Value of PET/CT 3D visualization of head and neck squamous cell carcinoma extended to mandible.

PURPOSE: To study an original 3D visualization of head and neck squamous cell carcinoma extending to the mandible by using [18F]-NaF PET/CT and [18F]-FDG PET/CT imaging along with a new innovative FDG and NaF image analysis using dedicated software. The main interest of the 3D evaluation is to have a better visualization of bone extension in such cancers and that could also avoid unsatisfying surgical treatment later on. PATIENTS AND METHODS: A prospective study was carried out from November 2016 to September 2017. Twenty patients with head and neck squamous cell carcinoma extending to the mandible (stage 4 in the UICC classification) underwent [18F]-NaF and [18F]-FDG PET/CT. We compared the delineation of 3D quantification obtained with [18F]-NaF and [18F]-FDG PET/CT. In order to carry out this comparison, a method of visualisation and quantification of PET images was developed. This new approach was based on a process of quantification of radioactive activity within the mandibular bone that objectively defined the significant limits of this activity on PET images and on a 3D visualization. Furthermore, the spatial limits obtained by analysis of the PET/CT 3D images were compared to those obtained by histopathological examination of mandibular resection which confirmed intraosseous extension to the mandible. RESULTS: The [18F]-NaF PET/CT imaging confirmed the mandibular extension in 85% of cases and was not shown in [18F]-FDG PET/CT imaging. The [18F]-NaF PET/CT was significantly more accurate than [18F]-FDG PET/CT in 3D assessment of intraosseous extension of head and neck squamous cell carcinoma. This new 3D information shows the importance in the imaging approach of cancers. All cases of mandibular extension suspected on [18F]-NaF PET/CT imaging were confirmed based on histopathological results as a reference. CONCLUSIONS: The [18F]-NaF PET/CT 3D visualization should be included in the pre-treatment workups of head and neck cancers. With the use of a dedicated software which enables objective delineation of radioactive activity within the bone, it gives a very encouraging results. The [18F]-FDG PET/CT appears insufficient to confirm mandibular extension. This new 3D simulation management is expected to avoid under treatment of patients with intraosseous mandibular extension of head and neck cancers. However, there is also a need for a further study that will compare the interest of PET/CT and PET/MRI in this indication.

[Gastric perforation caused by a lactobezoar in an infant: a case report]. / Lactobézoard du nourrisson compliqué de perforation gastrique.

Lactobezoar is a compact mass of undigested milk concretions and mucous secretions in the gastrointestinal tract. It is usually located in the stomach, resulting in various degrees of gastric outlet obstruction. Lactobezoar is the most common type of bezoar in infancy. We report the case of rare and complicated gastric outlet obstruction secondary to lactobezoar. A female infant, 35weeks and 4days' gestation, one of dichorionic, diamniotic twins (birth weight, 1.890kg), was referred to our center at 5days of life for shock and food intolerance. She was on discontinuous oral feedings with a maltodextrin-enriched infant formula. On examination on day 4, there was a tender mass palpable in the left hypochondrium and on day 5, there was abdominal distension with signs of hemodynamic instability and sepsis. Plain abdominal X-ray showed a pneumoperitoneum associated with a heterogeneous mass in a distended stomach, consistent with a bezoar. An emergency laparotomy revealed a gastric perforation secondary to a large lactobezoar, with necrosis of the greater curvature and anterior wall of the stomach. Surgical treatment consisted of extraction of the lactobezoar, partial gastrectomy (resection of necrotic areas), and gastrostomy. Pathological examination confirmed the necrosis of the gastric mucosa. The postoperative course was complicated by prolonged sepsis. The child was kept NPO for 21days. On day 21 postsurgery, an upper gastrointestinal contrast study showed a well-dimensioned stomach, with a good pyloric passage. Gastrostomy and oral feedings were then initiated with good outcome at 6months. Etiopathogenic factors of lactobezoar are prematurity, low birth weight, altered gastric secretions and disturbed gastric emptying, hypercaloric and predominantly casein-based formulas, and inadequate milk composition. Lactobezoar should be considered in infants with symptoms of gastrointestinal obstruction with evocative images. Conservative management with nil per os, parenteral nutrition, and regular saline gastric washes has a good prognosis with rapid resolution of symptoms. Surgical indications are rare, and early and appropriate diagnosis should help limit and reduce the morbidity of lactobezoar.

[Radio-guided resection of residual metastatic lymph node from a previously resected neuroendocrine tumor]. / Exérèse radioguidée d'une adénopathie résiduelle métastatique d'une tumeur neuroendocrine antérieurement réséquée.

Neuroendocrine tumors are slowly growing and carry a high risk of recurrence. Somatostatin receptor scintigraphy is considered as the gold standard for preoperative evaluation and postoperative follow-up. The use of an intraoperative detection probe makes easier a complete resection of abdominal residual or recurrent tumor. These resections may be incomplete because of the small size of the tumor and the postoperative adhesions. Radio-guided surgery is recommended in order to reduce the need for reoperation.