tomography and/or magnetic resonance imaging. Median follow-up was 52 months. RESULTS: A total of 59 patients with 77 lesions were randomized to 24 Gy SDRT and 58 patients with 77 lesions to 3 × 9 Gy SBRT. The cumulative incidence of local recurrence for SDRT-treated lesions was 2.7% (95% confidence interval [CI], 0%-6.5%) and 5.8% (95% CI, 0.2%-11.5%) at years 2 and 3, respectively, compared with 9.1% (95% CI, 2.6%-15.6%) and 22% (95% CI, 11.9%-32.1%) for SBRT-treated lesions (P = .0048). The 2- and 3-year cumulative incidences of distant metastatic progression in the SDRT patients were 5.3% (95% CI, 0%-11.1%), compared with 10.7% (95% CI, 2.5%-18.8%) and 22.5% (95% CI, 11.1%-33.9%), respectively, for the SBRT patients (P = .010). No differences in toxicity were observed. CONCLUSIONS: The study confirms SDRT as a superior ablative treatment, indicating that effective ablation of oligometastatic lesions is associated with significant mitigation of distant metastatic progression.

Survival Trends After Surgery for Spinal Metastatic Tumors: 20-Year Cancer Center Experience.

BACKGROUND: Over the last 2 decades, advances in systemic therapy have increased the expected overall survival for patients with cancer. It is unclear whether the same survival benefit has been conferred to patients requiring surgery for metastatic spinal disease. OBJECTIVE: To examine trends in postoperative survival over a 20-yr period for patients surgically treated for spinal metastatic disease. METHODS: Data were obtained for 1515 patients who underwent surgery for metastatic epidural spinal cord compression or tumor-related mechanical instability. Postoperative overall survival was calculated for all included patients using Kaplan-Meier methodology from date of surgery until death or last follow-up for those who were censored. Trends were analyzed using Cox proportional hazards modeling. RESULTS: Patients with renal, breast, lung, and colon cancers experienced a statistically significant improvement in survival over time based on the year of surgery (40%-100% improvement over the study period), whereas the overall survival trend for the entire cohort did not reach statistical significance (P = .12, median survival 0.71 yr, 95% CI 0.63-0.78). Patients presenting with synchronous metastatic disease had better survival compared to those presenting with metachronous disease (median overall survival: 0.94 vs 0.63 yr, respectively; log-rank P-value = .00001). CONCLUSION: The postoperative survival among patients with spinal metastases has improved over the past 20 yr, particularly in patients with kidney, breast, lung, and colon tumors metastatic to the spine. The observed survival improvement emphasizes the need for long-term outcome consideration in treatment decisions for patients undergoing surgery for spinal metastatic tumors.

T1-weighted Dynamic Contrast-enhanced MRI to Differentiate Nonneoplastic and Malignant Vertebral Body Lesions in the Spine.

Background Dynamic contrast agent-enhanced (DCE) perfusion MRI may help differentiate between nonneoplastic and malignant lesions in the spine. Purpose To investigate the correlation between fractional plasma volume (Vp), a parameter derived from DCE perfusion MRI, and histopathologic diagnosis for spinal lesions. Materials and Methods In this retrospective study, patients who underwent DCE perfusion MRI and lesion biopsy between May 2015 and May 2018 were included. Inclusion criteria were short time interval (<30 days) between DCE perfusion MRI and biopsy, DCE perfusion MRI performed before biopsy, and DCE perfusion MRI performed at the same spine level as biopsy. Exclusion criteria were prior radiation treatment on vertebrae of interest, poor DCE perfusion MRI quality, nondiagnostic biopsy, and extensive spinal metastasis or prior kyphoplasty. One hundred thirty-four lesions were separated into a nonneoplastic group (n = 51) and a malignant group (n = 83) on the basis of histopathologic analysis. Two investigators manually defined regions of interest in the vertebrae. DCE perfusion MRI parameter Vp was calculated by using the Tofts pharmacokinetic two-compartment model. Vp was quantified, normalized to adjacent normal vertebrae, and compared between the two groups. A Mann-Whitney U test and receiver operating characteristic analysis was performed to verify the difference in Vp between the nonneoplastic and malignant groups. Reproducibility was assessed by calculating the Cohen κ coefficient. Results One hundred patients (mean age, 65 years ± 11 [standard deviation]; 52 men) were evaluated. Vp was lower in nonneoplastic lesions versus malignant lesions (1.6 ± 1.3 vs 4.2 ± 3.0, respectively; P < .001). The sensitivity of Vp was 93% (77 of 83; 95% confidence interval [CI]: 85%, 97%), specificity was 78% (40 of 51; 95% CI: 65%, 89%), and area under the receiver operating characteristic curve was 0.88 (95% CI: 0.82, 0.95). Cohen κ coefficient suggested substantial agreement in both intra- (κ = 0.72) and interreader (κ = 0.70) reproducibility. Conclusion This study indicated that dynamic contrast agent-enhanced perfusion MRI parameter, fractional plasma volume, was able to differentiate between nonneoplastic spinal lesions and malignant lesions. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Haller in this issue.

Hypofractionated spinal stereotactic body radiation therapy for high-grade epidural disease.

OBJECTIVE: To characterize the clinical outcomes when stereotactic body radiation therapy (SBRT) alone is used to treat high-grade epidural disease without prior surgical decompression, the authors conducted a retrospective cohort study of patients treated at the Memorial Sloan Kettering Cancer Center between 2014 and 2018. The authors report locoregional failure (LRF) for a cohort of 31 cases treated with hypofractionated SBRT alone for grade 2 epidural spinal cord compression (ESCC) with radioresistant primary cancer histology. METHODS: High-grade epidural disease was defined as grade 2 ESCC, which is notable for radiographic deformation of the spinal cord by metastatic disease. Kaplan-Meier survival curves and cumulative incidence functions were generated to examine the survival and incidence experiences of the sample level with respect to overall survival, LRF, and subsequent requirement of vertebral same-level surgery (SLS) due to tumor progression or fracture. Associations with dosimetric analysis were also examined. RESULTS: Twenty-nine patients undergoing 31 episodes of hypofractionated SBRT alone for grade 2 ESCC between 2014 and 2018 were identified. The 1-year and 2-year cumulative incidences of LRF were 10.4% (95% CI 0-21.9) and 22.0% (95% CI 5.5-38.4), respectively. The median survival was 9.81 months (95% CI 8.12-18.54). The 1-year cumulative incidence of SLS was 6.8% (95% CI 0-16.0) and the 2-year incidence of SLS was 14.5% (95% CI 0.6-28.4). All patients who progressed to requiring surgery had index lesions at the thoracic apex (T5-7). CONCLUSIONS: In carefully selected patients, treatment of grade 2 ESCC disease with hypofractionated SBRT alone offers a 1-year cumulative incidence of LRF similar to that in low-grade ESCC and postseparation surgery adjuvant hypofractionated SBRT. Use of SBRT alone has a favorable safety profile and a low cumulative incidence of progressive disease requiring open surgical intervention (14.5%).

Whole-body magnetic resonance imaging as surveillance for subsequent malignancies in preadolescent, adolescent, and young adult survivors of germline retinoblastoma: An update.

BACKGROUND: Germline retinoblastoma (Rb) survivors are at lifelong risk for developing subsequent malignancies (SMNs). Optimal surveillance modalities are needed to detect SMN at an early stage in this high-risk cohort. We investigated the use of rapid whole-body magnetic resonance imaging (WB-MRI) as a noninvasive screening modality in this cohort. PROCEDURE: WB-MRI was performed in asymptomatic preadolescent, adolescent, or young adult survivors of germline Rb from February 1, 2008 to December 31, 2018 at a tertiary cancer center. We calculated sensitivity and specificity of WB-MRI and rate of false-positive findings requiring additional evaluation. RESULTS: Overall, 110 WB-MRI were performed in 47 germline Rb survivors (51% female; median age at initial WB-MRI: 15.5 years [range 8-25.3]). Patients received 1-10 annual WB-MRI examinations (median: two). Thirteen patients had an abnormal WB-MRI; three findings were deemed to be likely benign and were not evaluated further. Ten patients required dedicated imaging and three required biopsy; two patients were diagnosed with localized high-grade osteosarcoma, while the other eight had benign findings. One patient was diagnosed with secondary osteosarcoma 3 months after normal WB-MRI. In total, there were 96 true negatives, 11 false positives, two true positives, and one false negative. The sensitivity of WB-MRI in this cohort was 66.7% (95% confidence interval [CI], 14.2-96.0) and the specificity was 89.7% (95% CI, 83.6-93.7). CONCLUSIONS: Based on our 10-year experience, surveillance WB-MRI appears to have limited utility as a surveillance modality for SMN in germline Rb survivors. Alternate screening modalities should be investigated.

Technical Note: A custom-designed flexible MR coil array for spine radiotherapy treatment planning.

PURPOSE: To assess the performance and optimize the MR image quality when using a custom-built flexible radiofrequency (RF) spine coil array fitted between the immobilization device and the patient for spine radiotherapy treatment planning. METHODS: A 32 channel flexible custom-designed receive-only coil array has been developed for spine radiotherapy simulation for a 3 T Philips MR scanner. Coil signal-to-noise performance and interactions with standard vendor hardware were assessed. In four volunteers, immobilization molds were created with a dummy version of the array within the mold, and subjects were scanned using the custom array in the mold. Phantoms and normal volunteers were scanned with both the custom spine coil array and the vendor's FDA-approved in-table posterior coil array to compare performance. RESULTS: The superior-inferior field of view for the custom spine array was ~30 cm encompassing at least 10 vertebrae. A noise correlation matrix showed at least 25 dB isolation between all coil elements. Signal-to-noise ratio (SNR) calculated on a phantom scan at the depth of the spinal cord was a factor of 3 higher with the form-fit spine array as compared to the vendor's posterior coil array. The body coil B1 transmit map was equivalent with and without the spine array in place demonstrating that the elements are decoupled from the body coil. Volunteer imaging showed improved SNR as compared to the vendor's posterior coil array. The custom array permitted a high degree of acceleration making possible the acquisition of isotropic high-resolution 1.1 × 1.1 × 1.1 mm3 three-dimensional data set over a 30-cm section of the spine in less than 5 min. CONCLUSION: The custom-designed form-fitting flexible spine coil array provided enhanced SNR and increased acceleration compared to the vendor's posterior array. Future studies will assess MR-based spinal cord imaging with the custom coil in comparison to CT myelogram.