Intensity-modulated radiotherapy results in significant decrease in clinical toxicities compared with conventional wedge-based breast radiotherapy.
OBJECTIVE
We have previously demonstrated that intensity-modulated radiotherapy (IMRT) with a static multileaf collimator process results in a more homogenous dose distribution compared with conventional wedge-based whole breast irradiation (WBI). In the present analysis, we reviewed the acute and chronic toxicity of this IMRT approach compared with conventional wedge-based treatment.


METHODS
A total of 172 patients with Stage 0-IIB breast cancer were treated with lumpectomy followed by WBI. All patients underwent treatment planning computed tomography and received WBI (median dose, 45 Gy) followed by a boost to 61 Gy. Of the 172 patients, 93 (54%) were treated with IMRT, and the 79 patients (46%) treated with wedge-based RT in a consecutive fashion immediately before this cohort served as the control group. The median follow-up was 4.7 years.


RESULTS
A significant reduction in acute Grade 2 or worse dermatitis, edema, and hyperpigmentation was seen with IMRT compared with wedges. A trend was found toward reduced acute Grade 3 or greater dermatitis (6% vs. 1%, p = 0.09) in favor of IMRT. Chronic Grade 2 or worse breast edema was significantly reduced with IMRT compared with conventional wedges. No difference was found in cosmesis scores between the two groups. In patients with larger breasts (> or =1,600 cm(3), n = 64), IMRT resulted in reduced acute (Grade 2 or greater) breast edema (0% vs. 36%, p <0.001) and hyperpigmentation (3% vs. 41%, p = 0.001) and chronic (Grade 2 or greater) long-term edema (3% vs. 30%, p = 0.007).


CONCLUSIONS
The use of IMRT in the treatment of the whole breast results in a significant decrease in acute dermatitis, edema, and hyperpigmentation and a reduction in the development of chronic breast edema compared with conventional wedge-based RT.
Harsolia
Asif
A
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48073, USA.
Kestin
Larry
L
Grills
Inga
I
Wallace
Michelle
M
Jolly
Shruti
S
Jones
Cortney
C
Lala
Moinaktar
M
Martinez
Alvaro
A
Schell
Scott
S
Vicini
Frank A
FA
D000208:Acute Disease; D001940:Breast / Q000473:pathology; D001941:Breast Diseases / Q000209:etiology; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D016022:Case-Control Studies; D002908:Chronic Disease; D004487:Edema / Q000209:etiology; D005260:Female; D006801:Humans; D017495:Hyperpigmentation / Q000209:etiology; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology*; D011855:Radiodermatitis / Q000209:etiology; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*