Intra-Operative Radiotherapy (IORT) in Breast Conserving Therapy in Early-Stage Breast Cancer and DCIS

PURPOSE/OBJECTIVE(S)

Initial breast intra-operative radiotherapy (IORT) results in clinical trials were encouraging though with longer follow up, increased local recurrences have been reported compared with whole breast radiation or other partial breast radiation including accelerated partial breast irradiation (APBI) methods. The goal of the study is to report our prospective single institution IORT breast study outcomes of local recurrence (LR) including true recurrence and breast elsewhere failures, breast cancer specific survival (BCSS), and overall survival (OS) with low energy x-ray IORT in early-stage breast cancer or ductal carcinoma in situ.

MATERIALS/METHODS

A total of 480 patients with early-stage breast cancer or DCIS were prospectively enrolled in an IRB approved single institution trial and treated with low energy X-ray IORT 20 Gy at time of breast-conserving surgery. Eligibility criteria included ≥ 45 years of age with unifocal tumors < 3 cm deemed candidates for partial mastectomy. Supplemental external beam radiation was recommended for patients with high-risk surgical pathology including multifocal disease, positive nodes, close margins < 2 mm, or lymphovascular invasion. Ipsilateral breast tumor recurrences were classified as true recurrence versus elsewhere failure by location and histology: same/different quadrant and similar/different histology. Kaplan-Meier methods were used to estimate survival probabilities across time.

RESULTS

Median age of enrolled patients was 64 years with the majority of patients having favorable phenotype with 94% ER+ and 93% Her-2 - disease. 110 patients (23%) had supplemental EBRT delivered; 103 to the whole breast and 7 to the breast and regional nodes. At a median follow up of 73 months (range 17 - 131 months), there were 23 (4.8%) ipsilateral breast tumor recurrences, of which 9 were true recurrences (1.9%) and 14 elsewhere failures (2.9%). One patient with true recurrence and 3 patients with elsewhere breast failures synchronously presented with clinical or radiographic regional node involvement. Seven patient developed contralateral breast cancer and 8 patients developed distant metastases during the follow-up period. There were 2 breast cancer related deaths. At 6-years, overall survival rate was 96.8% and breast cancer specific survival was 98.7%.

CONCLUSION

Our study outcomes reflect similar outcomes as other reported IORT studies with electron or low energy X-ray in breast cancer, with higher risk of local failure than historical whole breast and other partial breast radiation techniques. This supports current radiation society guidelines for IORT monotherapy for breast cancer to be optimally considered in the context of prospective clinical trials.

[State-of-the-art status on airborne antibiotic resistant bacteria and antibiotic resistance genes]

The world is facing more deaths due to increasing antibiotic-resistant bacterial infections and the shortage of new highly effective antibiotics, however the air media as its important transmission route has not been adequately studied. Based on the latest literature acquired in this work, we have discussed the state-of-the-art research progress of the concentration, distribution and spread of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in different environmental air media, and also analyzed some future prevention and control measures. The large use of antibiotics in the medical settings and animal husbandry places has resulted in higher abundances of ARB and ARGs in the relevant and surrounding atmosphere than in urban and general indoor air environments. ARGs can be spread by adhering to airborne particles, and researchers have also found that air media contain more abundant ARGs than other environmental media such as soil, water and sediment. It was suggested in this review that strengthening the monitoring, study on spreading factors and biological toxicity, and also research and development on pathogen accurate diagnosis and new green antibiotic are expected to help effectively monitor, prevent and control of the impacts of airborne resistant bacteria and resistance genes on both human and ecologies.

Sphenoid sinus osteoma at the sella turcica associated with empty sella: CT and MR imaging findings

SUMMARY

A 50-year-old woman presented with intermittent headache for the past few years. A paranasal sinus CT scan showed a diffusely calcified lesion at the roof of the sphenoid sinus and sella turcica, with the sellar floor bony cortex involved. Empty sella was noted. MR imaging revealed a soft-tissue lesion with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and heterogeneous enhancement on postgadolinium images. Histologic examination revealed an osteoma composed of mature lamellar bone.

Posterior epidural migration of a sequestrated lumbar disk fragment: MR imaging findings

We present a 75-year-old man who, for 2 weeks, had progressive pain in both of his thighs when standing straight. MR imaging showed a sequestrated disk fragment, which had a signal intensity similar to that of a herniated disk with a rim enhancement in the posterior epidural space and a ruptured outermost annulus of the intervertebral disk at L2-3. Awareness of these MR imaging findings can help in the diagnosis of posterior epidural disk migration.

Endobronchial brachytherapy

High-dose rate endobronchial brachytherapy is a well-tolerated out-patient procedure that provides a high likelihood for durable palliation of symptoms associated with endobronchial tumor. The most significant associated toxicity is late massive hemoptysis, the risk for which can be minimized by careful treatment planning and limiting the size of the delivered dose per fraction to less than 10 Gy, prescribed at 1 cm distance.

Disruption of mRad50 causes embryonic stem cell lethality, abnormal embryonic development, and sensitivity to ionizing radiation

The Mre11/Rad50 protein complex functions in diverse aspects of the cellular response to double-strand breaks (DSBs), including the detection of DNA damage, the activation of cell cycle checkpoints, and DSB repair. Whereas genetic analyses in Saccharomyces cerevisiae have provided insight regarding DSB repair functions of this highly conserved complex, the implication of the human complex in Nijmegen breakage syndrome reveals its role in cell cycle checkpoint functions. We established mRad50 mutant mice to examine the role of the mammalian Mre11/Rad50 protein complex in the DNA damage response. Early embryonic cells deficient in mRad50 are hypersensitive to ionizing radiation, consistent with a role for this complex in the repair of ionizing radiation-induced DSBs. However, the null mrad50 mutation is lethal in cultured embryonic stem cells and in early developing embryos, indicating that the mammalian Mre11/Rad50 protein complex mediates functions in normally growing cells that are essential for viability.

Finite element analysis of a Gamma nail within a fractured femur

Failures of Gamma nails which treat unstable femoral fractures have been reported. In this paper, a finite element model to include a Gamma nail within a fractured femur was used to investigate the stresses in the Gamma nail. The effects for different types of fracture were investigated. The results show that its use for subtrochanteric fractures will cause higher stresses at the lag screw and upper distal screw insertion holes in the nail than when used for femur neck fractures.

The effect of M-stage on patterns of failure in posterior fossa primitive neuroectodermal tumors treated on CCG-921: a phase III study in a high-risk patient population

PURPOSE

To analyze patterns of failure in patients (pts) with high-risk posterior fossa primitive neuroectodermal tumors (PF-PNETs) treated with combined modality therapy on a large, randomized multiinstitutional study.

METHODS AND MATERIALS

One hundred eighty-eight prospectively staged pts with PF-PNET confirmed by central pathology review, with high-risk features, were treated on Children's Cancer Group Study 921 (CCG-921), comparing two chemoradiotherapy regimens. Patterns of initial sites of failure were analyzed, specifically evaluating the impact of Chang M-stage.

RESULTS

Progression-free survival (PFS) correlated with the presence or absence of metastatic disease (p < 0.001), with 5-year PFS of 68 +/- 5.8% for M0 vs. 43 +/- 6.8% for M+ pts. The cumulative incidence functions (CIF) of recurrence were different (p = 0.005) and at 5 years were 29 +/- 4.7% for M0 pts and 48 +/- 5.5% for M+ pts. Involvement of the PF at time of initial failure as measured by CIF correlated with M-stage (p = 0.047) and occurred in 18 +/- 3.9% of M0 pts and 8 +/- 2.9% of M+ pts overall; PF as the only site of relapse also correlated with M-stage (p = 0.019) and was seen in 6 +/- 2.5 and 0% of M0 and M+ pts, respectively, at 5 years. Relapse in the spine and/or cerebrospinal fluid (CSF) at initial recurrence was correlated with M-stage (p < 0.002), with 5-year cumulative incidences of 14 +/- 3.7%, 26 +/- 8.2%, 40 +/- 15%, and 40 +/- 7.7% for M0, M1, M2, and M3 pts, respectively. Isolated spine/CSF recurrence correlated with M-stage (p = 0.034) and occurred in 2 +/- 1.5% of M0 and 9 +/- 3.2% of M+ pts by 5 years. The median time to relapse for pts who failed was 1.2 years (range 0.2-5.3). Ninety percent of all relapses occurred by 3 years.

CONCLUSIONS

Original sites of disease are at the highest risk for relapse, but the entire neuraxis remains at significant risk, despite combined-modality treatment. M-Stage was prognostic for spine/CSF relapse as well as PFS and may be an important tool in guiding therapy. A more aggressive approach to local control in the neuraxis is warranted, especially in M+ patients.

The RAD52 epistasis group in mammalian double strand break repair

The S. cerevisiae RAD52 epistasis group gene products mediate DNA double strand break repair and recombination. These proteins and their modes of action have been extensively characterized. The existence of highly conserved mammalian RAD52 epistasis group homologues suggests that information regarding the functions and mechanisms of double strand break repair proteins in yeast may be applicable to mammalian recombinational DNA repair. Herein, we provide an overview of the S. cerevisiae RAD52 epistasis group and describe the characterization of the five mammalian RAD52 epistasis group homologues identified to date. In the context of their expression patterns and other functional analyses, we discuss potential roles for these proteins in mammalian recombinational DNA repair and specialized recombination events such as V(D)J recombination.