Initial efficacy results of RTOG 0319: three-dimensional conformal radiation therapy (3D-CRT) confined to the region of the lumpectomy cavity for stage I/ II breast carcinoma.
OBJECTIVE
This prospective study (Radiation Therapy Oncology Group 0319) examines the use of three-dimensional conformal external beam radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI). Initial data on efficacy and toxicity are presented.


METHODS
Patients with Stage I or II breast cancer with lesions < or =3 cm, negative margins and with < or =3 positive nodes were eligible. The 3D-CRT was 38.5 Gy in 3.85 Gy/fraction delivered 2x/day. Ipsilateral breast, ipsilateral nodal, contralateral breast, and distant failure (IBF, INF, CBF, DF) were estimated using the cumulative incidence method. Mastectomy-free, disease-free, and overall survival (MFS, DFS, OS) were recorded. The National Cancer Institute Common Terminology Criteria for Adverse Events, version 3, was used to grade acute and late toxicity.


RESULTS
Fifty-eight patients were entered and 52 patients are eligible and evaluable for efficacy. The median age of patients was 61 years with the following characteristics: 46% tumor size <1 cm; 87% invasive ductal histology; 94% American Joint Committee on Cancer Stage I; 65% postmenopausal; 83% no chemotherapy; and 71% with no hormone therapy. Median follow-up is 4.5 years (1.7-4.8). Four-year estimates (95% CI) of efficacy are: IBF 6% (0-12%) [4% within field (0-9%)]; INF 2% (0-6%); CBF 0%; DF 8% (0-15%); MFS 90% (78-96%); DFS 84% (71-92%); and OS 96% (85-99%). Only two (4%) Grade 3 toxicities were observed.


CONCLUSIONS
Initial efficacy and toxicity using 3D-CRT to deliver APBI appears comparable to other experiences with similar follow-up. However, additional patients, further follow-up, and mature Phase III data are needed to evaluate the extent of application, limitations, and value of this particular form of APBI.
Vicini
Frank
F
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48073, USA. fvicini@beaumont.edu
Winter
Kathryn
K
Wong
John
J
Pass
Helen
H
Rabinovitch
Rachel
R
Chafe
Susan
S
Arthur
Douglas
D
Petersen
Ivy
I
White
Julia
J
McCormick
Beryl
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011446:Prospective Studies; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D015203:Reproducibility of Results; D016019:Survival Analysis; D016896:Treatment Outcome; D047368:Tumor Burden