Radiation doses to those accompanying nuclear medicine department patients: a waiting room survey

In a multi-centre European trial we have assessed the radiation dose to those accompanying patients undergoing nuclear medicine investigations. Dosemeters were first calibrated against each other and then used to measure the radiation dose to the nurse or relative while they were in the waiting room. In departments where there was one waiting room the median radiation dose was 13 LSv, and the corresponding figures for where there were two waiting rooms and where the patients were allowed to leave the department with their nurse or relative were 12 and 11 Sv, respectively. These figures are not significantly different. However, we found that the median radiation dose to relatives was 13 Sv while that to nurses was 3 Sv (P<0.01), although the waiting times were not significantly different. The reasons for these differences are discussed. Our data do not support the need for a second waiting room for injected patients in a nuclear medicine department. Correspondence to: L.K. Harding     

Dose reduction to radiosensitive tissues in CT. Do commercially available shields meet the users' needs?

AIM: To assess the effectiveness and economy of routinely using commercially available in-plane bismuth shielding during CT scanning of the chest and brain. METHODS AND MATERIALS: Forty patients were scanned with thermoluminescent dosemeters (TLDs) in situ to measure the radiation dose to the thyroid and eye during CT scanning of the brain and chest. Half of the patients had the "AttenuRad" shield in place during scanning. RESULTS: Use of the shielding reduced the mean dose to the eye from 6.0 +/- 0.3 mGy to 4.9 mGy +/- 0.2 mGy and the thyroid dose from 16.4 mGy +/- 1.2 mGy to 7.1 mGy +/- 0.5 mGy. CONCLUSION: Use of the thyroid shield is recommended for all CT scanning of the chest. The eye shield does not produce as marked a reduction in radiation dose to the lens of the eye, when an angled gantry is used, since the eyes are not in the primary beam. Use of the eyeshield is justifiable where irradiation of the orbit is unavoidable, although whether artifacts would be a problem if the shield was used in this way was not assessed.     

Indications for tomotherapy/intensity-modulated radiation therapy in paediatric radiotherapy: extracranial disease

The potential conformality advantages of intensity-modulated radiation therapy (IMRT; TomoTherapy Hi Art system) over conventional linear accelerator based therapy was assessed in six consecutive children referred for extracranial radiotherapy. IMRT/tomotherapy was considered advantageous for (i) small abdominal tumours, compared with parallel opposed or single portal technology using a conventional linear accelerator, and (ii) re-treatment of an ethmoidal sarcoma, but not for palliation of a small spinal metastasis, or therapy for a whole deep cervical node chain or a pelvic side wall tumour in a young child. Considerations integral to the treatment decision included target volume dose conformality, "low-dose bath" effects (oncogenic and late growth sequelae) and treatment delivery time. IMRT/tomotherapy was the selected modality for therapy when the conformality advantages were perceived to outweigh any disadvantages in three out of the six cases. The dose conformality advantages of IMRT/tomotherapy are sufficient to selectively recommend its availability to the paediatric practice in accordance to the following criteria: (i) where conformality of radiation therapy to the target/tumour is critical and where the margin of safety (from gross/clinical target volume to planning target volume (PTV)) around the tumour is narrow; (ii) where adjacent organs at risk of radiation damage have a low threshold for damage; and (iii) where the "low-dose bath" phenomenon, which occurs between the upper and lower axial limits of the PTV, is not sufficiently disadvantageous (with regard to late oncogenesis or growth retardation) to outweigh the more confined (non-tumour) integral doses received in higher dose corridors through the body when utilizing conventional radiation techniques.     

Radioprotective effectiveness of the paramunity inducer "pind-avi": investigation using the model "protective tetanic vaccination in mice" after exposure to X-rays (author's transl)

The model "protective tetanic vaccination in mice" was used in order to try whether the paramunity inducer Pind-Avi may diminish or suspend radiation-induced immunosuppression. The radioprotective effect was ascertained from the different results of immunization in mice exposed to radiation after pretreatment with either Pind-Avi or placebo. The dose delivered amounted to 300 R. Tetanus toxoid was used for immunization. Effectiveness of the tetanic vaccination was analysed by means of load tests with 10 LD50 tetanus toxin, and of antibody determination with passive hemagglutination. Evidence was shown of significant radiation protection following subcutaneous application of Pind-Avi once a day during three days before of after exposure. Efficiency in mice treated with Pind-Avi amounted to 75% (pre-irradiation treatment) and to 43% (postirradiation treatment), whereas the efficiency in controls was zero in all cases. Thus, it was possible with Pind-Avi to suspend radiation-induced immunosuppression within a period of 3 days before or after radiation exposure, not only by means of prophylactic but also by therapeutic administration.     

Reirradiation of recurrent node-positive non-small cell lung cancer after previous stereotactic radiotherapy for stage I disease

Background

Practice guidelines have been developed for early-stage and locally advanced non-small cell lung cancer (NSCLC). However, many common clinical scenarios still require individualized decision making. This is true for locoregional relapse after initial stereotactic radiotherapy (stereotactic body radiation therapy or stereotactic ablative radiotherapy; SBRT or SABR), an increasingly utilized curative treatment option for stage I NSCLC.

Methods

A consortium of expert radiation oncologists was established with the aim of providing treatment recommendations. In this scenario, a case was distributed to six radiation oncologists who provided their institutions’ treatment recommendations. In this case, a patient developed local and mediastinal relapse after SABR (45?Gy, 3 fractions), comparable to the tumor burden in de novo stage IIIA NSCLC. Treatment recommendations were tabulated and a consensus conclusion was developed.

Results

Three institutions recommended evaluation for surgery. If the patient was not a surgical candidate, and/or refused surgery, definitive chemoradiation was recommended, including retreating the primary to full dose. European participants were more in favor of a non-surgical approach. None of the participants were reluctant to prescribe reirradiation, but two institutions prescribed doses lower than 60?Gy. Platinum-based doublets together with intensity-modulated radiotherapy were preferred.

Conclusion

The institutional recommendations reflect the questions and uncertainties discussed in current stage III guidelines. All institutions agreed that previous SABR is not a contraindication for salvage chemoradiation. In the absence of high-quality prospective trials for recurrent NSCLC, all treatment options recommended in current guidelines for stage III disease can be considered in clinical scenarios such as this.

     

Radiation therapy in small cell lung cancer: a national Italian survey

Introduction

Radiation therapy plays an important role in the management of SCLC both in curative and palliative setting, however, conflicting data from clinical trials incite debate over the appropriate use of radiation therapy regarding prophylactic cranial irradiation (PCI) and/or thoracic consolidative in extensive-stage SCLC (ES-SCLC). This survey is conducted to evaluate the current pattern of care among Italian radiation oncologists.

Methods

In June 2016, all Italian radiation oncologists were invited to a web-based survey. The survey contained 34 questions regarding the role of RT in SCLC. Questions pertaining the role of RT in the clinical management of both limited-stage (LS) and ES-SCLC were included.

Results

We received 48 responses from Italian radiation oncologists. More than half of respondents had been practicing for more than 10 years after completing residency training and 55% are subspecialists in lung cancer. Preferred management of LS-SCLC favored primary concurrent chemoradiotherapy (89%), even if the 36.9% usually delivered RT during or after the cycle 3 of chemotherapy, due to organizational issues. The most common dose and fractionation schedule in this setting was 60 Gy in 30 once-daily fractions. Furthermore, almost all respondents recommended PCI in patients with LS-SCLC. For ES-SCLC scenario, chemotherapy was defined the standard treatment by all respondents. PCI was recommended in ES-SCLC patients with thoracic complete remission (63% of respondents), with thoracic partial response (45%) and with thoracic stable disease (17%) after first-line chemotherapy. Lastly, the thoracic consolidative RT was recommended by 51% of respondents in patients with ES-SCLC in good response after first-line chemotherapy and a great variability was shown in clinical target volume definition, doses and fractionation schedules.

Conclusions

Our analysis showed a high adherence to current guidelines among the respondents in regard to chemoradiation approach in LS-SCLC patients and to PCI indications and doses. The great variability in radiation therapy doses and volumes in the thoracic consolidative radiotherapy in ES-SCLC is concerning. Future clinical trials are needed to standardize these treatment approaches to improve treatment outcomes among patients with ES-SCLC.

     

Effective dose--personnel occupationally exposed to radiation--medical supervision (the new x-ray ordinance)

The Federal German X-Ray Regulations have been adapted to the latest state of the art in respect of dose definitions, physical radiation protection control, examination by an authorized physician and have been brought in line with existing regulations and guidelines. This has resulted in making some things easier to some extent, at least in a few areas. This applies in particular to monitoring the dose in respect of individuals and to the requisite examination of an individual by an authorized physician. The definition of an "effective dose" will hardly exercise any impact on medical practice, since it is required to be calculated in very rare cases only.     

"Truncation" artifact in MR images of the internal auditory canal

Dry skulls and a phantom were studied to determine whether an intracanalicular dark band in MR images of some acoustic neuromas could be artifactual. A "truncation" artifact was detected in the internal auditory canals of the dry skulls and in a simulated internal auditory canal of the phantom when the width of the canal approximately equaled 4 X (field of view) /N, where N equals 128 or 256, depending on the number of gradient steps chosen. The "truncation" artifact should not be confused with CSF between normal nerves when a canal contains tumor.     

Mapping very low level occupational exposure in medical imaging: A useful tool in risk communication and decision making

Objectives

The use of ionising radiation in medical imaging is accompanied with occupational exposure which should be limited by optimised room design and safety instructions. These measures can however not prevent that workers are exposed to instantaneous dose rates, e.g. the residual exposure through shielding or the exposure of discharged nuclear medicine patients. The latter elements are often questioned by workers and detailed assessment should give more information about the impact on the individual radiation dose.

Methods

Cumulated radiation exposure was measured in a university hospital during a period of 6 months by means of thermoluminescent dosimeters. Radiation exposure was measured at background locations and at locations where enhanced exposure levels are expected but where the impact on the individual exposure is unclear.

Results

The results show a normal distribution of the cumulated background radiation level. No enhanced cumulated radiation exposure which significantly differs from this background level could be found during the operation of intra-oral apparatus, during ultrasonography procedures among nuclear medicine patients and at operator consoles of most CT-rooms.

Conclusions

This 6 months survey offers useful information about occupational low level exposure in medical imaging and the findings can be useful in both risk communication and decision making.     

河南“4.26”60Co源辐射事故一例受照者患非霍奇金淋巴瘤的病因探讨

关于电离辐射是否可诱发非霍奇金淋巴瘤（NHL）,目前的研究结果尚未获得一致结论。笔者报道了河南“4.26” 60Co源辐射事故中1例中度骨髓型急性放射病患者受照后第13年患NHL的病例,结合患者的受照史、病史特点、诊断及国际多项大型研究,从流行病学资料和影响因素两方面分析了患者“天”患非霍奇金淋巴瘤与电离辐射的关系,为电离辐射致NHL提供辐射流行病学依据。     

Response of Balloon-Expandable Endoprosthetic Metallic Stents Subjected to Over-Expansion <Emphasis Type="Italic">In Vitro</Emphasis>

We attempted to evaluate the in vitro behavior and performance of balloon-expandable endoprosthetic metallic stents subjected to over-expansion (OE). Seventy-two balloon-expandable endoprosthetic stents, representing 22 models from six manufacturers, were over- expanded in vitro. Stents were initially expanded to their maximum manufacturer- recommended diameter and then over-expanded incrementally to their endpoints. Endpoints for OE were either stent disarticulation or an inability to undergo further expansion despite balloon insufflation to maximum burst pressure. Measurements of stent dimensions were recorded at each overexpanded diameter and comparisons were made to manufacturers specifications. A total of 288 balloon-driven expansions were performed on 72 stents. Sixteen stents were expanded to large diameters ( 16 mm), 20 stents underwent OE of 50% or greater. One model tended to disarticulate after OE greater than 50%. There were five models that had a tendency to disarticulate after minimal OE. Five models were resistant to OE (25% or less OE) but did not disarticulate. Nearly all stents showed some degree of foreshortening with OE, while 36 stents underwent foreshortening of 30% or more. Models that are not recommended for OE include Intrastent, Intrastent DoubleStrut, NIR Royale and Omniflex. Good candidates for OE include Intrastent DoubleStrut LD, Palmaz large, Medtronic Extra Support Biliary Plus and Medtronic Flexible Biliary. Palmaz XL remains the only model available for expansion from 20 to 28 mm in diameter. For the remaining stents, OE is possible, however, caution should be used.     

Evaluation of a "no-cost" Internet technology-based system for teleradiology and co-operative work

The aim of this study was to assess the suitability of a no-cost system based on standard Internet technology components for teleradiology. The system was composed of free software (communication, DICOM viewer, compression) and standard off-the-shelf hardware components. For different image (CR, CT, MR) and network types (LAN and ISDN) the File Transfer, Audio and Video Conference, and Co-operative Work properties were examined and compared with the literature referring to standard complete packages and dedicated teleradiology systems. The main advantages of the no-cost system are: price; ease of use; independence from specific hardware; and potential connection to any possible partner. The performance of the File Transfer and the Audio and Video Conference was comparable to the other system groups with slight disadvantages in the usability. For Co-operative Work the employed "application sharing" technology does not meet the clinical requirements, which applies identically to the standard complete packages. Here the specialized systems prove superior, although they are proprietary. With minimal restraints the evaluated no-cost solution can be used for File Transfer and Conference scenarios. The usage for Co-operative Work with ISDN is not recommended, unless for the purpose of gaining experience or when dealing with small amounts of cases or images. Electronic Publication     

"Anode heel effect" on patient dose in lumbar spine radiography

Appropriate use of the "anode heel effect" of the output beam from an X-ray tube can reduce the effective dose to patients in some common radiological examinations. We investigated the variation in radiation intensity across the X-ray beam caused by the anode heel effect, and quantified the difference in absorbed dose to critical organs resulting from lumbar spine X-ray projections carried out with the two possible orientations of the patient along the tube axis (cathode to anode). A Rando phantom and some high sensitivity thermoluminescent dosemeters (TLDs) (LiF:Mg,Cu,P) were used. With the tube axis horizontal, radiation intensity profiles, parallel and perpendicular to the axis, were measured. Lumbar spine radiographs were recorded using the Rando phantom in the standard anteroposterior (AP) and lateral projections. TLD pellets were used to measure the absorbed radiation dose at various sites corresponding to critical organ tissues (ovaries, testes, breasts, thyroid and lens). Each set of projections was recorded in two phantom orientations, first with the phantom head placed towards the cathode end of the X-ray tube, and then in the reverse direction. From the radiation intensity profile of the incident X-ray beam, the "cathode end" to "anode end" air dose ratio was found to be 1.8. In lumbar spine radiography, with the phantom head placed towards the anode end of the X-ray tube, the ovaries and testes received an average dose 17% and 12% higher, respectively, in the lateral projection, and 16% and 27% higher, respectively, in the AP projection, than those obtained in the reverse "patient" orientation. These results indicate that patients (particularly females) should always be positioned with the head placed towards the cathode end of the X-ray tube for lumbar spine radiography to achieve significant dose reductions.     

"Effort" thrombosis of the subclavian vein in a competitive swimmer

"Effort" thrombosis is a unique form of subclavian and axillary vein thrombosis because it is the result of an unusual variant of the thoracic outlet syndrome. Another cause of subclavian vein thrombosis is local compression from trauma, tumor, or development anomalies; a third is intimal damage from indwelling central venous catheters. This is a case report of "effort" thrombosis of the subclavian vein in a competitive swimmer. A recently developed technique of local infusion of low-dose streptokinase therapy is used for clot lysis. Early diagnosis is essential for effective thrombus dissolution with streptokinase. The rationale, risk, and method of streptokinase administration are discussed. Since "effort" thrombosis is secondary to thoracic outlet syndrome (TOS), decompression of the thoracic outlet by removal of the first rib after clot lysis is recommended.     

The "ring sign" of necrotic pheochromocytoma.

Pheochromocytomas are usually hypervascular tumors exhibiting dense stain during angiography. The cystic nature of the neoplasm or tumor necrosis can result in failure of opacification of the mass or a central lucent area. Four cases of pheochromocytoma are described where a central avascular zone was surrounded by a dense rim of contrast, giving a "ring sign." Since this appearance is best seen in the capillary and venous phases, delayed films are essential.     

Behavior and Awareness of Thyroid Cancer Patients in Korea Having Non-Hospitalized Low-Dose Radioiodine Treatment with Regard to Radiation Safety

Purpose

With the recent increase in incidence of thyroid cancer, non-hospitalized low-dose (NH-LD) radioiodine treatment (RIT) has also increased rapidly. The radioactivity limit that is allowed to be administered without hospitalization depends on individual calculation, based partly on patients’ behavior. In this study, Korean patients’ behavior in relation to radiation safety in NHLD RIT was surveyed.

Methods

A total of 218 patients who underwent NH-LD RIT of 1.1 GBq ¹³¹I in a single center were surveyed. The patients underwent RIT with a standard protocol and the survey was performed by interview when they visited subsequently for a whole-body scan. The survey questionnaire included three parts of questions: general information, behavior relating to isolation during RIT, and awareness of radiation safety.

Results

After administration of radioiodine, 40% of patients who returned home used mass transportation, and another 47% went home by taxi or in car driven by another person. Isolation at home was generally sufficient. However, 7% of patients did not stay in a separate room. Among the 218 patients, 34% did not go home and chose self-isolation away from home, mostly due to concerns about radiation safety of family members. However, the places were mostly public places, including hotels, resorts, and hospitals. About half of the patients replied that access to radiation safety information was not easy and their awareness of radiation safety was not satisfactory. As a result, 45% of patients wanted hospitalized RIT.

Conclusions

In many countries, including Korea, RIT is continuously increasing. Considering the radiation safety of patients’ family members or the public and the convenience of patients, the pretreatment education of patients should be enhanced. In addition, the hospitalization of patients having low-dose therapy is recommended to be seriously considered and expanded, with the expansion of dedicated treatment facilities.     

河南“4.26”60Co辐射事故中3例中、重度骨髓型急性放射病患者免疫系统变化的20年医学随访

目的 观察河南“4.26”60Co辐射事故中3例中、重度骨髓型急性放射病患者免疫系统的远期效应,总结急性辐射损伤后免疫系统长期的变化特点。 方法 对1999年河南“4.26”60Co辐射事故中2例中度骨髓型急性放射病患者（“天”和“旺”,均为男性,年龄分别为37岁和8岁）和1例重度骨髓型急性放射病患者（“梅”,女性,38岁）进行临床随访。采用免疫透射比浊法检测患者的外周血血清免疫球蛋白（Ig）A、IgG、IgM和补体C3的水平以评估体液免疫情况;采用流式细胞术检测患者T淋巴细胞亚群的CD3+、CD3+CD4+、CD3+CD8+T细胞的百分比及CD3+CD4+/CD3+CD8+T细胞的比值以评估细胞免疫情况。 结果 随访时间截至2019年9月4日,共随访11次。体液免疫评估结果显示,患者“梅”在受照后半年和第2年,补体C3水平均下降,第5、11、13、20年,IgG水平均升高;患者“天”在受照后第3年,IgM水平下降,第5年,IgG水平升高;患者“旺”在受照后第1、5年,补体C3水平均升高。Ig的异常频次及延续时间表现为“梅”>“天”=“旺”。细胞免疫评估结果显示,患者“梅”在受照后半年,CD3+、CD3+CD4+ T细胞的百分比及CD3+CD4+/CD3+CD8+T细胞的比值均显著下降,第7、11年,CD3+、CD3+CD4+、CD3+CD8+ T细胞的百分比均下降,第15年,CD3+、CD3+CD4+ T细胞的百分比均下降;患者“天”在受照后第5、11年,CD3+CD4+ T细胞的百分比均升高,第7年,CD3+、CD3+CD8+ T细胞的百分比均下降;“旺”在受照后第7年,CD3+、CD3+CD4+、CD3+CD8+ T细胞的百分比均下降。T淋巴细胞亚群的异常频次及延续时间表现为“梅”>“天”>“旺”。 结论 急性照射对免疫系统的损伤存在长期性、剂量依赖性和可逆性。对于个体而言,免疫系统的受损情况与受照剂量呈正相关,年龄和性别是其可能的影响因素。     

What we know and what we don't know about cancer risks associated with radiation doses from radiological imaging

Quantifying radiation-induced cancer risks associated with radiological examinations is not easy, which has resulted in much controversy. We can clarify the situation by distinguishing between higher dose examinations, such as CT, positron emission tomography–CT or fluoroscopically guided interventions, and lower dose “conventional” X-ray examinations. For higher dose examinations, the epidemiological data, from atomic bomb survivors exposed to low doses and from direct epidemiological studies of paediatric CT, are reasonably consistent, suggesting that we do have a reasonable quantitative understanding of the individual risks: in summary, very small but unlikely to be zero. For lower dose examinations, we have very little data, and the situation is much less certain, however, the collective dose from these lower dose examinations is comparatively unimportant from a public health perspective.The debates about the cancer risks associated with very low-dose radiation exposures will surely not end soon. Even if we really could quantitate the risks (or lack of risks) associated with some very low radiation doses, we would immediately start to wonder about the risks associated with further lower doses. We will focus here on what we know (and what we do not know) about the cancer risks associated with doses from radiological imaging.Almost all radiological doses are “small”, in the context of, for example, radiotherapeutic doses; however, one can clearly distinguish between low radiological doses associated with many conventional examinations such as dental or chest examinations (organ doses typically <0.5 mGy) and higher radiological doses associated with CT, positron emission tomography (PET)-CT or fluoroscopically guided complex interventions (organ doses for a single examination or series of examinations typically between 5 and 100 mGy). As we shall discuss, this divide in dose ranges corresponds quite well to the dose range where we do know a good deal about radiation risks (5–100 mGy) and the dose range (<1 mGy) where we know far less.We shall discuss briefly what we know and do not know in both these radiation dose ranges, but it is important to view these considerations in the context of the potential benefits associated with the corresponding imaging procedure.¹ When a radiological examination of any sort is clinically justified, its benefits will almost always far outweigh any radiation risks. That being said, we still need to optimize radiological examinations (use the lowest dose consistent with obtaining the required information) and to justify radiological examinations (minimize clinically unnecessary procedures); however, the significance of such optimization and justification depends entirely on the magnitude (if any) of the associated radiation risks.^1–3     

A case of "precocious" mummification

Mummification is a peculiar transformative process consisting of the total drying of the body soft tissues. It is produced, in particular conditions, between 6 and 12 months after death. "Precocious" mummification has been reported in countries where recorded weather conditions are more extreme than in Italy, in a confined environment, or with particular micro-climate conditions. Here we present a case of mummification produced in a central region of Italy in four weeks. We also analyze conditions allowing for the rapidity of this phenomenon.     

Study on the "toxic oxygen effect" of Janus green B in mouse ascites tumour cells.

10(7) mouse ascites tumor cells/ml incubated at 37 degrees C in 0.5 to 1.0 X 10(-4) M Janus green B or in 1.0 X 10(-4) M phenazine methosulphate are destroyed in 100 per cent oxygen atmosphere but remain transplantable in nitrogen atmosphere. The "sensitizing" effect of oxygen can be substituted by SH inhibitors (iodoacetic acid, iodoacetamide and their spinlabelled variants) as well as by some nitroxide free radicals. The "oxygen effect" is blocked by mercaptoethanole or cooling. Compared with the spectrum of native cells a more symmetrical singlet of larger amplitude, approximately g = 2 value, arose in the ESR spectrum of Janus green B treated cells. The "oxygen effect" observed in the presence of Janus green B differs in several ways from the oxygen effect of ionizing radiation and from the "photodynamic" effect.