Optimisation strategies and justification: an example in uterine artery embolisation for fibroids

Radiation risk has to be justified and optimised. This study discusses the radiation risk of uterine artery embolisation (UAE) for the treatment of fibroids. A total of 70 consecutive UAE dosimetry parameters were assessed. Using Monte Carlo simulation, organ and effective doses and dose conversion coefficients (DCCs) (mSv Gy cm(-2)) were calculated. During UAE optimisation, avoidance of oblique views and use of last-image-hold (LIH) documentation instead of digital subtraction angiography (DSA) were investigated. Mean dose-area product (DAP) was 37.1 Gy cm2 (median 23.7 Gy cm2) and mean fluoroscopy time was 18.4 min (median 16.6 min). Dose values decreased as the study progressed: mean DAP for patients 1-21, 68.5 Gy cm2; patients 22-43, 35.7 Gy cm2; and patients 44-69, 13.0 Gy cm2. Average DCC for DSA image procedures was 0.572, yielding a mean effective dose of 29.6 mSv (median 17.1 mSv). For LIH-only procedures, an average DCC of 0.813 was estimated [using mean effective dose: 10.6 mSv (median 8.1 mSv)].

A randomised trial comparing local versus general anaesthesia for microwave endometrial ablation

OBJECTIVE

To compare the acceptability of microwave endometrial ablation using a local anaesthesia/sedation regime or general anaesthesia. To compare recovery following treatment with each type of anaesthetic.

DESIGN

Prospective randomised controlled trial with follow up of women who declined randomisation.

SETTING

The gynaecology department of a large teaching hospital in the UK.

POPULATION

All women referred for microwave endometrial ablation at the Aberdeen Royal Infirmary between July 1999 and September 2000 without a medical reason to favour one or other type of anaesthetic.

METHODS

191 women were equally randomised to undergo microwave endometrial ablation under general or local anaesthesia. Details were also collected for women not randomised because of an anaesthetic preference. All procedures were undertaken in an operating theatre.

MAIN OUTCOME MEASURES

Data collected by questionnaire including the woman's view of treatment acceptability, operative details and post-operative recovery.

RESULTS

Sixty-nine percent of eligible women would consider treatment under local anaesthesia. Ninety-one percent of microwave endometrial ablation procedures that started under local anaesthesia were completed without conversion to general anaesthesia. Anaesthetic type and allocation by randomisation or preference made no significant difference to the proportion of women describing treatment as totally or generally acceptable at two weeks. Neither parity nor cavity size predicted acceptability. Women allocated general anaesthesia were more likely to describe the procedure as totally acceptable and to choose the same anaesthetic again. There was no significant difference between anaesthetic groups regarding post-operative pain, nausea or recovery time.

CONCLUSIONS

Microwave endometrial ablation under local anaesthesia was acceptable to the majority of women referred for treatment. There was no recovery advantage from local anaesthesia and almost 1 in 10 women who starting treatment under local anaesthesia needed a general anaesthetic because of discomfort. The incidence of post-operative pain and nausea means that treatment with this local anaesthetic/sedation regime remains a day case rather than an outpatient procedure.

Chromosome aberrations in lymphocytes from women irradiated for benign and malignant gynecological disease

Excess leukemias have occurred after partial-body radiotherapy for cervical cancer and benign gynecological disease (BGD). However, the level of risk is nearly the same in both groups, about twofold, despite a tenfold difference in average dose to active bone marrow (8 Gy vs 0.7 Gy, respectively). High-dose cell killing has been postulated as one explanation for this apparent inconsistency. To examine whether chromosome aberration rates observed in lymphocytes many years after exposure might serve as population markers of cancer risk, blood samples were taken from 60 women treated for BGD (34 with radiation) and cytogenetic data compared with previous results from 96 women irradiated for cervical cancer. Remarkably, the rate of stable aberrations, which reflects nonlethal damage in surviving stem cells, was only slightly higher among the cancer patients. Thus the lower-dose regimens to treat benign disorders resulted in much higher aberration yields per unit dose than those for cervical cancer. Assuming that the fraction of cytogenetically aberrant stem cells that survive radiotherapy contributes to the leukemogenic process, these data are then consistent with the epidemiological observations of comparable overall leukemia risks seen in these two irradiated populations. Accordingly, for patient populations given partial-body radiotherapy, stable aberrations at a long time after exposure appear to serve as biomarkers of effective risk rather than as biomarkers of radiation dose received.

Malignant disease after radiation treatment of benign gynaecological disorders. A study of a cohort of metropathia patients

One hundred and seven cases of malignant tumours occurred among 788 women irradiated 1912 to 1977 for metropathia. One hundred and seventy-three women out of 1,219 referred for the same diagnosis and not irradiated developed a malignant tumour. The tumours were diagnosed between 1958 and 1982. The relative risk of malignant tumours among the irradiated women was 1.22 and among the non-irradiated 1.09 compared to cancer registry data. A statistically non-significant increase of the relative risk was found in the irradiated patients for tumours of the rectum (1.58), colon (1.46), and the nervous system (1.67). A decreased overall relative risk was seen for cancer of the breast (0.92) after irradiation, but women treated at the age of 50 or more had an increased risk (2.08). The relative cancer risk of the heavily irradiated sites was not increased during the first 20 years after irradiation, but a statistically significant increase of the risk was seen after 30 years.