Results of NYU 05-181: A Prospective Trial to Determine Optimal Position (prone Versus Supine) for Breast Radiotherapy

Purpose/Objective(s)Prone whole breast radiotherapy is feasible and can be delivered with a hypo-fractionated, concomitant boost IMRT regimen (Formenti SC, JCO, 2007). However, in occasional patients a supine setup better spares heart irradiation. NYU 05-181 identified the optimal radiation treatment position for breast cancer patients.Materials/MethodsStage 0-II A breast cancer patients with negative margins of lumpectomy were eligible to this IRB-approved prospective study. Each consented patient underwent two CT simulations and planning, one supine and one prone. The breast tissue was first outlined supine using traditional borders, and then re-imaged prone. Optimal position was defined as that which best covered the contoured breast volume and tumor bed, while minimizing inclusion of heart and lung tissue in the treatment field. For patients with left breast cancer the plan which minimized the volume of heart in the field was chosen for treatment. For patients with right breast cancer, the plan with the least volume of lung was chosen.ResultsBetween 2006 and 2008, the study met the planned accrual of 400 patients: 200 with left and 200 with right breast cancer. Among right breast cancer patients the prone position was optimal in sparing lung volume in 98% (195/200), reducing the volume of lung in the treatment field by a mean 107 cc (SD 75, range 463,0). In the five patients treated supine the choice for supine treatment was based on patient's preference since there was no significant difference in lung sparing between the two positions. For left breast cancer patients, the prone position was optimal in 85% (170/200), with lung volume reduced by a mean of 93 cc (SD 72, range 334, 9) and heart volume reduced by a mean of 11 cc (SD 23, range 0,220). However, in 15% of left breast patients the best position was supine reducing the amount of heart in the treatment field by a mean of 6 cc (SD 8, range 0,41). Breast volume failed to reliably predict for optimal prone positioning. Among patients with A/B cup size (<750 cc breast volume), 83 % were better treated prone (125/151), consisting of 69% of left and 97% of right breast cancer patients. For patients with C cup (>750 cc and <1500 cc) and D cup (≥1500 cc) the prone position was optimal in 96% (168/175) and 99% (73/74), respectively.ConclusionsBased on the trial criteria for an optimal setup for treatment, the majority of patients were treated prone (91%). Prone setup enabled a drastic reduction in the amount of lung volume irradiated in all patients. Contrary to generalizations that prone radiotherapy is best reserved for large-breasted women, in this prospective study it was also preferred among smaller breast-size patients. Further research is ongoing to predict which left breast cancer patient benefits from supine setup. Purpose/Objective(s)Prone whole breast radiotherapy is feasible and can be delivered with a hypo-fractionated, concomitant boost IMRT regimen (Formenti SC, JCO, 2007). However, in occasional patients a supine setup better spares heart irradiation. NYU 05-181 identified the optimal radiation treatment position for breast cancer patients. Prone whole breast radiotherapy is feasible and can be delivered with a hypo-fractionated, concomitant boost IMRT regimen (Formenti SC, JCO, 2007). However, in occasional patients a supine setup better spares heart irradiation. NYU 05-181 identified the optimal radiation treatment position for breast cancer patients. Materials/MethodsStage 0-II A breast cancer patients with negative margins of lumpectomy were eligible to this IRB-approved prospective study. Each consented patient underwent two CT simulations and planning, one supine and one prone. The breast tissue was first outlined supine using traditional borders, and then re-imaged prone. Optimal position was defined as that which best covered the contoured breast volume and tumor bed, while minimizing inclusion of heart and lung tissue in the treatment field. For patients with left breast cancer the plan which minimized the volume of heart in the field was chosen for treatment. For patients with right breast cancer, the plan with the least volume of lung was chosen. Stage 0-II A breast cancer patients with negative margins of lumpectomy were eligible to this IRB-approved prospective study. Each consented patient underwent two CT simulations and planning, one supine and one prone. The breast tissue was first outlined supine using traditional borders, and then re-imaged prone. Optimal position was defined as that which best covered the contoured breast volume and tumor bed, while minimizing inclusion of heart and lung tissue in the treatment field. For patients with left breast cancer the plan which minimized the volume of heart in the field was chosen for treatment. For patients with right breast cancer, the plan with the least volume of lung was chosen. ResultsBetween 2006 and 2008, the study met the planned accrual of 400 patients: 200 with left and 200 with right breast cancer. Among right breast cancer patients the prone position was optimal in sparing lung volume in 98% (195/200), reducing the volume of lung in the treatment field by a mean 107 cc (SD 75, range 463,0). In the five patients treated supine the choice for supine treatment was based on patient's preference since there was no significant difference in lung sparing between the two positions. For left breast cancer patients, the prone position was optimal in 85% (170/200), with lung volume reduced by a mean of 93 cc (SD 72, range 334, 9) and heart volume reduced by a mean of 11 cc (SD 23, range 0,220). However, in 15% of left breast patients the best position was supine reducing the amount of heart in the treatment field by a mean of 6 cc (SD 8, range 0,41). Breast volume failed to reliably predict for optimal prone positioning. Among patients with A/B cup size (<750 cc breast volume), 83 % were better treated prone (125/151), consisting of 69% of left and 97% of right breast cancer patients. For patients with C cup (>750 cc and <1500 cc) and D cup (≥1500 cc) the prone position was optimal in 96% (168/175) and 99% (73/74), respectively. Between 2006 and 2008, the study met the planned accrual of 400 patients: 200 with left and 200 with right breast cancer. Among right breast cancer patients the prone position was optimal in sparing lung volume in 98% (195/200), reducing the volume of lung in the treatment field by a mean 107 cc (SD 75, range 463,0). In the five patients treated supine the choice for supine treatment was based on patient's preference since there was no significant difference in lung sparing between the two positions. For left breast cancer patients, the prone position was optimal in 85% (170/200), with lung volume reduced by a mean of 93 cc (SD 72, range 334, 9) and heart volume reduced by a mean of 11 cc (SD 23, range 0,220). However, in 15% of left breast patients the best position was supine reducing the amount of heart in the treatment field by a mean of 6 cc (SD 8, range 0,41). Breast volume failed to reliably predict for optimal prone positioning. Among patients with A/B cup size (<750 cc breast volume), 83 % were better treated prone (125/151), consisting of 69% of left and 97% of right breast cancer patients. For patients with C cup (>750 cc and <1500 cc) and D cup (≥1500 cc) the prone position was optimal in 96% (168/175) and 99% (73/74), respectively. ConclusionsBased on the trial criteria for an optimal setup for treatment, the majority of patients were treated prone (91%). Prone setup enabled a drastic reduction in the amount of lung volume irradiated in all patients. Contrary to generalizations that prone radiotherapy is best reserved for large-breasted women, in this prospective study it was also preferred among smaller breast-size patients. Further research is ongoing to predict which left breast cancer patient benefits from supine setup. Based on the trial criteria for an optimal setup for treatment, the majority of patients were treated prone (91%). Prone setup enabled a drastic reduction in the amount of lung volume irradiated in all patients. Contrary to generalizations that prone radiotherapy is best reserved for large-breasted women, in this prospective study it was also preferred among smaller breast-size patients. Further research is ongoing to predict which left breast cancer patient benefits from supine setup.