Additive Benefit of Radiomics Over Size Alone in the Distinction Between Benign Lesions and Luminal A Cancers on a Large Clinical Breast MRI Dataset.

RATIONALE AND OBJECTIVES: The objective of this study was to demonstrate improvement in distinguishing between benign lesions and luminal A breast cancers in a large clinical breast magnetic resonance imaging database by using quantitative radiomics over maximum linear size alone. MATERIALS AND METHODS: In this retrospective study, 264 benign lesions and 390 luminal A breast cancers were automatically segmented from dynamic contrast-enhanced breast magnetic resonance images. Thirty-eight radiomic features were extracted. Tenfold cross validation was performed to assess the ability to distinguish between lesions and cancers using maximum linear size alone and lesion signatures obtained with stepwise feature selection and a linear discriminant analysis classifier including and excluding size features. Area under the receiver operating characteristic curve (AUC) was used as the figure of merit. RESULTS: For maximum linear size alone, AUC and 95% confidence interval was 0.684 (0.642, 0.724) compared to 0.728 (0.687, 0.766) (P = 0.005) and 0.729 (0.689, 0.767) (P = 0.005) for lesion signature feature selection protocols including and excluding size features, respectively. The features of irregularity and entropy were chosen in all folds when size features were included and excluded. AUC for the radiomic signature using feature selection from all features was statistically equivalent to using feature selection from all features excluding size features, within an equivalence margin of 2%. CONCLUSIONS: Inclusion of multiple radiomic features, automatically extracted from magnetic resonance images, in a lesion signature significantly improved the ability to distinguish between benign lesions and luminal A breast cancers, compared to using maximum linear size alone. The radiomic features of irregularity and entropy appear to play an important but not a solitary role within the context of feature selection and computer-aided diagnosis.

Great auricular nerve injury, the "subauricular band" phenomenon, and the periauricular adipose compartments.

BACKGROUND: Experience with anatomical dissection has suggested that two potential complications of rhytidectomy are related to the anatomy of the periauricular adipose compartments: great auricular nerve injury and the "subauricular band" phenomenon. This study describes this anatomy and its relationship to these potential complications. METHODS: The results of 24 fresh hemifacial cadaver dissections were included in this study. Injections included the use of methylene blue and fixable dye injected into specific regions around the ear. The study incorporated digital macro photography, time-lapse photography, and three-dimensional cross-sections in multiple planes (coronal, sagittal, and axial planes) to identify structural relationships. RESULTS: This study defined five periauricular adipose compartments. The main branch of the great auricular nerve always ran within the subauricular membrane. The subauricular membrane was located between the subauricular and inferior adipose compartments. Inadequate dissection of the lateral neck and postauricular area along with failure to release this membrane completely results in banding of the lateral neck, a stigma of face lift surgery. McKinney's point was consistently found to lie where the great auricular nerve travels deep to the inferior border of Lore's fascia and the tail of the parotid. Below this point, the great auricular nerve is closer to the skin surface and more susceptible to potential injury. CONCLUSION: Two possible complications of rhytidectomy, great auricular nerve injury and the "subauricular band" phenomenon, are avoidable by understanding the anatomy of the periauricular adipose compartments.

The role of the latissimus dorsi flap in reconstruction of the irradiated breast.

BACKGROUND: The role of the latissimus dorsi flap with a prosthesis in reconstruction of the previously irradiated breast is examined in this retrospective review of one surgeon's 10-year experience. METHODS: Twenty-eight patients with available charts were divided into five groups: (1) 11 patients with previous breast conservation therapy and recurrence; (2) eight patients with previous mastectomy and radiation; (3) four patients with an expander that had been irradiated; (4) three patients with prior irradiation and implant reconstruction presenting for revision; and (5) two patients with breast deformity from breast conservation therapy. RESULTS: Eighteen patients had a latissimus flap placed at the time of the expander and 10 had a latissimus flap at the time of implant placement or exchange. Average follow-up was 28.8 months (range, 1 week to 7 years). All patients had soft breasts at follow-up, with no evidence of capsular contracture. Donor-site complications included five donor-site seromas. The majority of patients (65 percent) underwent a planned two-stage reconstruction, and the majority of the revision operations were for exchanges to smaller implants. The response rate to a patient satisfaction survey was 67 percent. The average cosmetic satisfaction rating was 8.5 of 10 (with 10 being the highest). The average pain rating was 1.7 of 10 (with 10 being the worst). The overall satisfaction rating was 8.8 of 10. Fourteen of 16 patients indicated that they would undergo this procedure again. CONCLUSIONS: Although purely autologous reconstructions may be the best choice for many irradiated breasts, it has been shown in this study that a cosmetically acceptable reconstruction with manageable risk can be performed using a prosthesis combined with a latissimus dorsi flap.

Relationship between peripheral nerve decompression and gain of pedal sensibility and balance in patients with peripheral neuropathy.

This was an initial exploratory study to determine if decompression of the 4 medial ankle tunnels (neurolysis of the tibial, medial and lateral plantar, and calcaneal nerves) could lead to improved foot sensibility, increased proprioception and balance, and decreased falls in a population of patients with impaired lower extremity sensation. Fourteen patients with peripheral neuropathy were included in this study. Seventy-one percent of patients were females. Average age was 67 years. All patients were evaluated preoperatively and postoperatively to assess their lower extremity sensibility, as well as their ability to stand still, maintaining their balance with their eyes open and then closed, which is defined as "sway." Lower extremity sensibility was measured with the Pressure-Specified Sensory Device (PSSD), which evaluates 1- and 2-point discrimination for the pulp of the big toe and medial heel. The MatScan Measurement System measured each patient's sway. Neuropathy was the result of diabetes in 72% of patients, a combination of diabetes and hypothyroidism in 7%, chemotherapy in 7%, and idiopathic in 14%. Eight patients underwent peripheral nerve decompression on 1 lower extremity, whereas 6 patients underwent bilateral lower extremity peripheral nerve decompression. Mean toe and heel sensibility improved 9% and 7%, respectively, in the unilateral group, whereas the bilateral group experienced an improvement in mean toe and heel sensibility of 42% (P = 0.02) and 32%, respectively. Preoperative and postoperative sway comparison in the unilateral group revealed a reduction in sway with eyes open and eyes closed by 5% and 31%, respectively. Comparison of preoperative and postoperative sway in the bilateral group showed a reduction with eyes open and eyes closed by 23% and 145% (P = 0.05), respectively. This initial study suggests that there may be benefit from bilateral lower extremity peripheral nerve decompression in helping improve pedal sensibility and balance within the peripheral neuropathy patient population, although further investigation with a larger sample size is warranted to further evaluate these preliminary findings.

Decompression of the lateral femoral cutaneous nerve in the treatment of meralgia paresthetica.

Meralgia paresthetica (MP) is a painful mononeuropathy of the lateral femoral cutaneous nerve (LFCN). Neurolysis is reserved for patients with MP who respond poorly to medical management. This study retrospectively evaluated the outcomes of 41 patients who underwent either unilateral or bilateral neurolysis of the LFCN for a total of 48 procedures. Twenty-nine procedures involved neurolysis of the LFCN alone and 19 procedures involved neurolysis of the LFCN and resection of one or more additional nerves (ilioinguinal, iliohypogastric, genitofemoral). Overall, surgical outcome was considered by patients to be successful in 77 percent of cases. LFCN neurolysis alone had better results, compared to combined LFCN neurolysis and nerve resection. The conclusion is that neurolysis of the LFCN is an effective treatment for MP in properly selected patients.