Relational reasoning network for anatomical landmarking.

Purpose: We perform anatomical landmarking for craniomaxillofacial (CMF) bones without explicitly segmenting them. Toward this, we propose a simple, yet efficient, deep network architecture, called relational reasoning network (RRN), to accurately learn the local and the global relations among the landmarks in CMF bones; specifically, mandible, maxilla, and nasal bones. Approach: The proposed RRN works in an end-to-end manner, utilizing learned relations of the landmarks based on dense-block units. For a given few landmarks as input, RRN treats the landmarking process similar to a data imputation problem where predicted landmarks are considered missing. Results: We applied RRN to cone-beam computed tomography scans obtained from 250 patients. With a fourfold cross-validation technique, we obtained an average root mean squared error of < 2 mm per landmark. Our proposed RRN has revealed unique relationships among the landmarks that help us in inferring informativeness of the landmark points. The proposed system identifies the missing landmark locations accurately even when severe pathology or deformations are present in the bones. Conclusions: Accurately identifying anatomical landmarks is a crucial step in deformation analysis and surgical planning for CMF surgeries. Achieving this goal without the need for explicit bone segmentation addresses a major limitation of segmentation-based approaches, where segmentation failure (as often is the case in bones with severe pathology or deformation) could easily lead to incorrect landmarking. To the best of our knowledge, this is the first-of-its-kind algorithm finding anatomical relations of the objects using deep learning.

Nasopharyngeal granulomatous mass after radiotherapy for nasopharyngeal carcinoma.

OBJECTIVE: To evaluate the diagnosis, management and nasal endoscopic surgical outcome of nasopharyngeal granulomatous mass in post-radiation nasopharyngeal carcinoma (NPC) patients. MATERIALS AND METHODS: A total of 23 cases of granulomatous mass after radiotherapy for NPC from 2008 to 2013 treated with nasal endoscopic surgery were retrospectively reviewed. RESULTS: Radiotherapy dose (p=0.036) and chemotherapy (p<0.001) correlated with the latency period after the treatment against NPC. The symptoms of the 23 patients before the treatment were nonspecific including nasal obstruction, purulent discharge, headache, epistaxis, foreign body sensation and/or hearing impairment. 12 patients (52.2%) were misdiagnosed to be recurrence of NPC by imaging examination (CT/MRI). After the endoscopic surgery treatment, 18 patients were disease free while the other 5 patients had developed a recurrence. Four of those five recurrent patients were cured with the repeated treatment. Histologic findings of granulation tissue with fibrin and inflammatory cells were found in all of the patients. CONCLUSIONS: In situ granulomatous masses in post-radiation NPC patients are very prone to be misdiagnosed as recurrence of nasopharyngeal carcinoma. Chemotherapy is a significant independent factor affecting latency period (p=0.029). The nasal endoscopic surgery is an effective therapy for post-radiation nasopharyngeal granuloma; surgery can not only alleviate symptoms, what is more important, but it also helps to confirm the diagnosis.

Impact of different surgical and postoperative adjuvant treatment modalities on survival of sinonasal malignant melanoma.

BACKGROUND: The role of postoperative adjuvant treatment for sinonasal malignant melanoma remains unclear. This study evaluates the impact of three different surgical and postoperative adjuvant treatment modalities: surgery alone(open and endoscopic approaches), surgery plus radiotherapy and surgery, radiotherapy plus chemotherapy on survival of patients with primary sinonasal malignant melanoma (SMM). METHODS: The data of 69 patients who underwent primary surgical treatments at Eye & ENT hospital of Fudan University between January 1st, 2000 and December 31st, 2010 were retrospectively reviewed. Survival comparison of different surgical and postoperative adjuvant treatment modalities (surgery alone, surgery plus radiotherapy and surgery, radiotherapy plus chemotherapy), as well as survival comparison between open and endoscopic surgical approaches were performed. Curves depicting survival were performed using Kaplan-Meier method. Statistical analysis was performed using log-rank test software SPSS19 and p < .05 is considered as statistically significant. RESULTS: The median overall survival time was found to be 18 months for surgery alone (27 cases), 32 months for surgery plus radiotherapy (24 cases), 42 months for surgery, radiotherapy plus chemotherapy (18 cases). The 3 and 5 year survival rates for groups mentioned above were 14.8% and 5.6%, 45.1% and 31.6%, 55% and 32.1%, respectively. Statistical significances were found not only between surgery alone and surgery plus radiotherapy treatment group (P = 0.012), but also surgery alone and surgery, radiotherapy plus chemotherapy group (P = 0.002). There was no statistically significant survival difference found between the two different surgical approaches (41 cases for open approach and 28 cases for endoscopic approach). CONCLUSIONS: Sinonasal malignant melanoma is a disease with a poor prognosis. Patients who underwent surgery plus radiotherapy or surgery, radiotherapy plus chemotherapy had better survival outcomes than those underwent surgery alone. Endoscopic approach provided similar survival outcome as an open approach.

Pressure necrosis of septal cartilage associated with bilateral extended spreader grafts in rhinoplasty.

OBJECTIVE: To investigate septal cartilage compressive changes as a result of bilateral extended spreader grafts (ESGs), which are commonly used in rhinoplasty. The buckling, rupturing, or necrosis of the recipient site leads to nasal tip structural deformity. These pathologic changes associated with bilateral ESGs warrant the clinician's attention and in-depth basic and clinical research. METHODS: The basic experimental study involves New Zealand rabbits, randomly assigned to groups A, B, C, and D, with group A as a reference. The right auricular cartilage was harvested and transplanted into a corresponding anatomic location of the left ear. The compressive effect was studied by gross observation and microscopic examination with hematoxylin-eosin staining after 3 months. In a clinical experiment, revision rhinoplasty surgical procedures were performed in 10 human patients 6 months to 1 year after placement of bilateral ESGs. The compressive changes of septal cartilages between the ESGs were observed intraoperatively. RESULTS: In group A of the rabbits, no pathologic change was noted, but 2 cases of attenuation were observed in group B (33.3%), 6 cases of central fracture (100%) with 1 case of perforation (16.7%) in group C, and 6 cases of different degrees of defects in group D (100%). Clinical intraoperative observations revealed 1 case of defects and necrosis (10%), 4 cases of attenuations and cracks (40%), and 5 cases of attenuations (50%). CONCLUSIONS: Septal cartilage compressive necrosis leading to structural damage by bilateral septal ESGs is a clinically significant complication of rhinoplasty. Owing to its affect on the viability of the original septal cartilages, we believe the unilateral ESG with columellar strut is preferred, especially in Asian patients.

Gross and pathologic analysis of long-term silicone implants inserted into the human body for augmentation rhinoplasty: 221 revision cases.

BACKGROUND: In augmentation rhinoplasty, delayed morphologic changes are often observed with silicone implants, despite them being known as a safe implant material. The purpose of this study was to identify the cause and time course of delayed shape changes of silicone implants, through the long-term evaluation of inserted implants and their surrounding nasal soft tissues after their removal at revision rhinoplasty operations. METHODS: Two hundred twenty-one silicone implants removed during revision rhinoplasty were studied. The period of insertion ranged from 1 month to 25 years, with an average of 6 years 7 months. Calcification within the silicone implants and, when available, the capsular soft-tissue attachments were examined with the naked eye and light microscopy. RESULTS: Calcification was first observed grossly with the naked eye after 5 years 8 months of insertion. With light microscopy, calcification debris could be seen after 4 years. After implant insertion for more than 9 years, focal calcification could be seen in 50 percent of implants. When implants had been inserted for more than 15 years, a denatured type of large calcification was clearly observed. Plasma cell, macrophage, and neutrophil proliferation was noted in the soft-tissue capsule surrounding the superficial calcifications in those individuals with an early inflammatory response, and lymphocyte proliferation was noted in those with a late inflammatory response. CONCLUSIONS: Silicone implants were noted to induce calcification when inserted for a long time, causing long-term morphologic changes. This should be taken into consideration when choosing silicone implants for augmentation rhinoplasty.