A Single Institution Retrospective Comparison Study of Locoregional Recurrence After Accelerated Partial Breast Irradiation Using External Beam Fractionation Compared with Whole Breast Irradiation with 8 Years of Follow-Up.

BACKGROUND: Accelerated partial breast irradiation (APBI) was developed to address disadvantages of overall treatment time and potentially unnecessary radiation associated with whole breast irradiation (WBI). We report updated results of our single institution study using an external beam APBI regimen with a median follow-up of 8 years. METHODS: A total of 290 APBI patients with AJCC Stage 0-II breast cancer were compared with 290 WBI patients with matched tumor characteristics. Toxicities were scored based on the Common Terminology Criteria for Adverse Events (CTCAE v3.0). Cox regression models were used to predict likelihood of freedom from ipsilateral failure. RESULTS: Median follow-up was 8 years in the APBI group and 7.5 years in the WBI group. In the APBI group, there were 18 (6.2%) ipsilateral breast tumor recurrence (IBTR), 13 (72%) had elsewhere failures (EF), and 5 (28%) had local failures (LF) with a median time to failure of 64.1 months. In the WBI group, there were three (1.0%) IBTR; one (33%) was an EF and two (67%) were LF with a median time to failure of 91 months. APBI was 4.6 times more likely (hazard ratio 4.57, 95% confidence interval 1.3-16.2, p = 0.02) to have an IBTR than WBI after adjusting for age, tumor size, histology, grade, and estrogen receptor status. Fatigue, erythema, and desquamation toxicities were significantly less in the APBI group then the WBI group. CONCLUSIONS: IBTR rates were higher in external beam APBI group compared with WBI, but APBI had fewer toxicities. Clinicians must weigh the risks and benefits of APBI when making a recommendation for partial breast irradiation after lumpectomy.

TIMING OF RADIOACTIVE IODINE THERAPY DOES NOT IMPACT OVERALL SURVIVAL IN HIGH-RISK PAPILLARY THYROID CARCINOMA.

OBJECTIVE: Postthyroidectomy radioiodine (RAI) therapy is indicated for papillary thyroid carcinoma (PTC) with high-risk features. There is variability in the timing of RAI therapy with no consensus. We analyzed the impact of the timing of initial RAI therapy on overall survival (OS) in PTC. METHODS: The National Cancer Data Base (NCDB) was queried from 2003 to 2006 for patients with PTC undergoing near/subtotal or total thyroidectomy and RAI therapy. High-risk patients had tumors >4 cm in size, lymph node involvement, or grossly positive margins. Early RAI was ≤3 months, whereas delayed was between 3 and 12 months after thyroidectomy. Kaplan-Meier (KM) and Cox survival analyses were performed after adjusting for patient and tumor-related variables. A propensity-matched set of high-risk patients after eliminating bias in RAI timing was also analyzed. RESULTS: There were 9,706 patients in the high-risk group. The median survival was 74.7 months. KM analysis showed a survival benefit for early RAI in high-risk patients (P = .025). However, this difference disappeared (hazard ratio [HR] 1.26, 95% confidence interval [CI] 0.98-1.62, P = .07) on adjusted Cox multivariable analysis. Timing of RAI therapy failed to affect OS in propensity-matched high-risk patients (HR 1.09, 95% CI 0.75-1.58, P = .662). CONCLUSION: The timing of postthyroidectomy initial RAI therapy does not affect OS in patients with high-risk PTC. ABBREVIATIONS: CI = confidence interval CLNM = cervical lymph node metastasis FVPTC = follicular variant papillary thyroid carcinoma HR = hazard ratio KM = Kaplan-Meier NCDB = National Cancer Data Base OS = overall survival PTC = papillary thyroid carcinoma RAI = radioactive iodine.

Accelerated partial breast irradiation using once-daily fractionation: analysis of 312 cases with four years median follow-up.

BACKGROUND: There are limited data on accelerated partial breast irradiation (APBI) using external beam techniques. Moreover, there are recent reports of increased fibrosis and unacceptable cosmesis with APBI using external beam with BID fractionation. We adopted a once daily regimen of APBI with fractionation similar to that shown to be effective in a Canadian randomized trial of whole breast irradiation. It is unclear whether patients with DCIS or invasive lobular carcinoma (ILC) are suitable for APBI. METHODS: The retrospective cohort included 310 patients with 312 tumors of T1-T2N0-N1micM0 invasive ductal carcinoma (IDC), ILC, or Tis (DCIS) treated with APBI via external beam. Most patients were treated using IMRT with 16 daily fractions of 270 cGy to a dose of 4320 cGy. The target volume included the lumpectomy cavity plus 1.0 cm to account for microscopic disease and an additional 0.5 to 1.0 cm for setup uncertainty and breathing motion. Ipsilateral breast failure (IBF) was pathologically confirmed as a local failure (LF) or an elsewhere failure (EF). RESULTS: Median follow-up was 49 months. Among the 312 cases, 213 were IDC, 31 ILC, and 68 DCIS. Median tumor size was 1.0 cm. There were 9 IBFs (2.9%) including 5 LFs and 4 EFs. The IBF rates among patients with IDC, ILC, and DCIS were 2.4%, 3.2%, and 4.4%, respectively, with no significant difference between histologies. When patients were analyzed by the ASTRO APBI consensus statement risk groups, 32% of treated cases were considered suitable, 50% cautionary, and 18% unsuitable. The IBF rates among suitable, cautionary, and unsuitable patients were 4.0%, 2.6%, and 1.8%, respectively, with no significant difference between risk groups. Acute skin reactions were rare and long-term cosmetic outcome was very good to excellent. CONCLUSIONS: External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not differentiate a subset of patients with a higher rate of IBF. APBI may be an appropriate treatment for women with DCIS and ILC.