Control of Dose Administered Once a Week and Three Times a Day According to Schedules Calculated by the CRE Formula, Using Skin Reaction as a Biological Parameter

Abstract

Patients with breast cancer were irradiated postoperatively to bilateral parasternal fields. The validity of the Cumulative Radiation Effect (CRE) formula for treatment once a week and three times a day was analyzed, and both schedules were compared with treatment once a day (five times a week). The biological radiation effect on normal tissue was studied by reflectance spectrophotometry of skin erythema and pigmentation. Early skin reactions were identical after irradiation daily and once a week, respectively, but were found to be significantly more pronounced after irradiation three times a day than after treatment once a day, corresponding to an overexposure of 7-10%.

A Prospective Randomized Study of Preoperative Irradiation with Cystectomy or Cystectomy Alone for Invasive Bladder Carcinoma

“…The biological effects of fractioned irradiation can be estimated using the cumulative radiation effect formula [24]. This formula takes into account days of treatment, number of fractions and dose (rad) per fraction while CRE seems superior to rad in the characterization of irra diation treatment.…”

Verrucous Squamous Cell Carcinoma of the Larynx: Evidence for Increased Metastatic Potential after Irradiation

“…The target dose ranged from 58 to 82 Gy, corresponding to CRE 18 to 20. 8 The difference in dose was because of variations in fractionation pattern and total treatment time. In no case were cervical nodes included in the radiation field.…”

Radiation physiology – evidence for a higher biological effect of 24 Gy in four fractions as compared to three

“…In 1971, Kirk et al [2] presented a formula for calculating the biological effects on normal tissue, effects designated as the cumulative radiation effect (CRE). Their work was an effort to understand the results by Ellis and coworkers, to make an extended use of results concerning skin sensitivity and implement these in clinical practice [3,4]. In refining the formulas, our arsenal has been enriched with approaches that also take into account injured cells (Biological Effective Dose, BED) [5,6].…”

“…The decision to incorporate radiotherapy in the treatment plan may be influenced by numerous variables, particularly the age of the child, extent of resection, risk of significant neurologic morbidity in the event of tumor progression, and presenting symptoms [2,3]. The debate regarding the use of radiotherapy stems from the concern of late effects in survivors, including neurocognitive deficits, hearing loss, vasculopathy, endocrinopathies and second malignancies [4][5][6][7][8]. As therapeutic techniques have improved, some studies have reported overall survival rates as high as 94-100% at 10 years [3,[9][10][11][12][13].…”