Predictors for clinical outcomes after accelerated partial breast intensity-modulated radiotherapy.
OBJECTIVE
To correlate the treatment planning parameters with the clinical outcomes in patients treated with accelerated partial breast intensity-modulated radiotherapy.


METHODS
A total of 105 patients with Stage I breast cancer were treated between February 2004 and March 2007 in a Phase II prospective trial and had detailed information available on the planning target volume (PTV), ipsilateral breast volume (IBV), PTV/IBV ratio, lung volume, chest wall volume, surgery to radiotherapy interval, follow-up interval, breast pain, and cosmesis. The first 7 of these patients were treated to 34 Gy, and the remaining 98 were treated to 38.5 Gy. All patients were treated twice daily for 5 consecutive days. Univariate and multivariate analyses were performed.


RESULTS
The median follow-up was 13 months. No recurrences or deaths were observed. Of the 105 patients, 30 reported mild or moderate breast pain in their most recently recorded follow-up visit. The irradiated lung volume (p < 0.05) and chest wall volume receiving >35 Gy (p < 0.01) were associated with pain. The PTV, but not the PTV/IBV ratio, also correlated with pain (p < 0.01 and p = 0.42, respectively). A total of 72 patients reported excellent, 32 reported good, and 1 reported poor cosmesis. Physician-rated cosmesis reported 90 excellent and 15 good. None of the tested variables correlated with the cosmetic outcomes.


CONCLUSIONS
Radiotherapy to the chest wall (chest wall volume receiving >35 Gy) and to lung correlated with reports of mild pain after accelerated partial breast intensity-modulated radiotherapy. Also, the PTV, but not the PTV/IBV ratio, was predictive of post-treatment reports of pain.
Reeder
Reed
R
Northwest Nazarene University, Nampa, ID, USA.
Carter
Dennis L
DL
Howell
Kathryn
K
Henkenberns
Phyllis
P
Tallhamer
Michael
M
Johnson
Tim
T
Kercher
Jane
J
Widner
Jodi
J
Kaske
Terese
T
Paul
Devchand
D
Sedlacek
Scot
S
Leonard
Charles E
CE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001941:Breast Diseases / Q000209:etiology; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000528:radiation effects; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D011446:Prospective Studies; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D035441:Thoracic Wall / Q000528:radiation effects; D016896:Treatment Outcome; D047368:Tumor Burden