Usefulness of frozen section in rhinocerebral mucormycosis diagnosis and management.

AIMS: Rhinocerebral mucormycosis (RCM) is a well-described fulminant fungal infection that presents acutely in patients with ketoacidosis and immunosuppression. Very early diagnosis, established with the demonstration of characterised hyphae in tissues, greatly improves the prognosis of RCM. In this regard, the specificity and the sensitivity of frozen section for the diagnosis and the surgical debridement of RCM were evaluated in this study. METHODS AND RESULTS: Frozen section was performed for the diagnosis (six of seven cases) and surgical treatment (three of seven cases) of RCM. In all cases, diagnosis was made by frozen section and confirmed by histological examination. Frozen section allowed radical surgical excision of infected tissue. In all cases, invasive, broad-based non-septated hyphae with branching at right angles were well demonstrated on toluidine blue staining. Cultures were positive for Rhizopus oryzae in three of seven cases. Outcome was favourable for five of seven patients and two patients died after the diagnosis. CONCLUSIONS: Frozen section is a specific and sensitive method to make both a quick initial diagnosis of RCM and to successfully eradicate the tissue infected by organisms belonging to the order Mucorales.

Dentalmaps: automatic dental delineation for radiotherapy planning in head-and-neck cancer.

PURPOSE: To propose an automatic atlas-based segmentation framework of the dental structures, called Dentalmaps, and to assess its accuracy and relevance to guide dental care in the context of intensity-modulated radiotherapy. METHODS AND MATERIALS: A multi-atlas-based segmentation, less sensitive to artifacts than previously published head-and-neck segmentation methods, was used. The manual segmentations of a 21-patient database were first deformed onto the query using nonlinear registrations with the training images and then fused to estimate the consensus segmentation of the query. RESULTS: The framework was evaluated with a leave-one-out protocol. The maximum doses estimated using manual contours were considered as ground truth and compared with the maximum doses estimated using automatic contours. The dose estimation error was within 2-Gy accuracy in 75% of cases (with a median of 0.9 Gy), whereas it was within 2-Gy accuracy in 30% of cases only with the visual estimation method without any contour, which is the routine practice procedure. CONCLUSIONS: Dose estimates using this framework were more accurate than visual estimates without dental contour. Dentalmaps represents a useful documentation and communication tool between radiation oncologists and dentists in routine practice. Prospective multicenter assessment is underway on patients extrinsic to the database.