Treatment of autonomous thyroid nodules with percutaneous ethanol injection: preliminary results. Work in progress

Eight patients with autonomous thyroid nodules 2.4-4.3 cm in diameter received percutaneous ethanol injections (PEIs) under guidance by means of ultrasound (US). Sterile ethanol at 95% was injected with a 22-gauge needle and a 7.5-MHz probe with a guide device. Each patient received one or two treatments, with 1-3 mL of alcohol (depending on the nodule size) per treatment, each week for a total of three to six injections per lesion. After a total of 36 injections in all eight patients, there were no complications. Follow-up ranged from 2 to 10 months. After therapy, symptoms subsided and hormonal levels became normal or reached the range of subclinical hypothyroidism. Scintigrams showed that the previously suppressed thyroid tissue had resumed functioning. At US, all nodules had shrunk. PEI was risk free and easy to perform. If these preliminary results are confirmed in a larger study with longer follow-up, the new treatment may become an alternative to surgical or radioiodine ablation of autonomous thyroid nodules.

COX-1 and COX-2 inhibition in horse blood by phenylbutazone, flunixin, carprofen and meloxicam: An in vitro analysis

We report on the inhibitory activity of the NSAIDs meloxicam, carprofen, phenylbutazone and flunixin, on blood cyclooxygenases in the horse using in vitro enzyme-linked assays. As expected, comparison of IC50 indicated that meloxicam and carprofen are more selective inhibitors of COX-2 than phenylbutazone and flunixin; meloxicam was the most advantageous for horses of four NSAIDs examined. However at IC80, phenylbutazone (+134.4%) and flunixin (+29.7%) had greater COX-2 selectivity than at IC50, and meloxicam (-41.2%) and carprofen (-12.9%) had lower COX-2 selectivity than at IC50. We therefore propose that the selectivity of NSAIDs should be assessed at the 80% as well as 50% inhibition level.

Quality assurance in conservative treatment of early breast cancer. Report on a consensus meeting of the EORTC Radiotherapy and Breast Cancer Cooperative Groups and the EUSOMA (European Society of Mastology)

A consensus on a quality assurance programme of the treatment of early breast cancer was reached in a multidisciplinary meeting of surgeons, pathologists, radiotherapists, physicists and radiographers. Guidelines for treatment preparation and execution have been set up, including careful location and excision with marking of the primary tumour. The target volumes for irradiation of the whole breast and boost area have been defined. Radiation dose prescription rules, specification and checking procedures are given, together with measures to achieve a homogeneous dose within the target volume. The rules for a quality assurance programme in each clinic are designed for checking equipment and treatment method.

Clinical impact of dosimetry quality assurance programmes assessed by radiobiological modelling of data from the thermoluminescent dosimetry study of the European Organization for Research and Treatment of Cancer

The European Organization for Research and Treatment of Cancer (EORTC) Radiotherapy Group initiated its mailed thermoluminescence dosimetry (TLD) programme in 1986. The aim of the present study was to evaluate the clinical relevance of variations in beam output detected in the period 1993 to 1996. A total of 140 beam outputs were checked (26 for cobalt-60 units and 114 for linear accelerators) in 35 centres. Clinical dose-response data for tumour control and normal tissue morbidity were used to assess the variation in clinical outcome resulting from variability in beam output. For 75 checked beams with nominal accelerating potentials (n. a.p.) of 6 MV or less the mean ratio, +/- standard deviation (S.D.) of measured to stated output was 1.004+/-0.020. For 65 beams with n. a.p. of 8 MV or more, the ratio was 1.009+/-0.021. Even with this relatively high level of precision, broad distributions of estimated tumour control or normal tissue morbidity were found. In the 10% of the beams with the most pronounced underdosage, the loss in tumour control probability was estimated at 7-8 percentage points. Likewise, in the 10% of the beams with the most pronounced overdosage, the increase in mild/moderate morbidity was 19-22 percentage points. For severe morbidity the same beams raised the estimated incidence of severe complications from 5% to 9-10%. An estimation of the loss of uncomplicated cure probability was about 1% for both high and low energy beams. Sequential mailings considerably improved the uniformity of clinical outcome. We conclude that small deviations in beam output may lead to clinically important variations in outcome. Substantial reductions in the variation between measured and stated output can be achieved by sequential mailings. Mailed TLD checks should be an integral part of a continuously ongoing quality assurance activity in radiotherapy.

Quality assurance of the EORTC radiotherapy trial 22931 for head and neck carcinomas: the dummy run

PURPOSE

A dummy run was organized to test the compliance of participating centres with the guidelines of EORTC protocol 22931, which compares high dose radiotherapy with concomitant radiochemotherapy in a postoperative setting for patients presenting with locally advanced head and neck carcinomas.

METHODS

In a first step the participants (seven centres, six replies) were asked to define the planning target volume (PTV) in a given patient on the basis of clinical, surgical and radiological (CT-images) data-sets and according to the protocol guidelines. In a second phase a series of CT-reconstructed slices with on- and off-axis PTV outlines were sent to 11 centres (10 replies), which were asked to plan a treatment following the recommendations made in the frame of the trial.

RESULTS

The first step of this dummy run emphasized wide intercentre variations in PTV extensions. This fact raises the question of the reproducibility when pooling patients in multicentric trials. The second step indicated a large variability in the field arrangements which was left to the discretion of the investigators. Only three out of 10 of the institutions followed the ICRU 50 recommendations for dose reporting. Moreover, protocol requirements were not met for dose distribution homogeneity in any centre.

CONCLUSIONS

In order to reduce intercentre treatment heterogeneities, several actions have been taken by the EORTC Radiotherapy Group, e.g. amendments have been brought to protocol 22931 regarding a better definition of clinical and planning target volumes. Furthermore, a stricter application of the ICRU 50 recommendations for dose reporting has been sought.

EORTC guidelines for writing protocols for clinical trials of radiotherapy

The concept of a Master Protocol for phase III studies was raised at the Steering Committee of the EORTC Radiotherapy Group, in order to make the work of the study coordinators easier, when writing protocols and to give them more homogeneity. The Master Protocol defines and clarifies in a logical order the different steps which must be taken when designing a randomized trial--from the rationale to the references. It pays particular attention to eligibility criteria, volumes of interest defined in agreement with ICRU Report 50 (gross tumor volume, clinical target volume, planning target volume and organs at risk), simulation procedure, treatment technique, normal tissue sparing, dose computation, equipment, dose specification (also in agreement with ICRU Report 50). Last but not least, the different procedures of quality assurance for protocols and patients are also defined (site visits, dummy run procedure, in vivo dosimetry, individual case review) to allow working plans to be made in advance. We are aware that this work is not exhaustive, but hope that the contents will be of help to those who are writing a protocol.

Quality assurance of the EORTC radiotherapy trial 22863 for prostatic cancer: the dummy run

The results of a dummy run involving nine centers participating in a study comparing radiotherapy alone with radiotherapy plus hormone therapy in patients with high metastatic risk prostatic cancer (EORTC protocol 22863) show that, in all centers but one, patients are treated in the same way. However, they have also indicated that protocol compliance could be improved by a better assessment of the target volume, by taking into account of the use of protective shields and of variations in radiological density, by determining beam position on a large number of slices, and by the use of CT scan images for treatment planning.

The Quality Assurance programme of the Radiotherapy Group of the European Organization for Research and Treatment of Cancer (EORTC): a critical appraisal of 20 years of continuous efforts

In 1982, the European Organization for Research and Treatment of Cancer (EORTC) Radiotherapy Group established the Quality Assurance (QA) programme. During the past 20 years, QA procedures have become a major part of the activities of the group. The methodology and steps of the QA programme over the past 20 years are briefly described. Problems and conclusions arising from the results of the long-lasting QA programme in the EORTC radiotherapy group are discussed and emphasised. The EORTC radiotherapy group continues to lead QA in the European radiotherapy community. Future challenges and perspectives are proposed.

Influence of patient activity on femoral osteolysis at five and ten years following hybrid total hip replacement

We conducted a longitudinal study including patients with the same type of primary hybrid total hip replacement and evaluated patient activity and femoral osteolysis at either five or ten years post-operatively. Activity was measured using the University of California, Los Angeles scale. The primary outcome was the radiological assessment of femoral osteolysis. Secondary outcomes were revision of the femoral component for aseptic loosening and the patients' quality of life. Of 503 hip replacements in 433 patients with a mean age of 67.7 years (30 to 91), 241 (48%) were seen at five and 262 (52%) at ten years post-operatively. Osteolytic lesions were identified in nine of 166 total hip replacements (5.4%) in patients with low activity, 21 of 279 (7.5%) with moderate activity, and 14 of 58 (24.1%) patients with high activity. The risk of osteolysis increased with participation in a greater number of sporting activities. In multivariate logistic regression adjusting for age, gender, body mass index and the inclination angle of the acetabular component, the adjusted odds ratio for osteolysis comparing high vs moderate activity was 3.6 (95% confidence interval 1.6 to 8.3). Stratification for the cementing technique revealed that lower quality cementing increased the effect of high activity on osteolysis. Revision for aseptic loosening was most frequent with high activity. Patients with the highest activity had the best outcome and highest satisfaction. In conclusion, of patients engaged in high activity, 24% had developed femoral osteolysis five to ten years post-operatively.

Quality assurance in radiotherapy: the importance of medical physics staffing levels. Recommendations from an ESTRO/EFOMP joint task group

The safe application of ionising radiation for diagnosis and therapy requires a high level of knowledge of the underlying processes and of quality assurance. Sophisticated modern equipment can be used effectively for complicated diagnostic and therapeutic techniques only with adequate physics support. In the light of recent analyses and recommendations by national and international societies a joint working group of representatives from ESTRO (European Society for Therapeutic Radiology and Oncology) and from EFOMP (European Federation of Organisations for Medical Physics) was set up to assess the necessary staffing levels for physics support to radiotherapy. The method used to assess the staffing levels, the resulting recommendations and examples of their practical application are described.

Measurement of lead content of children's teeth in situ by x-ray fluorescence

The central nervous system of young children is particularly sensitive to neurological damage due to excessive lead exposure. The lead stored in a tooth is permanent and related to the quantity of ingested lead. The lead is assayed by measuring the characterisitc radiation from lead in a tooth in situ irradiated with gamma rays from a cobalt-57 source. The sensitivity of the method is adequate to measure lead levels commonly associated with environmental background. The X-ray exposure to the tooth necessary for this determination is approximately one tenth of that required for a routine dental examination.

Wedge factors: dependence on depth and field size

Wedge factor (WF) variation with field size and depth has been analysed for 6 and 15 MV X-ray beams. The measured field size effect is 1.4% in the worst case, whereas the WF shows a linear dependence with depth giving a maximum variation of 0.22%/cm (60 degrees wedge, 6 MV beam). An empirical correction for WF depth dependence on wedge thickness is proposed.

A comparative assessment of small-head metal-on-metal and ceramic-on-polyethylene total hip replacement

Large-head metal-on-metal (MoM) total hip replacements (THR) have given rise to concern. Comparative studies of small-head MoM THRs over a longer follow-up period are lacking. Our objective was to compare the incidence of complications such as infection, dislocation, revision, adverse local tissue reactions, mortality and radiological and clinical outcomes in small-head (28 mm) MoM and ceramic-on-polyethylene (CoP) THRs up to 12 years post-operatively. A prospective cohort study included 3341 THRs in 2714 patients. The mean age was 69.1 years (range 24 to 98) and 1848 (55.3%) were performed in women, with a mean follow-up of 115 months (18 to 201). There were 883 MoM and 2458 CoP bearings. Crude incidence rates (cases/1000 person-years) were: infection 1.3 vs 0.8; dislocation 3.3 vs 3.1 and all-cause revision 4.3 vs 2.2, respectively. There was a significantly higher revision rate after ten years (adjusted hazard ratio 9.4; 95% CI 2.6 to 33.6) in the MoM group, and ten of 26 patients presented with an adverse local tissue reaction at revision. No differences in mortality, osteolysis or clinical outcome were seen. In conclusion, we found similar results for small-head MoM and CoP bearings up to ten years post-operatively, but after ten years MoM THRs had a higher risk of all-cause revision. Furthermore, the presence of an adverse response to metal debris seen in the small-head MOM group at revision is a cause for concern.

Field separation of adjoining therapy fields

The question of optimal portal separation between two contiguous fields is of importance in radiotherapy. An analytical linear model based on experimental data has been developed for a Co-60 unit (Siemens Gammatron S 65 K). It allows the computation of the separation distance for any combination of field sizes not necessarily having the same source-surface-distance, defined either with penumbra trimmers or focused shaping blocks.

Improved dose distribution homogeneity in conservative breast cancer irradiation

At the occasion of recent meetings of the radiation oncology community, the description of a whole breast irradiation technique making use of cranio-caudal oriented wedge filters to compensate for dose distribution inhomogeneity in this direction has given rise to some discussions and misunderstandings. It is the scope of this presentation to describe the technique and its possible use for other localizations.

Diagnosis of occult scaphoid fracture with high-spatial-resolution sonography: a prospective blind study

BACKGROUND

Evaluation of diagnostic accuracy of high-spatial-resolution sonography (HSR-S) in occult scaphoid fractures.

PATIENTS AND METHODS

HSR-S was performed in 24 patients with clinically suspected fracture and normal radiographs. Three levels of clinical suspicion were considered (high, intermediate, and low). Three levels of sonographic suspicion were defined on the basis of cortical interruption, radiocarpal effusion, and scapho-trapezium-trapezoid effusion. Three positive criteria were interpreted as being highly indicative of fracture. Data from sonograms were compared with computed tomography (CT) scans.

RESULTS

CT scanning demonstrated a fracture of the scaphoid in five patients. The global sensitivity of HSR-S for detection of occult scaphoid fracture was 100% and the specificity 79%. All patients with demonstrated occult fracture had a high sonography index of suspicion. A high sonography index of suspicion was correlated with 100% sensitivity, specificity, positive predictive value, and negative predictive value.

CONCLUSION

HSR-S is a reliable, available, and cost-effective method in early diagnosis of occult fractures of the scaphoid. The presence of three defined criteria is required to assess the diagnosis.

Disparate cardiac effects of afterload reduction in hypertension

Cardiac performance, as judged by preload, afterload, and myocardial contractility, was evaluated by non-invasive M-mode echocardiography before and after acute oral administration of calcium entry blockers (nitrendipine and verapamil), angiotensin converting enzyme (ACE) inhibitors (captopril and lisinopril), and a dopamine receptor agonist (fenoldopam) in patients with mild to moderate essential hypertension. Left ventricular end diastolic volume was taken as an index of preload, end systolic stress as an index of afterload, and the ratio of systolic pressure to end systolic volume (SBP:ESV), ejection fraction (EF), and mean velocity of circumferential fibre shortening (Vcf) as indices of contractility. Reductions of afterload and mean arterial pressure were achieved with all antihypertensive agents involved (mean percentage change +/- s.e.m.: 15 +/- 2% and 10 +/- 1%, respectively, P < 0.05) but the afterload reduction with lisinopril was greatest (21 +/- 9%; P < 0.01). The dopamine receptor agonist fenoldopam decreased by preload 24% (P < 0.05) and increased all of the three parameters of myocardial contractility (SBP:SV 66%; EF 17%, Vcf 19%; P < 0.01). In contrast, no effect on these parameters was observed with either calcium entry blocker or either ACE inhibitor.