Relationship between Eustachian tube dysfunction and otitis media with effusion in radiotherapy patients.

OBJECTIVE: This study evaluated the relationship between radiation and Eustachian tube dysfunction, and examined the radiation dose required to induce otitis media with effusion. METHODS: The function of 36 Eustachian tubes in 18 patients with head and neck cancer were examined sonotubometrically before, during, and 1, 2 and 3 months after, intensity-modulated radiotherapy. Patients with an increase of 5 dB or less in sound pressure level (dB) during swallowing were categorised as being in the dysfunction group. Additionally, radiation dose distributions were assessed in all Eustachian tubes using three dose-volume histogram parameters. RESULTS: Twenty-two of 25 normally functioning Eustachian tubes before radiotherapy (88.0 per cent) shifted to the dysfunction group after therapy. All ears that developed otitis media with effusion belonged to the dysfunction group. The radiation dose threshold evaluation revealed that ears with otitis media with effusion received significantly higher doses to the Eustachian tubes. CONCLUSION: The results indicate a relationship between radiation dose and Eustachian tube dysfunction and otitis media with effusion.

[New CT program simulating kidney displacement during retroperitoneal laparoscopic nephrectomy].

A total of 12 patients with malignant localized renal or ureteral neoplasms underwent multi-slice computed tomography. Imaging data were sent to the dedicated workstation to create volume rendering and virtual laparoscopic images of the kidney which was displaced ventrally with retroperitoneal balloon. These findings were compared with video images obtained during retroperitoneal laparoscopic nephrectomy. The kidney displacement simulator depicted all renal arteries (100% sensitivity) and 13 of 14 renal veins (93% sensitivity). Hilar anatomy, including the tumor, major vessels and their relationships were visualized as in the actual laparoscopic views. The desired portions of major vessels as well as the left adrenal and gonadal veins visualized with this system completely corresponded with the actual laparoscopic images during surgery. The kidney displacement simulator is useful to foresee desired portions of major vessels and branched small vessels such as the adrenal or gonadal veins in advance of surgery. It is thus able to guide surgeons and reduce operative risks and possible complications.