A change in treatment process with a modern record and verify system

Purpose: With the introduction of new treatment devices, such as a multileaf collimator (MLC) and dynamic wedge (DW), therapists have an increased responsibility to ensure correct treatment. Simultaneously, three-dimensional treatment planning (3DTP) has led to an increased number of portals and table movements. To counteract this challenge and maintain efficiency, a comprehensive record and verify (R&V) system is mandatory. We evaluated a commercial system (Varis) for reliability, ease of use, efficiency, and integration with our planning systems.

Methods and Materials: Some key elements of the Varis system are: integration of MLC and DW; auto setup for MLC, jaw, collimator, gantry, and limited table parameters; direct download of simulation beam data; and a regimented field scheduling system that prescribes all beam data for particular fractions. Evaluation of the system was driven by treatment time analysis, error rates, and an increased workload. These issues were governed by how we disseminated duties and how the system accommodated or changed our processes.

Results: Most data entry is performed by our dosimetry staff. Data can be downloaded from the simulator, but more patients now move from CT simulation and/or 3DTP to the treatment machine. Varis does not link to these systems. The physics staff confirms all entries to correct data entry errors. The workload for dosimetrists increased by an average of 8 minutes/patient entry; physics time increased by 7 minutes/patient entry; the weekly electronic chart check takes approximately 3 minutes/patient. Therapists who used Varis efficiently showed a slight decrease in treatment times, attributed to MLC integration and auto-setup. Some therapists experienced a decrease in efficiency, because of unfamiliarity and excess intervention. On a positive note, notable events have decreased by a factor of 10 since full initiation. Unfortunately, the remaining errors are often the result of a therapist relying on incorrect electronic information.

Conclusion: The Varis R&V system has had an impact on our clinic’s process and efficiency. Checking of all beam data and related field scheduling have helped reduce errors and misconceptions. We feel a dual-energy machine can be operated with two experienced therapists and an up-to-date R&V system more accurately and efficiently than with three therapists working without an integrated R&V. We anticipate future Varis releases will further promote efficiency and accuracy.     

HEMATURIA FROM LEFT INTERNAL PUDENDAL AND OBTURATOR ARTERIAL BLEEDING FOLLOWING SEXUAL INTERCOURSE

Bladder tamponade is an uncommon clinical symptom among men who experience suffering related to sexual intercourse. The authors report on a 46-year-old man with this symptom 4-5 years before hospitalization. Angiography confirmed the presence of left pudendal and obturator arterial bleeding, and embolotherapy of the internal pudendal and obturator arteries was performed. There was no mortality, or limb loss or loss of sexual potency at follow-up.     

256层低剂量CT对细支气管肺泡癌的诊断价值

目的回顾性分析细支气管肺泡癌的低剂量CT表现,旨在提高细支气管肺泡癌的诊断水平。方法收集经手术病理证实为BAC病例31例,分析其低剂量CT上的表现。评价指标包括:病灶形态、边缘、内部密度等特征以及有无淋巴结肿大等;同时记录单次扫描的辐射剂量,并对图像质量进行主观评分。结果所有病灶均表现为磨玻璃密度(GGO)结节,96.7%边界清晰,分叶征、毛刺征及空泡征的发生率分别为93.5%、57%及54.8%,均无肺门纵隔淋巴结转移。低剂量CT的平均辐射剂量为(1.29±0.16)m Sv,图像质量均能满足临床诊断要求。结论 BAC具有特征性的CT表现;低剂量CT在保证图像质量的前提下,有效降低辐射剂量,对BAC的诊断具有重要价值。     

放射性直肠炎的预后危险因素分析

目的探讨与放射性直肠炎预后相关的危险因素。方法对2007年8月至2010年2月期间收治的33例放射性直肠炎患者的临床疗效及生活质量进行随访以评价预后,并进一步通过回顾性分析不同预后患者临床资料的差异．寻找与预后相关的危险因素。结果33例患者的原发肿瘤包括宫颈癌22例、前列腺癌3例、卵巢癌2例、直肠癌2例、子宫内膜癌2例、宫颈癌合并卵巢癌1例、阴道癌1例。在收集到放疗资料的18例患者中,照射剂量为（61．3±12．9）Gy。接受放疗至出现放射性直肠炎症状的时间为（11．7±12．8）个月,均通过临床症状及结肠镜检查确诊。治疗方法包括药物保留灌肠11例．甲醛局部烧灼止血9例,手术治疗12例（为直肠阴道瘘、大出血、肠梗阻等严重并发症者．其中行病变肠管切除9例,单纯造瘘3例）,1例未行任何治疗。患者总的临床有效率75％,总体生活质量（63．79±20．92）分,预后良好者占75％;手术治疗的有效率为91．7％。性别为与预后相关的危险因素（P〈0．05）,而病变程度、治疗方法并非预后的危险因素（均P〉0．05）。结论性别是放射性直肠炎预后的危险因素：病变程度不同并不意味着预后不同：对出现严重并发症的患者采取手术治疗可明显改善其近期生活质量。     

Preliminary safety evaluation of a cyclotron facility for positron emission tomography imaging

This work describes the design characteristics of a medical imaging centre which uses positron emission tomography, with a cyclotron for fluorine-18 and nitrogen-13 production, and which has provided experimental information on operational data recorded by area dosimetry since 1995. Doses to radiopharmacy and medical staff have been measured both in normal work and in some handling incidents. Data on radiation levels in the installation have also been obtained and related to design details and shielding. Area dosimetry was carried out using a five-stationary detector network, with a sampling rate of 2 min^–1, and by thermoluminescent dosimetry (TLD). Staff were also monitored by TLD, using extra chips for finger dosimetry and to duplicate individual whole-body dosimetry in order to measure doses in certain single operations. For normal work, average whole-body doses to radiopharmacy staff were between 0.03 and 0.28 mSv/month, wrist doses were between 0.42 and 2.67 mSv/month, and finger doses were between 1.4 and 7.7 mSv/day for the left hand and 0.8 and 2.4 mSv/day for the right hand; such variation reflects the differing expertise of staff and the role played by optimisation. Finger doses between 16 and 131 mSv were measured in handling incidents, and finger doses of 20.2 and 20.7 mSv for the left hand and 22.0 and 22.3 mSv for the right hand were measured during handling of a syringe without shielding, containing 3 GBq. For medical staff, contributions to the whole-body dose of 2.0 and 1.9 μSv/procedure were measured for injection and placing the patient on the examination couch, respectively. Dose measurement on the middle finger of the right hand gives an average of 70 μSv during the injection. The provisions regarding the shielding design have proved to be adequate and effective during a 3-year operational period. Operational doses to medical staff are comparatively low, while radiopharmacy staff are the most exposed. The finger doses in these professionals may exceed the annual limit, unless operational restrictions in daily practice are adopted. On-line area dosimetry records based on dose rate probes have proved to be effective both for monitoring radiation levels during the operation and for detecting changes in the behaviour of the facility in the irradiation process. Received 23 January and in revised form 12 April 1999     

Erbium filtration: a cost-effective, dose-reducing filter which maintains abdominal image quality

The current study investigated the effect of erbium filtration on an anteroposterior abdominal image. The radiation dose reductions achieveable and the costeffectiveness of this filter were also evaluated. An assessment of the radiation dose delivered employing either the standard total filtration (3 mm Al equivalent) or 0.1 mm of erbium filtration added to the standard filtration was undertaken on 21 patients. Image quality was assessed using the Commission of European Communities (CEC) criteria. Significant reductions of 64.6 % in entrance surface (p = 0.0001) and 23.4 % in effective dose (p = 0.0099) were recorded with erbium filtration. Image quality was maintained and the cost per manSievert saved was ￡ 128. More widespread use of this dose reducing filter is advocated. Received: 7 August 1998; Revised: 19 February 1999; Accepted: 19 April 1999     

低剂量β-射线预防自体移植静脉内膜增生和狭窄的实验研究

目的 观察不同剂量^32P照射对兔自体移植静脉（AVG）内膜增生和狭窄的预防作用。方法 用苏木素-伊红（HE）染色、增殖细胞核抗原（PCNA）1免疫组织化学染色和计算机图像分析等方法观察每平方厘米25.9、51.8、103.6和207.2MBq/cm^2^32P照射30min后AVG内膜面积、平滑肌细胞（SMC）增殖和管腔相对丢失率,并与卡托普利治疗效果比较。结果 207.2MBq/cm^2和103.6MBq/cm^2组无明显新生内膜形成,但血管结构,细胞大量坏死;51.8MBq/cm^2组少量新生内膜形成,血管结构完整,内膜面积、SMC增殖和管腔丢失明显低于对照组和卡托普利治疗组;25.9MBq/cm^2组各指标与对照组及卡托普利组差异无显著性。结论 低剂量^32P照射（51.8MBq/cm^2,30min)可有效抑制AVG内膜增生和狭窄,且作用优于卡托普利。     

Value of repeat CT scans in low back pain and radiculopathy

We assessed the clinical value of repeat spine CT scan in 108 patients aged 18–60 years who underwent repeat lumbar spine CT scan for low back pain or radiculopathy from January 2008 to December 2010. Patients with a neoplasm or symptoms suggesting underlying disease were excluded from the study. Clinical data was retrospectively reviewed. Index examinations and repeat CT scan performed at a mean of 24.3 ± 11.3 months later were compared by a senior musculoskeletal radiologist. Disc abnormalities (herniation, sequestration, bulge), spinal stenosis, disc space narrowing, and bony changes (osteophytes, fractures, other changes) were documented. Indications for CT scan were low back pain (60 patients, 55%), radiculopathy (46 patients, 43%), or nonspecific back pain (two patients, 2%). A total of 292 spine pathologies were identified in 98 patients (90.7%); in 10 patients (9.3%) no spine pathology was seen on index or repeat CT scan. At repeat CT scan, 269/292 pathologies were unchanged (92.1%); 10/292 improved (3.4%), 8/292 worsened (2.8%, disc herniation or spinal stenosis), and five new pathologies were identified. No substantial therapeutic change was required in patients with worsened or new pathology. Added diagnostic value from repeat CT scan performed within 2–3 years was rare in patients suffering chronic or recurrent low back pain or radiculopathy, suggesting that repeat CT scan should be considered only in patients with progressive neurologic deficits, new neurologic complaints, or signs implying serious underlying conditions.