Five-Fraction Prone Accelerated Partial Breast Irradiation: Long-Term Oncologic, Dosimetric, and Cosmetic Outcome
PURPOSE/OBJECTIVE:Randomized data support accelerated partial breast irradiation (APBI) for early-stage breast cancer with variable techniques and cosmesis outcomes. We have treated patients with 5-fraction prone external beam APBI for over a decade and herein report acute and late outcomes. METHODS AND MATERIALS/METHODS:Patients receiving APBI 600 cGyÂ Ã—Â 5 between 2010 and 2019 were included. APBI was primarily delivered prone, with opposed tangents targeting the tumor bed expanded by 1.5 cm (cropped 6 mm from skin). Ipsilateral breast was constrained to V50% < 60% and V100% < 35%. Survival was estimated with Kaplan-Meier. Late toxicities and clinician- and patient-rated cosmesis were evaluated for patients with >6 months follow-up (FU). RESULTS:Of 345 patients meeting criteria, 14 were excluded due to APBI given for ipsilateral breast tumor recurrence (IBTR; nÂ =Â 3), palliation (nÂ =Â 9), and incomplete radiation therapy course (nÂ =Â 2). Of the 331 remaining, median age was 70, 7.2% had ductal carcinoma in situ, and 94.3% were treated prone, with 32% treated every other day and 68% on consecutive days. Mean heart dose was 23.8 cGy for left-sided and 12.7 cGy for right-sided cancers. Ipsilateral lung V30% was 0.4%. At 5-year median FU, there were 7 (2.1%) IBTR, 9 (2.7%) contralateral recurrences, and 1 (0.3%) distant metastasis. Five-year local recurrence-free, disease-free, and overall survival was 99.5%, 96.7%, and 98.1%, respectively. When comparing patients with IBTR versus without, a higher proportion did not receive hormone therapy (71.4% vs. 26.2%, PÂ =Â .018). Rates of acute grade 1 to 2 dermatitis, fatigue, and pain were 35.4%, 21.8%, and 9.4%, respectively, with no grade 3 toxicity. The rate of good-excellent physician- and patient-rated cosmesis (nÂ =Â 199, median FU 2.8 years) was 92.5% and 89.4%, respectively. Patients experienced low rates of telangiectasia, fibrosis, and retraction/atrophy. CONCLUSIONS:We report excellent dosimetric, oncologic, cosmetic, and late toxicity outcomes for patients treated with 5-fraction APBI. To our knowledge this is the largest series of women treated with prone APBI.
Boost to Unresectable Nodal Disease in Locally Advanced Breast Cancer: Outcomes and Toxicity
PURPOSE/OBJECTIVE(S): The supraclavicular (SCV), medial axillary and internal mammary nodes (IMNs) are not typically resected in breast cancer patients (pts). The optimal local therapy of pts with nodal disease in these regions is not well-studied. We aim to evaluate outcomes of breast cancer patients with unresected nodal disease. MATERIALS/METHODS: We identified 79 pts at our institution from 2016- 2021 with unresected nodal disease in the axilla, SCV and/or IMNs defined as grossly enlarged nodes on CT, MRI or PET scan +/- biopsy confirmation. Pts were treated with breast/chest wall and regional nodal irradiation with an additional boost to the unresected nodal region. Distant failure (DF) and local-regional failure (LRF) were assessed. Kaplan-Meier was used to calculate disease-free survival (DFS), overall survival (OS) and local recurrence-free survival (LRFS). Logistic regression was used to identify variables associated with worse DFS. Acute and late toxicity of RT were evaluated.
RESULT(S): 33% of pts were treated with breast-conserving surgery, 65% with mastectomy and all had axillary surgery (81% ALND, 19% SLNB). 47% of pts received IMN boost (IMN), 40% axillary/SCV boost (axSCV) and 15% both IMN and axSCV boost (IMN/axSCV). Most had cT2-3 (72%), hormone receptor positive (75%), and HER-2 negative disease (84%). 57% of axSCV had cN3A disease; 84% of IMN and 83% of IMN/axSCV had cN3b disease. 7% of axSCV and 17% of IMN/axSCV had cN3c disease. Most pts received chemotherapy (97%). Median nodal boost dose was 10 Gy (range 10-20 Gy), with 17% axSCV, 22% IMN, and 17% IMN/axSCV receiving 14-20 Gy. Rates of acute and late grade 3 toxicity did not differ by boost location (acute: IMN: 20%, axSCV: 11% and IMN/axSCV 20%, P=0.559; late: IMN: 40%, axSCV: 25%, IMN/axSCV: 40%, P=0.630) nor by boost dose (10 Gy vs 14-20 Gy). There were no grade 4+ toxicities. With a median follow up of 30 months, the 3-year LRR, DFS, and OS was 94.5%, 86.3% and 93.8% respectively. Crude rates of failure for the entire group were 13.9% (10.1% DF; 3.8% DF+LRF). Rates of failure by boost group were axSCV: 13.3% (10% DF; 3.3% DF+LRF), IMN: 5.4% (2.7% DF, 2.7% DF+LRF), IMN/axSCV 41.7% (33.3% DF, 8.3% DF+LRF). There were no LRFs without DFs. Median time to failure was 23 months (IQR 18-34). On univariate analysis clinical tumor size (cT) and IMN/axSCV vs. IMN or axSCV alone was associated with worse DFS (HR: 9.78 95% CI 2.07-46.2, P=0.004 and HR: 9.49 95% CI 2.67-33.7, P=0.001). On multivariate analysis, cT approached significance (HR 6.15; 95% CI 0.95-39.8, P=0.05). IMN/axSCV vs. IMN or axSCV alone retained significance (HR 4.80; 95% CI 1.27-18.13, P=0.02). The difference between the axSCV vs. IMN group was not significant.
CONCLUSION(S): In this population of pts with unresected nodal disease, boost RT to radiographically positive LN regions can be safely delivered with low rates of grade 3+ toxicity. The majority of failures were distant with no isolated LRFs. Failures were highest in the IMN/axSCV group (~40%). Further treatment escalation is necessary for these pts.
A prospective trial to compare deep inspiratory breath hold (DIBH) with prone breast irradiation
PURPOSE/OBJECTIVE:To compare heart and lung doses for adjuvant whole breast irradiation (WBI) between radiation plans generated supine with deep inspiratory breath hold (S-DIBH) and prone with free-breathing (P-FB) and examine the effect of breast volume (BV) on dosimetric parameters. MATERIALS/METHODS/METHODS:Patients with left breast DCIS or invasive cancer receiving adjuvant WBI were enrolled on a single-institutional prospective protocol. Patients were simulated S-DIBH and P-FB; plans were generated using both scans. Wilcoxon's Signed Rank and Rank Sum tests were used to compare intra-patient differences between plans for the entire cohort and within BV groups defined by tertiles. RESULTS:Forty patients were enrolled. Thirty-four patients are included in the analysis due to patient withdrawal or inability to hold breath. With WBI dose of 4005 - 4256 cGy, mean heart dose (MHD) was 80 cGy in S-DIBH, 77 cGy in P-FB (p=0.08). Mean ipsilateral lung dose (MLD) was 453 cGy in S-DIBH, 45 cGy in P-FB (p<0.0001). Mean and max LAD dose were 251 cGy and 551 cGy in S-DIBH respectively, 324 cGy (p=0.1) and 993 cGy in P-FB (p=0.3) respectively. Hot spot and separation was 109% and 22 cm in S-DIBH respectively, 107% and 16 cm in P-FB respectively (p<0.0001). For patients with smallest BV, S-DIBH improved MHD and LAD doses; for those with largest BV, P-FB improved cardiac dosimetry. With increasing BV, there was an increasing advantage of P-FB for MHD (p=0.05), and max (p=0.03) and mean (p=0.02) LAD dose, and the reduction in MLD, hot spot, and separation with P-FB increased (p<0.05). CONCLUSIONS:MHD did not differ between P-FB and S-DIBH, whereas MLD was significantly lower with P-FB. Analysis according to breast volume revealed improved cardiac dosimetry with S-DIBH for women with smallest BV and improved cardiac dosimetry with P-FB for women with larger BV, thereby providing a dosimetric rationale for using breast size to help determine the optimal positioning for WBI.
Radiation effect on late cardiopulmonary toxicity: An analysis comparing supine DIBH versus prone techniques for breast treatment
Two commonly used whole breast irradiation (WBI) techniques, deep inspiration breath hold (DIBH) and prone positioning, are compared with regard to dosimetry and estimated late cardiac morbidity and secondary lung cancer mortality using published models. Forty patients with left-sided DCIS or breast cancer who underwent lumpectomy and required adjuvant WBI were enrolled on a prospective trial comparing supine DIBH (S-DIBH) with prone free breathing (P-FB) planning. Patients underwent CT simulation in both positions; two plans were generated for each patient. Comparative dosimetry was available for 34 patients. Mean cardiac and lung doses were calculated. Risk of death from ischemic heart disease (IHD), risk of at least one acute coronary event (ACE), and lung cancer mortality were estimated from published data. Difference between S-DIBH and P-FB plans was compared using paired two-tailed t test. Estimated mean risk of death from IHD by age 80 was 0.1% (range 0.0%-0.2%) for both plans (PÂ =Â 1.0). Mean risk of at least one ACE was 0.3% (range 0.1%-0.6%) for both plans (PÂ =Â .6). Mean lung cancerÂ mortality risk was 1.4% (range 0.5%-15.4%) for S-DIBH and 1.0% (range 0.4%-9.8%) for P-FB (PÂ =Â .008). Excess lung cancer mortality due to radiation was 0.5% (range 0.1%-6.0%) with S-DIBH and 0.0% (range 0.0%-0.4%) with P-FB (PÂ =Â .008). Both S-DIBH and P-FB provide excellent cardiac sparing. Prone positioning results in lower lung dose than S-DIBH and leads to an absolute decrease of 0.5% in excess lung cancer mortality for patients receiving WBI.
Ipsilateral breast tumor recurrence in early stage breast cancer patients treated with breast conserving surgery and adjuvant radiation therapy: Concordance of biomarkers and tumor location from primary tumor to in-breast tumor recurrence
BACKGROUND:Patients with an in-breast tumor recurrence (IBTR) after breast-conserving therapy have a high risk of distant metastasis and disease-related mortality. Classifying clinical parameters that increase risk for recurrence after IBTR remains a challenge. AIM/OBJECTIVE:To describe primary and recurrent tumor characteristics in patients who experience an IBTR and understand the relationship between these characteristics and disease outcomes. METHODS:Patients with stage 0-II breast cancer treated with lumpectomy and adjuvant radiation were identified from institutional databases of patients treated from 2003-2017 at our institution. Overall survival (OS), disease-free survival, and local recurrence-free survival (LRFS) were estimated using the Kaplan Meier method. We identified patients who experienced an isolated IBTR. Concordance of hormone receptor status and location of tumor from primary to recurrence was evaluated. The effect of clinical and treatment parameters on disease outcomes was also evaluated. RESULTS:= 0.004) decreased the risk of IBTR. CONCLUSION/CONCLUSIONS:Among patients with early stage breast cancer who had breast conserving surgery treated with adjuvant RT, ER/PR status and quadrant were highly concordant from primary to IBTR. Tumor size greater than 1.5 cm and use of adjuvant endocrine therapy were significantly associated with decreased risk of IBTR.
Whole breast irradiation with high tangents in the prone position
Five-Fraction Prone Accelerated Partial Breast Irradiation: Long-Term Oncologic and Cosmetic Outcomes [Meeting Abstract]
Coverage of Axillary Lymph Nodes with High Tangents in the Prone Position [Meeting Abstract]
Breast Conservation and Hypofractionation in Women with Hereditary Breast Cancer [Meeting Abstract]
The Location of Implantable Bioabsorable Tissue Marker in Relation to Preoperative Tumor Location and Postoperative Seroma: Implications for Target Delineation [Meeting Abstract]