Risk of malignancy with systemic psoriasis treatment in the Psoriasis Longitudinal Assessment Registry

The effect of systemic therapy on malignancy risk among patients with psoriasis is not fully understood.

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Genotoxic potential of diesel exhaust particles from the combustion of first- and second-generation biodiesel fuels—the FuelHealth project

Abstract

Epidemiological data indicate that exposure to diesel exhaust particles (DEPs) from traffic emissions is associated with higher risk of morbidity and mortality related to cardiovascular and pulmonary diseases, accelerated progression of atherosclerotic plaques, and possible lung cancer. While the impact of DEPs from combustion of fossil diesel fuel on human health has been extensively studied, current knowledge of DEPs from combustion of biofuels provides limited and inconsistent information about its mutagenicity and genotoxicity, as well as possible adverse health risks. The objective of the present work was to compare the genotoxicity of DEPs from combustion of two first-generation fuels, 7% fatty acid methyl esters (FAME) (B7) and 20% FAME (B20), and a second-generation 20% FAME/hydrotreated vegetable oil (SHB: synthetic hydrocarbon biofuel) fuel. Our results revealed that particulate engine emissions from each type of biodiesel fuel induced genotoxic effects in BEAS-2B and A549 cells, manifested as the increased levels of single-strand breaks, the increased frequencies of micronuclei, or the deregulated expression of genes involved in DNA damage signaling pathways. We also found that none of the tested DEPs showed the induction of oxidative DNA damage and the gamma-H2AX-detectable double-strand breaks. The most pronounced differences concerning the tested particles were observed for the induction of single-strand breaks, with the greatest genotoxicity being associated with the B7-derived DEPs. The differences in other effects between DEPs from the different biodiesel blend percentage and biodiesel feedstock were also observed, but the magnitude of these variations was limited.

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A systematic review of synthetic CT generation methodologies for use in MRI-only radiotherapy

Publication date: Available online 8 September 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Emily Johnstone, Jonathan J. Wyatt, Ann M. Henry, Susan C. Short, David Sebag-Montefiore, Louise Murray, Charles G. Kelly, Hazel M. McCallum, Richard Speight
MRI offers superior soft tissue contrast as compared to CT, which is conventionally used for radiotherapy treatment planning (RTP) and patient positioning verification, resulting in improved target definition. The two modalities are co-registered for RTP, however this introduces a systematic error. Implementing an MRI-only radiotherapy workflow would be advantageous as this error would be eliminated, the patient pathway simplified and patient dose reduced. Unlike CT, in MRI there is no direct relationship between signal intensity and electron density, however various methodologies for MRI-only RTP have been reported. A systematic review of these methods was undertaken.The PRISMA guidelines(1) were followed. Embase and Medline databases were searched (1996-03/2017) for studies which generated synthetic CTs (sCT)s for MRI-only radiotherapy. 61 articles met the inclusion criteria.This review showed that MRI-only RTP techniques could be grouped into three categories: i]bulk density override ii]atlas-based and iii]voxel-based techniques, which all produce an sCT scan from MR image(s).Bulk density override techniques either used a single homogeneous or multiple tissue override. The former produced large dosimetric errors (>2%) in some cases and the latter frequently required manual bone contouring. Atlas-based techniques used both single and multiple atlases and included methods incorporating pattern recognition techniques. Clinically acceptable sCTs were reported, but atypical anatomy led to erroneous results in some cases. Voxel-based techniques included methods using routine and specialised MRI sequences, namely ultra-short echo time imaging. High quality sCTs were produced, however use of multiple sequences led to long scanning times increasing the chances of patient movement. Using non-routine sequences would currently be problematic in most radiotherapy centres.Atlas-based and voxel-based techniques were found to be the most clinically useful methods, with some studies reporting dosimetric differences of <1% between planning on the sCT and CT and <1mm deviations when using sCTs for positional verification.



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IGRT strategies for pelvic lymph node irradiation in high-risk prostate cancer: motion and margins

Publication date: Available online 8 September 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Lucy Kershaw, Laila van Zadelhoff, Wilma Heemsbergen, Floris Pos, Marcel van Herk
PurposeFor optimal irradiation of pelvic lymph nodes (LN) in high-risk prostate cancer, definition of margins to determine the planning target volume(s) is essential. Detailed quantification of the relative motion of the LN, seminal vesicles (SV) and prostate is currently lacking. This work aimed to quantify these motions and define margins for image-guided radiotherapy based on bony anatomy or prostate correction strategies for a 3 or 6 degrees-of-freedom couch.Material and MethodsNineteen patients had a planning CT followed by a mean of 11 repeated CTs during radiotherapy. The prostate, SV, external and internal iliac LN regions on the left and right were outlined on each CT. Systematic and random uncertainties were determined along with correlations between the motion of these regions. CTV-PTV margins required to take only motion into account were calculated for each guidance method.ResultsFor bone guidance, motion of prostate and LNs was largely uncorrelated. Margins to compensate for motion ((LR, SI, AP) in cm) based on a 3 degrees-of-freedom couch were; prostate: (0.2, 0.6, 0.8), SV: (0.4, 0.9, 1.0) and LN: (0.3, 0.4, 0.6). For prostate guidance, margins were calculated for correlated motion; prostate: (0, 0, 0), SV: (0.3, 0.5, 0.4) and LN: (0.3, 0.5, 0.9). For a 6 degrees-of-freedom couch, these margins were; prostate: (0.2, 0.6, 0.8), SV: (0.3, 0.9, 1.0) and LN: (0.3, 0.4, 0.3) for bone guidance. For prostate guidance, margins were; prostate: (0, 0, 0), SV: (0.2, 0.5, 0.4) and LN: (0.3, 0.6, 0.6)ConclusionsImage-guided radiotherapy based on bony anatomy requires larger prostate and SV margins, and guidance on prostate requires larger LN margins. Neither guidance strategy is optimal, and a combination of the two, or treatment adaption after a number of fractions might be preferable. Calculation of the total margin should also include delineation uncertainties.

Teaser

Definition of margins to determine the optimal image-guided radiotherapy (IGRT) strategy for pelvic lymph node irradiation is essential in high-risk prostate cancer. In this work, these margins were derived from systematic and random motions measured using repeated CT scans in 19 patients, based on matching to either bony anatomy or prostate for a 3 or 6 degrees-of-freedom (DOF) couch. When matching to bony anatomy, margins were smaller for lymph nodes than when matching to prostate, but larger for prostate and seminal vesicles. The prostate and seminal vesicle margins were unchanged when using a 3 vs 6 DOF couch, but lymph node margins were smaller in the anterior-posterior direction.


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Subcutaneous implant-based breast reconstruction, a modern challenge in post mastectomy radiation planning

Publication date: Available online 8 September 2017
Source:Practical Radiation Oncology
Author(s): Melissa P. Mitchell, Jamie Wagner, James Butterworth
As survival rates for breast cancer continue to improve, there has been increasing interest in reducing toxicity of therapy. In the field of breast surgery, we have seen advancements in the surgical approach from total mastectomy to skin and nipple sparing mastectomy. Nodal surgery has also been significantly impacted by a "less is more" approach, sparing patients with healthy lymph nodes the side effect of axillary lymph node dissection by performing sentinel lymph node dissection to accurately assess the draining nodal basin. More recently, there have been increasing reports of techniques to improve options for reconstruction. A growing trend has been use of acellular dermal matrix (ADM). This has been reported to improve cosmesis and reduce the number of surgical procedures required to obtain desired aesthetic results. Additionally, there have been increasing reports of use of prepectoral ADM covered implants. As compared to traditional methods of using submuscular tissue expanders, devices placed in the prepectoral plane have been reported to reduce animation deformities and postoperative pain. There is also the benefit that muscular function will be preserved with a subcutaneous expander. Furthermore, there is a growing push for single stage procedures made possible through the use of ADM. This benefits the patient by subjecting them to less operations and benefits the health care system by decreasing health care costs, as compared to multiple stage surgeries.



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Factors Associated with Fatigue in Prostate Cancer (PC) Patients Undergoing External Beam Radiation Therapy (EBRT)

Publication date: Available online 8 September 2017
Source:Practical Radiation Oncology
Author(s): Hann-Hsiang Chao, Abigail Doucette, David M. Raizen, Neha Vapiwala
PurposeFatigue is a common adverse effect among cancer patients undergoing external beam radiation therapy (EBRT), yet the underlying disease- and treatment-related factors influencing its development are poorly understood. We hypothesized that clinical, demographic, and treatment-related factors differentially affect fatigue and aimed to better characterize variables related to fatigue development in prostate cancer (PC) patients during EBRT.MethodsWe identified a 681 patient cohort with non-metastatic PC undergoing a 6–9week EBRT course. Patient fatigue scores (range 0–3) were prospectively recorded by providers during treatment visits using standardized criteria. Clinical and demographic factors including age, race, EBRT details, disease staging, smoking status, comorbidities, urinary symptoms, employment status, weight, and concurrent medication use were assessed for their relationship to fatigue levels. Significant differences in fatigue severity by each variable at the beginning and end of EBRT were assessed by non-parametric-means testing, and differences in the level of fatigue increase over the treatment course were assessed using an ordered logistic regression model.ResultsSignificant increases in reported fatigue severity were seen in patients with: age<60years (p=0.006), depressive symptoms (p<0.001) and use of androgen deprivation therapy prior to radiation start (p=0.04). In addition, the prescription of antiemetics prior to radiation start was associated with reduced fatigue severity (p=0.03).ConclusionsWe identify factors associated with increased (young age, depressive symptoms, androgen deprivation therapy) and decreased (antiemetic prescription) fatigue in a large cohort of PC patients receiving EBRT. Continued investigation is needed to further elucidate clinical drivers and biological underpinnings of increased fatigue to guide potential interventions.



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HPV related Nasopharyngeal and Cervical Cancer in a Married Couple in North America

Publication date: Available online 8 September 2017
Source:Practical Radiation Oncology
Author(s): Daniel B. Vanderbilt, Quoc-Anh Ho, Uma Goyal, Robert C. Bell, Robert R. Klein, Sun K. Yi




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