Post-gadolinium Magnetic Resonance Imaging Research Articles

Magnetic resonance imaging evaluation of cochlear and vestibular nerve calibre: a case-control study in Ménière's disease and endolymphatic hydrops.

To compare the calibre of the cochlear (CN), superior vestibular (SVN) and inferior vestibular (IVN) nerves on magnetic resonance imaging (MRI), both between Ménière's Disease (MD) ears and clinical controls, and between inner ears with and without endolymphatic hydrops (EH) on MRI. A retrospective case-control study evaluated patients undergoing MRI for suspected hydropic ear disease from 9/2017 to 8/2022. The CN, SVN, IVN and facial nerve (FN) diameters and cross-sectional areas (CSA) were measured on T2-weighted sequences whilst EH was evaluated on delayed post-gadolinium MRI. Absolute nerve calibre (and that relative to the FN) in unilateral definite MD ears (2015 Barany criteria) was compared to that in both asymptomatic contralateral ears and clinical control ears. Nerve calibre in ears with severe cochlear and vestibular EH was compared to ears without EH. t tests or Wilcoxon signed-rank test/Mann-Whitney U test were applied (p < 0.001). 173 patients (mean age 51.3 ± 15.1, 65 men) with 84 MD (62 unilateral) and 62 clinical control ears were studied. Absolute and relative CN dimensions were decreased in both MD ears (CSA and diameter) and the contralateral asymptomatic ears (CSA) when compared to clinical controls (p < 0.001). Absolute nerve dimensions were reduced in both severe vestibular EH (CN, IVN and SVN) and severe cochlear EH (CN) (p < 0.001), however this was not evident when adjusted according to facial nerve calibre. There is decreased absolute CN calibre in both symptomatic and asymptomatic MD ears as well as ears with severe cochlear and vestibular EH on MRI.

Symptoms: Sudden Sensorineural Hearing Loss and Aural Fullness

Symptoms: Sudden Sensorineural Hearing Loss and Aural Fullness

Delayed post gadolinium MRI descriptors for Meniere's disease: a systematic review and meta-analysis.

Delayed post-gadolinium magnetic resonance imaging (MRI) detects changes of endolymphatic hydrops (EH) within the inner ear in Meniere's disease (MD). A systematic review with meta-analysis was conducted to summarise the diagnostic performance of MRI descriptors across the range of MD clinical classifications. Case-controlled studies documenting the diagnostic performance of MRI descriptors in distinguishing MD ears from asymptomatic ears or ears with other audio-vestibular conditions were identified (MEDLINE, EMBASE, Web of Science, Scopus databases: updated 17/2/2022). Methodological quality was evaluated with Quality Assessment of Diagnostic Accuracy Studies version 2. Results were pooled using a bivariate random-effects model for evaluation of sensitivity, specificity and diagnostic odds ratio (DOR). Meta-regression evaluated sources of heterogeneity, and subgroup analysis for individual clinical classifications was performed. The meta-analysis included 66 unique studies and 3073 ears with MD (mean age 40.2-67.2years), evaluating 11 MRI descriptors. The combination of increased perilymphatic enhancement (PLE) and EH (3 studies, 122 MD ears) achieved the highest sensitivity (87% (95% CI: 79.92%)) whilst maintaining high specificity (91% (95% CI: 85.95%)). The diagnostic performance of "high grade cochlear EH" and "any EH" descriptors did not significantly differ between monosymptomatic cochlear MD and the latest reference standard for definite MD (p = 0.3; p = 0.09). Potential sources of bias were case-controlled design, unblinded observers and variable reference standard, whilst differing MRI techniques introduced heterogeneity. The combination of increased PLE and EH optimised sensitivity and specificity for MD, whilst some MRI descriptors also performed well in diagnosing monosymptomatic cochlear MD. • A meta-analysis of delayed post-gadolinium magnetic resonance imaging (MRI) for the diagnosis of Meniere's disease is reported for the first time and comprised 66 studies (3073 ears). • Increased enhancement of the perilymphatic space of the inner ear is shown to be a key MRI feature for the diagnosis of Meniere's disease. • MRI diagnosis of Meniere's disease can be usefully applied across a range of clinical classifications including patients with cochlear symptoms alone.

Symptoms: Purple Ear Drum and Hearing Loss

Symptoms: Purple Ear Drum and Hearing Loss

Symptoms: Unilateral Hearing Loss and Facial Paresis

Symptoms: Unilateral Hearing Loss and Facial Paresis

Low Frequency Air-Bone Gap in Meniere's Disease: Relationship With Magnetic Resonance Imaging Features of Endolymphatic Hydrops.

Objectives:The appearance of low-frequency air-bone gaps (LFABGs) in Meniere’s disease (MD) is a recognized but relatively unexplored phenomenon. Two theories have been proposed to explain their etiology: increased perilymphatic pressure resulting in either reduced stapedial mobility or dampened transmission of acoustic energy, and direct contact between the dilated saccule and the stapes footplate. The aim of this study was to evaluate these two hypotheses by comparing delayed postgadolinium magnetic resonance imaging (MRI) features of two groups of patients with unilateral definite MD, those with and without LFABGs.Design:This retrospective case-control study was conducted at a tertiary otolaryngology unit in the United Kingdom. The study included 35 patients who satisfied the 2015 Barany criteria for unilateral definite MD. The cohort was divided into two groups, those with LFABGs (LFABG+ group) and those without (LFABG− group), according to the pure-tone audiometry performed within 6 months of MRI. Alternative potential causes for the LFABGs were excluded on the basis of otologic history, otoscopy, tympanometry, and/or imaging. Using a 4-hr delayed postgadolinium 3-dimensional fluid-attenuated inversion recovery sequence, two observers evaluated the severity of cochlear and vestibular endolymphatic hydrops (EH) and the presence of vestibular endolymphatic space contacting the oval window (VESCO). The air and bone conduction thresholds, ABGs and MRI features were compared between the LFABG+ and LFABG− groups. Where any of the variables were found to be significantly associated with the presence of ABGs, further analysis was performed to determine whether or not they were independent predictors. Continuous variables were compared using the independent t test if normally distributed, and the Mann–Whitney U test or Kruskall–Wallis test if not normally distributed. Categorical variables were compared with Pearson’s Chi-squared test or Fishers/Fisher-Freeman-Halton exact tests.Results:There were 10 patients in the LFABG+ group (28.6%) and 25 patients in the LFABG− group (71.4%). The mean ABGs in the symptomatic ear at 500 Hz, 1 kHz, and 2 kHz were 15.1 dB ± 6.4, 10.5 dB ± 9.0, and 4.0 dB ± 7.7, respectively, in the LFABG+ group and 2.0 ± 5.8, 2.4 ± 4.4, and −0.8 ± 4.7 dB in the LFABG− group. The differences in ABGs between the two groups were statistically significant at all three test frequencies (p < 0.001 at 500 Hz, p = 0.007 at 1 kHz, and p = 0.041 at 2 kHz). The presence of ABGs was significantly associated with both the grade of vestibular EH (p = 0.049) and VESCO (p = 0.009). Further analysis showed a statistically significant association between the grade of vestibular EH and VESCO (p = 0.007), and only VESCO was an independent variable associated with the presence of LFABGs (p = 0.045).Conclusions:The study findings add to the existing body of evidence that LFABGs are a true audiological finding in MD and allow us to propose a mechanism. Analysis of delayed gadolinium-enhanced MRI suggests that direct contact between the distended saccule and the inner surface of the stapes footplate is the more likely underlying pathophysiological mechanism for this audiometric phenomenon.

Symptoms: Sudden Hearing Loss and Vertigo

Symptoms: Sudden Hearing Loss and Vertigo

Symptoms: Middle Ear Mass and Hearing Loss

Symptoms: Middle Ear Mass and Hearing Loss

A Dose-Response Model of Local Tumor Control Probability After Stereotactic Radiosurgery for Brain Metastases Resection Cavities

PurposeRecent randomized controlled trials evaluating stereotactic surgery (SRS) for resected brain metastases question the high rates of local control previously reported in retrospective studies. Tumor control probability (TCP) models were developed to quantify the relationship between radiation dose and local control after SRS for resected brain metastases. Methods and MaterialsPatients with resected brain metastases treated with SRS were evaluated retrospectively. Melanoma, sarcoma, and renal cell carcinoma were considered radio-resistant histologies. The planning target volume (PTV) was the region of enhancement on T1 post-gadolinium magnetic resonance imaging plus a 2-mm uniform margin. The primary outcome was local recurrence, defined as tumor progression within the resection cavity. Cox regression evaluated predictors of local recurrence. Dose-volume histograms for the PTV were obtained from treatment plans and converted to 3-fraction equivalent doses (α/β = 12 Gy). TCP models evaluated local control at 1-year follow-up as a logistic function of dose-volume histogram data. ResultsAmong 150 cavities, 41 (27.3%) were radio-resistant. The median PTV volume was 14.6 mL (range, 1.3-65.3). The median prescription was 21 Gy (range, 15-25) in 3 fractions (range, 1-5). Local control rates at 12 and 24 months were 86% and 82%. On Cox regression, larger cavities (PTV > 12 cm3) predicted increased risk of local recurrence (P = .03). TCP modeling demonstrated relationships between improved 1-year local control and higher radiation doses delivered to radio-resistant cavities. Maximum PTV doses of 30, 35, and 40 Gy predicted 78%, 89%, and 94% local control among all radio-resistant cavities, versus 69%, 79%, and 86% among larger radio-resistant cavities. ConclusionsAfter SRS for resected brain metastases, larger cavities are at greater risk of local recurrence. TCP models suggests that higher radiation doses may improve local control among cavities of radio-resistant histology. Given maximum tolerated doses established for single-fraction SRS, fractionated regimens may be required to optimize local control in large radio-resistant cavities.

NIMG-71. DETECTION OF CYSTIC GLIOBLASTOMA FROM MAGNETIC RESONANCE IMAGING USING DEEP LEARNING TECHNIQUES

Abstract Glioblastoma (GBM) is the most aggressive primary brain tumor with an average survival of 15 months with standard of care treatment. GBM patients typically present with necrosis surrounded by enhancement on T1-weighted post gadolinium magnetic resonance imaging (T1gd MRI), however some patients present with a significant cystic component. Cysts are caused by different underlying biological mechanisms to necrosis and are important to identify for future clinical investigations. These cystic components can be manually identified through MRI but this process can be time consuming for large patient cohorts. Over the last two decades, our lab has collected serial MRI data of brain tumor patients. With over 70,000 images now in the database and that number increasing daily, it is clear that we have a unique resource for clinical investigation and a need to automate this process. To this end, the aim of this work was to develop and assess the performance of a convolution neural network (CNN) model for automatic detection of cystic GBMs. In this retrospective IRB-approved work, we collected pretreatment MRIs of a patient cohort consisting of 85 patients with a significant cystic component at presentation along with 400 non-cystic GBM, both identified manually through MRI. Image slices with a view of the cystic component were used as positive samples for training. Data were randomly split into training, validation, and test sets using a 70:15:15 ratio. The proportion of positive to negative cases was comparable between sets. Prior to training, we used image augmentation techniques to compensate for the class imbalance in our data. Our results showed that deep learning networks can automatically detect cystic GBMs on MRIs with high accuracy and thus illustrates the potential use of this technique in clinically relevant settings.

Improved performance of the 2017 McDonald criteria for diagnosis of multiple sclerosis in children in a real-life cohort

Objective: To compare the performance of the 2017 McDonald criteria with that of the 2010 criteria for the diagnosis of multiple sclerosis (MS) in children in the clinical setting. Methods: In this retrospective, multi-centre study, we identified children who presented with symptoms suggestive of a clinically isolated syndrome (CIS) and were followed up for at least 2 years or until their second attack. Results: Of 156 children with CIS followed up for a median of 4.17 years, 94 (60.3%) were diagnosed with MS. In all, 83 (88.3%) of these fulfilled the 2010 dissemination in space (DIS) criteria at onset. Three additional children fulfilled the 2017 DIS criteria because of the inclusion of symptomatic lesions. Of the 59 children with MS who underwent post-gadolinium magnetic resonance imaging (MRI), 44 (74.6%) fulfilled the 2010 dissemination in time (DIT) criteria at baseline. When the presence of oligoclonal bands (OCBs) was used to substitute DIT, an additional 35 children (79/94, 84.0%) were diagnosed with MS according to the 2017 criteria. The 2017 criteria had higher accuracy (87.2% vs 66.7%), higher sensitivity (84.0% vs 46.8%), but reduced specificity (91.9% vs 96.8%) when compared to the 2010 criteria. Conclusion: The improved performance of the 2017 criteria when compared to the 2010 criteria was predominantly due to the inclusion of intrathecal OCBs.

Bevacizumab Monotherapy Reduces Radiation-induced Brain Necrosis in Nasopharyngeal Carcinoma Patients: A Randomized Controlled Trial

Studies have shown that addition of bevacizumab to corticosteroids improves outcome against radiation-induced brain necrosis (RN). Here, we aimed to evaluate the effectiveness and safety of bevacizumab monotherapy on RN in nasopharyngeal carcinoma (NPC) patients. In this multicenter open-label study, patients with RN were randomly assigned (1:1) into a bevacizumab group (5mg/kg intravenously every 2weeks, for 4 cycles) or a corticosteroid group (methylprednisolone 500mg/day intravenously for 3 consecutive days and then gradually tapered, followed by 10mg/day oral prednisone, for 2months in total). Magnetic resonance imaging (MRI) was performed pre- and post-treatment to define the radiographic response. The primary outcome was a 2-month response rate as determined by MRI and clinical symptoms. All of the patients were followed up with for 6months. The trial was registered at www.clinicaltrials.gov (NCT01621880). Of 121 patients screened, 112 patients met the entry criteria. Thirty-eight (65.5%) patients in the bevacizumab group showed response, which was significantly higher than that in the corticosteroid group (65.5% vs 31.5%, P<.001). The mean percentage decrease in RN volume seen on T1 post-gadolinium and T2-weighted fluid-attenuated inversion recovery (FLAIR) MRI was 25.5% and 51.8%, respectively, in the bevacizumab group, versus 5.0% and 19.3%, respectively, in the corticosteroid group. Moreover, 36 patients (62.1%) on bevacizumab and 23 patients (42.6%) on corticosteroids demonstrated clinical improvement (P=.039). During the 6-month follow up, fourteen patients on bevacizumab and 13 patients on corticosteroids showed RN recurrence. The most frequent adverse event in the bevacizumab group was hypertension (20.6%). Our study indicate that compared with corticosteroids, bevacizumab offers improved symptomatic relief and radiographic response.

Local recurrence patterns after postoperative stereotactic radiation surgery to resected brain metastases: A quantitative analysis to guide target delineation

PurposeIn the treatment of resected metastatic brain disease, a recent phase 3 trial by the North Central Cancer Treatment Group (N107C/CEC.3) surprisingly found that the local control rate for whole-brain radiation therapy was better than that of stereotactic radiation surgery (SRS). To optimize target delineation, we performed a quantitative analysis of local failure patterns after postoperative SRS. Methods and materialsPatients with brain metastases who were treated with surgery and SRS to the cavity were evaluated. Local failure was defined by pathologic confirmation or magnetic resonance imaging evidence of progression leading to further overlapping radiation therapy. T1 postgadolinium magnetic resonance imaging scans that were taken preoperatively and at recurrence were co-registered to the simulation computed tomography. Three volumes were compared: (1) Preoperative tumors, (2) resection cavities that were originally contoured as clinical target volumes for SRS, and (3) recurrent tumors. Overlap volume histograms quantified the proximity of the three volumes to the meninges. ResultsIn the cohort of 173 patients, 18 patients experienced local failure in 19 resection cavities. The original SRS target volume overlapped with a median of 69.6% of the recurrent tumor. When the entire preoperative tumor was included, the overlap with the recurrent tumor increased to a median of 76.8%. Recurrent tumors were closer to the meninges than corresponding preoperative tumors (P = .03) but a median 8.2 mm expansion of the target volume from the meninges was needed to increase overlap with the recurrent tumor to 90%. Increases in overlap with the recurrent tumor were achieved most efficiently by uniformly expanding the contoured cavity and a median 2.8 mm expansion covered 90% of the recurrent tumor. ConclusionsOur quantitative analysis of recurrence patterns suggests that a larger 3 mm uniform expansion of the SRS target volume substantially increases coverage of the volume that is later occupied by the recurrent tumor and may provide improved local control. The extent of the preoperative tumor in the target volume or expanding the target volume from the meninges provides little benefit.

Osseous Vascularity of the Medial Elbow After Ulnar Collateral Ligament Reconstruction: A Comparison of the Docking and Modified Jobe Techniques.

Background:Although vascularity plays a critical role in healing after ulnar collateral ligament (UCL) reconstruction, intraosseous blood flow to the medial epicondyle (ME) and sublime tubercle remains undefined.Purpose:To quantify vascular disruption caused by tunnel drilling with the modified Jobe and docking techniques for UCL reconstruction.Study Design:Controlled laboratory study.Methods:Eight matched pairs (16 specimens) of fresh-frozen cadaveric upper extremities were randomized to 1 of 2 study groups: docking technique or modified Jobe technique. One elbow in each pair underwent tunnel drilling by the assigned technique, while the contralateral elbow served as a control. Pregadolinium and postgadolinium magnetic resonance imaging were performed to quantify intraosseous vascularity within the ME, trochlea, and proximal ulna. Three-dimensional computed tomography (CT) and gross dissection were performed to assess terminal vessel integrity.Results:Ulnar tunnel drilling had minimal impact on vascularity of the proximal ulna, with maintenance of >95% blood flow for each technique. Perfusion in the ME was reduced 14% (to 86% of baseline) for the docking technique and 60% (to 40% of baseline) for the modified Jobe technique (mean difference, 46%; P = .029). Three-dimensional CT and gross dissection revealed increased disruption of small perforating vessels of the posterior aspect of the ME for the modified Jobe technique.Conclusion:Although tunnel drilling in the sublime tubercle appears to have a minimal effect on intraosseous vascularity of the proximal ulna, both the docking and modified Jobe techniques reduce flow in the ME. This reduction was 4 times greater for the modified Jobe technique, and these findings have important implications for UCL reconstruction surgery.Clinical Relevance:As the rate of revision UCL reconstructions continues to rise, investigation into causes for failure of primary surgery is needed. One potential cause is poor tendon-to-bone healing due to inadequate vascularity. This study quantifies the amount of vascular insult that is incurred in the ME during UCL reconstruction. While vascular insult is only one of many factors that affects the surgical success rate, surgeons performing this procedure should be mindful of this potential for vascular disruption.

Diagnosing Neoplastic Hematoma: Role of MR Perfusion.

The imaging appearance of neoplastic hematoma can be complicated by the presence of alarge hematoma, even on magnetic resonance imaging (MRI). We describe the role of MR perfusion (MRP) in detecting neoplastic hematomas in patients with intraparenchymal hematoma (IPH). Aretrospective review was performed for consecutive patients with IPH, where MRP was performed. Routine, post-gadolinium MRI and MRP were analyzed. All patients were either operated on for evacuation of IPH or followed up on imaging. The MRP parameters of cerebral blood volume (CBV) and cerebral blood flow (CBF) and pattern of enhancement (peripheral linear vs. nodular) were recorded. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated for these parameters for diagnosing neoplastic hematoma. Of 116 patients with MRP, 16patients (male 8; mean age-65.5 years) had IPH on their initial MRI. For diagnosing neoplastic hematoma, the sensitivity, specificity, PPV and NPV for increased CBF and CBV were 100%, 88.9%, 87.5%, and 100%; for peripheral linear enhancement were 100%, 28.6%, 50%, 100% and for nodular enhancement were 85.7%, 77.8%, 75% and 12.5%, respectively. The combination of peripheral linear enhancement and increased CBF and CBV showed 100% sensitivity, specificity, PPV and NPV. In our small series, the combination of peripheral linear enhancement and increased CBF and CBV showed 100% sensitivity, specificity, PPV and NPV for diagnosing aneoplastic hematoma. These findings need to be validated in alarger study.

Neuroinflammation in Response to Intracerebral Injections of Different HMGB1 Redox Isoforms

Background: Neuroinflammation triggered by infection or trauma is the cause of central nervous system dysfunction. High-mobility group box 1 protein (HMGB1), released from stressed and dying brain cells, is a potent neuroinflammatory mediator. The proinflammatory functions of HMGB1 are tightly regulated by post-translational redox modifications, and we here investigated detailed neuroinflammatory responses induced by the individual redox isoforms. Methods: Male Dark Agouti rats received a stereotactic injection of saline, lipopolysaccharide, disulfide HMGB1, or fully reduced HMGB1, and were accessed for blood-brain barrier modifications using magnetic resonance imaging (MRI) and inflammatory responses by immunohistochemistry. Results and Conclusions: Significant blood-brain barrier disruption appeared 24 h after injection of lipopolysaccharide, disulfide HMGB1, or fully reduced HMGB1 compared to controls, as assessed in post-gadolinium T1-weighted MRI images and confirmed by increased uptake of FITC-conjugated dextran. Immunohistochemistry revealed that both HMGB1 isoforms also induced a local production of IL-1β. Additionally, disulfide HMGB1 increased major histocompatibility complex class II expression and apoptosis. Together, the results demonstrate that extracellular, cerebral HMGB1 causes significant blood-brain barrier disruption in a redox-independent manner and activates several components of neuroinflammation. Blocking HMGB1 might potentially improve clinical outcome in conditions such as stroke and traumatic brain injury.

3-Tesla magnetic resonance imaging evaluation of intraspinal extramedullary nonosseous neoplastic lesions with their postsurgical and histopathological correlation

Aims: This study aimed to evaluate the diagnostic ability of 3-Tesla magnetic resonance imaging (MRI) in detection and characterization of intraspinal extramedullary nonosseous neoplastic lesions and their histopathological correlation. Settings and Design: It was a prospective study involving fifty patients who presented with low backache and lower limb weakness with MRI findings suggestive of a neoplastic extramedullary intraspinal lesion. Patients and Methods: A 3-Tesla 16-channel MRI scanner was used for imaging. Multiplanar imaging was done using T1, T2, short-tau inversion recovery sequences and T1 fat-saturated sequences. All patients then underwent postgadolinium MRI. The findings of MRI were then reviewed. An analysis of correlation between MRI findings and surgical and histopathological findings was done. Results: Out of the fifty patients evaluated, intradural lesions were noted in forty patients and extradural lesions in ten patients. Schwannoma was the most common tumor, followed by meningioma in the intradural category. Two rare cases of intradural lipoma and malignant peripheral nerve sheath tumors were also detected. In extradural category, metastasis was the most common lesion along with two rare lesions of epidural meningioma and leukemia-associated granulocytic sarcoma. Conclusions: MRI is an indispensable tool in the evaluation of spinal neoplasms. Its multiplanar capability, high-quality soft-tissue resolution, and depiction of various anatomic landmarks help the neurosurgeon to make a road map for the surgery. In most of the cases, MRI can give information regarding the histopathology of the lesion. However, in some cases, differential diagnosis needs to be included, especially in cases of extradural meningiomas and malignant peripheral nerve sheath tumors, because of their rare incidence.

Gadolinium Contrast Enhancement Improves Confidence in Diagnosing Recurrent Soft Tissue Sarcoma by MRI

To determine how utilization of postgadolinium magnetic resonance imaging (MRI) influenced reader accuracy and confidence at identifying postoperative soft tissue sarcoma (STS) recurrence among readers with various levels of expertise. This retrospective study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Postoperative MRI from 26 patients with prior STS resection (13 patients with confirmed recurrence, 13 without recurrence) was reviewed. Four blinded readers of varying expertise (radiology resident, fellow, attending, and orthopedic oncologist) initially evaluated only the precontrast images and rated each MRI for recurrence on a 5-point confidence scale. Assessment was repeated with the addition of contrast-enhanced sequences. Diagnostic accuracy based on confidence ratings was evaluated using the area under the receiver operating characteristic curve (AUC). Changes in confidence ratings were calculated using Wilcoxon signed-rank test. All readers demonstrated good diagnostic accuracy both with and without contrast-enhanced images (AUC >0.98 for each reader). When contrast-enhanced images were made available, the resident recorded improved confidence with both assigning (P = 0.031) and excluding recurrence (P = 0.006); the fellow showed improved confidence only with assigning recurrence (P = 0.015); and the surgeon showed improved confidence in excluding recurrence (P = 0.003). The addition of contrast-enhanced images did not significantly influence the diagnostic confidence of the attending radiologist. Diagnostic accuracy of MRI was excellent in evaluating postoperative STS recurrence, and reader confidence improved depending on expertise when postgadolinium imaging was included in the assessment.

Comparison of endorectal ultrasound versus pelvic magnetic resonance imaging for radiation treatment planning in locally advanced rectal cancer

PurposeCurrent National Comprehensive Cancer Network guidelines for rectal cancer recommend tumor and nodal staging using endorectal ultrasound (EUS) or pelvic magnetic resonance imaging (MRI). EUS and MRI have similar accuracy for staging rectal cancers. The relative benefits of each modality for radiation therapy (RT) treatment planning are unknown. Methods and materialsEUS, MRI, and treatment planning computed tomography scans were reviewed for 6 patients with locally advanced rectal cancer treated with neoadjuvant chemotherapy followed by neoadjuvant chemoradiation therapy. Thirty rectal gross tumor volumes (GTVs) were contoured: 2 GTVEUS (contoured independently by 2 radiation oncologists), 2 GTVMRI, and one GTV treatment (contoured by the treating physician for the original treatment plan) per patient from the original treatment plan. GTVEUS was based on colonoscopy and EUS. GTVMRI was based on T2 postgadolinium MRI sequences fused with treatment planning computed tomography. GTVEUS and GTVMRI volume, craniocaudal length, and number of suspicious lymph nodes (LN) were compared between EUS vs MRI and compared to GTV treatment. Agreement between contours was calculated as the percentage of overlapping slices over total slices for MRI and EUS-based contours. Paired t test was used to assess relationships between imaging modality and treatment volume, craniocaudal length, and LN number. ResultsFor volume and craniocaudal length, mean GTVEUS was significantly smaller than mean GTVMRI (P = .02 and P = .04, respectively). The mean number of suspicious LN identified by MRI was significantly greater than by EUS (4.8 vs 3.0; P = .03). Agreement between radiation oncologist GTV contours was greater for GTVMRI than for GTVEUS (71% vs 44%), although not statistically significantly so (P = .11). ConclusionsPelvic MRI for RT treatment planning in locally advanced rectal cancer generates more comprehensive and reproducible GTV contours than does the use of EUS. Pelvic MRI can be recommended to aid in RT treatment planning for all eligible patients undergoing RT for locally advanced rectal cancer.

Conservative Management of Vestibular Schwannoma in the West of Scotland: A 20‐Year Experience

Objectives: In our skull base unit, large vestibular schwannomas (VS) over 30 mm at presentation are usually offered surgery but the remainder have their growth monitored by interval imaging with treatment (surgery or stereotactic radiotherapy) being offered to patients whose tumors are growing significantly. Methods: A prospective database of consecutive patients diagnosed with sporadic VS and referred to the Skull Base unit in South Glasgow, United Kingdom, over the last 20 years was retrospectively reviewed. Patients with neurofibromatosis type II were excluded. Patients who consented to being managed conservatively by initial interval imaging using 6-monthly axial T1-weighted post-gadolinium magnetic resonance imaging (MRI) had the growth of their VS assessed. Growth (defined as &gt;2mm) was the primary outcome measure. Intracanalicular tumors were compared to cerebellopontine angle (CPA) ones. Results: There were 62 intracanalicular (IC) tumors, mean size of 8mm, and 102 CPA VS, mean size of 11mm. One third of patients managed conservatively showed evidence of growth and 50% showed no change (IC &gt; CPA). Twenty percent reduced in size (CPA &gt; IC). Two-thirds of the VS showing growth stabilized or regressed over time. Audiometry was not found to be a useful tool to predict growth but interval MRI scans were. The quality of life of the VS group managed conservatively was found to be comparable across all domains of the short-form 36 (SF-36) with an age and sex match control group. Conclusions: All asymptomatic patients and symptomatic ones with a VS size of &lt;30 mm should initially be offered conservative management with interval imaging.