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Symposium The necessity of quality assurance in brachytherapy 198 speaker ACCIDENTS IN LDR AND HDR BRACHYTHERAPY J. M. Cosset1 1 I NSTITUT C URIE, Radiation Oncology, Paris, France
In 2000, the International Commission on Radiological Protection (ICRP) released its publication 86, "Prevention of accidental exposures to patients undergoing radiation therapy". In this document, several specific chapters were devoted to brachytherapy. The document in particular analyzed in details the causes and factors contributing to accidental exposures in brachytherapy; problems linked to the equipment, to the source ordering, delivery, calibration and acceptance, problems with the treatment planning, the source preparation, the treatment delivery and the source removal. Accidents involving the public and /or leading to environmental contamination were not forgotten, and finally, generic lessons were drawn from the existing experience. In 2005, the ICRP publication 97 concentrated more specifically on "Prevention of High-dose-rate brachytherapy accidents". It was estimated at that time that about 500,000 HDR procedures were performed annually in the world, with over 10,000 HDR sources transported, with the resultant potential for accidents. More than 500 accidents involving HDR brachytherapy had been reported, human errors being the prime cause of radiation events. Finally, also in 2005, ICRP published its publication 98; "Radiation safety aspects of brachytherapy for prostate cancer using permanently implanted sources", dealing with the permanent implantation of Iodin 125 or Palladium 103 seeds in the prostate for the treatment of selected localized prostate cancers. The presentation will be mainly based on those three publications. It will take as examples the worst accident occurring with an HDR procedure ( the patient died and 94 persons were irradiated) , and the worst accident with LDR implanted sources ( with 97 suboptimal implants in a cohort of 116 patients, during a 6-years period). It will finally focus on the generic lessons to be drawn. In the same way it has to be done in external radiotherapy, all precursor events, incidents or accidents in brachytherapy have to be immediately reported and analyzed, in order to rapidly propose corrective procedures, to circulate the information and to learn from experience.
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recommendations such as AAPM TG 56 state that a trained medical physicist or radiation safety officer should be present during each HDR BT treatment procedure. Furthermore documented emergency procedures should be practiced with the entire team at a regular interval (e.g. yearly). Before each procedure it should be checked that proper emergency equipment is in place, and that radiation monitors and signals are operational. A few incidents with sources becoming disengaged from the source transfer cable have been reported in the past, the most infamous happened at the Indiana Regional Cancer Center in the US in 1992. It could be stated that source and afterloader manufacturers have learned from these events, and that the risk of such an event happening with modern machines is certainly less than in the past. Manufacturers now guarantee a number of fault-free source transfers which largely exceeds the actual number of transfers that will be performed with a normally clinical operated afterloader during the useful lifetime of the source. In this respect a note of care should be made when using long lived isotopes such as Co60. However other events can also lead to a source getting blocked in the patient, and the risk of such an event to happen can never be ignored. In Belgium e.g. recently an incident was reported with a PDR-afterloader unit. At the end of the treatment, during the source retraction the unit failed, causing the drive motors to stop. However this failure was not recognized by the software and the machine did not go in an error state. The problem was fortunately noticed by a member of the nursing staff who was able to retract the source by pressing the emergency source retraction button. It was the first time that such an error occurred on this type of unit, while this popular model of afterloader has been on the marked for more then 2 decades. The probability of a source getting disengaged or otherwise stuck in the patient may be extremely low, and other risks may show up to be more important in a Failure Modes and Effects Analyses. But taking into account the severity of a possible incident, the possible harm to the patient and the relatively low costs of installing appropriate emergency procedures, the existing recommendations should be applied and appropriate safety procedures should be set up in every department. The entire BT staff should be trained at a regular basis in applying these emergency procedures. 200 speaker QUALITY ASSURANCE IN BRACHYTHERAPY B. Al-Qaisieh Abstract not received.
199 speaker EMERGENCY PROCEDURES: IS YOUR LIFE JACKET READY - OR WILL YOU LEARN TO SWIM WHEN LANDING ON WATER? A. Rijnders1 1
E UROPE H OSPITALS - S ITE 2 A LICE, Department of Medical Physics, Brussels, Belgium
ESTRO-ESTS-ERS Joint symposium: Lung Cancer - What is the evidence that is being created right now? - The best of clinical trials - Early stage NSCLC 201 speaker
Although quality assurance has been getting more and more attention over the last decades, the number of reported incidents in radiation oncology does not seem to be decreasing. Partly this might be due to a better detection and reporting rate, but on the other hand the increasing input of advanced technology in radiotherapy also increases the potential of errors and malfunctions and demands more stringent QA procedures. A particular danger in any type of radiation therapy is that of an overdosage due to administering the treatment during a longer time than intended, either because of a human error (in the case of manually controlled devices), or because of a technical failure of the radiation device (failure in the timer or radiation counter,&) or a combination of both. When the irradiation beam is electronically generated, such as is the case in external beam radiotherapy using accelerators or in BT using electronic BT sources, the irradiation can always be stopped with 100% certainty, ultimately by breaking the power circuit to the radiation device. When using radioactive isotopes for BT however the possibility exists that the radioactive source or sources remain in the patient while the calculated treatment time has elapsed, leading to a continued irradiation. In classical LDR applications, using manual (after)loading of the sources, this risk was most often linked to a human error, as the sources had to be manually removed once the treatment time had elapsed. Several incidents have been reported, and often lack of training, non-existing or insufficient procedures or lack of radiation detectors were one of the root causes of these incidents. Due to the low dose rate (typically 60 cGy/h) consequences for the patient were usually moderate or even negligible. In afterloading techniques using a stepping source, and certainly in HDR techniques, the danger is much higher. Due to the high reference air kerma strength of the sources used (up to about 40 mGy/h for HDR sources) the instantaneous dose rate in HDR implants can go up to 7 Gy/min at 1 cm distance. If a source should for some reason remain stuck in the patient, critical doses leading to severe complications or even death can be reached in the time span of several minutes, and emergency procedures should be applied without delay. For this reason many (inter)national regulations and
LIMITED RESECTION H. J. Hansen1 C OPENHAGEN U NIVERSITY H OSPITAL - R IGSHOSPITALET, Cardiothoracic Surgery RT 2152, Copenhagen, Denmark
1
A resection can be limited both in the way the surgery is performed and by the amount of tissue that is resected. Video-Assisted Thoracic Surgery (VATS) lobectomy has become an accepted, safe and oncologically effective strategy in the surgical management of early stage lung cancer. In Copenhagen 71% of all cancer lobectomies were done by VATS in 2009. On the short term basis VATS lobectomy is associated with less postoperative pain, shorter chest tube duration, less intra-operative blood loss, lees need for blood transfusion less complications, shorter length of hospital stay, shorter stay in intensive care unit (ICU) and therefore it is cost effective to the hospital. It does allow the general or pulmonary marginal patient to have a prober lobectomy with lymph node handling performed. On the long term basis VATS lobectomy is associated with less chronic pain, better preservation of lung function, earlier return to daily activities and better shoulder function. Furthermore VATS lobectomy is less immunosuppressive and seems to facilitate the deliverance of adjuvant chemotherapy. The 5 year survival rate is comparable to or maybe even better than lobectomy by thoracotomy. As lung cancers are detected at a smaller size and in a peripheral location, lesser surgical resections may be an option. But the only randomized study shows a benefit to a lobectomy over a sublobar resection. This study was done in an earlier era when tumors were often more central, many were squamous cell cancers, and they were larger stage I tumors. More recent data are retrospective and most often single-institution reports, but for carefully selected patients with small peripheral tumors, the outcomes for sublobar resectionswhen possible, anatomic segmentectomyare excellent and compa-
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rable in cancer outcome to lobectomy. The optimal tumors for segmentectomy are those NSCLC that are well centered in the segment of interest and sized 2.0 cm or less. In addition, a patient who has limited pulmonary function (forced expiratory volume in 1 second less than 50% of predicted) or has other lesions that will need to be resected should be given consideration for a segmental resection. The surgeon should always resect all intersegmental lymph nodes in addition to the hilar and mediastinal nodes that are routinely taken at the time of a lobectomy. Using a video-assisted thoracic surgical approach to segmentectomy decreases the morbidity and hastens the recovery of patients having this operation relative to a thoracotomy. This technique can be easily learned by surgeons who use video-assisted thoracic surgery to perform other operations. Surgery is still the only way to offer total clearing of the affected lung tissue and the possible affected local N1 and N2 lymph nodes. In selected centres VATS lobectomy/segmentectomy now is the standard operation in early stage lung cancer and in near future it must be expected to be so throughout Europe. As the surgery is more demanding it is preferable, that it is done in high volume centres by dedicated general thoracic surgeons. 202 speaker STEREOTACTIC RT. THE NEW PATIENTS WITH STAGE 1 NSCLC? F. Lagerwaard1
STANDARD
FOR
HIGH-RISK
1 VU U NIVERSITY M EDICAL C ENTER, Radiation Oncology, Amsterdam, Netherlands
Stereotactic ablative radiotherapy (SABR) or stereotactic body radiotherapy has rapidly gained acceptance by chest physicians and patients as a curative non-invasive treatment of early stage non-small cell lung cancer (NSCLC). In countries where SABR implementation has taken place, this has led to detectable survival gains in stage I NSCLC on a population level [Palma 2010]. In addition, the availability of SABR in The Netherlands resulted in a change in treatment utilization and patterns of care in elderly patients with a significant decrease in elderly patients being left untreated [Palma 2010]. Although no exact definition of SABR exists, it can be regarded as a form of high-precision image-guided radiotherapy, involving the following features: (1) an individualized incorporation of tumour mobility, e.g. using 4-dimensional CT scans or slow CT scans (2) accurate online patient setup using orthogonal imaging, on-board kV imaging (OBI), cone-beam CT-scans or fiducial markers at the treatment delivery unit, (3) the use of up to 10 or more radiation fields or intensity-modulated arcs to minimize normal tissue exposure and (5) the use of ablative doses, typically delivered in 3-5 fractions. Despite the lack of a randomized trial, superior local control rates of around 90% reported after SABR in multicenter studies, phase I-II trials and single institution series substantially exceed those obtained with conventional radiotherapy schemes. These excellent local control rates are particularly seen in series where biological effective doses of above 100 Gy10 for tumour tissue have been used. The superiority of outpatient SABR, which is typically delivered in 3-8 fractions, was confirmed by recent a meta-analysis of observational studies [Grutters 2010]. SABR is well tolerated with fatigue and mild chest wall pain the most commonly reported patient-reported early symptoms. The incidence of late toxicity is also low with symptomatic radiation-induced pneumonitis and chest wall complications including chronic pain and rib fractures each observed in less than 5% of patients. Despite early reports of excessive toxicity after SABR for centrally located lesions, the risk of such toxicity appears to be low when appropriate risk-adapted fraction schemes are used [Timmerman 2006, Haasbeek 2010]. Both pulmonary function and health-related quality of life are maintained following SABR, even in patients with considerable comorbidity [Stephans 2009, Senan 2010]. The excellent local control and low toxicity of SABR have challenged the assumption that surgery should be the preferred treatment for all potentially operable patients with Stage I NSCLC. However, randomized prospective trials comparing surgery and SABR in operable patients have not been completed. Two single-arm phase II trials of SBRT in patients who are fit to undergo surgery have been completed, and the mature results of JCOG 0403 (NCT00238875) and RTOG 0618 (NCT00551369) are awaited. Data from operable Japanese patients who elected to undergo SABR in 14 Japanese institutions over a 9-year period, reported 5-year overall survival rates of 72% and 62%, respectively, for Stage IA and IB subgroups [Onishi 2010]. Preceding the outcome of randomized trials, we observe a growing number of potentially operable patients who, after discussion within local multi-disciplinary tumor board meetings, are referred for SABR instead of surgery. The percentage of potentially operable patients in the Netherlands being referred for SABR, particularly elderly patients with an increased surgical mortality risk, has increased to 25% in recent years [Lagerwaard WCLC 2011]. In conclusion, SABR is rapidly replacing conventional radiotherapy as a curative treatment in medically inoperable patients. Until the outcome of prospective randomized clinical trials of SABR and surgery emerges, patients should be routinely informed of the option of SABR as a possible curative alternative to anatomical resection.
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203 speaker HIGH FREQUENCY ABLATION T. DeBaere Abstract not received.
204 speaker ROLE OF ADJUVANT CHEMOTHERAPY J. P. Sculier1 1 I NSTITUT JULES B ORDET (ULB), Intensive Care Brussels, Belgium
Thoracic Oncology,
Adjuvant chemotherapy is today considered in Europe and America as a standard in the management of stages II and III resected non-small cell lung cancer (NSCLC). Its theoretic advantages are the assessment of the pathological stage, the eradication of micrometastases, the lack delay for surgery in case of ineffective chemotherapy; its disadvantages are the drugs toxicity and the impossibility of delivering for patients who become unfit due to surgery. The decision to administer postoperative chemotherapy is based on the pathological TN. The level of evidence consists in multiple randomised trials and meta-analyses with regimens containing platinum derivatives (1;2). The absolute 5-year survival gain is estimated around 5 to 10 %. In Japan, by using the tegafur + uracil regimen, a benefit has been demonstrated for T1bN0M0 and stage IB NSCLC (3). Some subgroup analyses suggest for Caucasians a significant survival benefit in patients with tumour size > 4 cm (4). There is only one three-arm randomised trial having compared surgery alone or neoadjuvant or with adjuvant chemotherapy (5), including mainly stage I diseases and without survival benefit. According to meta-analyses of the literature, there seems to be no major differences between adjuvant and neoadjuvant chemotherapy (6). At very long-term, the benefit of chemotherapy seems to be cancelled by early deaths due to the occurrence of multiple diseases (7). The points that will be discussed during the presentation are the routine indications for adjuvant chemotherapy after complete resection of NSCLC, the implications of the new TNM staging system for good interpretation of the guidelines on the topic, the choice between adjuvant and neoadjuvant chemotherapy, the follow up to be performed after treatment. References: 1. Meert AP, Sculier JP. What has the meta-analysis contributed to today’s standard of care in the treatment of thoracic malignancies? Lung Cancer 2008 August;61(2):141-51. 2. Arriagada R, Auperin A, Burdett S et al. Adjuvant chemotherapy, with or without postoperative radiotherapy, in operable non-small-cell lung cancer: two meta-analyses of individual patient data. Lancet 2010 April 10;375(9722):1267-77. 3. Hamada C, Tsuboi M, Ohta M et al. Effect of postoperative adjuvant chemotherapy with tegafur-uracil on survival in patients with stage IA non-small cell lung cancer: an exploratory analysis from a metaanalysis of six randomized controlled trials. J Thorac Oncol 2009 December;4(12):1511-6. 4. Strauss GM, Herndon JE, Maddaus MA et al. Adjuvant paclitaxel plus carboplatin compared with observation in stage IB non-small-cell lung cancer: CALGB 9633 with the Cancer and Leukemia Group B, Radiation Therapy Oncology Group, and North Central Cancer Treatment Group Study Groups. J Clin Oncol 2008 November 1;26(31):5043-51. 5. Felip E, Rosell R, Maestre JA et al. Preoperative chemotherapy plus surgery versus surgery plus adjuvant chemotherapy versus surgery alone in early-stage non-small-cell lung cancer. J Clin Oncol 2010 July 1;28(19):3138-45. 6. Lim E, Harris G, Patel A et al. Preoperative versus postoperative chemotherapy in patients with resectable non-small cell lung cancer: systematic review and indirect comparison meta-analysis of randomized trials. J Thorac Oncol 2009 November;4(11):1380-8. 7. Arriagada R, Dunant A, Pignon JP et al. Long-term results of the international adjuvant lung cancer trial evaluating adjuvant Cisplatin-based chemotherapy in resected lung cancer. J Clin Oncol 2010 January 1;28(1):35-42. Adjuvant chemotherapy is today considered in Europe and America as a standard in the management of stages II and III resected non-small cell lung cancer (NSCLC). Its theoretic advantages are the assessment of the pathological stage, the eradication of micrometastases, the lack delay for surgery in case of ineffective chemotherapy; its disadvantages are the drugs toxicity and the impossibility of delivering for patients who become unfit due to surgery. The decision to administer postoperative chemotherapy is based on the pathological TN. The level of evidence consists in multiple randomised trials and