Acute and chronic radiation injury

Randomized, self-controlled, prospective assessment of the efficacy of mometasone furoate local application in reducing acute radiation dermatitis in patients with head and neck squamous cell carcinomas

BACKGROUND

Acute radiation dermatitis (ARD) is a common adverse effect in patients undergoing radiotherapy. Mometasone furoate cream (MMF) was reported to significantly reduce ARD, especially in breast cancer. Clinically, ARD is more critical and more difficult to prevent in patients with head and neck squamous cell carcinoma (HNSCC) than in those with breast cancer, because a higher dose of radiotherapy is required in HNSCC cases. The aim of this study was to evaluate the effect of MMF local application on radiation dermatitis in patients with HNSCC.

METHODS

HNSCC patients scheduled for bilateral radical radiotherapy to the neck with identical radiation doses were enrolled. One side of the neck skin (test groups) of the patients were randomized to apply a thin layer of MMF once a day from the date of first radiotherapy until either 2 weeks after end of radiotherapy or until the test side skin developed ARD lesions, while the other side of neck (control groups) didn't apply any medication. The severity of ARD was evaluated weekly by using the modified radiation therapy oncology group score, pain intensity, and itch stages.

RESULTS

Forty-one patients (82 targets) were analyzed. There was a significant difference between the ARD scores on the test side and the control side. MMF reduced the stages of ARD when the radiotherapy dose was <6000 cGY (P = .01) but showed no improvement when the dose was ≥6000 cGY (P = .699). Compared to the control side, local application of MMF significantly reduced the itch and pain scores of the test side skin regardless of the radiotherapy dose and ARD stage (P < .001) during radiotherapy.

CONCLUSIONS

This study showed that MMF inunction after high-dose radiotherapy (>50 Gy) can prevent ARD, especially when the radiation dose is <6000 cGY.

Ophthalmic manifestations of ionising radiation among interventionalists

Background: Ionising radiation (IR) is an occupational hazard for interventionalists. Dry eye syndrome may develop. There may be damage to the corneal epithelium, causing irritation and ulceration. Radiation-induced cataracts commonly develop in the posterior sub-capsular (PSC) region of the lens and are more common in the left eye.Aim: The aim of this study was to describe the ophthalmological findings in South African interventionalists occupationally exposed to IR.Setting: This study was conducted in South Africa.Methods: A prospective cross-sectional study was conducted. Interventional radiologists (25), adult cardiologists (42) and paediatric cardiologists (31) were recruited at conferences and included in the study. Convenience sampling was used. Participants completed a survey that collected data on their demographics, their cataract risk factors and co-morbid diseases, their occupational history, their radiation safety practices and their training in occupational history. Participants’ eyes were examined using a slit lamp after dilation of the eyes. Ethics clearance was obtained and each participant gave informed consent. A descriptive analysis was done.Results: The median age of the 98 interventionalists screened was 43.5 years. They worked with radiation for a median of 7.5 years. Cataracts occurred in the left eye of 17 (17.3%) participants and in the right eye of nine (9.2%). There were five (5.1%) PSC cataracts in the left eye and one (1%) in the right eye. The vitreous was abnormal in 19.4% of participants. The tear break-up time was abnormal in 48% of participants.Conclusion: Ionising radiation is an occupational hazard posing a risk to interventionalists’ eyes. They are at increased risk of cataracts and dry eye syndrome, which can affect their occupational performance and quality of life. Education can positively influence the radiation safety practices of interventionalists that could reduce the detrimental effects of IR on their eyes.

ShRNA-mediated matrix metalloproteinase-2 gene silencing protects normal cells and sensitizes cancer cells against ionizing-radiation induced damage

INTRODUCTION

Ionizing radiation (IR) affects healthy tissues during the treatment of cancer radiation therapy and other nuclear and radiological accidents. Some natural compounds showed nonspecific radioprotective activity with severe side effects. The present study is aimed to develop potent and specific radioprotective short hairpin RNA (shRNA), which selectively protects normal cells from IR by specifically targeting matrix metalloproteinases (MMP-2).

RESULTS

IR reduced the viability of human normal dermal fibroblasts (HDFs) in a dose-response manner. It enhanced the expression of MMP-2 at 10 Gy. Plasmid MMP-2shRNA (pMMP-2) reduced the IR (10 Gy) induced cytotoxicity analyzed by lactate dehydrogenase (LDH) assay, normalized IR induced cellular and morphological changes with enhanced the clonogenicity in 48 hours at 2 µg/mL. It reduced the ROS generation, released HDFs from G₂ /M arrest and rescued from apoptosis analyzed by DCFDA dye, cell cycle analysis by PI stain and annexin V assay, respectively. pMMP-2 also modulates the expression of EGFR and reduced IR induced expression of DNA damage response protein, ATM and increased the expression of repair proteins, KU70/KU80, and RAD51. In addition, decreased the expression of cell cycle regulatory proteins cyclin-dependent kinases (CDK1) and Cyclin B as well as proapoptotic proteins BAX, caspase-3, and Cytochrome-C and increased the expression of survival protein, Bcl-2. In contrary pMMP-2 decreased the LDH activity, survival fraction and blocked G₂ /M phase of cell cycle and increased apoptosis in MCF-7 cells. In addition, decreased the expression of EGFR, proapoptotic BAX and DNA repair proteins ATM, KU70/80 and RAD51, increased expression of cyclinB as well as CDK1.

CONCLUSION

Results conclude that pMMP-2 protected HDFs from IR and sensitized the MCF-7 cells. Therefore, pMMP-2 can be employed for better treatment of radiation accidents and during the treatment of radiotherapy.

Platelet-rich plasma activates AKT signaling to promote wound healing in a mouse model of radiation-induced skin injury

Background

The skin is impacted by every form of external radiation therapy. However, effective therapeutic options for severe, acute radiation-induced skin reactions are limited. Although platelet-rich plasma (PRP) is known to improve cutaneous wound healing, its effects in the context of high-dose irradiation are still poorly understood.

Methods

We investigated the regenerative functions of PRP by subjecting the dorsal skin of mice to local irradiation (40 Gy) and exposing HaCaT cells to gamma rays (5 Gy). The cutaneous benefits of PRP were gauged by wound size, histologic features, immunostains, western blot, and transepithelial water loss (TEWL). To assess the molecular effects of PRP on keratinocytes of healing radiation-induced wounds, we evaluated AKT signaling.

Results

Heightened expression of keratin 14 (K14) was documented in irradiated HaCaT cells and skin tissue, although the healing capacity of injured HaCaT cells declined. By applying PRP, this capacity was restored via augmented AKT signaling. In our mouse model, PRP use achieved the following: (1) healing of desquamated skin, acutely injured by radiation; (2) activated AKT signaling, improving migration and proliferation of K14 cells; (3) greater expression of involucrin in keratin 10 cells and sebaceous glands; and (4) reduced TEWL, strengthening the cutaneous barrier function.

Conclusions

Our findings indicate that PRP enhances the functions of K14 cells via AKT signaling, accelerating the regeneration of irradiated skin. These wound-healing benefits may have merit in a clinical setting.

Retrospective study of patients radiation dose during cardiac catheterization procedures

OBJECTIVE

Cardiac catheterization procedures provide tremendous benefits to modern healthcare and the benefit derived by the patient should far outweigh the radiation risk associated with a properly optimized procedure. With increasing utilization of such procedures, there is growing concern regarding the magnitude and variations of dose to patients associated with procedure complexity and techniques parameters. Therefore, this study investigated radiation dose to patients from six cardiac catheterization procedures at our facility and suggest possible initial dose values for benchmark for patient radiation dose from these procedures. This initial benchmark data will be used for clinical radiation dose management which is essential for assessing the impact of any quality improvement initiatives in the cardiac catheterization laboratory.

METHODS

We retrospectively analyzed the dose parameters of 1000 patients who underwent various cardiac catheterization procedures: left heart catheterization (LH), percutaneous coronary intervention (PCI), complex PCI, LH with complex PCI, LH with PCI and cardiac resynchronization therapy (CRT) pacemaker in our cardiac catheterization laboratories. Patient's clinical radiation dose data [kerma-area-product (KAP) and air-kerma at the interventional reference point (Ka,r)] and technique parameters (fluoroscopy time, tube potential, current, pulse width and number of cine images) along with demographic information (age, height and weight) were collected from the hospital's RIS (Synapse), Sensis/Syngo Dynamics and Siemens Sensis Stats Manager electronic database. Statistical analysis was performed with the IBM SPSS Modeler v. 18.1 software.

RESULTS

The overall patient median age was 67.0 (range: 26.0-97.0) years and the median body mass index (BMI) was 28.8 (range: 15.9-61.7) kg/m2 . The median KAP for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 44.4 (4.1-203.2), 80.2 (18.9-208.5), 83.7 (48.0-246.1), 113.8 (60.9-284.5), 91.7 (6.0-426.0) and 51.1 (7.0-175.9) Gy-cm2 . The median Ka,r for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 701.0 (35.3-3794.0), 1384.7 (291.7-4021.8), 1607.0 (883.5-4448.3), 2260.2 (867.4-5311.9), 1589.3 (100.2-7237.4) and 463.8 (67.7-1695.9) mGy respectively.

CONCLUSION

We have analyzed patient radiation doses from six commonly used procedures in our cardiac catheterization laboratories and suggested possible initial values for benchmark from these procedures for the fluoroscopy time, KAP and air-kerma at the interventional reference point based on our current practices. Our data compare well with published values reported in the literature by investigators who have also studied patient doses and established benchmark dose levels for their facilities. Procedure-specific benchmark dose data for various groups of patients can provide the motivation for monitoring practices to promote improvements in patient radiation dose optimization in the cardiac catheterization laboratories.

ADVANCES IN KNOWLEDGE

We have investigated local patients' radiation doses and established benchmark radiation data which are essential for assessing the impact of any quality improvement initiatives for radiation dose optimization.

Personal Protective Equipment Availability and Utilization Among Interventionalists

OBJECTIVE

This study explored personal protective equipment (PPE) availability and PPE utilization among interventionalists in the catheterization laboratory, which is a highly contextualized workplace.

METHODS

This is a cross-sectional study using mixed methods. Participants (108) completed a survey. A hyperlink was sent to the participants, or they were asked to complete a paper-based survey. Purposively selected participants (54) were selected for individual (30) or group (six) interviews. The interviews were conducted at conferences, or appointments were made to see the participants. Logistic regression analysis was performed. The qualitative data were analyzed thematically.

RESULTS

Lead glasses were consistently used 10.2% and never used 61.1% of the time. All forms of PPE were inconsistently used by 92.6% of participants. Women were 4.3 times more likely to report that PPE was not available. PPE compliance was related to fit and availability.

CONCLUSIONS

PPE use was inconsistent and not always available. Improving the culture of radiation protection in catheterization laboratories is essential to improve PPE compliance with the aim of protecting patients and operators. This culture of radiation protection must include all those involved including the users of PPE and the administrators and managers who are responsible for supplying sufficient, appropriate, fitting PPE for all workers requiring such protection.

Skin Cancer Early Detection Practices among Adult Survivors of Childhood Cancer Treated with Radiation

Because rates of skin cancer are greater among adult survivors of childhood cancer who received radiation therapy than among the general population, the National Cancer Institute recommends skin self-examinations and annual physician examination. There has been no comprehensive assessment of survivors' adherence to the skin cancer screening guidelines associated with skin self-examination (SSE) and physician whole-body skin examination (PSE). We conducted a cross-sectional survey of radiation-treated, adult 5-year survivors of childhood cancer, diagnosed between 1970 and 1986, in the Childhood Cancer Survivor Study cohort. Multivariate multinomial logit regression investigated the association between demographic, cancer diagnosis, patient activation, cancer treatment characteristics, and skin cancer screening practice. Among 728 survivors, 13.1% reported performing SSE in the prior 2 months plus receiving PSE in the prior 12 months, and 16.4% and 11.0% reported performing only an SSE or a PSE, respectively; 59.5% of survivors reported having had neither. Participants at the highest patient activation score were most likely to report SSE plus PSE compared with neither (adjusted relative risk ratio = 4.16, 95% confidence interval = 1.34-12.85). Most adult survivors of childhood cancer who had radiation therapy do not practice strategies that promote early detection of skin cancer. Interventions designed to activate survivors to increase their participation in screening are needed.

A scoring system predicting acute radiation dermatitis in patients with head and neck cancer treated with intensity-modulated radiotherapy

Background and purpose

We created a scoring system incorporating dosimetric and clinical factors to assess the risk of severe, acute skin reactions in patients undergoing intensity-modulated radiation therapy (IMRT) to treat head and neck cancer (HNC).

Materials and methods

A total of 101 consecutive patients who received definitive IMRT or volumetric modulated arc therapy (VMAT) with a prescription dose of 70 Gy to treat HNC between 2013 and 2017 in our hospital were enrolled. Skin V_5Gy, V_10Gy, V_20Gy, V_30Gy, V_40Gy, V_50Gy, and V_60Gy values delivered 5 mm within the body contour were compared between patients with Grades 1–2 and Grade 3 dermatitis. A scoring system was created based on logistic regression analysis (LRA) that identified the most significant dosimetric and clinical factors.

Results

The V_60Gy was significantly associated with radiation dermatitis grade in both LRA and recursive partitioning analysis (RPA). A scoring system incorporating the V_60Gy, concurrent chemotherapy status, age, and body mass index was used to divide all patients into three subgroups (0–1, 2–3, and 4–6 points) in the RPA. The incidence of Grade 3 dermatitis significantly differed among the subgroups (0, 20.5, and 58.6%, respectively, P < 0.01).

Conclusions

A risk analysis model incorporating dose-volume parameters successfully predicted acute skin reactions and will aid in the appropriate management of radiation dermatitis.

Skeletal Morbidity in Children and Adolescents during and following Cancer Therapy

Skeletal abnormalities are common in children and adolescents diagnosed and treated for a malignancy. The spectrum ranges from mild pain to debilitating osteonecrosis and fractures. In this review, we summarize the impact of cancer therapy on the developing skeleton, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life in childhood cancer survivors.

Differential expression of flowering genes in Arabidopsis thaliana under chronic and acute ionizing radiation

PURPOSE

Chronic and acute irradiations have drastic effects on flowering stage that plays an important role in further seed development and can determine seed yield. The expression of the key flowering genes, AP1, CO, GI, FT, FLC, and LFY, sensitive to irradiation repair gene RAD51 and the proliferation gene PCNA2 were studied in the wild-type Arabidopsis thaliana (Columbia ecotype) under chronic and acute irradiations.

MATERIALS AND METHODS

Chronic irradiation was performed using the radioactive isotope ¹³⁷СsCl in two total doses of 3 cGy and 17 cGy, with the dose rate of 10^-7 cGy/s and 6.8 10^-6 cGy/s, respectively. The plants were grown under chronic irradiation during 6 weeks, from seeds till the 6.3 stage of flowering. For acute exposure, the plants were X-ray irradiated one time at the 5.0 development stage (20 days old) by a total dose of 15 Gy with the dose rate of 89 cGy/s.

RESULTS

After chronic irradiation with the 3 cGy dose the irradiated plants demonstrated 8 ± 2.8 days earlier flowering than in the control group. However, at the 17 cGy chronic and at the 15 Gy acute doses plants showed 14 ± 3.7 and 2 ± 1.4 days later flowering, respectively. The 3 cGy chronic exposure significantly increased the expression of the CO gene by a factor of 1.152 (1.087-1.217 95% C.I.) and decreased the expression of the FT gene by a factor of 0.128 (0.021-0.396 95% C.I.). The 17 cGy chronic exposure decreased expression of the AP1 gene by a factor of 0.872 (0.803-0.940 95% C.I.) and the LFY gene by a factor of 0.471 (0.306-0.687 95% C.I.). The 15 Gy acute exposure decreased the expression of the AP1 gene by a factor of 0.104 (0.074-0.144 95% C.I.) and the PCNA2 gene by a factor of 0.346 (0.238-0.488 95% C.I.).

CONCLUSIONS

The increased expression of the CO gene and decreased expression of the AP1 and FT genes under the lower dose of chronic exposure were associated with earlier flowering. The acute exposure increased the expression of the PCNA2 gene and decreased the expression of the flowering genes, except AP1. The flowering was delayed under both the higher dose of chronic exposure and under acute exposure, but it was less affected by the latter. Presumably, it was related to the activation of DNA repair under the 3 cGy chronic and 15 Gy acute irradiations.

APPLICATION OF REFLECTANCE CONFOCAL MICROSCOPY FOR EARLY DIAGNOSIS OF RADIATION-INDUCED ACUTE DERMATITIS IN RADIOSENSITIVE PATIENT: CASE STUDY

According to the guidelines on cancer treatment up to 52% of newly diagnosed cancer patients should be treated with external beam radiotherapy. Ionizing radiation (IR)-induced skin injury (radiation dermatitis) occurs in up to 95% of radiotherapy patients and can manifest from mild erythema till necrosis and ulceration. Individual radiosensitivity was proposed to be an important factor for the development of adverse reactions to IR. Therefore, assessment of radiosensitivity could be useful in predicting and dealing with radiation injuries caused by both radiotherapy and accidental overexposure. Here, we present a case of early diagnosis of IR-induced skin lesions performed by reflectance confocal microscopy in comparison to clinical evaluation in a highly radiosensitive patient.

Early and Late Protective Effect of Bone Marrow Mononuclear Cell Transplantation on Radiation-Induced Vascular Dysfunction and Skin Lesions

Skin lesions caused by accidental exposure to radiation or by radiotherapy are a major clinical challenge. We evaluated the effect of bone marrow mononuclear cells (BMMNC) on collagen remodeling and vascular function in radiation-induced skin lesions in the acute and late phases in mice. We studied the effect of BMMNC transplantation in a mouse model of cutaneous radiation injury combining local skin gamma-irradiation and biopsy punch wound. Mice were first irradiated, punched and then BMMNC were intramuscularly administered. Seven days after injury, BMMNC promoted wound healing by (i) increasing re-epithelialization, tissue collagen density and mRNA levels of collagens 1A1, 1A2, and 3A1, and (ii) inhibiting the radiation-induced vascular activation and limiting interactions between leukocytes and the vascular endothelium compared with control. Importantly, BMMNC did not amplify the inflammatory response despite the infiltration of neutrophils and macrophages associated with the expression of IL-6 and MCP-1 mRNAs in the tissue. Remarkably, the beneficial effects of BMMNC therapy on matrix remodeling were maintained for 2 months. Furthermore, BMMNC injection restored vascular function in skin tissue by increasing vascular density and vascular permeability. This therapeutic strategy based on BMMNC injection protects against radiation-induced skin lesions by preventing vascular dysfunction and unfavorable remodeling in the acute and late phases.

Outcomes of 200 consecutive, fluoroless atrial fibrillation ablations using a new technique

INTRODUCTION

A technique was developed to eliminate radiation exposure for routine atrial fibrillation (AF) ablation, to simplify the procedure and to achieve cost effectiveness. We here report the outcomes of this approach.

METHODS

Two hundred consecutive AF ablations (55% paroxysmal) were performed by a single operator. Pulmonary vein isolation (PVI) was achieved by antral ablation without left atrial anatomic mapping, guided by contact force sensing and intracardiac echocardiogram (ICE). All ablations were performed using three ipsilateral 8 French catheters (ICE, Lasso, and ablation). Eighty-two percent of the patients underwent ablation of atrial flutter or non-pulmonary vein triggers. All patients underwent provocative testing after PVI.

RESULTS

No fluoroscopy was used for the entire study. Two ablations were performed without x-ray available due to unexpected equipment failure. The mean procedure time was 90.3 ± 17.7 (minutes) in patients who only required PVI and 106.2 ± 23.2 (minutes) for the entire cohort, with a success rate of 76% (mean follow-up of 11 months). In contrast, the procedure time and success rate were 127.9 ± 38.2 (minutes) (P < 0.01) and 74%, respectively, for the last 50 standard ablations guided by fluoroscopy (without contact force sensing). Complications included one case of partial right phrenic nerve palsy and one case of right femoral artery pesudoaneurysm. Compared to our previous ablation approaches, the new method resulted in catheter savings of $2,168-$4,568/case.

CONCLUSION

The new technique eliminated radiation exposure and shortened the procedure time without significant negative impact on safety or success rate. Substantial cost savings were also achieved by using a minimal number of mostly reprocessed catheters.

The emerging role of non-radiation endoscopic management of biliary tract disorders

Endoscopic retrograde cholangiopancreatography (ERCP) has evolved from a diagnostic and therapeutic technique into a therapeutic-centered modality for managing biliary disorders. Despite its many therapeutic benefits, radiation exposure from ERCP fluoroscopy is of concern and should be minimized as much as possible. Although the use of personal equipment offers significant protection against radiation, attention has been given to the development of non-radiation-based ERCP techniques. To this end, digital cholangioscopy and endoscopic ultrasound-assisted ERCP have emerged as alternatives to standard ERCP. Both techniques have sufficient feasibility and potential diagnostic accuracy to eliminate the need for fluoroscopy. Here we discuss the advances in non-radiation ERCP techniques and their role in the management of biliary stones.

Radiation Induces Apoptosis and Osteogenic Impairment through miR-22-Mediated Intracellular Oxidative Stress in Bone Marrow Mesenchymal Stem Cells

Bone marrow mesenchymal stem cells (BMSCs) were characterized by their multilineage potential and were involved in both bony and soft tissue repair. Exposure of cells to ionizing radiation (IR) triggers numerous biological reactions, including reactive oxygen species (ROS), cellular apoptosis, and impaired differentiation capacity, while the mechanisms of IR-induced BMSC apoptosis and osteogenic impairment are still unclear. Through a recent study, we found that 6 Gy IR significantly increased the apoptotic ratio and ROS generation, characterized by ROS staining and mean fluorescent intensity. Intervention with antioxidant (NAC) indicated that IR-induced cellular apoptosis was partly due to the accumulation of intracellular ROS. Furthermore, we found that the upregulation of miR-22 in rBMSCs following 6 Gy IR played an important role on the ROS generation and subsequent apoptosis. In addition, we firstly demonstrated that miR-22-mediated ROS accumulation and cell injury had an important regulated role on the osteogenic capacity of BMSCs both in vitro and in vivo. In conclusion, IR-induced overexpression of miR-22 regulated the cell viability and differentiation potential through targeting the intracellular ROS.

Patient doses in endovascular and hybrid revascularization of the lower extremities

OBJECTIVE:

Hybrid surgical methods such as remote endarterectomy and endovascular revascularization are fluoroscopy-guided procedures successfully replacing conventional open surgery for treatment of peripheral artery disease (PAD). The aim of this study was to: (1) evaluate the dose parameters describing exposure of patients undergoing endovascular or hybrid revascularization of the lower limb (below the inguinal ligament); (2) compare the data available in the literature with the evaluations of patients' dose values and related factors for patients undergoing such procedures; (3) examine the correlation of doses with certain parameters; (4) estimate the peak skin dose and assess the potential for radiation-induced skin injuries during the procedures.

METHODS:

Data for 259 patients were extracted retrospectively and analyzed. The procedures were grouped by type of intervention, vascular approach, and level of complexity. The analyses included the correlation of dose values with the operating team.

RESULTS:

The air kerma-area product (KAP) and fluoroscopy time (FT) values greatly varied depending on the procedure type but also among patients undergoing the same procedure. The type of vascular access has the largest impact on patients' doses. The KAP and FT values for brachial artery were: 347 Gy.cm² and FT: NA; for contralateral common femoral artery (CFA) approach: 207 Gy.cm² and 153 s; e.g. significantly higher than for ipsilateral CFA: 96 Gy.cm² and 78 s; for hybrid surgery: 77 Gy.cm² and 41 s; and for ipsilateral retrograde popliteal approach: 61 Gy.cm² and 53 s. The same tendency is observed for the peak skin dose (PSD) values: the highest are for brachial artery (2053 mGy) and contralateral CFA (1325 mGy) approach, followed by the ipsilateral CFA (748 mGy), hybrid surgery (649 mGy), and ipsilateral retrograde popliteal approach (566 mGy).

CONCLUSION:

Registered dose values and FT for the different procedures do not exceed the International Atomic Energy Agency (IAEA) proposed trigger values for patients' follow-up for radiation-induced skin injuries. The type of vascular access has the highest negative impact on radiation dose levels and resultant KAP, PSD, and FT values. There is a significant increase of the dose values with increase of the number of inserted stents and the level of complexity. This should be considered in planning, especially for patients who undergo multiple diagnostic and therapeutic procedures.

ADVANCES IN KNOWLEDGE:

This study gives a systematic understanding for patient radiation exposure in endovascular and hybrid revascularization of the lower extremities, thus far absent in the literature.

Orbital pathology - Iatrogenic findings and artefacts

The relationship between the ophthalmologist and ophthalmic pathologist is particularly important in orbital disease, as diagnosis is heavily dependent on correlation with clinical context. If the patient has previously had treatment to the orbit or an adjacent area, whether for the same or a different condition, tissue changes may occur which affect the histological appearance of any specimen taken. This article is an overview of therapeutic interventions which may cause either orbital pathology or an altered appearance of the tissue, either of which can pose a diagnostic challenge. The problem of artefact is also addressed as another factor which may alter the appearance of a specimen. It is hoped that the information provided in this brief review will help clinicians better evaluate what information may be relevant when submitting a specimen.

Occupation-associated health hazards for the gastroenterologist/endoscopist

Advances in the field of endoscopy have allowed gastroenterologists to obtain detailed imaging of anatomical structures and to treat gastrointestinal diseases with endoscopic therapies. However, these technological developments have exposed endoscopists and staff to hazards such as musculoskeletal injuries, exposure to infectious agents, and ionizing radiation. We aimed to review the occupational hazards for the gastroenterologist and endoscopist. Using PubMed, Medline, Medscape, and Google Scholar, we identified peer-reviewed articles with the keywords “occupational hazards,” “health hazards,” “occupational health hazards,” “endoscopy,” “gastroenterologist,” “infectious agents,” “musculoskeletal injuries,” and “radiation.” Strategies for reducing exposure to infectious agents, radiation, and the risk of musculoskeletal injuries related to gastroenterology include compliance with established standard measures, the use of thyroid shields and radioprotective eyewear, and ergonomic practices. We conclude that educating endoscopic personnel and trainees in these practices, in addition to further research in these areas, will likely lead to the development of more efficient and user-friendly workspaces that are safer for patients and personnel.

Interventionalists' perceptions on a culture of radiation protection

BACKGROUND

Occupational exposure to ionising radiation poses potential health risks to radiation workers unless adequate protection is in place. The catheterisation laboratory is a highly contextualised workplace with a distinctive organisational and workplace culture.

OBJECTIVE

This study was conducted to understand the culture of radiation protection (CRP).

METHODS

This study was a qualitative study and data were collected through 30 in-depth and 6 group interviews with 54 purposively selected South African interventionalists (interventional radiologists and cardiologists). The participants included a diversity of interventionalists who varied in sex, geographic location and years of experience with fluoroscopy. The transcribed data were analysed thematically using a deductive and inductive approach.

RESULTS

'Culture of radiation protection' emerged as a complex theme that intersected with other themes: 'knowledge and awareness of radiation', 'radiation safety practice', 'personal protective equipment (PPE) utilisation' and 'education and training'.

CONCLUSION

Establishing and sustaining a CRP provides an opportunity to mitigate the potentially detrimental health effects of occupational radiation exposure. Education and training are pivotal to establishing a CRP. The time to establish a culture of radiation in the catheterisation laboratory is now.

[Physical and chemical emergencies in dermatology]

Physical and chemical emergencies are often caused by household or work accidents. Regardless of the medical field and outside specialized clinics, the physician may be confronted with the situation for first or secondary care. The identification of the causing agent and a rapid assessment of the extent and severity of the tissue damage are essential to initiate early transfer to a specialized burn clinic. Grade 2b tissue damage is usually surgically treated. Smaller and superficial injuries can often be conservatively treated. Even supposedly safe and over-the-counter medicines can also lead to serious tissue damage.

Pattern and degree of radiation exposure during endovascular surgery performed using a mobile C-arm or in a hybrid room

Purpose

A prospective study was conducted to compare radiation exposure to different parts of an endovascular surgeon's body when using a mobile C-arm with that in a hybrid room.

Methods

Exposure during individual procedures performed on 39 patients with a mobile C-arm and 42 patients in a hybrid room, from July 2016 to December 2016, was evaluated.

Results

The procedures performed, fluoroscopy time, and dose-area product were not significantly different between groups. The dose-area product per second in the hybrid room group appeared greater than in the C-arm group (4.5 µGym²/sec vs. 3.1 µGym²/sec). In the C-arm group, the peak skin dose on the right neck (1.77 mSv) and shoulder (1.48 mSv) appeared higher than those on their left side (0.32 mSv, 0.53 mSv, respectively) and the counterparts of the hybrid room group (0.88 mSv, 0.20 mSv, respectively).

Conclusion

The peak skin dose in the hybrid room appeared highest for the lower part of the protective apron. The dose-area product per second seemed to be greater in the hybrid room than when using the C-arm. Thus, attention should be focused on protecting the surgeon's upper body when using the C-arm and the lower body when using the hybrid room.

Protective effect of FGF-2 and low-molecular-weight heparin/protamine nanoparticles on radiation-induced healing-impaired wound repair in rats

We examined the effectiveness of localized administration of fibroblast growth factor-2 containing low-molecular-weight heparin/protamine nanoparticles (FGF-2&LMWH/P NPs) on apoptosis in vivo and on healing of radiation-induced skin injury in a rat model. FGF-2 binds onto LMWH/P NPs, which can significantly enhance and stabilize FGF-2 as a local carrier. X-irradiation at a dose of 25 Gy was administered to the lower part of the back (using a lead sheet with two holes) 1 h before the administration of FGF-2&LMWH/P NPs. Cutaneous full-thickness defect wounds were then formed in X-irradiated areas to examine the time-course of wound healing, and the wound tissues were microscopically and histologically compared and examined. Wound healing was significantly delayed by X-irradiation, but FGF-2&LMWH/P NPs administration prior to irradiation led to a significantly shorter delay compared with FGF-2 alone, LMWH/P NPs alone, and controls. Furthermore, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining showed that the proportions of apoptotic dermal fibroblasts in X-irradiated skin were significantly lower in rats administered FGF-2&LMWH/P NPs than in controls. However, 8-hydroxy-2'-deoxyguanosine (8-OHdG) staining showed no differences. Thus, localized administration of FGF-2&LMWH/P NPs prior to irradiation may alleviate X-irradiation-induced healing-impaired wound repair in normal tissue.

Assessing liver proteins and enzymes of medical workers exposed to ionizing radiation (IR)

The cross-sectional study was conducted to examine hepatic function via liver enzymes/proteins assessments, along with the estimation of an inflammatory response from C-reactive protein (CRP)-which is a liver-synthesized protein. The liver function tests with aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and bilirubin (BBN), and CRP test were conducted for radiation-exposed workers-REW (n = 32) and radiation-unexposed workers-RUW (n = 21). The annual average effective doses (AAED) were measured from thermoluminescent dosimeter. A t test and bivariate correlation analyses were applied. Only one worker had a high AST value (50 U/L), one worker had a negligible high ALT value (43 U/L) and only one worker had a negligible high bilirubin value (1.3 g/dL). There were normal levels of CRP (up to 6 mg/L) in all individuals. There existed a nonsignificant difference (p < 0.050) between the mean values of liver enzymes and proteins in all exposed and unexposed workers. Nonsignificant weak correlations are reported in liver enzymes/proteins parameters: AST, ALT, ALP, BBN, CRP with the AAED range (whole-body: 0.91-3.39 mSv) during 2011-2015. The normal values of liver enzymes/proteins' (AST, ALT, ALP, BBN, CRP) values may ensure a good hepatic health of radiation-exposed medical workers with AAED range mentioned. We found that low ionizing radiation doses did not alter the liver function test parameters and did not affect the concentration of an inflammatory response protein, i.e., CRP.

Acute radiation dermatitis in breast cancer patients: challenges and solutions

Nearly all women who receive radiotherapy (RT) for breast cancer experience some degree of radiation dermatitis. However, evidence describing the appropriate management of radiation dermatitis is often lacking or contradictory. Here, we summarize the available literature regarding radiation dermatitis causes, the presentation and timing of symptoms, methods for dermatitis assessment and prevention, and review evidence-based management strategies.

Preventive and therapeutic application of molecular hydrogen in situations with excessive production of free radicals

Excessive production of oxygen free radicals has been regarded as a causative common denominator of many pathological processes in the animal kingdom. Hydroxyl and nitrosyl radicals represent the major cause of the destruction of biomolecules either by a direct reaction or by triggering a chain reaction of free radicals. Scavenging of free radicals may act preventively or therapeutically. A number of substances that preferentially react with free radicals can serve as scavengers, thus increasing the internal capacity/activity of endogenous antioxidants and protecting cells and tissues against oxidative damage. Molecular hydrogen (H(2)) reacts with strong oxidants, such as hydroxyl and nitrosyl radicals, in the cells, that enables utilization of its potential for preventive and therapeutic applications. H(2) rapidly diffuses into tissues and cells without affecting metabolic redox reactions and signaling reactive species. H(2) reduces oxidative stress also by regulating gene expression, and functions as an anti-inflammatory and anti-apoptotic agent. There is a growing body of evidence based on the results of animal experiments and clinical observations that H(2) may represent an effective antioxidant for the prevention of oxidative stress-related diseases. Application of molecular hydrogen in situations with excessive production of free radicals, in particular, hydroxyl and nitrosyl radicals is relatively simple and effective, therefore, it deserves special attention.

Radiation-Induced Dermatitis is Mediated by IL17-Expressing γδ T Cells

Radiation dermatitis is a serious cutaneous injury caused by radiation therapy or upon accidental nuclear exposure. However, the pathogenic immune mechanisms underlying this injury are still poorly understood. We seek to discover how the dysregulated immune response after irradiation orchestrates skin inflammation. The skin on the left flank of C57BL/6J wild-type and C57BL/6J Tcrd-/- mice, which are deficit in γδ T cells, was exposed to a single X-ray dose of 25 Gy, and the right-flank skin was used as a sham-irradiated control. At 4 weeks postirradiation, the wild-type skin exhibited signs of depilation, erythema and desquamation. Histological analysis showed hyperproliferation of keratinocytes and acanthosis. Dramatic elevation of IL17-expressing T cells was identified from the irradiated skin, which was mainly contributed by γδ T cells and innate lymphoid cells, rather than Th17 cells. Furthermore, protein levels of critical cytokines for IL17-expressing γδ T cell activation, IL1β and IL23 were found markedly upregulated. Lastly, radiation-induced dermatitis was significantly attenuated in γδ T cell knockout mice. In vitro, normal human epidermal keratinocytes (NHEKs) could be initiator cells of inflammation by providing a great number of pro-inflammatory mediators upon radiation, and as well as effector cells of epidermal hyperplasia in response to exogenous IL17 and/or IL22 treatment. Our findings implicate a novel role of IL17-expressing γδ T cells in mediating radiation-induced skin inflammation. This study reveals the innate immune response pathway as a potential therapeutic target for radiation skin injury.

Increased risk of active tuberculosis after cancer diagnosis

BACKGROUND

Cancer may increase risk of active tuberculosis but evidence is sparse. We therefore examined tuberculosis risk in patients with incident cancer using Danish nationwide medical databases.

METHODS

We conducted a matched follow-up study comparing risk of active tuberculosis in cancer-exposed individuals to that in a general population comparison cohort, matched on gender, age, and country of origin, in different follow-up intervals using Cox regression.

FINDINGS

We identified 290,944 patients with incident cancer and 871,147 matched comparison cohort members during 1 January, 2004-30 November, 2013. After adjusting for comorbidities, the overall adjusted hazard ratio (aHR) for tuberculosis among cancer patients was 2.48 (95% confidence interval [CI]: 1.99-3.10). The highest tuberculosis risks were observed following cancers of the aerodigestive tract (aHR = 8.12; 95% CI: 4.33-15.22), tobacco-related cancers (aHR = 5.01; 95% CI: 3.37-7.44), and hematological cancers (aHR = 4.88; 95% CI: 2.27-10.48). Tuberculosis risk was highly elevated within the first year after cancer diagnosis (aHR = 4.14; 95% CI: 2.88-5.96), with a 6.78-fold increased aHR for cancer patients receiving cytostatics or radiotherapy. Beyond five years of observation, the overall aHR for tuberculosis remained at 2.66 (95% CI: 1.22-5.81).

INTERPRETATION

Cancer is a clinical predictor for increased risk of active tuberculosis, probably related to decreased infection barriers, immunosuppression, and shared risk factors.

Radiation hazards to vascular surgeon and scrub nurse in mobile fluoroscopy equipped hybrid vascular room

PURPOSE

The aim of the present study was to identify the radiation hazards to vascular surgeons and scrub nurses working in mobile fluoroscopy equipped hybrid vascular operation rooms; additionally, to estimate cumulative cancer risk due to certain exposure dosages.

METHODS

The study was conducted prospectively in 71 patients (53 men and 18 women) who had undergone vascular intervention at our hybrid vascular theater for 6 months. OEC 9900 fluoroscopy was used as mobile C-arm. Exposure dose (ED) was measured by attaching optically stimulated luminescence at in and outside of the radiation protectors. To measure X-ray scatter with the anthropomorphic phantom model, the dose was measured at 3 distances (20, 50, 100 cm) and 3 angles (horizontal, upward 45°, downward 45°) using a personal gamma radiation dosimeter, Ecotest CARD DKG-21, for 1, 3, 5, 10 minutes.

RESULTS

Lifetime attributable risk of cancer was estimated using the approach of the Biological Effects of Ionizing Radiation report VII. The 6-month ED of vascular surgeons and scrub nurses were 3.85, 1.31 mSv, respectively. The attenuation rate of lead apron, neck protector and goggle were 74.6%, 60.6%, and 70.1%, respectively. All cancer incidences among surgeons and scrub nurses correspond to 2,355 and 795 per 100,000 persons. The 10-minute dose at 100-cm distance was 0.004 mSv at horizontal, 0.009 mSv at downward 45°, 0.003 mSv at upward 45°.

CONCLUSION

Although yearly radiation hazards for vascular surgeons and scrub nurses are still within safety guidelines, protection principles can never be too stringent when aiming to minimize the cumulative harmful effects.

Regional variation in patient selection and treatment for lower extremity vascular disease in the Vascular Quality Initiative

OBJECTIVE

Prior studies on the cause and effect of surgical variation have been limited by utilization of administrative data. The Vascular Quality Initiative (VQI), a robust national clinical registry, provides anatomic and perioperative details allowing a more robust analysis of variation in surgical practice.

METHODS

The VQI was used to identify all patients undergoing infrainguinal open bypass or endovascular intervention from 2009 to 2014. Asymptomatic patients were excluded. The 16 regional groups of the VQI were used to compare variation in patient selection, operative indication, technical approach, and process measures. χ² analysis was used to assess for differences across regions where appropriate.

RESULTS

A total of 52,373 interventions were included (31%). Of the 16,145 bypasses, 5% were performed for asymptomatic disease, 26% for claudication, 56% for chronic limb-threatening ischemia (CLI) (61% of these for tissue loss), and 13% for acute limb-threatening ischemia. Of the 35,338 endovascular procedures, 4% were for asymptomatic disease, 40% for claudication, 46% for CLI (73% tissue loss), and 12% for acute limb-threatening ischemia. Potentially unwarranted variation included proportion of prosthetic conduit for infrapopliteal bypass in claudication (13%-41%, median, 29%; P < .001), isolated tibial endovascular intervention for claudication (0.0%-5.0%, median, 3.0%; P < .001), discharge on antiplatelet and statin (bypass: 62%-84%; P < .001; endovascular: 63%-89%; P < .001), and ultrasound guidance for percutaneous access (claudication: range, 7%-60%; P < .001; CLI: 5%-65%; P < .001). Notable areas needing further research with significant variation include proportion of CLI vs claudication treated by bypass (38%-71%; P < .001) and endovascular intervention (28%-63%; P < .001), and use of closure devices in percutaneous access (claudication; 26%-76%; P < .001; CLI: 30%-78%; P < .001).

CONCLUSIONS

Significant variation exists both in areas where evidence exists for best practice and, therefore, potentially unwarranted variation, and in areas of clinical ambiguity. Quality improvement efforts should be focused on reducing unwarranted variation. Further research should be directed at identifying best practice where no established guidelines and high variation exists.

Preoperative Pelvic Tilt Analysis Reduces Fluoroscopy Time in Direct Anterior Total Hip Arthroplasty

The direct anterior approach for total hip arthroplasty (THA) requires the use of intraoperative imaging, exposing the patient and surgical team to radiation. The authors hypothesized that calculation of the preoperative pelvic tilt angle and communication of this value with the fluoroscopy technician may result in a decrease in intraoperative fluoroscopy use. The study also examined total radiation exposure during the procedure to ensure that it was within safe limits. The pelvic tilt was calculated preoperatively for 100 consecutive patients undergoing THA by the direct anterior approach. The fluoroscopy technician was blinded to the value of pelvic tilt for the first 50 cases (control group), with the angle being communicated for the following 50 cases (test group). The total duration of fluoroscopy use for each case was recorded. The values were compared for the 2 experienced technicians involved in the study. The surgeon was blinded to the duration of fluoroscopy use in all cases. Mean fluoroscopy time was 28.65 seconds in the control group and 23.61 seconds in the test group (P=.033). No significant difference in duration of fluoroscopy use was found between the 2 fluoroscopy technicians. The control group and the test group were within safe limits of radiation exposure to both the patient and the surgical team. Preoperative pelvic tilt calculation significantly decreases the amount of imaging used during THA by the direct anterior approach. Although it was a statistically significant reduction, both groups were within safe limits for both the surgical team and the patients, and thus the clinical significance is unknown. [Orthopedics.2016; 39(5):e962-e966.].

Guideline Implementation: Radiation Safety

Because radiologic technology is used in a variety of perioperative procedures and settings, it is essential for perioperative RNs to be knowledgeable of the risks related to radiation and the ways to adequately protect patients and health care providers from unintended radiation exposure. The updated AORN "Guideline for radiation safety" provides guidance on preventing injury from ionizing radiation exposure during therapeutic, diagnostic, and interventional procedures. This article focuses on key points of the guideline to help perioperative personnel practice radiation safety. The key points address the requirements for an organization's radiation safety program, measures used to keep radiation exposure as low as reasonably achievable, proper handling and testing of radiation protection devices, and considerations for protecting employees and patients who are pregnant and who will be exposed to radiation. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

Management of radiotherapy-induced skin reactions

Radiotherapy is a highly effective cancer treatment that not only offers cure but also excellent palliation of disease related symptoms and complications. Although radiotherapy is primarily an outpatient treatment, delivered within specialist centres, a diverse range of health professionals may be involved in the treatment pathway before, during and after treatment. Radiotherapy can, and does, make a significant contribution to improving a patient's wellbeing through effective symptom management. However, treatment-related side-effects do occur, with an acute skin reaction being one of the most common. It is imperative that radiotherapy-induced skin reactions are correctly assessed and appropriately managed in promoting patient comfort, treatment compliance and enhanced quality of life. This article describes how the use of a recognised assessment tool and evidence-based guidelines can facilitate consistent, high-quality care in the management of radiotherapy-induced skin reactions.

Radiation exposure to eye lens and operator hands during endovascular procedures in hybrid operating rooms

OBJECTIVE

The purpose of this study was to evaluate the radiation exposure of vascular surgeons' eye lens and fingers during complex endovascular procedures in modern hybrid operating rooms.

METHODS

Prospective, nonrandomized multicenter study design. One hundred seventy-one consecutive patients (138 male; median age, 72.5 years [interquartile range, 65-77 years]) underwent an endovascular procedure in a hybrid operating room between March 2012 and July 2013 in two vascular centers. The dose-area product (DAP), fluoroscopy time, operating time, and amount of contrast dye were registered prospectively. For radiation dose recordings, single-use dosimeters were attached at eye level and to the ring finger of the hand next to the radiation field of the operator for each endovascular procedure. Dose recordings were evaluated by an independent institution. Before the study, precursory investigations were obtained to simulate the radiation dose to eye lens and fingers with an Alderson phantome (RSD, Long Beach, Calif).

RESULTS

Interventions were classified into six treatment categories: endovascular repair of infrarenal abdominal aneurysm (n = 65), thoracic endovascular aortic repair (n = 32), branched endovascular aortic repair for thoracoabdominal aneurysms (n = 17), fenestrated endovascular aortic repair for complex abdominal aortic aneurysm, (n = 25), iliac branched device (n = 8), and peripheral interventions (n = 24). There was a significant correlation in DAP between both lens (P < .01; r = 0.55) and finger (P < .01; r = 0.56) doses. The estimated fluoroscopy time to reach a radiation threshold of 20 mSv/y was 1404.10 minutes (90% confidence limit, 1160, 1650 minutes). According to correlation of the lens dose with the DAP an estimated cumulative DAP of 932,000 mGy/m(2) (90% confidence limit, 822,000, 1,039,000) would be critical for a threshold of 20 mSv/y for the eyes.

CONCLUSIONS

Radiation protection is a serious issue for vascular surgeons because most complex endovascular procedures are delivering measurable radiation to the eyes. With the correlation of the DAP obtained in standard endovascular procedures a critical threshold of 20 mSv/y to the eyes can be predicted and thus an estimate of a potential harmful exposure to the eyes can be obtained.

Live-cell imaging to detect phosphatidylserine externalization in brain endothelial cells exposed to ionizing radiation: implications for the treatment of brain arteriovenous malformations

OBJECT Stereotactic radiosurgery (SRS) is an established intervention for brain arteriovenous malformations (AVMs). The processes of AVM vessel occlusion after SRS are poorly understood. To improve SRS efficacy, it is important to understand the cellular response of blood vessels to radiation. The molecular changes on the surface of AVM endothelial cells after irradiation may also be used for vascular targeting. This study investigates radiation-induced externalization of phosphatidylserine (PS) on endothelial cells using live-cell imaging. METHODS An immortalized cell line generated from mouse brain endothelium, bEnd.3 cells, was cultured and irradiated at different radiation doses using a linear accelerator. PS externalization in the cells was subsequently visualized using polarity-sensitive indicator of viability and apoptosis (pSIVA)-IANBD, a polarity-sensitive probe. Live-cell imaging was used to monitor PS externalization in real time. The effects of radiation on the cell cycle of bEnd.3 cells were also examined by flow cytometry. RESULTS Ionizing radiation effects are dose dependent. Reduction in the cell proliferation rate was observed after exposure to 5 Gy radiation, whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with cells treated with sham radiation, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA-positive cells were significantly higher (p = 0.04) 24 hours after treatment in the cultures that received 25- and 15-Gy doses of radiation. This effect was sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation controls at any time points (p > 0.15). Flow cytometric analysis data indicate that irradiation induced growth arrest of bEnd.3 cells, with cells accumulating in the G2 phase of the cell cycle. CONCLUSIONS Ionizing radiation causes remarkable cellular changes in endothelial cells. Significant PS externalization is induced by radiation at doses of 15 Gy or higher, concomitant with a block in the cell cycle. Radiation-induced markers/targets may have high discriminating power to be harnessed in vascular targeting for AVM treatment.

Prophylactic Treatment with Adlay Bran Extract Reduces the Risk of Severe Acute Radiation Dermatitis: A Prospective, Randomized, Double-Blind Study

Acute radiation dermatitis is a frequent adverse effect in patients with breast cancer undergoing radiotherapy, but there are only a small number of studies providing evidence-based interventions for this clinical condition. Adlay is a cereal crop that has been previously shown to have anti-inflammatory and antioxidant properties. In this study, we seek to evaluate the effectiveness of oral prophylactic treatment with adlay bran extract in reducing the risk of severe acute radiation dermatitis. A total of 110 patients with breast cancer undergoing radiotherapy were analyzed. Using a prospective, randomized, double-blind design, 73 patients received oral treatment with adlay bran extract and 37 patients received olive oil (placebo). Treatment was started at the beginning of radiation therapy and continued until the termination of radiation treatment. Our results showed that the occurrence of severe acute radiation dermatitis (RTOG grade 2 or higher) was significantly lower in patients treated with oral adlay bran extract compared to placebo (45.2% versus 75.7%, adjusted odds ratio 0.24). No serious adverse effects from adlay bran treatment were noted. In conclusion, prophylactic oral treatment with adlay bran extract reduces the risk of severe acute radiation dermatitis and may have potential use in patients with breast cancer undergoing radiotherapy.

Transcriptional corepressor MTG16 regulates small intestinal crypt proliferation and crypt regeneration after radiation-induced injury

Myeloid translocation genes (MTGs) are transcriptional corepressors implicated in development, malignancy, differentiation, and stem cell function. While MTG16 loss renders mice sensitive to chemical colitis, the role of MTG16 in the small intestine is unknown. Histological examination revealed that Mtg16(-/-) mice have increased enterocyte proliferation and goblet cell deficiency. After exposure to radiation, Mtg16(-/-) mice exhibited increased crypt viability and decreased apoptosis compared with wild-type (WT) mice. Flow cytometric and immunofluorescence analysis of intestinal epithelial cells for phospho-histone H2A.X also indicated decreased DNA damage and apoptosis in Mtg16(-/-) intestines. To determine if Mtg16 deletion affected epithelial cells in a cell-autonomous fashion, intestinal crypts were isolated from Mtg16(-/-) mice. Mtg16(-/-) and WT intestinal crypts showed similar enterosphere forming efficiencies when cultured in the presence of EGF, Noggin, and R-spondin. However, when Mtg16(-/-) crypts were cultured in the presence of Wnt3a, they demonstrated higher enterosphere forming efficiencies and delayed progression to mature enteroids. Mtg16(-/-) intestinal crypts isolated from irradiated mice exhibited increased survival compared with WT intestinal crypts. Interestingly, Mtg16 expression was reduced in a stem cell-enriched population at the time of crypt regeneration. This is consistent with MTG16 negatively regulating regeneration in vivo. Taken together, our data demonstrate that MTG16 loss promotes radioresistance and impacts intestinal stem cell function, possibly due to shifting cellular response away from DNA damage-induced apoptosis and towards DNA repair after injury.

Radiotherapy-induced mesorectum alterations: histological evaluation of 90 consecutive cases

OBJECTIVE

In order to identify the radiotherapy-induced histological modifications in the mesorectum, we reviewed the surgical specimens of 90 rectal resections comprehensive of the total mesorectal excision (23 cases radiologically classified as cT2N0M0 and 67 as cT3N0M0). All patients were preoperative treated with radiotherapy: 20 with 50 Gy, 20 with 20 Gy and 50 Gy irradiation associated to FOLFOX scheme chemotherapy.

MATERIAL AND METHODS

Routine hematoxylin and eosin stained serial slides at 5 mm of intervals were obtained from surgical specimens and included the tumor site and the adjacent irradiated mucosa, the submucosa and the muscular layers of the rectal wall and the mesorectal adipose tissue, completely removed until to the mesorectal fascia. Ten subjects (eight cT2N0M0 and two cT3N0M0), who did not received preoperative oncological treatments were adopted as controls.

RESULTS

Histologically, examination revealed fibrosis of the adipose tissue in 86 cases (95%), vascular damage including vasculities and fibrotic thickening wall of arteries and veins in 46 cases (51%), sclero-hyalinosis of lymph nodes with pericapsular fibrosis in 22 cases (23%) and perineural deposition of fibrosis in 12 (13%). These findings were ubiquitously observed in the whole mesorectum. Fibrosis of the adipose tissue and vasculitis were mainly associated to the combination of 50 Gy radiations plus chemotherapy (p < 0.05).

CONCLUSION

The detection of histopathological alterations in the mesorectum can give reason of the well-known postoperative complications and long-term sequels.

Chronic radiodermatitis developing after iridium-192 exposure: a case report

Iridium-192 (Ir(192)) is a radioactive isotope which has high-penetration ability in humans. Due to occupational accidents, industrial radiography workers may be rarely exposed to high doses of ionizing radiation, and acute radiodermatitis may develop after the exposure. After an asymptomatic period which can last several months, poikiloderma, sclerosis, necrosis, and ulceration of the skin may be observed as typical clinical features of chronic radiodermatitis. Herein, we report the case of a 26-year-old man presented with ulceration and sclerosis on the second digit of the left hand and was diagnosed with chronic radiodermatitis induced by Ir(192).

Bone morbidity in childhood leukemia: epidemiology, mechanisms, diagnosis, and treatment

Skeletal abnormalities are commonly seen in children and adolescents with leukemia. The spectrum ranges from mild pain to debilitating osteonecrosis (ON) and fractures. In this review, we summarize the skeletal manifestations, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life observed in children and adolescents with leukemia.