Study to See Whether Breath-Hold Techniques During RT Are Effective in Helping to Improve Sparing of the Heart

Study to See Whether Breath-Hold Techniques During RT Are Effective in Helping to Improve Sparing of the Heart

A Cohort Study Assessing Cardiac Function With MRI in Left-Sided Breast Cancer Patients Treated With Deep Inspiration Breath Hold (DIBH) Technique to Improve Cardiac Sparing During Adjuvant Radiotherapy

The study hopes to determine whether patients with left-sided breast cancer are at an increased risk of cardiac changes due to radiation to the breast +/- Anthracycline-based chemotherapy +/- Herceptin and whether a deep inspiration breath hold (DIBH) technique during radiotherapy treatments would further reduce dosimetric dose to the heart as compared to the conventional free breathing (FB) technique thus reducing cardiac toxicity as measured by cardiac MRI using left ventricular end-diastolic volume (LVEDV) as a metric. Bio fluid samples will also be collected to investigate specific biomarkers of breast cancer: BNP, PIIINP and CITP

Patients with left-sided breast cancer who receive adjuvant breast or chest wall radiation have increased risk of treatment related cardiovascular morbidity. The risk of cardiac morbidity and mortality is increased when a patient receives radiation following adjuvant chemotherapy and Herceptin. The dose-volume histogram (DVH) parameters associated with increased cardiac toxicity include volume of heart irradiated, total radiation dose received by the left ventricle (LV), V25 and mean cardiac dose. Even though modern RT treatments like 3DCRT and IMRT can reduce the mean dose to the heart, the maximum dose to the left side of the heart/LV may not be reduced if the target is close to the heart. The hypothesis is that DIBH RT can safely and effectively reduce the heart dose, especially the dose to the LV, that could lead to reduction in the incidence of radiation induced cardiovascular morbidity and mortality. Radiotherapy has detrimental effects on cardiac function due to remodeling of the cardiac tissue that receive radiation. We believe that the radiation related acute effects on heart tissue can be detected with cardiac functional MRI. The study will quantify the acute RT related effects. To our knowledge, cardiac MRI has not been explored as a non invasive technique to quantify RT +/- chemotherapy related effects.

Cohort 1 - No prior anthracycline-based chemotherapy or herceptin, deep inspiration breath hold breast radiation therapy

Cohort II - no prior Anthracycline based chemotherapy or Herceptin and (ii) to receive FB RT (not able to hold breath for at least 20 seconds or does not have a minimum of 1.0 cm of heart on at least 3 slices (3mm slices) on the FB scan)

Cohort III - Prior Anthracycline-based chemotherapy or Herceptin, and (ii) eligible to receive DIBH RT. (Patient has a minimum of 1.0 cm of heart on at least 3 slices (3mm slices) on the FB scan)

Radiation related acute and long term functional changes in patients treated with deep-inspiration breath hold compared to free-breathing technique

Using MRI-based cardiac functional imaging to measure radiation-related acute and long term cardiac functional changes in patients treated with deep-inspiration breath-hold (DIBH) compared to free breathing (FB) treatment

Radiation dosimetry is the accurate calculation and measurement of radiation doses received by tissue resulting from the exposure to radiation. A radiation dosimetric comparison will be performed between the deep inspiration breath hold (DIBH) technique treatment plan and the free breathing (FB) technique treatment plan to explore sparing of cardiac sub-structures from radiation, if any

Inclusion Criteria: Female patients with pathologically confirmed left sided breast cancer eligible for adjuvant breast/chest wall plus or minus regional nodal radiotherapy Women patients with age group between 18 and 70 years old Karnofsky performance score ≥ 70 Ability to hold breath for at least 20 sec (for DIBH cohorts only) Life expectancy >10 years Exclusion Criteria: For patients with prior Anthracycline based chemotherapy or Herceptin, if there is < 1.0 cm of heart on at least 3 slices ( 3 mm slices) on the FB scan, the patient will be considered a screen failure. Previously irradiated or recurrent breast/chest wall tumours or previous malignancy other than non-melanoma skin cancer unless disease free for a minimum of 5 years prior to study entry Patients that require a shell for breast immobilization Patients requiring a boost Stage IV disease