Slow breathing training reduces resting blood pressure and the pressure responses to exercise.

Slow breathing training reduces resting blood pressure, probably by modifying central autonomic control, but evidence for this is lacking. The pressor response to static handgrip exercise is a measure of autonomic control and the aim of this study was to determine whether slow breathing training modulates the pressor responses to exercise of untrained muscles. Twenty hypertensive patients trained for 8 weeks, 10 with unloaded slow breathing (Unloaded) and 10 breathing against an inspiratory load of 20 cm H(2)O (Loaded). Ten subjects were untrained controls. Subjects performed a 2 min handgrip pressor test (30 % MVC) pre- and post-training, and blood pressure and heart rate (HR) were measured before the contraction, at the end and following 2 min recovery. Resting systolic (sBP) and HR were reduced as a result of training, as reported previously. After training there was both a smaller pressor response to hand grip exercise and a more rapid recovery of sBP and HR compared to pre-training. There were no changes in the Controls and no differences between the Unloaded and Loaded groups. Combining the two training groups, the sBP response to handgrip exercise after training was reduced by 10 mm Hg (95 % CI: -7, -13) and HR by 5 bpm (95 % CI: -4, -6), all p<0.05. These results are consistent with slow breathing training modifying central mechanisms regulating cardiovascular function.

Can costs be measured and predicted by modeling within a cooperative clinical trials group? Economic methodologic pilot studies of the radiation therapy oncology group (RTOG) studies 90-03 and 91-04.

PURPOSE: To (1) measure radiation therapy costs for patients in randomized controlled clinical trials, (2) compare measured costs to modeling predictions, (3) examine cost distributions, and (4) assess feasibility of collecting economic data within a cooperative group. METHODS: The Radiation Therapy Oncology Group conducted economic pilot studies for two Phase III studies that compared fractionation patterns. Expected quantities of Current Procedural Terminology (CPT) codes and relative value units (RVU) were modeled. Institutions retrospectively provided procedure codes, quantities, and components, which were converted to RVUs used for Medicare payments. Cases were included if the radiation therapy quality control review judged them to have been treated per protocol or with minor variation. Cases were excluded if economic quality review found incomplete economic data. RESULTS: The median and mean RVUs were within the range predicted by the model for all arms of one study and above the predicted range for the other study. CONCLUSION: The model predicted resource use well for patients who completed treatment per protocol. Actual economic data can be collected for critical cost items. Some institutions experienced difficulty collecting retrospective data, and prospective collection of data is likely to allow wider participation in future Radiation Therapy Oncology Group economic studies.

Timing of swallowing events after single-modality treatment of head and neck carcinomas with radiotherapy.

This paper reports the results of a preliminary study designed to evaluate swallowing function in 20 patients 1 year after successful treatment of head and neck carcinomas with radiotherapy. The timing of swallowing events was evaluated by videofluoroscopy. The mean values for each measure were compared to the normative data from 60 control subjects. The radiotherapy patients demonstrated prolonged pharyngeal bolus transit and a delay of laryngeal closure. Hyoid bone elevation began late relative to the onset of bolus movement. A strong trend toward a delay in hyoid elevation relative to bolus movement was demonstrated. The time required for the hyoid bone to reach maximal elevation did not differ from that in normals, but the hyoid was held in an elevated position for a longer period of time. As a result of changes in hyoid movement, the upper esophageal sphincter tended to open early relative to the arrival of the bolus. In conclusion, changes in deglutition occur after radiotherapy, presumably as an adaptation to changes in tissue compliance.

A Radiation Therapy Oncology Group (RTOG) phase III randomized study to compare hyperfractionation and two variants of accelerated fractionation to standard fractionation radiotherapy for head and neck squamous cell carcinomas: first report of RTOG 9003.

PURPOSE: The optimal fractionation schedule for radiotherapy of head and neck cancer has been controversial. The objective of this randomized trial was to test the efficacy of hyperfractionation and two types of accelerated fractionation individually against standard fractionation. METHODS AND MATERIALS: Patients with locally advanced head and neck cancer were randomly assigned to receive radiotherapy delivered with: 1) standard fractionation at 2 Gy/fraction/day, 5 days/week, to 70 Gy/35 fractions/7 weeks; 2) hyperfractionation at 1. 2 Gy/fraction, twice daily, 5 days/week to 81.6 Gy/68 fractions/7 weeks; 3) accelerated fractionation with split at 1.6 Gy/fraction, twice daily, 5 days/week, to 67.2 Gy/42 fractions/6 weeks including a 2-week rest after 38.4 Gy; or 4) accelerated fractionation with concomitant boost at 1.8 Gy/fraction/day, 5 days/week and 1.5 Gy/fraction/day to a boost field as a second daily treatment for the last 12 treatment days to 72 Gy/42 fractions/6 weeks. Of the 1113 patients entered, 1073 patients were analyzable for outcome. The median follow-up was 23 months for all analyzable patients and 41.2 months for patients alive. RESULTS: Patients treated with hyperfractionation and accelerated fractionation with concomitant boost had significantly better local-regional control (p = 0.045 and p = 0.050 respectively) than those treated with standard fractionation. There was also a trend toward improved disease-free survival (p = 0.067 and p = 0.054 respectively) although the difference in overall survival was not significant. Patients treated with accelerated fractionation with split had similar outcome to those treated with standard fractionation. All three altered fractionation groups had significantly greater acute side effects compared to standard fractionation. However, there was no significant increase of late effects. CONCLUSIONS: Hyperfractionation and accelerated fractionation with concomitant boost are more efficacious than standard fractionation for locally advanced head and neck cancer. Acute but not late effects are also increased.

Validation and predictive power of Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis classes for malignant glioma patients: a report using RTOG 90-06.

PURPOSE: The recursive partitioning analysis (RPA) classes for malignant glioma patients were previously established using data on over 1500 patients entered on Radiation Therapy Oncology Group (RTOG) clinical trials. The purpose of the current analysis was to validate the RPA classes with a new dataset (RTOG 90-06), determine the predictive power of the RPA classes, and establish the usefulness of the database norms for the RPA classes. PATIENTS AND METHODS: There are six RPA classes for malignant glioma patients that comprise distinct groups of patients with significantly different survival outcome. RTOG 90-06 is a randomized Phase III study of 712 patients accrued from 1990 to 1994. The minimum potential follow-up is 18 months. The treatment arms were combined for the purpose of this analysis. There were 84, 13, 105, 240, 150, and 23 patients in the RPA Classes I-VI from RTOG 90-06, respectively. RESULTS: The median survival times (MST) and 2-year survival rates for the six RPA classes in RTOG 90-06 are compared to those previously published. The MST and 2-year survival rates for the RTOG RPA classes were within 95% confidence intervals of the 90-06 estimates for Classes I, III, IV, and V. The RPA classes explained 43% of the variation (squared error loss). By comparison, a Cox model explains 30% of the variation. The RPA classes within RTOG 90-06 are statistically distinct with all comparisons exceeding 0.0001, except those involving Class II. A survival analysis from a prior RTOG study indicated that 72.0 Gy had superior outcome to literature controls; analysis of this data by RPA classes indicates the survival results were not superior to the RTOG database norms. CONCLUSION: The validity of the model is verified by the reliability of the RPA classes to define distinct groups with respect to survival. Further evidence is given by prediction of MST and 2-year survival for all classes except Class II. The RPA classes explained a good portion of the variation in survival outcome in the data. Lack of correlation in RPA Class II between datasets may be an artifact of the small sample size or an indication that this class is not distinct. The validation of the RPA classes attests to their usefulness as historical controls for the comparison of future Phase II results.