TY - JOUR
T1 - A phase I/II study piloting accelerated partial breast irradiation using CT-guided intensity modulated radiation therapy in the prone position
AU - Bergom, Carmen
AU - Prior, Phillip
AU - Kainz, Kristofer
AU - Morrow, Natalya V.
AU - Ahunbay, Ergun E.
AU - Walker, Alonzo
AU - Allen Li, X.
AU - White, Julia
N1 - Funding Information:
The research presented was supported, in part, by the Komen Foundation Grant , BCTR0504070 .
PY - 2013/8
Y1 - 2013/8
N2 - Background and purpose External beam accelerated partial breast irradiation (EB-aPBI) is noninvasive with broader potential applicability than aPBI using brachytherapy. However, it has inherent challenges in daily reproducibility. Image-guide radiotherapy (IGRT) can improve daily reproducibility, allowing smaller treatment margins. Our institution proposed IG-IMRT in the prone position to evaluate dose homogeneity, conformality, normal tissue avoidance, and reliable targeting for EB-aPBI. We report preliminary results and toxicity from a phase I/II study evaluating the feasibility of EB-aPBI in the prone position using IG-IMRT. Materials and methods Twenty post-menopausal women with node-negative breast cancer, excised tumors <3.0 cm, negative sentinel lymph node biopsy, and surgical clips demarcating the lumpectomy cavity underwent prone EB-aPBI using IG-IMRT on an IRB-approved phase I/II study. All patients underwent CT planning in the prone position. The lumpectomy cavity PTV represented a 2.0 cm expansion. 38.5 Gy was delivered in 10 fractions over 5 days, such that 95% of the prescribed dose covered >99% of the PTV. Dose constraints for the whole breast, lungs and heart were met. Results The median patient age was 61.5. Mean tumor size was 1.0 cm. 35% of patients had DCIS. Median PTV was 243 cc (108-530) and median breast reference volume was 1698 cc (647-3627). Average daily shifts for IGRT were (0.6, -4.6, 1.7 mm) with standard deviations of (6.3, 6.5, 6.4 mm). Acute toxicity was G1 erythema in 80%, and G2 erythema, G2 fatigue, and G2 breast pain each occurred in 1 patient. With a median follow-up of 18.9 months (12-35), 40% of patients have G1 fibrosis and 30% have G1 hyperpigmentation. 95% of patients have good to excellent cosmesis. There have been no recurrences. Conclusions These data demonstrate that EB-aPBI in the prone position using IG-IMRT is well tolerated, yields good dosimetric conformality, and results in promising early toxicity profiles.
AB - Background and purpose External beam accelerated partial breast irradiation (EB-aPBI) is noninvasive with broader potential applicability than aPBI using brachytherapy. However, it has inherent challenges in daily reproducibility. Image-guide radiotherapy (IGRT) can improve daily reproducibility, allowing smaller treatment margins. Our institution proposed IG-IMRT in the prone position to evaluate dose homogeneity, conformality, normal tissue avoidance, and reliable targeting for EB-aPBI. We report preliminary results and toxicity from a phase I/II study evaluating the feasibility of EB-aPBI in the prone position using IG-IMRT. Materials and methods Twenty post-menopausal women with node-negative breast cancer, excised tumors <3.0 cm, negative sentinel lymph node biopsy, and surgical clips demarcating the lumpectomy cavity underwent prone EB-aPBI using IG-IMRT on an IRB-approved phase I/II study. All patients underwent CT planning in the prone position. The lumpectomy cavity PTV represented a 2.0 cm expansion. 38.5 Gy was delivered in 10 fractions over 5 days, such that 95% of the prescribed dose covered >99% of the PTV. Dose constraints for the whole breast, lungs and heart were met. Results The median patient age was 61.5. Mean tumor size was 1.0 cm. 35% of patients had DCIS. Median PTV was 243 cc (108-530) and median breast reference volume was 1698 cc (647-3627). Average daily shifts for IGRT were (0.6, -4.6, 1.7 mm) with standard deviations of (6.3, 6.5, 6.4 mm). Acute toxicity was G1 erythema in 80%, and G2 erythema, G2 fatigue, and G2 breast pain each occurred in 1 patient. With a median follow-up of 18.9 months (12-35), 40% of patients have G1 fibrosis and 30% have G1 hyperpigmentation. 95% of patients have good to excellent cosmesis. There have been no recurrences. Conclusions These data demonstrate that EB-aPBI in the prone position using IG-IMRT is well tolerated, yields good dosimetric conformality, and results in promising early toxicity profiles.
KW - Accelerated partial breast irradiation
KW - Breast cancer
KW - CT guidance
KW - Image-guided radiation therapy
KW - Prone Intensity modulated radiation therapy
UR - http://www.scopus.com/inward/record.url?scp=84885371100&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2013.05.039
DO - 10.1016/j.radonc.2013.05.039
M3 - Article
C2 - 23932158
AN - SCOPUS:84885371100
SN - 0167-8140
VL - 108
SP - 215
EP - 219
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
IS - 2
ER -