Outcomes of intraoperative radiotherapy for early-stage breast cancer: Experience from a multidisciplinary breast oncology program.

BACKGROUND: Intraoperative radiotherapy (IORT) was implemented at our institution for early stage breast cancer patients including those with geographic or medical co-morbidity limitations to whole breast radiation therapy (WBRT). METHODS: Retrospective review of patients (n = 127) who underwent IORT from 2009 to 2016 for breast cancer. Demographics, pathology, toxicity, and recurrences were ascertained. RESULTS: The median age was 67 years (interquartile range: 62-73). At median follow-up (49.6 months), 5 patients (4%) had ipsilateral breast tumor recurrence with median time to recurrence of 36.8 months. Acute and late grade ≥3 skin toxicities were observed in 3.1% and 4.7% of patients, respectively. A subset (n = 7) who received prior ipsilateral WBRT was found to have no subsequent local recurrence, one case of acute grade 3 skin toxicity, and no late toxicity. CONCLUSIONS: IORT is a safe and effective alternative to whole breast radiotherapy, and serves as a suitable alternative to completion mastectomy in locally recurrent breast cancer.

Inverse planning simulated annealing for magnetic resonance imaging-based intracavitary high-dose-rate brachytherapy for cervical cancer.

PURPOSE: To develop a technique using exclusively magnetic resonance imaging (MRI) to perform dwell position identification, targets and organs at risk delineation, and to apply inverse planning dose optimization to high-dose-rate brachytherapy for cervical cancer. METHODS AND MATERIALS: We included 15 consecutive women treated with high-dose-rate (HDR) brachytherapy for cervical cancer. All patients underwent MRI after placement of tandem and ring applicator containing a gadodiamide-filled dummy marker. This technique allowed direct visualization of the source pathway and precise definition of the intra-applicator source positions. For each patient, we delineated gross target volume (GTV), high-risk clinical target volume (HR-CTV), and organs at risk on MRI, according to the European Gynecological GEC-ESTRO Working Group definitions. We performed inverse planning simulated annealing (IPSA) and analyzed the dose-volume histograms with the following endpoints: D(90), D(100), and V(100) for GTV and HR-CTV; D0.1 cc, D1 cc, D2 cc for bladder, rectum, and bowel; and dose at Point A. RESULTS: The intra-applicator source pathway was easily visualized on MRI using the gadodiamide-filled marker. IPSA provided excellent target coverage. The mean D(90) and V(100) for HR-CTV were 103+/-5% and 92+/-3%, respectively. IPSA provided excellent bladder sparing. D1 cc and D2 cc of bladder were 73+/-10% and 67+/-10%, respectively. CONCLUSIONS: We developed a novel technique that allows direct visualization of the intra-applicator source pathway on MRI. Using this technique, we successfully performed inverse planning directly from MRI.

Imaging characteristic analysis of metastatic spine lesions from breast, prostate, lung, and renal cell carcinomas for surgical planning: Osteolytic versus osteoblastic.

BACKGROUND: Surgeons treating metastatic spine disease can use computed tomography (CT) imaging to determine whether lesions are osteolytic, osteoblastic, or mixed. This enables treatment that considers the structural integrity of the vertebral body (VB), which is impaired with lytic lesions but not blastic lesions. The authors analyzed CT imaging characteristics of spine metastasis from breast, lung, prostate, and renal cell carcinomas (RCCs) to determine the metastasis patterns of each of these common tumors. METHODS: The authors identified patients with metastatic spine disease treated during a 3-year period. Variables studied included age, sex, and cancer type. Lesions from breast, lung, prostate, and RCC primary lesions were selected for imaging analysis. RESULTS: Sixty-six patients were identified: 17 had breast metastasis, 14 prostate, 18 lung, and 17 RCC. Breast cancer metastasis involved 33% of VBs with 56%, 20%, and 24% osteolytic, osteoblastic, and mixed, respectively. Prostate cancer metastasis involved 35% of VBs with 14%, 62%, and 24% osteolytic, osteoblastic, and mixed, respectively. Lung cancer metastasis involved 13% of VBs with 64%, 33%, and 3% osteolytic, osteoblastic, and mixed, respectively. RCC metastasis involved 11% of VBs with 91%, 7%, and 2% osteolytic, osteoblastic, and mixed lesions, respectively. CONCLUSIONS: To improve surgical planning, we advocate the use of CT prior to surgery to evaluate whether spine metastases are osteolytic or osteoblastic. In cases of osteolytic lesions, the concern is of segmental instability requiring reconstruction and the risk for screw pull out should instrumentation be considered. In cases of osteoblastic lesions, surgeons should consider debulking dense bone.

The impact of anatomic tumor location on inter-fraction tumor motion during lung stereotactic body radiation therapy (SBRT).

PURPOSE: Narrow PTV margins and steep dose gradients underscore the importance of evaluating breathing-associated tumor motion for lung SBRT. The specific aim of this study was to determine the impact of anatomic tumor location on inter-fraction tumor motion. METHODS AND MATERIALS: Forty-one patients underwent standard free-breathing 4DCT simulation and daily image-guidance 4DCTs during lung SBRT. Absolute tumor motion amplitude in the mediolateral (ML), anterior-posterior (AP), and superior-inferior (SI) directions was analyzed from 159 total 4DCT scans (simulation and daily pre-treatment). RESULTS: Overall, the inter-fraction tumor motion amplitude in the ML, AP, and SI directions was small (mean ≤2.5 mm). Similarly, while both upper lobe (UL) and lower lobe (LL) tumors exhibited limited inter-fraction motion in both the ML and AP directions (mean ≤2.2 mm), tumors in the LL had increased inter-fraction motion in the SI direction compared to UL tumors (mean 4.3±4.0 mm vs. 1.7±1.7 mm, p=0.008). Moreover, 28.6% (n=4) of LL tumors exhibited mean inter-fraction motion along the SI direction >5 mm (all of which resided in the supra-diaphragmatic basal segments of the LL). CONCLUSIONS: Mean inter-fraction tumor motion amplitude along the SI direction exceeded our PTV margins (an isotropic 5 mm expansion of the ITV) in 28.6% of LL tumors (all of which resided in the basal segments). These results suggest that typical ITV-to-PTV margins may be insufficient for a subset of LL lesions and that increased PTV margins, daily breathing motion re-assessment and/or adaptive re-planning may benefit patients with supra-diaphragmatic tumors in the LL.

Rare primary central nervous system tumors.

There are close to 70,000 new cases of primary central nervous system tumors diagnosed annually in the United States. Meningiomas, gliomas, nerve sheath tumors and pituitary tumors account for 85% of them. There is abundant literature on these commonly occurring tumors but data from the literature on infrequently encountered tumors such as atypical teratoid/rhabdoid tumor, choroid plexus carcinoma, ganglioglioma, hemangiopericytoma, and pleomorphic xanthoastrocytoma are limited. This review provides an overview of the clinicopathologic and therapeutic aspects of these rare primary central nervous system tumors.