Biomedical subjects
Publications and source records attributed to D Jaffray.
A case of tetraplegia due to weight training is presented. Emergency surgery revealed a huge C5/6 disc sequestration trapped within the canal by the posterior longitudinal ligament. The disc was removed and C5-C7 were fused using an iliac crest tricortical graft and stabilised. The patient made a good recovery and returned to sporting activity.
PURPOSE: We present the preliminary results of our in-house protocol using outpatient high-dose-rate (HDR) brachytherapy as the sole radiation modality following lumpectomy in patients with early-stage breast cancer. METHODS AND MATERIALS: Thirty-seven patients with 38 Stage I-II breast cancers received radiation to the lumpectomy cavity alone using an HDR interstitial implant with (192)Ir. A minimum dose of 32 Gy was delivered on an outpatient basis in 8 fractions of 4 Gy to the lumpectomy cavity plus a 1- to 2-cm margin over consecutive 4 days. RESULTS: Median follow-up is 31 months. There has been one ipsilateral breast recurrence for a crude failure rate of 2.6% and no regional or distant failures. Wound healing was not impaired in patients undergoing an open-cavity implant. Three minor breast infections occurred, and all resolved with oral antibiotics. The cosmetic outcome was good to excellent in all patients. CONCLUSION: In selected patients with early-stage breast cancer, treatment of the lumpectomy cavity alone with outpatient HDR brachytherapy is both technically feasible and well tolerated. Early results are encouraging, however, longer follow-up is necessary before equivalence to standard whole-breast irradiation can be established and to determine the most optimal radiation therapy technique to be employed.
PURPOSE: We hypothesize that the difference in image quality between the traditional kilovoltage (kV) prescription radiographs and megavoltage (MV) treatment radiographs is a major factor hindering our ability to accurately measure, thus correct, setup error in radiation therapy. The objective of this work is to study the accuracy of on-line correction of setup errors achievable using either kV- or MV-localization (i.e., open-field) radiographs. METHODS AND MATERIALS: Using a gantry mounted kV and MV dual-beam imaging system, the accuracy of on-line measurement and correction of setup error using electronic kV- and MV-localization images was examined based on anthropomorphic phantom and patient imaging studies. For the phantom study, the user's ability to accurately detect known translational shifts was analyzed. The clinical study included 14 patients with disease in the head and neck, thoracic, and pelvic regions. For each patient, 4 orthogonal kV radiographs acquired during treatment simulation from the right lateral, anterior-to-posterior, left lateral, and posterior-to-anterior directions were employed as reference prescription images. Two-dimensional (2D) anatomic templates were defined on each of the 4 reference images. On each treatment day, after positioning the patient for treatment, 4 orthogonal electronic localization images were acquired with both kV and 6-MV photon beams. On alternate weeks, setup errors were determined from either the kV- or MV-localization images but not both. Setup error was determined by aligning each 2D template with the anatomic information on the corresponding localization image, ignoring rotational and nonrigid variations. For each set of 4 orthogonal images, the results from template alignments were averaged. Based on the results from the phantom study and a parallel study of the inter- and intraobserver template alignment variability, a threshold for minimum correction was set at 2 mm in any direction. Setup correction was applied by translating the treatment couch in the lateral, superior-to-inferior and vertical directions only. During treatment, kV open-field images were acquired for off-line treatment verification and analysis. Each patient study spanned 2-6 weeks. The 14 patient studies were completed with 8248 electronic images acquired and analyzed. RESULTS: Results from the phantom studies showed that the users were able to detect the applied translational shift to better than 2 mm, and mostly to within 1 mm. The intraobserver variability of template alignment was on the order of 1 mm using a sample of either MV or kV patient images. The difference between using MV or kV images was significant for only a few cases. However in most cases, interobserver alignment variability was larger when using MV images than kV. For on-line setup correction, the study procedure added 10 min. to conventional treatment time. Setup variation measured with either kV- or MV-localization images was similar. The initial magnitude of setup error was appreciable, with a mean displacement of about 6.6 +/- 2.4 mm for the 14 patients. On-line correction using either kV- or MV-localization images improved setup accuracy. Over all study patients, setup errors occurred with standard deviations greater than 2 mm in any direction with a frequency of 48% before correction, and were reduced to 16% after correction. On average, kV image-based correction reduced radial setup variation to 2.6 +/- 1.6 mm compared to the 3.3 +/- 1.8 mm attained using MV images. The difference detected between the kV and MV data was not statistically significant when averaged over all patients. However, for on-line corrections in the neck and thoracic regions, using kV-localization images reduced setup error significantly more than using MV images. CONCLUSIONS: In our anatomic template alignment study, interobserver variability was smaller using kV images than MV images. Intraobserver variability was smaller for alignments on kV images
PURPOSE: Adaptive Radiation Therapy (ART) is a feedback treatment process that optimizes a patient's treatment according to the patient specific information measured during the course of treatment. Utilizing an electronic portal imaging device (EPID) and a computer-controlled multileaf collimator (MLC), the ART process is currently being implemented in our clinic to improve the treatment accuracy by compensating for the treatment setup error. A prospective study was conducted to evaluate the feasibility and efficacy of the ART process for clinical use. METHODS AND MATERIALS: The prospective study included 20 patients who underwent conventional radiotherapy on a linear accelerator equipped with an EPID and a MLC. No specific changes were made in the routine clinical procedures except daily portal images were obtained for each treatment field. Two-dimensional setup error for each treatment field was then measured offline using a software tool. The measured setup errors from initial treatment days were used to predict the systematic and random setup errors for each treatment field. An adjustment decision was made if the predicted systematic error was larger than or equal to 2 mm. Furthermore, the treatment field was extended if the predicted random setup error could not be effectively compensated by the predefined treatment setup margin. Instead of the conventional approach of patient repositioning, setup adjustment was implemented by reshaping the MLC field. The entire process from measuring setup error to reshaping the MLC field was performed offline through a computer network. After completion of a patient's treatment, the systematic and random setup errors after adjustment were compared with those predicted prior to the adjustment. The accuracy of the adjustment, and the reliability and stability of the process were analyzed. RESULTS: Treatment fields of 13 patients were modified to correct for systematic errors. The mean systematic error was 4 mm with a range of 2 to 7 mm before adjustment. It was reduced to 0.5 mm with a range of 0.2 to 1.4 mm after adjustment. There was no significant difference in random setup errors before and after adjustment. The ART process was found to be stable, as more than 95% of patient specific setup margins were predictable within 1 mm using the first four to nine fractions of treatment, confirming the feasibility of treatment plan reoptimization with the ART process. CONCLUSIONS: The prospective study demonstrates that the ART process can be effectively implemented in routine clinical practice to improve treatment accuracy. This process is also ready to be further extended to reoptimize the treatment plan by incorporating the predicted patient specific setup variation.
STUDY DESIGN: The neurologic outcomes in patients with conservatively managed incomplete closed traumatic cervical spinal cord injuries was evaluated using the motor scoring system and the Frankel classification. OBJECTIVES: To show that the motor scoring of recovery system combined with functional Frankel grading will make the documentation of final neurologic outcome more accurate for future comparisons of various methods of treatment. SUMMARY OF BACKGROUND DATA: The influence of surgical and pharmacologic methods of treatment on recovery remains debatable. METHODS: Sixty-three consecutive patients with incomplete cervical injuries who were admitted to the hospital within 2 days after injury were included. All patients were treated conservatively with 6 weeks of bedrest and 6 weeks of mobilization with neck support. RESULTS: Five patients had neurologic deterioration, and all but one patient recovered without surgery. The evaluation of 44 patients who were observed for more than 12 months showed that the preservation of sharp sensation below the level of injury was an indicator of a good prognosis in patients whose injuries were classified as Frankel B, and the degree of recovery of these patients according to the motor score system was comparable with that of patients who were classified as Frankel C. All patients classified as Frankel C who did not deteriorate recovered in Frankel grade. All but one of the patients in the Frankel D group recovered full motor power. The degrees of motor deficit and recovery did not correlate with the mechanism or the degree of the injury of the spinal axis. CONCLUSION: Conservative treatment remains a good option for patients with incomplete cervical cord injuries. It is hoped the current study will be a good basis for comparison of the neurologic outcomes of different treatment modalities.
Severe spondylolisthesis produces a kyphos at the lumbosacral junction. Reduction can be complicated by injury to the cauda equina. To prevent this, a posterior decompression and fusion is carried out before a slow reduction in extension. An anterior fusion with internal fixation then locks the reduction. Using these principles, a good reduction was achieved in 20 of 22 patients. Only two patients suffered a permanent neurologic deficit consisting of slight loss of ankle dorsiflexion. Severe spondylolisthesis can be safely reduced by this method.
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The Smith-Petersen anterior opening wedge osteotomy of the lumbar spine is currently the accepted technique for the correction of spinal deformity in ankylosing spondylitis. It has a mortality of 10%, uses force, is uncontrolled, and fixation is often feeble. The authors have devised a posterior closing wedge with transpedicular fixation. This technique is controlled, comparatively safe, and provides secure fixation. The procedure is a relatively safe and reliable means of dealing with a dangerous operation.
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We report the technique and early results of the Dwyer-Hartshill method for segmental fixation of the spine. This uses pedicular screws wired to a rectangular frame and is indicated after laminectomy.
Major vascular trauma is a much considered complication of lumbar extension osteotomy in ankylosing spondylitis. It has, however, only been reported twice in the literature. This paper analyzes in detail two additional cases and makes certain recommendations based on the findings.
Twenty patients with comminuted trochanteric fractures underwent fixation in the position of deformity. We explain the principles and rationale of this technique and analyse our results.
Anterior decompression relieved paraplegia in two women with primary vertebral osteosarcomas. Chemotherapy and radiotherapy did not prevent painful local tumor recurrences. Radical tumor excision could have improved the patients' outlook and general care.
A new technique is described for extra-articular subtalar arthrodesis; it combines the main elements of the Batchelor and the Grice procedures. Results were reviewed after a minimum of three years. Of the 25 feet treated 24 had solid fusion and had maintained the operative correction of the valgus deformity; the one non-union was due to deep infection.
We report and discuss a combined anterior, anterolateral and posterior approach to the lower cervical spine. This was used for the radical resection of a recurrent osteoblastoma which involved the lateral mass, pedicle, and lamina of the sixth cervical vertebra.
Seven patients underwent anterior interbody spinal fusions to alleviate pain due to resorption of an intervertebral disc. The anterior annulus of the discs at operation was inflamed. The specimens were studied histologically, and the findings are discussed. The demonstration of inflammation in the anterior annulus together with the recent identification of nerve fibres in the anterior annulus now allows a better understanding of discogenic pain and its management.
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