Determination of the accuracy of implant reconstruction and dose delivery in brachytherapy in The Netherlands and Belgium.

PURPOSE: To gain insight into the accuracy of brachytherapy treatments, the accuracy of implant reconstruction and dose delivery was investigated in 33 radiotherapy institutions in The Netherlands and Belgium. MATERIALS AND METHODS: The accuracy of the implant reconstruction method was determined using a cubic phantom containing 25 spheres at well-known positions. Reconstruction measurements were obtained on 41 brachytherapy localizers, 33 of which were simulators. The reconstructed distances between the spheres were compared with the true distances. The accuracy of the dose delivery was determined for high dose rate (HDR), pulsed dose rate (PDR) and low dose rate (LDR) afterloading systems using a polymethyl methacrylate cylindrical phantom containing a NE 2571 ionization chamber in its centre. The institutions were asked to deliver a prescribed dose at the centre of the phantom. The measured dose was compared with the prescribed dose. RESULTS: The average reconstruction accuracy was -0.07 mm (+/-0.4 mm, 1 SD) for 41 localizers. The average deviation of the measured dose from the prescribed dose was +0.9% (+/-1.3%, 1 SD) for 21 HDR afterloading systems, +1.0% (+/-2.3%, 1 SD) for 12 PDR afterloaders, and +1.8% (+/-2.5%, 1 SD) for 15 LDR afterloaders. CONCLUSIONS: This comparison showed a good accuracy of brachytherapy implant reconstruction and dose delivery in The Netherlands and Belgium.

Medical practice in Papua New Guinea.

Opportunities for medical service abound throughout the world. These experiences can allow development of clinical skills in the absence of advanced technology. We describe an eight-month experience in Papua New Guinea, including the most frequent illnesses treated and procedures performed.

Fine-needle aspiration of breast masses.

Evaluation of breast masses is a frequent dilemma encountered by a primary care physician. Adding fine-needle aspiration biopsy to the work-up of these lesions adds an inexpensive, highly accurate test with high patient acceptance. At our institution a technique using a butterfly needle has yielded a sensitivity of 91% and a specificity of 100%.

Colonic diverticula. When complications require surgery and when they don't.

The value of a high-fiber diet in preventing and treating colonic diverticula is firmly established. Although the diagnosis of diverticulosis is usually made with colonoscopy or barium enema examination, computed tomography has become the test of choice during acute diverticulitis, when the diagnosis cannot be confidently made clinically. Recently developed surgical principles for diverticulitis include radiographically directed drainage with delayed operation for peridiverticular abscess, resection of the site of disease in patients with general peritonitis, and primary anastomosis in most cases requiring urgent intervention. Diverticulosis accompanied by abdominal pain or irregular bowel habits is by itself rarely an indication for surgery. Diverticular bleeding usually resolves spontaneously, but persistent bleeding can usually be successfully treated with segmental colectomy after localization of the bleeding site with colonoscopy or arteriography.