ABSTRACT
Objectives A persistent craniopharyngeal canal (CPC) is a rare embryologic remnant that presents as a well-corticated defect of the midline sphenoid body extending from the sellar floor to the nasopharynx. Our case series aims to describe three unique presentations of this congenital anomaly and their subsequent management. Design Retrospective review. Setting Tertiary academic medical center. Participants Patients who underwent endoscopic transnasal surgical repair of a CPC lesion. Main Outcome Measures Resolution of symptoms and surgical outcomes. Results A total of three patients were identified. The clinical presentation varied, however, all cases prompted further imaging which demonstrated a persistent CPC and associated pathologic lesion. The presentation of a persistent CPC with nasal obstruction and subsequent iatrogenic cerebrospinal fluid leak as in Case 1 demonstrates the importance of imaging in this work-up. Cases 2 and 3 in the series were representative of the larger subset of patients in the literature who present with the defect incidentally but still warrant surgical management. Nonetheless, a standard approach to diagnosis with preoperative imaging and subsequent transnasal endoscopic repair of the skull base defect was undertaken. Conclusion The persistent CPC is a rare congenital anomaly associated with diverse pathology and careful review of preoperative radiology is critical to the management. When warranted, subsequent surgical repair and reconstruction is associated with excellent postoperative outcomes.
ABSTRACT
BACKGROUND: The purpose of these clinical studies was to validate a Tissue Change Monitoring (TCM) algorithm in vivo. TCM is a quantitative tool for the real-time assessment of HIFU dose. TCM provides quantitative analysis of the backscatter pulse echo signals (pre and immediately post HIFU) for each individual ablative site, using ultrasonic tissue characterization as a surrogate for monitoring tissue temperature. Real-time analysis generates an energy difference parameter (ΔE in dB) that is proportional to tissue temperature. METHODS: Post in vitro studies, two clinical studies were conducted to validate the TCM algorithm on the Sonablate® device. Studies enrolled histologically confirmed, organ confined prostate cancer patients. The first clinical study was conducted in two phases for whole gland ablation. First eight patients' data were used to measure the algorithm performance followed by 89 additional patients for long term outcome. The second clinical study enrolled five patients; four patients with focal cancer had hemi-ablation only and one had whole gland ablation. Four 3 Fr. needles containing three thermocouples each were placed transperineally in the prostate to record tissue temperatures in the focal zone, posterior to the focal zone and on the lateral gland where no HIFU was applied. Tissue temperatures from the focal zone were correlated to the ΔE parameter. RESULTS: In the first clinical study, the average TCM rate was 86%. Pre and 6 months post HIFU, median PSA was 7.64 and 0.025 ng/ml respectively and 97% patients had negative biopsy. For the second clinical study, the measured prostate tissue temperatures (Average, Max, and Min) in the ablation zones were 84°, 114° and 60 °C and the corresponding ΔE (dB/10) parameters were 1.05, 2.6 and 0.4 resulting in 83% of temperatures in the range of 75°-100 °C and 17% in the 60°-74 °C range. Outside the focal zone, the average temperature was 50 °C and in the lateral lobe where no HIFU was applied, peak temperature was 40.7 °C. CONCLUSIONS: The TCM algorithm is able to estimate tissue changes reliably during the HIFU procedure for prostate tissue ablation in real-time and can be used as a guide for HIFU dose delivery and tissue ablation control.
ABSTRACT
Current planning methods for transrectal high-intensity focused ultrasound treatment of prostate cancer rely on manually defining treatment regions in 15-20 sector transrectal ultrasound (TRUS) images of the prostate. Although effective, it is desirable to reduce user interaction time by identifying functionally related anatomic structures (segmenting), then automatically laying out treatment sites using these structures as a guide. Accordingly, a method has been developed to effectively generate solid three-dimensional (3-D) models of the prostate, urethra, and rectal wall from boundary trace data. Modeling the urethra and rectal wall are straightforward, but modeling the prostate is more difficult and has received much attention in the literature. New results presented here are aimed at overcoming many of the limitations of previous approaches to modeling the prostate while using boundary traces obtained via manual tracing in as few as 5 sector and 3 linear images. The results presented here are based on a new type of surface, the Fourier ellipsoid, and the use of sector and linear TRUS images. Tissue-specific 3-D models will ultimately permit finer control of energy deposition and more selective destruction of cancerous regions while sparing critical neighboring structures.
