Purpose To implement and evaluate a pseudorandom undersampling scheme for combined simultaneous multislice (SMS) balanced SSFP (bSSFP) and compressed‐sensing (CS) reconstruction to enable myocardial perfusion imaging with high spatial resolution and coverage at 1.5 T. Methods A prospective pseudorandom undersampling scheme that is compatible with SMS‐bSSFP phase‐cycling requirements and CS was developed. The SMS‐bSSFP CS with pseudorandom and linear undersampling schemes were compared in a phantom. A high‐resolution (1.4 × 1.4 mm2) six‐slice SMS‐bSSFP CS perfusion sequence was compared with a conventional (1.9 × 1.9 mm2) three‐slice sequence in 10 patients. Qualitative assessment of image quality, perceived SNR, and number of diagnostic segments and quantitative measurements of sharpness, upslope index, and contrast ratio were performed. Results In phantom experiments, pseudorandom undersampling resulted in residual artifact (RMS error) reduction by a factor of 7 compared with linear undersampling. In vivo, the proposed sequence demonstrated higher perceived SNR (2.9 ± 0.3 vs. 2.2 ± 0.6, P = .04), improved sharpness (0.35 ± 0.03 vs. 0.32 ± 0.05, P = .01), and a higher number of diagnostic segments (100% vs. 94%, P = .03) compared with the conventional sequence. There were no significant differences between the sequences in terms of image quality (2.5 ± 0.4 vs. 2.8 ± 0.2, P = .08), upslope index (0.11 ± 0.02 vs. 0.10 ± 0.01, P = .3), or contrast ratio (3.28 ± 0.35 vs. 3.36 ± 0.43, P = .7). Conclusion A pseudorandom k‐space undersampling compatible with SMS‐bSSFP and CS reconstruction has been developed and enables cardiac MR perfusion imaging with increased spatial resolution and myocardial coverage, increased number of diagnostic segments and perceived SNR, and no difference in image quality, upslope index, and contrast ratio.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

to higher dose, at least 50Gy in 4 fractions. The primary endpoint was pergroup cumulative incidence of local recurrence at 1 year (recurrence of treated tumor within same lobe), with distant recurrence and death as competing risks. Treated tumor recurrence (recurrence with epicenter within 1cm of PTV) and toxicity were also analyzed. Results: A total of 217 patients were enrolled from 2011-2018 (some patients were enrolled multiple times). Median age was 72, 59% were male, and 69% were current/former smokers. There were 240 treatment courses and 285 tumors treated (range 1-3 tumors per course). 211 tumors were peripheral and 74 were central. Tumor size distribution was: ≤10cc, 74%; 10-30cc, 19%; > 30cc, 7%. The most common dose was 25Gy in one fraction (158 tumors). Median follow-up was 30 months (range 2-95). Median overall survival was 57 months. Local recurrence data are currently being updated and will be presented at the meeting. The rate of grade 2 or higher pneumonitis was 16/217 (7%) and grade 3 or higher pneumonitis was 3/217 (1%). The rate of grade 2 or higher chest wall pain was 13/217 (6%). One patient had a grade 5 adverse event, developing pulmonary hemorrhage that was possibly related to radiotherapy, 17 months after treatment of a large central NSCLC. Conclusion: Individualized SABR to lung cancers resulted in excellent local control and favorable toxicity profile.

Background: In women amenable to breast conserving therapy, lumpectomy followed by adjuvant whole breast irradiation (WBI) remains the standard of care. Randomized trials have demonstrated that the addition of a lumpectomy cavity boost significantly reduces the risk of ipsilateral breast tumor recurrences but also increases the risk of breast fibrosis. Contemporary randomized trials define the lumpectomy cavity boost volume as a 1.7 cm isometric expansion on the lumpectomy cavity as delineated on CT. However, identifying the lumpectomy cavity can be challenging, especially in women that receive adjuvant chemotherapy and in cases in which surgical clips are not present. Recently, the use of oncoplastic techniques in breast conserving surgery has increased. These techniques are used to prevent the poor cosmetic results that can occur when a large volume of breast tissue is resected. Women that undergo oncoplastic reconstruction represent especially difficult cases for lumpectomy cavity delineation. Retrospective series have evaluated the use of intraoperative electron radiotherapy (IOERT) as a boost prior to WBI in women receiving lumpectomy without oncoplastic reconstruction. In the largest series of IOERT boost prior to WBI the local control rate of this approach was >99%. Prospective data regarding IOERT boost in women undergoing oncoplastic reconstruction are limited. Advantages of this approach include direct visualization/irradiation of the tumor bed, sparing the skin of irradiation, and reducing the treatment time by ˜1 week. We hypothesize that IOERT boost followed by WBI will result in acceptably low rates of grade 3 fibrosis in women undergoing lumpectomy with oncoplastic reconstruction. Trial Design: This is a single-arm, prospective study to evaluate the safety, toxicity and efficacy of IOERT boost at the time of breast conserving surgery in women with early-stage breast cancer undergoing oncoplastic reconstruction. Eligible women will receive 1 dose of 8 Gy to the surgical bed after lumpectomy but prior to oncoplastic reconstruction. Women will then receive adjuvant WBI of 40 Gy in 15 fractions or 50 Gy in 25 fractions. Eligibility: Key inclusion criteria include age≥18 yo, clinically node-negative stage I/II, any breast cancer subtype. Specific Aims: Our primary aim is to determine the rate of grade 3 breast fibrosis at 1 year. Additional aims include surgical complication rates, cosmesis, and local regional cancer control. Statistical Methods: Safety will be evaluated by the rate of surgical complications necessitating hospital readmission or return to the operating room within 30 days of surgery+IOERT. If ≥4 events in the first 10 patients, ≥7 events in the first 20 patients, or ≥9 events in the first 30 patients are seen, the study will be halted. We hypothesize that the grade 3 fibrosis rate in our study will be ≤5%. Assuming an actual rate of 4%, an unacceptable rate of 9%, and a drop-out rate of 10%, the expected sample size is 176. Patient Accrual: Current accrual is 0 of 176. Contact Information: Soyhum McElroy (soyhun.mcelroy@osumc.edu) or Jose Bazan (jose.bazan2@osumc.edu) Funding Source: Intraop Medical Citation Format: Bazan JG, Stephens J, Terando A, Skoracki R, McElroy S, Sexton J, Gupta N, White J. Multi-institution phase II trial of intraoperative electron beam radiotherapy boost at the time of breast conserving surgery with oncoplastic reconstruction in women with early-Stage breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-03-01.