Reliability and accuracy of skeletal muscle imaging in limb-girdle muscular dystrophies.

OBJECTIVE: To evaluate the reliability and accuracy of skeletal muscle CT to correctly identify different muscular dystrophies manifesting with limb-girdle weakness. METHODS: Four evaluators assessed scans from 118 patients with limb-girdle muscular dystrophy (LGMD) caused by mutations in 7 different genes and from 32 controls. The conditions studied were scans of genetically confirmed cases of Becker muscular dystrophy (BMD) (n = 28), LGMD2C-F (sarcoglycanopathies) (n = 11), LGMD2I (n = 4), LGMD1B (n = 26), LGMD2A (n = 24), Bethlem myopathy (n = 14), and LGMD2L (n = 11). The control group (n = 32) consisted of patients with neuromuscular disorders manifesting with limb-girdle weakness in which the aforementioned muscular dystrophies were excluded. The scans were compared with the characteristic patterns described in literature. RESULTS: The overall interobserver agreement was poor (κ = 0.27), with markedly higher scores for BMD (κ = 0.51) and Bethlem myopathy (κ = 0.59). The sensitivity to detect selective patterns in relation to the genetic diagnosis was 40% if all LGMDs were taken together. The specificity was 58%, positive predictive value (PPV) 77%, and 1 - negative predictive value (NPV) 79%. Markedly better scores were observed for BMD (sensitivity 91%, PPV 66%, 1 - NPV 3%) and Bethlem myopathy (sensitivity 90%, PPV 69%, 1 - NPV 1%). CONCLUSIONS: Our findings suggest that muscle CT might be an adjunct to the clinical diagnosis of BMD and Bethlem myopathy. However, pattern recognition was cumbersome in the other LGMDs.

MR imaging predictors of local control of glottic squamous cell carcinoma treated with radiation alone.

PURPOSE: To retrospectively evaluate the prognostic significance of magnetic resonance (MR) imaging-determined tumor parameters, especially the presence of cartilage invasion, regarding local control of glottic squamous cell carcinoma treated with radiation therapy (RT) alone. MATERIALS AND METHODS: The study was performed with the approval of our institutional review board; direct patient consent was waived. Pretreatment MR images of 118 patients aged 41-86 years (110 men, eight women) with glottic carcinoma treated with RT alone were reviewed for tumor involvement of specific laryngeal anatomic subsites (including laryngeal cartilage), tumor volume, and extralaryngeal tumor spread; these findings were compared with local control. Local control was defined as absence of a recurrence at the primary site for 2 years. Statistical significance of differences between curves for local control estimated with the Kaplan-Meier method was tested with log-rank test. RESULTS: Results of univariate analysis showed all MR imaging-determined parameters to be significant predictors of local control rate, compared with clinical parameters where T classification and vocal cord mobility were the only significant parameters associated with local control. Multivariate analysis (Cox regression model) of clinical and radiologic parameters revealed that hypopharyngeal extension (P=.04) and intermediate T2 signal intensity (SI) in cartilage similar to tumor SI (P<.001) were independent prognostic factors with regard to local control. CONCLUSION: Intermediate T2 SI in cartilage, which may suggest cartilage invasion, and hypopharyngeal extension of tumor, predict greater likelihood of local failure, whereas high T2 SI, which may suggest inflammatory tissue in cartilage, predicts lower likelihood of local failure.

Supraglottic carcinoma treated with curative radiation therapy: identification of prognostic groups with MR imaging.

PURPOSE: To retrospectively assess the prognostic meaning of tumor characteristics depicted on pretreatment magnetic resonance (MR) images for local outcome in supraglottic squamous cell carcinoma treated with definitive radiation therapy. MATERIALS AND METHODS: Pretreatment MR images acquired in 84 patients with supraglottic carcinoma treated with curative radiation therapy were reviewed for tumor involvement of laryngeal sites including glottis, subglottis, pre-epiglottic space, laryngeal cartilages, and hypopharynx, and for extralaryngeal extension. The volume of each tumor was estimated, and mean tumor volume was calculated for the group of tumors in each T staging category. RESULTS: Results of univariate analysis showed MR imaging-determined primary tumor volume (P =.03), involvement of pre-epiglottic space (P =.008), abnormal signal intensity in thyroid cartilage (P =.04), and extralaryngeal extension beyond thyroid and/or cricoid cartilage (P =.02) to be significant predictors of local control rate. Results of multivariate analysis with the Cox regression model confirmed statistical significance for invasion of pre-epiglottic space (P =.004) and for abnormal signal intensities in thyroid cartilage adjacent to the anterior commissure (P =.04) and in cricoid cartilage (P =.01). Five-year local control rates were calculated from the regression coefficients of three independent MR imaging prognostic factors, and three prognostic groups were identified on the basis of these control rates. The 5-year local control rate in the high-risk group was 35%, significantly lower than the rates in the intermediate- and low-risk groups (60% and 89%, respectively; P =.002). CONCLUSION: MR imaging-determined pre-epiglottic space involvement and abnormal signal intensities in the thyroid cartilage adjacent to the anterior commissure and/or the cricoid cartilage are strong predictors of local outcome in supraglottic carcinoma treated with definitive radiation therapy.