Maximal Respiratory Pressures After Radiotherapy
Condition: Respiratory Function Tests
Study type: Observational

Summary: 
      Objective: The purpose of this research was to study the Maximal Respiratory Pressures (MRP)
      after exposure to breast radiation therapy in women. Methods: Prospective observational study
      performed at the Hospital de cancer Alfred in Campo Grande/MS. The sample of this study
      consisted of women (N = 16) divided into two groups: women exposed to breast radiotherapy
      after underwent quadrantectomy surgery (n = 8); and women with no history of cancer (n = 8).
      We evaluated the strength of respiratory muscles through the Maximal Inspiratory Pressure
      (MIP) and Maximal Expiratory Pressure (MEP) using the handset called manovacuometer. The
      examination was performed before the first session and after the twenty-fifth session related
      to the last day of the radiation treatment; evaluation of anthropometric data of weight and
      height to detect the body mass index (BMI); evaluation of clinical respiratory symptoms of
      dyspnea using the Medical Research Council (MRC) Dyspnea Scale and characterization of cough
      with Common Pulmonary Toxicity Criteria, in the classification of clinical pneumonitis.
    

Detailed description: 
      Study design and sample The research consisted of an observational prospective study with
      control group. The study was approved by the Ethics Committee of the Federal University of
      Mato Grosso do Sul (UFMS) with the number 46913415.7.0000.002. All participants signed an
      informed consent form after being informed about the design and objectives of the study
      according to Resolution 466/12 of the National Council of Health Ministry of Health (CNS).

      The quadrantectomy group participants were selected consecutively among patients who
      initiated radiotherapy. While the control group was selected during routine exams of he image
      sector from Hospital de Cancer Alfred Abrão.

      Research site The execution of the research took place in the Radiotherapy sector of Hospital
      de Cancer Alfred Abrão in Campo Grande - Mato Grosso do Sul state, from December 2015 to
      February 2016.

      Radiotherapy Protocol The Quadrantectomy Group sample performed adjuvant radiotherapy with a
      linear accelerator, whose the total dosage was 5000 centigray (cGy), the daily dose 200 cGy
      distributed into twenty-five sessions, totaling 25 days of treatment.

      PROCEDURES Evaluation of maximal respiratory pressures (MRP) Quantification of MIP and MEP
      was performed with the portable device called manometer, Wika brand with pressure scale
      ranging from -150 to 150 centimeters of water (0 to -150 to (0 to -150 for MIP; 0 to 150 for
      MEP). The mouthpiece attached to the device had a hole of 2 mm in diameter, in order to
      function as a relief valve of the facial muscles. During the measurement of maximal
      respiratory pressures, the survey participants remained in seated position with the trunk in
      a 90 ° angle with the lower limbs. A forced expiration was requested until reaching the
      residual volume (RV) for the measurement of MIP, followed by a maximal inspiratory effort
      against the occluded airway (Maneuver Muller), this maneuver kept for up to 2 seconds. While
      the evaluation of MEP, a maximum inspiration was requested to Total Lung Capacity (TLC),
      followed by a maximal expiratory effort against the occluded airway (Muller maneuver),
      maintained for up to 2 seconds.

      Data from Maximal Respiratory Pressures were collected at two phases in the sample of
      quadrantectomy group: before the first session of radiotherapy and after the twenty-fifth
      session corresponding to the last day of the radiotherapy treatment.

      The evaluation of the MRP was performed according to the Brazilian Guidelines for Pulmonary
      Function Tests. The results were analyzed according to the predictive values of Neder
      regression equations (1999).

      Complementary evaluation Anthropometric data evaluated to detect the body mass index (BMI)
      were: weight and height. Evaluation of dyspnea and cough symptoms with modified Dyspnea
      Medical Research Council scale (MRC) with the Common Pulmonary Toxicity Common Criteria scale
      (CTC Version 2.0) was performed to classify the clinic pneumonitis according to the Common
      Toxicity Criteria (CTC Version 2.0).

      Statistics The variables classified as dependent were the maximal respiratory pressures.
      While the independent variables were sex, age, weight, height, BMI.

      The comparison data analysis between the control group and quadrantectomy in relation to the
      variables: age, height, weight, BMI, MIP and MEP, was performed using the student's t test.
      The comparison between the moments before and after the radiotherapy in relation to MIP and
      MEP was performed using the student's t test paired, considering a 5% significance level. The
      other results of this study were presented in the form of descriptive statistics or in tables
      and graphics. Statistical analysis was performed using the sigma plot version 12.5
      statistical program.
    

Intervention name(s): Radiotherapy breast cancer; Evaluation Maximal Respiratory Pressures
Intervention type(s): Radiation; Other
Other intervention name(s): MIP and MEP
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        The quadrantectomy group (QG) participants were selected consecutively among patients who
        initiated radiotherapy. While the control group (CG) was selected during routine exams of
        he image sector from Hospital de Cancer Alfred Abrão.
      
Keywords: Radiotherapy; Respiratory muscles; Neoplasms; Breast