Recommendations for the use of active personal dosemeters (APDs) in interventional workplaces in hospitals.

Occupational radiation doses from interventional procedures have the potential to be relatively high. The requirement to optimise these doses encourages the use of electronic or active personal dosimeters (APDs) which are now increasingly used in hospitals. They are typically used in tandem with a routine passive dosimetry monitoring programme, with APDs used for real-time readings, for training purposes and when new imaging technology is introduced. However, there are limitations when using APDs. A survey in hospitals to identify issues related to the use of APDs was recently completed, along with an extensive series of APD tests by the EURADOS Working Group 12 on Dosimetry for Medical Imaging. The aim of this review paper is to summarise the state of the art regarding the use of APDs. We also used the results of our survey and our tests to develop a set of recommendations for the use of APDs in the clinical interventional radiology/cardiology settings, and draw attention to some of the current challenges.

THE USE OF ACTIVE PERSONAL DOSEMETERS IN INTERVENTIONAL WORKPLACES IN HOSPITALS: COMPARISON BETWEEN ACTIVE AND PASSIVE DOSEMETERS WORN SIMULTANEOUSLY BY MEDICAL STAFF.

Medical staff in interventional procedures are among the professionals with the highest occupational doses. Active personal dosemeters (APDs) can help in optimizing the exposure during interventional procedures. However, there can be problems when using APDs during interventional procedures, due to the specific energy and angular distribution of the radiation field and because of the pulsed nature of the radiation. Many parameters like the type of interventional procedure, personal habits and working techniques, protection tools used and X-ray field characteristics influence the occupational exposure and the scattered radiation around the patient. In this paper, we compare the results from three types of APDs with a passive personal dosimetry system while being used in real clinical environment by the interventional staff. The results show that there is a large spread in the ratios of the passive and active devices.

Reconstructive management of cranial base defects after tumor ablation.

Successful reconstruction after cranial base tumor ablation is paramount in preventing potentially life-threatening complications. The purpose of this study was to evaluate experiences of cranial base reconstruction and to identify reconstructive management principles that may assist in achieving successful cranial base reconstruction. All cranial base reconstructions performed by the Department of Plastic Surgery at the University of Texas M. D. Anderson Cancer Center between January of 1993 and September of 1999 were reviewed. Analyses were performed to assess the impact of location of defect, type of reconstruction, type of dural repair, and history of preoperative radiation and chemotherapy on rates of complications, and patient survival. The 77 patients who underwent cranial base reconstruction after tumor ablation during the study period had a mean age of 52 years (6 to 84 years). The mean follow-up period was 28.7 months (1 to 76 months). Squamous cell carcinoma, the most common histopathologic type, was present in 24 patients (31 percent), and 35 patients (45 percent) presented with recurrent disease. Location of defects involved region I (anterior) in 31 patients (40 percent), region II (anterior-lateral) in 18 (23 percent), region III (lateral-posterior) in six (8 percent), and more than one region in 22 (29 percent). Reconstructive methods included free flaps in 52 patients (68 percent), temporalis muscle flaps in 14 (18 percent), pericranial flaps in eight (10 percent), and other local flaps (two galeal, one scalp) in three (4 percent). Of the 52 free flaps, 18 (35 percent) were used in region I, 14 (27 percent) in region II, six (12 percent) in region III, and 14 (27 percent) in defects involving more than one region. Of the 14 temporalis muscle flaps, 13 (93 percent) were used for defects involving regions I or II and one (7 percent) was used for a defect involving region III. Of the 11 pericranial and other local flaps, nine (82 percent) were used in region I, one (9 percent) in region II, and one (9 percent) in a combination of regions II and III. Complications occurred in 21 patients (27 percent): three total flap losses (4 percent), three partial flap losses (4 percent), two cerebrospinal fluid leaks (3 percent), two cases of meningitis (3 percent), two abscesses (3 percent), five cases of delayed wound healing (6 percent), two hematomas (3 percent), one wound infection (1 percent), and one cerebrovascular accident (1 percent). Overall survival was 77 percent at 2 years and 58 percent at 4 years. The type of reconstruction, location of defect, type of dural repair, and history of preoperative radiation and chemotherapy had no significant association with the incidence of complications. Neither the type of reconstruction nor the location of defect showed a significant effect on patient survival. In this experience, local flaps, such as pericranial or temporalis muscle flaps, are good choices for reconstruction of smaller anterior or lateral cranial base defects. For defects that require larger amounts of soft tissue, free flaps are appropriate. With proper patient selection, successful cranial base reconstruction can be performed with either local or free flaps with a low incidence of complications.

Greater superficial petrosal nerve: anatomy and MR findings in perineural tumor spread.

We report a case of perineural spread of adenoid cystic carcinoma along the greater superficial petrosal nerve. The anatomy of this nerve also is reviewed.

Current management of meningiomas.

Although generally benign tumors, meningiomas can cause serious neurological injury and, at times, vexatious management difficulties. Currently, the accepted management of these tumors is attempted total surgical excision when technically possible and associated with an acceptable risk. However, even with innovations in instrumentation and refinements in surgical technique, the goal of total resection may not be achievable. For these patients, and for those with recurrent tumors, options for treatment include reoperation, radiation therapy, and chemotherapy. Recent developments in surgical technique and instrumentation, radiosurgery, and brachytherapy have increased the treatment options, while clinical trials with tamoxifen and mifepristone (RU486) are adding information on the effectiveness of these drugs as chemotherapeutic agents. While the search continues for a uniformly successful management plan, physicians must be aware of the available options and try to help the patient decide which treatment is appropriate, based on current medical knowledge.