Anastrozole is superior to tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women: results of a North American multicenter randomized trial. Arimidex Study Group.

PURPOSE: The efficacy and tolerability of anastrozole (Arimidex; AstraZeneca, Wilmington, DE, and Macclesfield, United Kingdom) and tamoxifen were compared as first-line therapy for advanced breast cancer in 353 postmenopausal women. PATIENTS AND METHODS: The randomized, double-blind, multicenter study was designed to evaluate anastrozole 1 mg once daily relative to tamoxifen 20 mg once daily in patients with hormone receptor-positive tumors or tumors of unknown receptor status who were eligible for endocrine therapy. Primary end points were objective response (OR), defined as complete (CR) or partial (PR) response, time to progression (TTP), and tolerability. RESULTS: Anastrozole was as effective as tamoxifen in terms of OR (21% v 17% of patients, respectively), with clinical benefit (CR + PR + stabilization > or = 24 weeks) observed in 59% of patients on anastrozole and 46% on tamoxifen (two-sided P =.0098, retrospective analysis). Anastrozole had a significant advantage over tamoxifen in terms of TTP (median TTP of 11.1 and 5.6 months for anastrozole and tamoxifen, respectively; two-sided P =.005). The tamoxifen:anastrozole hazards ratio was 1.44 (lower one-sided 95% confidence limit, 1.16). Both treatments were well tolerated. However, thromboembolic events and vaginal bleeding were reported in fewer patients who received anastrozole compared with those who received tamoxifen (4.1% v 8.2% [thromboembolic events] and 1.2% v 3.8% [vaginal bleeding], respectively). CONCLUSION: Anastrozole satisfied the predefined criteria for equivalence to tamoxifen. Furthermore, we observed both a significant increase in TTP and a lower incidence of thromboembolic events and vaginal bleeding with anastrozole. These findings indicate that anastrozole should be considered as first-line therapy for postmenopausal women with advanced breast cancer.

Low doses of prophylactic cranial irradiation effective in limited stage small cell carcinoma of the lung.

PURPOSE: Prophylactic cranial irradiation (PCI) for the prevention of brain metastasis in small cell lung cancer remains controversial, both in terms of efficacy and the optimal dose-fractionation scheme. We performed this study to evaluate the efficacy of PCI at low doses. METHODS AND MATERIALS: One hundred and ninety-seven patients were referred to our institution for treatment of limited stage small cell carcinoma of the lung between June 1986 and December 1992. Follow-up ranged from 1.1 to 89.8 months, with a mean of 19 months. Eighty-five patients received PCI. RESULTS: Patients receiving PCI exhibited brain failure in 15%, while 38% of untreated patients developed metastases. This degree of prophylaxis was achieved with a median total dose of 25.20 Gy and a median fraction size of 1.80 Gy. At these doses, acute and late complications were minimal. Patients receiving PCI had significantly better 1-year and 2-year overall survivals (68% and 46% vs. 33% and 13%). However, patients with a complete response (CR) to chemotherapy and better Karnofsky performance status (KPS) were overrepresented in the PCI group. In an attempt to compare similar patients in both groups (PCI vs. no PCI), only patients with KPS > or = 80, CR or near-CR to chemotherapy, and treatment with attempt to cure, were compared. In this good prognostic group, survival was still better in the PCI group (p = 0.0018). CONCLUSION: In this patient population, relatively low doses of PCI have accomplished a significant reduction in the incidence of brain metastasis with little toxicity. Whether such treatment truly improves survival awaits the results of additional prospective randomized trials.

Small-cell lung carcinoma: an analysis of 194 consecutive patients.

The treatment of small-cell lung carcinoma (SCLC) requires the careful combination of chemotherapy and radiation therapy. To understand the factors involved in the outcome of these patients, the authors undertook a study of patients treated for limited stage SCLC. The charts of 194 consecutive patients treated at our facilities between 1986 and 1994 were reviewed. All patients underwent thoracic radiation therapy (TRT), 50% received prophylactic cranial irradiation (PCI), and all but one received chemotherapy. The probability of survival at 5 years was 14%, and the disease-free survival (DFS) was 17%. Patients receiving a combination of platinum and etoposide (PE) and Cytoxan (Bristol-Myers, Evansville, IN, U.S.A.), Adriamycin (Adria Laboratories, Dublin, OH, U.S.A.), and Vincristine (Eli Lilly, Indianapolis, IN, U.S.A.) (CAV) experienced a DFS at 3 years of 31%, versus 14% for CAV only and 18% for PE only (p = 0.004). In a multivariate survival analysis, only PCI (p = 0.001), having received PE and CAV (p = 0.01), and response to treatment (p = 0.001) were significant. Radiation dose and field size did not influence outcome. The combination of PE and CAV chemotherapy produced the best results in our series. Unanswered questions regarding the optimal TRT dose, field size, and timing of TRT await the results of ongoing randomized trials.

Methods for kinematic modeling of biological and robotic systems.

The main objective is to develop methods that automatically generate kinematic models for the movements of biological and robotic systems. Two methods for the identification of the kinematics are presented. The first method requires the elimination of the displacement variables that cannot be measured while the second method attempts to estimate the changes in these variables. The methods were tested using a planar two-revolute-joint linkage. Results show that the model parameters obtained agree with the actual parameters to within 5%. Moreover, the methods were applied to model head and neck movements in the sagittal plane. The results indicate that these movements are well modeled by a two-revolute-joint system. A spatial three-revolute-joint model was also discussed and tested.

Towards the control of a powered orthosis for people with muscular dystrophy.

The paper describes the development of a passive/active orthosis for people with limited anti-gravity strength in their arms. This is symptomatic of conditions such as muscular dystrophy and spinal muscular atrophy. A passive orthosis was designed and developed using linear elastic elements. The system is being tested with children with disabilities and preliminary results are encouraging. An RT200 robot was also used as a test-bed for an active orthosis. The robot was instrumented with a six-axis force/torque sensor at the end-effector. The force acted as the input to the robot. The robot kinematics and dynamics were modelled. A number of control schemes were implemented on the test-bed including force proportional to velocity and acceleration; these schemes were evaluated with two subjects.

An intelligent end-effector for a rehabilitation robot.

A UMI RTX robot, modified with limited end-effector sensors and a restricted but effective vision system, is currently used in a developmental education setting for severely physically disabled children. The low physical and cognitive abilities of the children involved in the project require a semi-autonomous robot with environmental sensing capability to operate in a task oriented mode. A variety of low-cost sensors including proximity, distance, force and slip sensors, have been investigated for integration in end-effectors for the RTX robot. The sensors employed on a modified end-effector are detailed and experimental results are presented. A design for an end-effector with integrated sensors is discussed. The integration of the sensor information into a high-level, task-oriented programming language is detailed and examples of high-level control sequences using sensor inputs are presented. Finally, the development of intelligent gripping strategies based on sensor information is discussed.

Robots with a gentle touch: advances in assistive robotics and prosthetics.

As healthcare costs rise and an aging population makes an increased demand on services, so new techniques must be introduced to promote an individuals independence and provide these services. Robots can now be designed so they can alter their dynamic properties changing from stiff to flaccid, or from giving no resistance to movement, to damping any large and sudden movements. This has some strong implications in health care in particular for rehabilitation where a robot must work in conjunction with an individual, and might guiding or assist a persons arm movements, or might be commanded to perform some set of autonomous actions. This paper presents the state-of-the-art of rehabilitation robots with examples from prosthetics, aids for daily living and physiotherapy. In all these situations there is the potential for the interaction to be non-passive with a resulting potential for the human/machine/environment combination to become unstable. To understand this instability we must develop better models of the human motor system and fit these models with realistic parameters. This paper concludes with a discussion of this problem and overviews some human models that can be used to facilitate the design of the human/machine interfaces.

Assessing the effectiveness of robot facilitated neurorehabilitation for relearning motor skills following a stroke.

A growing awareness of the potential for machine-mediated neurorehabilitation has led to several novel concepts for delivering these therapies. To get from laboratory demonstrators and prototypes to the point where the concepts can be used by clinicians in practice still requires significant additional effort, not least in the requirement to assess and measure the impact of any proposed solution. To be widely accepted a study is required to use validated clinical measures but these tend to be subjective, costly to administer and may be insensitive to the effect of the treatment. Although this situation will not change, there is good reason to consider both clinical and mechanical assessments of recovery. This article outlines the problems in measuring the impact of an intervention and explores the concept of providing more mechanical assessment techniques and ultimately the possibility of combining the assessment process with aspects of the intervention.

Performance statistics of a head-operated force-reflecting rehabilitation robot system.

Researchers in the rehabilitation engineering community have been designing and developing a variety of passive/active devices to help persons with limited upper extremity function to perform essential daily manipulations. Devices range from low-end tools such as head/mouth sticks to sophisticated robots using vision and speech input. While almost all of the high-end equipment developed to date relies on visual feedback alone to guide the user providing no tactile or proprioceptive cues, the "low-tech" head/mouth sticks deliver better "feel," because of the inherent force feedback through physical contact with the user's body. However, the disadvantage of a conventional head/mouth stick is that it can only function in a limited workspace and the performance is limited by the user's strength. It therefore seems reasonable to attempt to develop a system that exploits the advantages of the two approaches: the power and flexibility of robotic systems with the sensory feedback of a headstick. The system presented in this paper reflects the design philosophy stated above. This system contains a pair of master-slave robots with the master being operated by the user's head and the slave acting as a telestick. Described in this paper are the design, control strategies, implementation and performance evaluation of the head-controlled force-reflecting telestick system.

Analysis of intentional head gestures to assist computer access by physically disabled people.

Any human-computer interface requires both a means of transducing information flowing from the person and a way of classifying this information in a form that can be used by an application program. Since several interface devices exploit the head movements of disabled people to control computers, this paper includes a discussion of existing technologies based on head movements. As an alternative to simple techniques based on pointing to classify this information, this paper studies the possibility of using a combination of pointing and movement gestures to control an application program. By using hidden Markov models to classify movements into 'yes', 'no' and spurious gestures, it was possible to control a simple graphics application program. Subsequent analysis showed that the hidden Markov models achieved a 74% success rate.

Radiation and chemotherapy. Treatment of localized pancreatic carcinoma.

Patients unable to undergo a pancreatoduodenectomy for adenocarcinoma of the pancreas are often treated with radiation therapy. A randomized trial by the Gastrointestinal Tumor Study Group has shown an advantage in combining it with chemotherapy. A similar size retrospective study at a large community radiation therapy center assessed this finding in the nonprotocol setting. The study population consisted of 86 patients treated with primary radiation therapy between 1982 and 1992; 62 of them also received chemotherapy. The overall probability of survival was 39% and 13% at 12 and 24 months respectively. Patients receiving chemotherapy had a significantly (p = .018) longer survival (44% versus 25% at 12 months). Results confirm the Study Group's findings and suggest that they be applied to the community setting.