Reliable test of clinicians' mastery in skin cancer diagnostics

Differentiating between benign and malignant skin lesions can be very difficult and should only be done by sufficiently trained and skilled clinicians. To our knowledge there are no validated tests for reliable assessments of clinicians' ability to perform skin cancer diagnostics. To develop and gather validity evidence for a test in skin cancer diagnostics, a multiple-choice questionnaire (MCQ) was developed based on informal interviews with seven content experts from five skin cancer centers in Denmark. Validity evidence for the test was gathered from May until July 2019 using Messick's validity framework (content, response process, internal structure, relationship to other variables and consequences). Item content was revised through a Delphi-like review process and then piloted on 36 medical students and 136 doctors using a standardized response process. Results enabled an analysis of the internal structure and relationship to other variables of the test. Finally, the contrasting groups method was used to investigate the test's consequences (pass-fail standard). The initial 90-item MCQ was reduced to 40 items during the Delphi-like review process. Item analysis revealed that 25 of the 40 selected items were level I-III quality items with a high internal consistency (Cronbach's α = 0.83) and highly significant (P ≤ 0.0001) differences in test scores between participants with different occupations or levels of experience. A pass-fail standard of 12 (48%) correct answers was established using the contrasting groups' method. The skin cancer diagnostics MCQ developed in this study can be used for reliable assessments of clinicians' competencies.

Tumour response after hyperthermic isolated limb perfusion for locally advanced melanoma

INTRODUCTION

The aim was to describe tumour response, complications, recurrence and survival after hyperthermic isolated limb perfusion (ILP) with melphalan or melphalan in combination with tumour necrosis factor-alpha in patients with melanoma metastases confined to an extremity.

MATERIAL AND METHODS

A total of 84 perfusions were performed (53 women, 31 men, median age 63 years) from 1993 to 2010. 95% of the perfusions were administered to the lower limbs and 5% to the upper limbs. The inclusion criteria were recurrent and/or clinically apparent cutaneous/subcutaneous extremity in-transit melanoma metastases.

RESULTS

The response rate after ILP was 85%; 42% had complete response (CR), 43% partial response (PR), 12% no change (NC) and 3% progression. Two- and five-year survival rates were 57% and 31%, respectively, and they were higher for patients with than without lymph node metastases. Time from ILP to recurrence was a median of seven months (range 1-37 months) for patients with CR or PR. Survival was longer for patients with CR or PR than for patients showing NC or progression. Several patients had mild or moderate local toxicity reactions, two patients developed severe local toxicity.

CONCLUSION

ILP induces tumour regression in the vast majority of patients. One patient, i.e. 1% of the group, died from surgical complications. Otherwise, ILP treatment had an acceptable morbidity in this group of very sick patients. We are convinced that the treatment should be offered to improve local disease control in patients with multiple and/or recurrent melanoma confined to an extremity if surgical excision is not possible.

FUNDING

not relevant.

TRIAL REGISTRATION

not relevant.

Radiation exposure to surgical staff during F-18-FDG-guided cancer surgery

PURPOSE

High-energy gamma probes have recently become commercially available, developed for (18)F-FDG probe-guided surgery. The radiation received by the staff in the operating room might limit the use of it, but has never been determined. We therefore wanted to measure the absorbed staff doses at operations where patients had received a preoperative injection of (18)F-FDG.

METHODS

Thirty-four patients with different cancers (breast cancer, melanoma, gastrointestinal cancers, respectively) were operated. At every operation the surgeon was monitored with a TLD tablet on his finger of the operating hand and a TLD tablet on the abdomen. The surgeon and anaesthesiologist were also monitored using electronic dosimeters placed in the trousers lining at 25 operations.

RESULTS

The dose rate to the surgeon's abdominal wall varied between 7.5-13.2 microSv/h, depending on tumour location. The doses to the anaesthesiologists and the finger doses to the surgeon were much lower. About 350-400 MBq, i.e. ca. eight times higher activities than those used in the present study are supposed to be necessary for guiding surgery. It can be calculated from the body doses measured that a surgeon can perform between 150-260 h of surgery without exceeding permissible limits for professional workers.

CONCLUSIONS

The radiation load to the operating staff will generally be so small that it does not present any limitation for FDG-guided surgery. However, it is recommended to monitor the surgical staff considering that the surgeon may be exposed to other radiation sources, and since the staff often includes women of child-bearing age.

Radiation doses to staff involved in sentinel node operations for breast cancer

BACKGROUND

The use of radioactive compounds for sentinel node biopsy is now a generally accepted part of the surgical treatment of breast cancer and melanoma, with the risk of radiation exposure to the operating team. The aim of this investigation was to study the levels of this exposure in relation to the permissible radiation dose limits.

METHODS

The radiation exposure to the hands and bodies of the operating surgeons (the 'risk persons') was measured by thermoluminescent dosimeters in 79 operations and to the pathologists handling the specimens in 17 cases. Radioactivity and dose rate measurement from tumours and breast specimens were also performed.

RESULTS

During an operation the mean skin dose (+/-SD) to the thermoluminescent dosimeters placed at the hand and the abdominal wall were 0.04 +/- 0.04 mSv (79 operations) and 0.01 +/- 0.02 mSv (67 operations) respectively. For the pathologist, the mean hand dose per operation was below the detection limit (17 operations). Correlation between the measured dose rate and the radioactive content of the tumours was 0.998.

CONCLUSIONS

The radiation exposure to the staff involved in sentinel node (SN) biopsy for breast cancer using radioactive labelled tracers will be considerably below the permissible limits, even with high numbers of SN biopsy procedures. Pregnant staff members should participate in <100 SN operations.

Factors of importance for scintigraphic non-visualisation of sentinel nodes in breast cancer

PURPOSE

The aim of this study was to analyse different factors of possible significance for non-visualisation of sentinel nodes (SNs) by preoperative lymphoscintigraphy, in order to enable improvement of the success rate of SN visualisation through modification or alteration of some of the factors.

METHODS

Between March 1998 and January 2003 we analysed a series of 442 women with unilateral stage T1 and clinical N0 breast cancer. Lymphoscintigraphy was performed after periareolar or peritumoural injection of 99mTc-albumin nanocolloid, with image acquisition after 2-6 h or 18-24 h. Until January 2001, all patients received around 20 MBq tracer, irrespective of time to operation. From January 2001, patients injected on the day before surgery received at least 100 MBq while patients injected on the day of surgery received around 50 MBq.

RESULTS

An SN was visualised in 87% of the patients, and at surgery the SN was detected with the hand-held gamma probe in 42% of the remaining patients. By multiple logistic regression analysis, statistically significant independent variables that increased the risk for non-visualisation were increasing age (p=0.0007), increasing body weight (p=0.0189) and peritumoural injection (p<0.0001). Significant interaction was found for imaging time and injected activity (p=0.0017).

CONCLUSION

This study conclusively shows that the risk of unsuccessful SN imaging increases with age and body weight. Our findings suggest that the scintigraphic success rate may be improved by periareolar (rather than peritumoural) injection. Early and late imaging procedures are equally efficient, but if a late imaging procedure is used, activity (adjusted for physical decay) in the patient on day 2 should be more than 10 MBq.