Radiation Exposure to Surgeon and Assistant During Flat Panel Mini C-Arm Fluoroscopy in Hand and Wrist Surgical Procedures.

PURPOSE: During mini C-arm fluoroscopy, both the patient and surgical team are exposed to scatter radiation. The objective of this study was to quantify body, thyroid, and hand radiation exposure to surgeon and assistant during intraoperative use of flat panel mini C-arm fluoroscopy in hand and wrist surgical procedures. METHODS: Over 5 months, the surgeon's and assistant's radiation exposure was recorded during all osseous hand and wrist surgical procedures. Whole-body and thyroid radiation exposure were measured with 2 types of dosimeters: a photon thermoluminescence detector and a RaySafe i2 real-time dosimeter. Ring dosimeters were used to quantify hand radiation exposure. RESULTS: Mini C-arm fluoroscopy was used in 94 surgical procedures. Total fluoroscopy time was 1,996 seconds and varied between surgical procedures (range, 1-152 seconds; median, 11 seconds). No thermoluminescence detector photon dosimeter exceeded the threshold limit of 0.1 mSv. The RaySafe i2 real-time dosimeters recorded a cumulated dose of 0.029 mSv for the body and 0.012 mSv for the thyroid position of the surgeon. The assistant received a cumulated dose of 0.011 mSv for the body and 0.011 mSv for the thyroid position. The ring dosimeters showed a cumulated dosage of 1.28 mSv for the surgeon and 0.20 mSv for the assistant. CONCLUSIONS: Our results show that the surgeon's and assistant's body, thyroid, and hands were exposed to acceptable levels of scatter radiation during intraoperative use of the flat panel mini C-arm. The surgeon received the highest radiation exposure: 2.9% of the yearly radiation limits for the body, 0.05% for the thyroid position, and 2.56% for the hands. The assistant was exposed to less scatter radiation: 1.1% for the body, 0.04% for the thyroid, and 0.4% for the hands. CLINICAL RELEVANCE: This study quantified radiation levels to which surgeon and assistant are exposed during mini C-arm fluoroscopy in hand and wrist surgical procedures.

Effective Radiation Dose in the Wrist Resulting from a Radiographic Device, Two CBCT Devices and One MSCT Device: A Comparative Study.

The objective of the present study was to assess and compare the effective doses in the wrist region resulting from conventional radiography device, multislice computed tomography (MSCT) device and two cone beam computed tomography (CBCT) devices using MOSFET dosemeters and a custom made anthropomorphic RANDO phantom according to the ICRP 103 recommendation. The effective dose for the conventional radiography was 1.0 µSv. The effective doses for the NewTom 5 G CBCT ranged between 0.7 µSv and 1.6 µSv, for the Planmed Verity CBCT 2.4 µSv and for the MSCT 8.6 µSv. When compared with the effective dose for AP- and LAT projections of a conventional radiographic device, this study showed an 8.6-fold effective dose for standard MSCT protocol and between 0.7 and 2.4-fold effective dose for standard CBCT protocols. When compared to the MSCT device, the CBCT devices offer a 3D view of the wrist at significantly lower effective doses.

Laser acupuncture versus reflexology therapy in elderly with rheumatoid arthritis.

The purposes of this study are to determine and compare efficacy of laser acupuncture versus reflexology in elderly with rheumatoid arthritis. Thirty elderly patients with rheumatoid arthritis aged between 60 and 70 years were classified into two groups, 15 patients each. Group A received laser acupuncture therapy (904 nm, beam area of 1cm2, power 100 mW, power density 100 mW/cm2, energy dosage 4 J, energy density 4 J/cm2, irradiation time 40 s, and frequency 100,000 Hz). The acupuncture points that were exposed to laser radiation are LR3, ST25, ST36, SI3, SI4, LI4, LI11, SP6, SP9, GB25, GB34, and HT7. While group B received reflexology therapy, both offered 12 sessions over 4 weeks. The changes in RAQoL, HAQ, IL-6, MDA, ATP, and ROM at wrist and ankle joints were measured at the beginning and end of treatment. There was significant decrease in RAQoL, HAQ, IL-6, and MDA pre/posttreatment for both groups (p < 0.05); significant increase in ATP pre/posttreatment for both groups (p < 0.05); significant increase in ankle dorsi-flexion, plantar-flexion, wrist flexion, extension, and ulnar deviation ROM pre/posttreatment in group A (p < 0.05); and significant increase in ankle dorsi-flexion and ankle plantar-flexion ROM pre/posttreatment in group B (p < 0.05). Comparison between both groups showed a statistical significant decrease in MDA and a statistical significant increase in ATP in group A than group B. Percent of changes in MDA was 41.82%↓ in group A versus 21.68%↓ in group B; changes in ATP was 226.97%↑ in group A versus 67.02%↑ in group B. Moreover, there was a statistical significant increase in ankle dorsi-flexion, ankle plantar-flexion, wrist flexion, wrist extension, and radial deviation in group A than group B. Laser therapy is associated with significant improvement in MDA and ATP greater than reflexology. In addition, it is associated with significant improvement in ankle dorsi-flexion, ankle plantar-flexion, wrist flexion, wrist extension, and radial deviation greater than reflexology in elderly patients with rheumatoid arthritis.

Postoperative Radiotherapy After Limb-sparing Surgery for Soft-tissue Sarcomas of the Distal Extremities.

BACKGROUND: Soft-tissue sarcomas (STS) of the distal extremities are a rare disease entity, hence proper treatment strategy is not well established. We evaluated the local control, survival and complications of treating sarcomas in the wrist, hand, ankle and foot with limb-sparing surgery (LSS) and postoperative radiotherapy (PORT). PATIENTS AND METHODS: Seventeen patients with STS in wrist, hand, ankle and foot who received PORT after LSS from August 2008 to November 2015 were retrospectively reviewed. Primary outcome was 5-year local recurrence-free survival (LRFS). Secondary outcomes were 5-year distant metastasis-free survival (DMFS) and toxicities. RESULTS: The median age was 32 (range=12-78) years. The most frequent STS location was the foot in 11 patients (64%) followed by two patients each in the wrist, hand and ankle, respectively. Fourteen patients (82%) underwent wide resection with flap grafts and the same number of patients achieved clear resection margins. The median postoperative radiation dose was 54 (range=46-60) Gy. Five patients also received chemotherapy. At a median follow-up of 39 (range=6-87) months, 5-year LRFS and DMFS were both 100%. Only one patient experienced grade 3 radiation dermatitis and there was no major wound complication. Radiation-induced bone fracture occurred in two patients. CONCLUSION: PORT after LSS showed excellent local control for STS in the wrist, hand, ankle and foot. Considering the good local control and saving of limb function without any significant toxicity, the combination of LSS followed by PORT could be an appropriate and safe modality for STS of the distal extremities.

A PRACTICAL APPROACH TO PERFORM THE ISOTROPY TEST FOR EXTREMITY DOSEMETERS.

The requirements for determining extremity dosemeter performance have evolved over the past decade. In 2010, the Spanish Nuclear Safety Council (CSN) adopted a national protocol with performance requirements based on ISO 12794. Because of the lack of symmetry of ISO 4037-3 calibration phantoms, the isotropy test set up in the sagittal plane presented several challenges both for individual monitoring services and for calibration labs. This article proposes and validates a practical approach to reduce the number of irradiations. Results show that wrist and ring dosemeters in this study meet the ISO 12794 requirements for the isotropy test. However, additional studies would be needed to verify the newer IEC 62387 Standard.

ENHANCED RADIOACTIVE CONTENT OF 'BALANCE' BRACELETS.

During a routine whole body counting measurement of a worker at the Nuclear Research Center Negev, abnormal activities of (232)Th and (238)U were measured. After a thorough investigation, it was found that the radioactivity was due to a rubber bracelet ('balance bracelet') worn by the worker during the measurement. The bracelet was counted directly by an high pure germanium gamma spectrometry system, and the specific activities determined were 10.80 ± 1.37 Bq g(-1) for (232)Th and 5.68 ± 0.88 Bq g(-1) for natural uranium. These values are obviously high compared with normally occurring radioactive material (NORM) average values. The dose rate to the wrist surface was estimated to be ∼3.9 µGy h(-1) and ∼34 mGy for a whole year. The dose rate at the centre of the wrist was estimated to be ∼2.4 µGy h(-1) and ∼21 mGy for a whole year. The present findings stresses a more general issue, as synthetic rubber and silicone products are common and widely used, but their radioactivity content is mostly uncontrolled, thus causing unjustified exposure due to enhanced NORM radioactivity levels.

Low-level laser therapy with a wrist splint to treat carpal tunnel syndrome: a double-blinded randomized controlled trial.

The efficacy of low-level laser therapy (LLLT) was evaluated in a total of 66 patients with mild to moderate carpal tunnel syndrome (CTS) with a double-blinded randomized controlled study. The patients were randomly assigned into two groups. Group I received 15 sessions of a gallium-aluminum-arsenide laser treatment at a dosage of 18 J per session over the carpal tunnel area with neutral wrist splint. Group II received placebo laser therapy with neutral wrist splint. The patients were evaluated with the following parameters: (1) clinical parameters which consisted of visual analog scale, symptom severity scale, functional status scale, and pinch strength and grip strength before the treatment and at 5- and 12-week follow-ups and (2) electroneurophysiological parameters from nerve conduction study which were evaluated before the treatment and at 12-week follow-up. Fifty nine patients (112 hands: unilateral CTS = 6 hands and bilateral CTS = 106 hands) completed the study. Both groups I and II had n = 56 hands. Improvements were significantly more pronounced in the LLLT-treated group than the placebo group especially for grip strength at 5- and 12-week follow-ups. At 12-week follow-up, distal motor latency of the median nerve was significantly improved in the LLLT group than the placebo group (p < 0.05). LLLT therapy, as an alternative for a conservative treatment, is effective for treating mild to moderate CTS patients. It can improve hand grip strength and electroneurophysiological parameter with a carry-over effect up to 3 months after treatment for grip strength of the affected hands.

Radiation exposure of the operator during cardiac catheter ablation procedures.

Radiation exposure of the operator during cardiac catheter ablation procedures was assessed for an experienced cardiologist adopting various measures of radiation protection and utilised electroanatomic navigation. Chip thermoluminescent dosemeters were placed at the eyes, chest, wrists and legs of the operator. The ranges of fluoroscopy time and air kerma area product values associated with cardiac ablation procedures were wide (6.3-48.3 min and 1.7-80.3 Gy cm(2), respectively). The measured median radiation doses per procedure for each monitored position were 23.6 and 21.3 µSv to the left and right wrists, respectively, 25.3 and 30.4 µSv to the left and right legs, respectively. The doses to the eyes were below the minimum detectable dose of 9 µSv. The estimated median effective dose was 22.5 µSv. Considering the actual workload of the operator, the calculated annual doses to the hands, legs and eyes, as well as the annual effective dose, were all below the corresponding limits. The findings of this study indicate that cardiac ablation procedures performed at a modern laboratory do not impose a high radiation hazard to the operator when radiation protection measures are routinely adopted.

Exposure from the large C-arm versus the mini C-arm using hand/wrist and elbow phantoms.

PURPOSE: This study tests the conventional wisdom that using fluoroscopy under identical geometrical conditions results in less radiation when using the mini C-arm relative to the large C-arm. METHODS: We evaluated the radiation dose for both direct exposure and scatter 2.54 cm outside the intensifier. We used 3 mini and 3 large C-arms in a vertical orientation with the image intensifier below the specimen and the source above. We used 2 specimens: a cadaver hand/wrist and a cadaver elbow. Specimens were tested both directly on the intensifier and on a hand table placed on the intensifier. RESULTS: For the same setup, use of the mini C-arm resulted in direct patient radiation exposure greater than the exposure delivered by the large C-arm. Specifically, exposure using the mini C-arm was 53% to 70% greater than that using the large C-arm. In addition, use of the hand table resulted in exposure 80% to 94% greater compared with placing the specimen directly on the intensifier. In all cases, scatter at 2.54 cm from the intensifier resulted in an average exposure of 1.5% (SD, 0.24%) of the direct beam. Tube current, and therefore machine radiation output, was approximately 13 to 14 times greater for the large C-arm. CONCLUSIONS: Direct radiation exposure to the patient and scatter to the surgeon are minimized when the C-arm is positioned with the intensifier below and the extremity is placed directly on the intensifier. Under identical geometrical conditions with the intensifier below the specimen, the large C-arm with its greater source to image intensifier distance is associated with less radiation exposure than the mini C-arm.

Results of the EURADOS extremity dosemeter intercomparison 2009.

This paper presents the results of an intercomparison for extremity dosemeters organised by the European radiation dosimetry group in 2009. In total, 59 systems were tested during this exercise including ring, stall and wrist dosemeters. A total of 1652 dosemeters were irradiated in the selected fields of photons and beta radiation qualities on appropriate phantoms (ISO finger and pillar phantom) in the dose quantity H(p)(0.07). All irradiations were carried out in selected accredited reference dosemetry laboratories (Seibersdorf Laboratories, Austria and IRSN, France). The results show that, especially at low-energy beta radiations ((85)Kr) and for beta irradiations with large angles of incidence (60°), many tested systems show pronounced under responses. On the other hand, for photon irradiations down to energies of 16 keV most systems showed good results. A participants meeting was held at IM2010 with discussion on both general aspects of this intercomparison and specific problems.

Hp(0.07) photon irradiations at Seibersdorf for the EURADOS extremity dosemeter intercomparison 2009.

In August 2009, almost 1000 passive extremity dosemeters were irradiated at the Dosimetry Laboratory Seibersdorf as part of the EURADOS intercomparison IC2009. Forty-four European individual monitoring services participated, with a total of 59 dosimetry systems (46 finger ring, 4 finger tip and 9 wrist/ankle dosemeter systems). Additionally, finger-ring dosemeters from the Dosimetry Service Seibersdorf were irradiated in a non-competitive manner. Dosemeter irradiations on rod and pillar phantoms in four photon-radiation fields complying with the ISO standard 4037 were performed with personal dose equivalent values (H(p)(0.07)) ranging from 4 to 480 mSv. Traceability was established by using an air-kerma-calibrated monitor ionisation chamber together with the X-ray facility as well as a calibrated (137)Cs gamma radiation field with a collimated beam geometry. The ISO-tabulated conversion coefficients from air kerma free-in-air to H(p)(0.07) were applied, resulting in the main contribution to the expanded measurement uncertainties.

Preliminary assessment of the dose to the interventional radiologist in fluoro-CT-guided procedures.

A preliminary assessment of the occupational dose to the intervention radiologist received in fluoroscopy computerised tomography (CT) used to guide the collection of lung and bone biopsies is presented. The main aim of this work was to evaluate the capability of the reading system as well as of the available whole-body (WB) and extremity dosemeters used in routine monthly monitoring periods to measure per procedure dose values. The intervention radiologist was allocated 10 WB detectors (LiF: Mg, Ti, TLD-100) placed at chest and abdomen levels above and below the lead apron, and at both right and left arms, knees and feet. A special glove was developed with casings for the insertion of 11 extremity detectors (LiF:Mg, Cu, P, TLD-100H) for the identification of the most highly exposed fingers. The H(p)(10) dose values received above the lead apron (ranged 0.20-0.02 mSv) depend mainly on the duration of the examination and on the placement of physician relative to the beam, while values below the apron are relatively low. The left arm seems to receive a higher dose value. H(p)(0.07) values to the hand (ranged 36.30-0.06 mSv) show that the index, middle and ring fingers are the most highly exposed. In this study, the wrist dose was negligible compared with the finger dose. These results are preliminary and further studies are needed to better characterise the dose assessment in CT fluoroscopy.

The effect of sleep deprivation on median nerve somatosensory evoked potentials.

The purpose of the study was to determine the effect of one night's sleep deprivation on the early and middle-latency median nerve (MN) somatosensory evoked potentials (SEPs). In 20 healthy volunteers, SEPs in response to electrical stimulation of the MN at the wrist were recorded for the 100-ms post-stimulus period, before and after one night of sleep deprivation. The P14 latency was significantly prolonged after sleep deprivation. We found significant increases in the amplitudes of the early parietal (N20-P24) and the frontal middle-latency (P45-N60) components following sleep deprivation. Our results indicate that somatosensory processing is altered after sleep deprivation.

Localization of the human female breast in primary somatosensory cortex.

RATIONALE: Despite an extensive body of research on the topography of the primary somatosensory cortex (S1) little is known about the representation of the trunk. AIM: The aim of this study was to determine the representation of the breast in S1 in human females. RESULTS: The representation of the human breast in primary somatosensory cortex was determined in ten healthy female subjects. Non-painful electrical stimulation of the mammilla (Th4 dermatome), groin (L1 dermatome) and the first digit of both sides of the body activated cutaneous receptors and thus elicited somatosensory evoked potentials. The representation of these body parts in primary somatosensory cortex (S1) was determined using neuroelectric source imaging. Equivalent current dipole localizations were overlaid with individual structural magnetic resonance images to account for individual cortical differences. The breast representation was localized between the representation of the groin and the first digit. In the medial-lateral direction the representation of the breast was approximately 15 mm lateral of the longitudinal fissure in the contralateral hemisphere. Source localizations were stable across subjects. However, one subject showed ipsilateral representation of the breast, which might be related to bilateral receptive fields of the ventral body midline representation. This study confirms the Penfield and Rasmussen (1950) invasive data by use of noninvasive source imaging.

Facilitation of soleus H-reflex amplitude evoked by cutaneous nerve stimulation at the wrist is not suppressed by rhythmic arm movement.

Neural connections between the cervical and lumbosacral spinal cord may assist in arm and leg coordination during locomotion. Currently the extent to which arm activity can modulate reflex excitability of leg muscles is not fully understood. We showed recently that rhythmic arm movement significantly suppresses soleus H-reflex amplitude probably via modification of presynaptic inhibition of the IA afferent pathway. Further, during walking reflexes evoked in leg muscles by stimulation of a cutaneous nerve at the wrist (superficial radial nerve; SR) are phase and task dependent. However, during walking both the arms and legs are rhythmically active thus it is difficult to identify the locus of such modulation. Here we examined the influence of SR nerve stimulation on transmission through the soleus H-reflex pathway in the leg during static contractions and during rhythmic arm movements. Nerve stimulation was delivered with the right shoulder in flexion or extension. H-reflexes were evoked alone (unconditioned) or with cutaneous conditioning via stimulation of the SR nerve (also delivered alone without H-reflex in separate trials). SR nerve stimulation significantly facilitated H-reflex amplitude during static contractions with the arm extended and countered the suppression of reflex amplitude induced by arm cycling. The results demonstrate that cutaneous feedback from the hand on to the soleus H-reflex pathway in the legs is not suppressed during rhythmic arm movement. This contrasts with the observation that rhythmic arm movement suppresses facilitation of soleus H-reflex when cutaneous nerves innervating the leg are stimulated. In conjunction with other data taken during walking, this suggests that the modulation of transmission through pathways from the SR nerve to the lumbosacral spinal cord is partly determined by rhythmic activity of both the arms and legs.

The relationship between localised SAR in the arm and wrist current.

Calculations are presented of the specific energy absorption rate, SAR, in the lower arm of the NRPB anatomically realistic voxel model. NORMAN, for induced currents from 100 kHz to 80 MHz. The wrist region has a narrow cross section and contains little high conductivity muscle, comprising mainly low conductivity bone, tendon and fat. Consequently there is a channelling of the current through the high conductivity muscle, which produces high, localised values of the SAR. Values averaged over 10 g and 100 g of tissue are calculated as a function of the current flowing through the wrist.

The accuracy of dose determination during total body irradiation.

AIM: The aim of this work was to estimate the error in dose calculations, to check the agreement between the measured and calculated doses and to analyse dose discrepancies in the group of patients undergoing total body irradiation. PATIENTS AND METHODS: A combination of lateral and anterior-posterior fields was used in 8 fractions and on 4 consecutive days. Doses were preliminarily calculated and then measured in vivo by thermoluminescent, semiconductor and ionization dosimeters attached to the body in 10 representative transverse cross-sections. Calculations and measurements were carried out for the beam at the body entry and exit. The error in dose calculations was estimated for each reference point. Dose deviations between calculations and measurements were analysed using the Student's t-test. RESULTS: The error in preliminary dose calculations ranged from 3% to 15% (Table 1). Standard deviations of the measurements and percent deviations from the calculations exceeded 10% only for the lung and neck exits (Table 3). Average thermoluminescent readings were 6% higher than the corresponding semiconductor readings. The measured doses fitted the calculated values within the limit of error, except for the lung, head and neck exits for the whole group, depending on the type of fields used (Table 4).

A cohort study with regard to the risk of haematological malignancies in patients treated with x-rays for benign lesions in the locomotor system. II. Estimation of absorbed dose in the red bone marrow.

A cohort study with regard to the risk of haematological malignancies was performed on about 20,000 patients who in 1950-1964 received roentgen treatment for benign conditions in the locomotor system. In order to estimate the mean absorbed red bone marrow dose the treatments were classified as concerning 10 sites (cervical spine, thoracic spine, lumbar spine, sacral region, shoulder, hip, elbow, wrist, knee and ankle). The four last-mentioned sites do not normally contain red bone marrow in adults and their contribution to the mean absorbed dose was regarded as zero. For the other 6 sites random samples consisting of 30 patients for each site were drawn from the cohort. By use of the treatment records and data from the literature on some physical parameters and red bone marrow distribution in normal adult persons, average conversion factors were calculated by which the subscribed surface dose could be converted into mean absorbed dose in red bone marrow. These conversion factors were then applied on the whole cohort and used for stratification of it according to different levels of exposure.