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]
Cost in perspective: direct assessment of American market acceptability of Co-60 in gynecologic high-dose-rate brachytherapy and contrast with experience abroad
Purpose/UNASSIGNED:While Ir-192 remains the mainstay isotope for gynecologic high-dose-rate (HDR) brachytherapy in the U.S., Co-60 is used abroad. Co-60 has a longer half-life than Ir-192, which may lead to long-term cost savings; however, its higher energy requires greater shielding. This study analyzes Co-60 acceptability based on a one-time expense of additional shielding and reports the financial experience of Co-60 in Peru's National Cancer Institute, which uses both isotopes. Material and methods/UNASSIGNED:A nationwide survey was undertaken assessing physician knowledge of Co-60 and willingness-to-pay (WTP) for additional shielding, assuming a source more cost-effective than Ir-192 was available. With 440 respondents, 280 clinicians were decision-makers and provided WTPs, with results previously reported. After completing a shielding report, we estimated costs for shielding expansion, noting acceptability to decision makers' WTP. Using activity-based costing, we note the Peruvian fiscal experience. Results/UNASSIGNED:Shielding estimates ranged from $173,000 to $418,000. The percentage of respondents accepting high-density modular or lead shielding (for union and non-union settings) were 17.5%, 11.4%, 3.9%, and 3.2%, respectively. Shielding acceptance was associated with greater number of radiation oncologists in a respondent's department but not time in practice or the American Brachytherapy Society membership. Peru's experience noted cost savings with Co-60 of $52,400 annually. Conclusions/UNASSIGNED:By comparing the cost of additional shielding for a sample institution's HDR suite with radiation oncologists' WTP, this multi-institutional collaboration noted < 20% of clinicians would accept additional shielding. Despite low acceptability in the US, Co-60 demonstrates cost-favorability in Peru and may similarly in other locations.
Radiation Effect on Late Cardiopulmonary Toxicity: An Analysis Comparing DIBH versus Prone Techniques for Breast Treatment [Meeting Abstract]