EAL

Intervention
Is there a relationship between supplementation of antioxidant vitamin E and the efficacy of radiotherapy treatment in patients with head and neck cancer?
- Conclusion
  Results of one RCT of strong design suggests three-year use of high-dose a-tocopherol supplements for older patients with stage I and II head and neck cancer receiving radiation therapy may be associated with an increased occurance of second primary cancers and decreased duration of cancer-free survival.
- Grade: II
  - Grade I means there is Good/Strong evidence supporting the statement;
  - Grade II is Fair;
  - Grade III is Limited/Weak;
  - Grade IV is Expert Opinion Only;
  - Grade V is Not Assignable.
  - High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
  - Moderate (B) means we are moderately confident in the effect estimate;
  - Low (C) means our confidence in the effect estimate is limited;
  - Very Low (D) means we have very little confidence in the effect estimate.
  - Ungraded means a grade is not assignable.
- Search Plan and Results: Antioxidants and Radiation Therapy 2006
Is there a relationship between supplementation of antioxidant vitamin E, which may interact with radiation therapy treatment, tolerance of radiation therapy treatment and late-effects of radiation therapy treatment in patients with chronic radiation-induced fibrosis resulting from breast cancer treatment?
- Conclusion
  Research neither supports nor refutes the use of oral vitamin E supplementation for improved tolerance to or outcome of treatment in breast cancer patients undergoing radiation therapy. However, some evidence shows that oral supplementation of vitamin E may be beneficial in treating late-effects of radiation therapy treatment. One positive quality RCT found no effectiveness of oral vitamin E on the treatment of chronic RIF resulting from breast cancer treatment as measured by perometer. A study of neutral quality found an effect, but the fibrosis measurement methodology was not validated. Larger PRCTs with validated measures of radiation therapy effect are needed.
- Grade: III
  - Grade I means there is Good/Strong evidence supporting the statement;
  - Grade II is Fair;
  - Grade III is Limited/Weak;
  - Grade IV is Expert Opinion Only;
  - Grade V is Not Assignable.
  - High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
  - Moderate (B) means we are moderately confident in the effect estimate;
  - Low (C) means our confidence in the effect estimate is limited;
  - Very Low (D) means we have very little confidence in the effect estimate.
  - Ungraded means a grade is not assignable.
- Search Plan and Results: Antioxidants and Radiation Therapy 2006
Is there a relationship between supplementation of antioxidant vitamin E, which may interact with radiation therapy treatment, tolerance of radiation therapy treatment and late-effects of radiation therapy treatment in patients with osteoradionecrosis resulting from head and neck cancer treatment?
- Conclusion
  Research neither supports nor refutes the use of oral vitamin E supplementation to improve tolerance or treatment outcome in head and neck cancer patients receiving radiation therapy; however, limited evidence shows that supplementation with vitamin E may be beneficial for late-effects of treatment. In a neutral quality, before-after time series study, a combination of pentoxifylline (800 mg per day) and vitamin E (1,000 IU/day), boosted for the most serious cases with clodronate (1,600 mg per day, 5 days per week), for 6 to 24 months induced mucosal and bone healing in patients with osteoradionecrosis. Well-designed studies are needed to determine the benefits of vitamin E supplementation.
- Grade: III
  - Grade I means there is Good/Strong evidence supporting the statement;
  - Grade II is Fair;
  - Grade III is Limited/Weak;
  - Grade IV is Expert Opinion Only;
  - Grade V is Not Assignable.
  - High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
  - Moderate (B) means we are moderately confident in the effect estimate;
  - Low (C) means our confidence in the effect estimate is limited;
  - Very Low (D) means we have very little confidence in the effect estimate.
  - Ungraded means a grade is not assignable.
- Search Plan and Results: Antioxidants and Radiation Therapy 2006
Is there a relationship between supplementation of antioxidant vitamins E and C, which may interact with radiotherapy treatment, tolerance of radiotherapy treatment and late-effects of radiotherapy treatment in patients with chronic radiation proctitis?
- Conclusion
  Research does not support or refute the use of supplemental vitamins C and E to improve tolerance or late-effects of radiotherapy treatment in patients with chronic proctitis. One small, negative quality, before-after time series study reported a reduction in bleeding, diarrhea, and fecal urgency beginning within six weeks of supplementation with 500 mg vitamin C and 400 IU vitamin (taken three times daily) and continued in a subset of patients still taking the supplements a year later. Large, well-designed studies are needed to address the potential interaction of antioxidants with radiotherapy and treatment outcome.
- Grade: III
  - Grade I means there is Good/Strong evidence supporting the statement;
  - Grade II is Fair;
  - Grade III is Limited/Weak;
  - Grade IV is Expert Opinion Only;
  - Grade V is Not Assignable.
  - High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
  - Moderate (B) means we are moderately confident in the effect estimate;
  - Low (C) means our confidence in the effect estimate is limited;
  - Very Low (D) means we have very little confidence in the effect estimate.
  - Ungraded means a grade is not assignable.
- Search Plan and Results: Antioxidants and Radiation Therapy 2006