11 research outputs found

    Intraoperative radiation therapy for early-stage breast cancer: a single-institution experience

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    Background: To assess outcomes and toxicity after low-energy intraoperative radiotherapy (IORT) for early-stage breast cancer (ESBC).  Materials and methods: We reviewed patients with unilateral ESBC treated with breast-conserving surgery and 50-kV IORT at our institution. Patients were prescribed 20 Gy to the surface of the spherical applicator, fitted to the surgical cavity during surgery. Patients who did not meet institutional guidelines for IORT alone on final pathology were recommended adjuvant treatment, including additional surgery and/or external-beam radiation therapy (EBRT). We analyzed ipsilateral breast tumor recurrence, overall survival, recurrence-free survival and toxicity. Results: Among 201 patients (median follow-up, 5.1 years; median age, 67 years), 88% were Her2 negative and ER positive and/or PR positive, 98% had invasive ductal carcinoma, 87% had grade 1 or 2, and 95% had clinical T1 disease. Most had pathological stage T1 (93%) N0 (95%) disease. Mean IORT applicator dose at 1-cm depth was 6.3 Gy. Post-IORT treatment included additional surgery, 10%; EBRT, 11%; adjuvant chemotherapy, 9%; and adjuvant hormonal therapy, 74%. Median total EBRT dose was 42.4 (range, 40.05-63) Gy and median dose per fraction was 2.65 Gy. At 5 years, the cumulative incidence of ipsilateral breast tumor recurrence was 2.7%, the overall survival rate was 95% with no breast cancer-related deaths, and the recurrence-free survival rate was 96%. For patients who were deemed unsuitable for postoperative IORT alone and did not receive recommended risk-adapted EBRT, the IBTR rate was 4.7% versus 1.7% (p = 0.23) for patients who were either suitable for IORT alone or unsuitable and received adjuvant EBRT. Cosmetic toxicity data was available for 83%, with 7% experiencing grade 3 breast toxicity and no grade 4–5 toxicity. Conclusions: IORT for select patients with ESBC results in acceptable outcomes in regard to ipsilateral breast tumor recurrence and toxicity

    Dose-Effect Analysis of Early Changes in Orbital Bone Morphology After Radiation Therapy for Rhabdomyosarcoma

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    Purpose: In survivors of orbital embryonal rhabdomyosarcoma (ERMS), late effects include facial deformation and asymmetry. We sought to quantify orbital asymmetry in ERMS survivors and characterize the dose effect of radiation to the orbital bones. Methods and Materials: We evaluated the most recent follow-up magnetic resonance imaging (MRI) in 17 children (≤21 years old) with stage 1 group III orbital ERMS treated with proton therapy between 2007 and 2018. For all patients, the orbital socket volumes were calculated and compared with the contralateral, unirradiated orbital socket. Patient age, orbital tumor quadrant, and the radiation dose delivered to the major orbital bones (maxillary, frontal, and zygomatic bones) were recorded and correlated with the orbital socket volume difference. Results: The mean age at diagnosis was 5.4 years old (range, 1.1-9.7 years). All patients received a prescription dose of 45 GyRBE. The mean time interval between radiation and MRI was 2.9 years (range, 0.8-3.2 years). The mean age at most recent MRI was 8.4 years (range, 2.3-12.9 years). In 16 of 17 patients, the volume of the ipsilateral orbit was significantly smaller than the contralateral orbit on follow-up MRI (P ≤ .0001). In one patient with nonviable tumor in situ, the irradiated orbit was larger. The volume difference increased with follow-up time and did not correlate with age at treatment or age at MRI. A dose >40 GyRBE to all bones of the orbital rim was associated with a significant decrease in orbital volume (P 40 GyRBE to either the frontal, maxillary, or zygomatic bone was not. Conclusions: Despite the dosimetric precision of proton therapy, orbital asymmetry will develop after >40 GyRBE to multiple bones of the orbital rim. These data may be used to guide treatment planning and counsel patients on expected cosmesis

    PIK3CA mutation is associated with increased local failure in lung stereotactic body radiation therapy (SBRT)

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    Objectives: Hyperactivation of the phosphatidylinositol-3-kinase (PI3K) pathway has been associated with radioresistance. It is unclear whether such mutations confer suboptimal local control for patients who receive lung stereotactic body radiation therapy (SBRT). Our objective was to examine whether mutations in the EGFR/AKT/PIK3CA signaling pathway are associated with local failure (LF) after lung SBRT. Methods: We retrospectively reviewed 166 patients who underwent SBRT to primary or metastatic lung lesions from 2007 to 2015 for whom genetic testing data was available for EGFR, AKT, and PIK3CA genes. Association between clinical factors, including molecular mutation status, and LF was evaluated. Results: Six patients (4%) had PIK3CA mutation, 36 patients (22%) had EGFR mutation, and one patient (0.6%) had AKT1 mutation. Median lesion size was 2.0â¯cm (range, 0.6â5.6â¯cm); median dose was 48â¯Gy in 4 fractions (range, 30â70â¯Gy in 3â10 fractions). Median follow-up for survivors was 27.3â¯months (range, 3.8â66.7â¯months). LF occurred in 16 patients (10%). On univariate analysis, PIK3CA mutation was associated with LF (HR 10.44 [95% CI 2.16â50.46], pâ¯=â¯.003), while tumor histology, tumor size, primary tumor site, BED and EGFR mutation were not. At one year, probability of LF in lesions with PIK3CA mutation was 20.0% vs. 2.9% in lesions without mutation (pâ¯<â¯.001 by log rank test). Conclusion: Although the number of patients affected was small, PIK3CA mutation was significantly associated with higher risk of LF in patients undergoing lung SBRT. This association has not previously been reported for lung SBRT and indicates the need for further validation. Keywords: Lung stereotactic body radiation therapy (SBRT), PIK3CA, Radiation resistance, Local failur
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