Volumetric changes in the lumpectomy cavity during whole breast irradiation after breast conserving surgery

PURPOSE: This study was performed to evaluate the change in the lumpectomy cavity volumes before and after whole breast radiation therapy (WBRT) and to identify factors associated with the change of volume. MATERIALS AND METHODS: From September 2009 to April 2010, the computed tomography (CT) simulation data from 70 patients obtained before and after WBRT was evaluated. The lumpectomy cavity volumes were contoured based on surgical clips, seroma, and postoperative changes. Significant differences in the data from pre-WBRT CT and post-WBRT CT were assessed. Multiple variables were examined for correlation with volume reduction in the lumpectomy cavity. RESULTS: The mean and median volume reduction in the lumpectomy cavity after WBRT were 17.6 cm3 and 16.1 cm3, respectively with the statistical significance (p < 0.001). The volume reduction in the lumpectomy cavity was inversely correlated with time from surgery to radiation therapy (R = 0.390). The presence of seroma was significantly associated with a volumetric change in the lumpectomy cavity after WBRT (p = 0.011). CONCLUSION: The volume of lumpectomy cavity reduced significantly after WBRT. As the time from surgery to the start of WBRT increased, the volume reduction in the lumpectomy cavity during WBRT decreased. A strong correlation was observed between the presence of seroma and the reduced volume. To ensure appropriate coverage and to limit normal tissue exposure during boost irradiation in patients who has seroma at the time of starting WBRT, repeating CT simulation at boost planning is suggested.

Comparison of Stereotactic Radiosurgery and Whole Brain Radiotherapy in Patients with Four or More Brain Metastases / 대한방사선종양학회지

PURPOSE: This study was a retrospective evaluation of the efficacy of stereotactic radiosurgery (SRS) in patients with >4 metastases to the brain. MATERIALS AND METHODS: Between January 2004 and December 2006, 68 patients with > or = 4 multiple brain metastases were included and reviewed retrospectively. Twenty-nine patients received SRS and 39 patients received whole brain radiotherapy (WBRT). Patients with small cell lung cancers and melanomas were excluded. The primary lesions were non-small cell lung cancer (69.0%) and breast cancer (13.8%) in the SRS group and non-small cell lung cancer (64.1%), breast cancer (15.4%), colorectal cancer (12.8%), esophageal cancer (5.1%) in the WBRT group. SRS involved gamma-knife radiosurgery and delivered 10~20 Gy (median, 16 Gy) in a single fraction with a 50% marginal dose. WBRT was delivered daily in 3 Gy fractions, for a total of 30 Gy. After completion of treatment, a follow-up brain MRI or a contrast-enhanced brain CT was reviewed. The overall survival and intracranial progression-free survival were compared in each group. RESULTS: The median follow-up period was 5 months (range, 2~19 months) in the SRS group and 6 months (range, 4~23 months) in the WBRT group. The mean number of metastatic lesions in the SRS and WBRT groups was 6 and 5, respectively. The intracranial progression-free survival and overall survival in the SRS group was 5.1 and 5.6 months, respectively, in comparison to 6.1 and 7.2 months, respectively, in the WBRT group. CONCLUSION: SRS was less effective than WBRT in the treatment of patients with >4 metastases to the brain.

Clinical Outcome after Breast Conserving Surgery and Radiation Therapy for Early Breast Cancer / 대한방사선종양학회지

PURPOSE: This study was performed to evaluate the disease-free survival and risk factors of recurrence in early breast cancer patients who have undergone breast conserving surgery and radiation therapy. MATERIALS AND METHODS: From March 1997 to December 2002, 77 breast cancer patients who underwent breast conserving surgery and radiation therapy were reviewed retrospectively. The median follow-up time was 58.4 months (range 43.8~129.4 months) and the mean subject age was 41 years. The frequency distribution of the different T stages, based on the tumor characteristics was 38 (49.3%) for T1, 28 (36.3%) for T2, 3 for T3, 7 for Tis and 1 for an unidentified sized tumor. In addition, 52 patients (67.5%) did not have axillary lymph metastasis, whereas 14 patients (18.1%) had 1~3 lymph node metastases and 3 (0.03%) had more than 4 lymph node metastases. The resection margin was negative in 59 patients, close (< or =2 mm) in 15, and positive in 4. All patients received radiation therapy at the intact breast using tangential fields with a subsequent electron beam boost to the tumor bed at a total dose ranging from 59.4 Gy to 66.4 Gy. Patients with more than four positive axillary lymph nodes received radiation therapy (41.4~60.4 Gy) at the axillary and supraclavicular area. Chemotherapy was administered in 59 patients and tamoxifen or fareston was administered in 29 patients. RESULTS: The 5 year overall survival and disease-free survival rates were 98.08% and 93.49%, respectively. Of the 77 patients, a total of 4 relapses (5.2%), including 1 isolated supraclavicular relapse, 1 supraclavicular relapse with synchronous multiple distant relapses, and 2 distant relapses were observed. No cases of local breast relapses were observed. Lymph node metastasis or number of metastatic lymph nodes was not found to be statistically related with a relapse (p=0.3289) nor disease-free survival (p=0.1430). Patients with positive margins had a significantly shorter disease-free survival period (p<0.0001) and higher relapse rates (p=0.0507). However, patients with close margins were at equal risk of relapse and disease-free survival as with negative margins (p=1.000). Patients younger than 40 years of age had higher relapse rates (9.3% vs. 0%) and lower disease-free survival periods, but the difference was not statistically significant (p=0.1255). The relapse rates for patients with tumors was 14% for tumor stage T2, compared to 0% for tumor stage T1 tumors (p=0.0284). A univariate analysis found that disease-free survival and relapse rates, T stage, positive resection margin and mutation of p53 were significant factors for clinical outcome. CONCLUSION: The results of this study have shown that breast conservation surgery and radiation therapy in early breast cancer patients has proven to be a safe treatment modality with a low relapse rate and high disease-free survival rate. The patients with a positive margin, T2 stage, and mutation of p53 are associated with statistically higher relapse rates and lower disease-free survival.