A study of respiration-correlated cone-beam CT scans to correct target positioning errors in radiotherapy of thoracic cancer.

PURPOSE: There is increasingly widespread usage of cone-beam CT (CBCT) for guiding radiation treatment in advanced-stage lung tumors, but difficulties associated with daily CBCT in conventionally fractionated treatments include imaging dose to the patient, increased workload and longer treatment times. Respiration-correlated cone-beam CT (RC-CBCT) can improve localization accuracy in mobile lung tumors, but further increases the time and workload for conventionally fractionated treatments. This study investigates whether RC-CBCT-guided correction of systematic tumor deviations in standard fractionated lung tumor radiation treatments is more effective than 2D image-based correction of skeletal deviations alone. A second study goal compares respiration-correlated vs respiration-averaged images for determining tumor deviations. METHODS: Eleven stage II-IV nonsmall cell lung cancer patients are enrolled in an IRB-approved prospective off-line protocol using RC-CBCT guidance to correct for systematic errors in GTV position. Patients receive a respiration-correlated planning CT (RCCT) at simulation, daily kilovoltage RC-CBCT scans during the first week of treatment and weekly scans thereafter. Four types of correction methods are compared: (1) systematic error in gross tumor volume (GTV) position, (2) systematic error in skeletal anatomy, (3) daily skeletal corrections, and (4) weekly skeletal corrections. The comparison is in terms of weighted average of the residual GTV deviations measured from the RC-CBCT scans and representing the estimated residual deviation over the treatment course. In the second study goal, GTV deviations computed from matching RCCT and RC-CBCT are compared to deviations computed from matching respiration-averaged images consisting of a CBCT reconstructed using all projections and an average-intensity-projection CT computed from the RCCT. RESULTS: Of the eleven patients in the GTV-based systematic correction protocol, two required no correction, seven required a single correction, one required two corrections, and one required three corrections. Mean residual GTV deviation (3D distance) following GTV-based systematic correction (mean ± 1 standard deviation 4.8 ± 1.5 mm) is significantly lower than for systematic skeletal-based (6.5 ± 2.9 mm, p = 0.015), and weekly skeletal-based correction (7.2 ± 3.0 mm, p = 0.001), but is not significantly lower than daily skeletal-based correction (5.4 ± 2.6 mm, p = 0.34). In two cases, first-day CBCT images reveal tumor changes-one showing tumor growth, the other showing large tumor displacement-that are not readily observed in radiographs. Differences in computed GTV deviations between respiration-correlated and respiration-averaged images are 0.2 ± 1.8 mm in the superior-inferior direction and are of similar magnitude in the other directions. CONCLUSIONS: An off-line protocol to correct GTV-based systematic error in locally advanced lung tumor cases can be effective at reducing tumor deviations, although the findings need confirmation with larger patient statistics. In some cases, a single cone-beam CT can be useful for assessing tumor changes early in treatment, if more than a few days elapse between simulation and the start of treatment. Tumor deviations measured with respiration-averaged CT and CBCT images are consistent with those measured with respiration-correlated images; the respiration-averaged method is more easily implemented in the clinic.

Follow-up of discrepancies in X-ray and electrocardiogram interpretations, and positive laboratory results.

This article describes the 1-year follow-up program implemented at Baystate Medical Center Emergency Department during 1999. Our previous system used staff who worked clinically, which led to prolonged delays in follow-up. Before initiating the program, 57% [95% confidence interval (CI): 55-59%] of all follow-up cases were done within 3 days. After program implementation, 69% (95% CI: 67-72%) of all follow-up cases were completed in the same time frame. We reduced our "delayed" follow-up cases from 20% (95% CI: 18-22%) to 4% (95% CI: 3-5%) of all cases. Critical to the new system is the assignment of nurse-physician pairing to do follow-up when they are not doing direct patient care.

Continuous passive motion following partial ankle joint arthroplasty.

Retrospective preliminary report of 19 cases undergoing partial ankle joint arthroplasties with open surgical procedures were rehabilitated with continuous passive motion (CPM). Preoperative and post-operative ankle range of motion and subjective findings (pain, physical signs, activity, quality of motion) were evaluated. Results indicated significant increases to ankle joint range of motion with the use of continuous passive motion, decreased pain, increased activity, decreased edema, and improved quality of motion in the majority of patients undergoing ankle joint arthroplasty with continuous passive motion.

The tendo Achillis as it relates to rearfoot position. A new classification for evaluation of calcaneal stance position.

In summary, it has been demonstrated by the statistical analysis of 48 subjects (96 feet) that as the foot moves from the neutral to the resting calcaneal stance position, the tendo Achillis alignment is displaced lateral to the center of gravity. Class I heels demonstrated a direct correlation with tendo Achillis deviation suggesting that their subtalar joint motion is in the transverse plane. Class II and III heels did not directly correlate with Achilles deviation, suggesting probable frontal plane variability. Class IV heels showed no correlation with rearfoot pathology and are considered to be a consequence of distal or proximal pronatory forces. We advocate the recognition of the Achilles tendon as it interacts with transverse and frontal plane subtalar joint motion and believe that it deserves ample attention when evaluating the patient biomechanically as well as surgically.

Use of the subcutaneous tissue expander for delayed primary closure of flaps.

Two cases of deforming, painful scars on the dorsum of the foot are presented. Simple excision and primary closure of these wounds was not possible. Subcutaneous tissue expanders were implanted proximal to the scar and inflated gradually. Once adequate expansion was obtained, the expanders were removed, and scars excised. Closure was obtained by a pedicle and rotational advancement flap, without stress on the skin over the defect. A discussion of the indications, techniques, and pitfalls of tissue expansion is provided.

Peroneal tendon balance procedure.

The authors introduce the peroneal tendon balance procedure and discuss normal and hypermobile function of the first ray. The procedure is based on the theory that the peroneus longus tendon is a primary retrograde stabilizer of the proximal portion of the first ray. The theory emphasizes that abnormal pronation results in a positional weakness of the peroneus longus tendon, which induces first ray hypermobility. This surgical procedure involves an anastomosis of the peroneus longus to the peroneus brevis tendon. It is designed to increase the force of the peroneus longus tendon in order to reduce first ray hypermobility.

Nonspecific inflammation in the foot demonstrated by magnetic resonance imaging.

The authors present a brief review of the literature concerning magnetic resonance imaging (MRI) as applied to the musculoskeletal system. Two patients are presented with nonspecific foot pain. MRI demonstrated an area of hyperintensity, suggestive of an inflammatory process, in both cases. Biopsy later confirmed the diagnosis of chronic inflammation.

Spontaneous rupture of the peroneus longus tendon with fracture of the os peroneum.

Injuries of the peroneus longus and os peroneum are rarely reported. Two cases are presented, each occurring with an inversion stress and resultant audible snap. One patient sustained a complete spontaneous disruption of the peroneus longus with fracture of the os peroneum. This 64-year-old male was treated by excision of the proximal fracture fragment of the os peroneum and primary tendon repair. A 2-week prodrome of pain in the lateral aspect of the foot, preceded the rupture. Case 2, a 39-year-old female, was treated nonoperatively, and represents the clinical dilemma that may occur when the os peroneum is traumatized. It is emphasized that diagnosis of fracture of this ossicle can only be confirmed with operative excision and microscopic study. The authors recommend primary surgical treatment in those cases where continuity of the peroneus longus is disrupted. Where continuity is maintained, surgical exploration should be reserved for those cases that fail to respond to prolonged and intensive rehabilitation. Both patients regained full function and remain symptom free 11 and 10 months after treatment.

The murder-suicide. A study of the postagressional suicide.

The authors studied a series of 18 cases of homicide followed by suicide or attempted suicide by the aggressor, analyzing: 1) the frequency of such acts; 2) the age and sex of the aggressors; 3) the means or arms used for the murder and suicide; 4) the period of time between the two events; and 5) the motives for the homicides and the relationship between the victims and their aggressors.