British Journal of Radiology (2004) 77, 1-2
© 2004 British Institute of Radiology
doi: 10.1259/bjr/30918615
Gynaecological brachytherapy: a 1 day seminar organized by the British Institute of Radiology Brachytherapy Working Party
L T Tan, MRCP, FRCR, MD
C J Orton, MRCPsych, FRCR
P R Blake, FRCR, MD
and
B Jones, MD, FRCP, FRCR
on behalf of the British Institute of Radiology Brachytherapy Working Party
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Introduction
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A 1 day seminar organized by the British Institute of Radiology (BIR) Brachytherapy Working Party was held on 26th April 2002. The subject of the meeting was Gynaecological Brachytherapy covering aspects of brachytherapy for carcinoma of the uterine cervix, uterine corpus and vulva.
Carcinoma of the uterine cervix
Prof. Richard Pötter from the University of Vienna, Austria described his experience of nearly 300 patients with cervical cancer treated with external beam radiotherapy, using conformal fields tailored to the pattern of lymph node involvement, and fractionated high dose rate (HDR) brachytherapy, using a CT/MRI compatible ring-tandem applicator [1]. Brachytherapy was planned three-dimensionally on CT, and more latterly on MRI, with the applicator in place. With the MRI-based technique, in particular, it was possible to adjust the brachytherapy isodose distribution by adapting source dwell times and locations, to take into account tumour volume and topography as well as the topography of the organs at risk. Using this highly individualized approach, Prof. Pötter showed that it was possible to escalate the dose to the tumour while at the same time reducing the dose to the rectum and bladder. The resulting local control rates for treated patients were impressive whilst the morbidity rates were extremely low.
Prof. Pötter's excellent lecture stimulated considerable discussion among the delegates. In particular, there was a great deal of interest in the potential of this highly individualized technique, and perhaps a little disappointment that such a sophisticated technique would be difficult to implement in most UK centres given the current state of our resources. Whilst HDR brachytherapy is currently used for the treatment of cervix cancer in a number of UK centres, most of the techniques are based on conventional triple applicator systems and the use of the ring-tandem applicator is extremely rare. It is likely that remote afterloading low dose rate (LDR) brachytherapy systems in UK centres will have to be replaced by HDR systems within the next 10 years due to cessation of manufacturer's support for existing systems. Those centres seeking to acquire new HDR systems should give serious consideration to adopting the ring-tandem applicator for the treatment of cervical cancer.
The session included two other presentations on brachytherapy for cervical cancer given by Dr Susan Davidson (Christie Hospital, Manchester) and Dr Peter Hoskins (Mount Vernon Hospital, Northwood, Middlesex). Dr Davidson described the Manchester LDR remote afterloading system, which is based on the traditional Manchester radium system. Lightweight metal applicators are utilized to mimic the size and shape of the radium applicators while source strengths and distribution are chosen to allow radium-like fractionation and isodose patterns to be maintained. A dose reduction of 10–17% is employed to account for the higher dose rate compared with radium; this has been shown to give a Grade 3 morbidity rate of 5% in clinical trials. Dr Hoskins described the technique for fractionated HDR brachytherapy used at Mount Vernon Hospital, which utilized a cervical sleeve that can be left in situ for at least 3 weeks without complications. This allowed subsequent fractions of brachytherapy to be delivered without the need for multiple general anaesthetics. However, typically less posterior packing is possible with the outpatient treatments. The need for verification films at each fraction and individualized dosimetry was emphasised. In addition, Dr Hoskins gave an overview of the various dose–fractionation schedules for HDR brachytherapy that are in use. Typically, UK centres used 2 fractions of 7 Gy each to point "A", whereas in the USA higher doses are often used delivering 3–5 fractions of 6–6.5 Gy each. There was some discussion on the feasibility of using higher doses in the UK, which is the subject of a proposed dose escalation study reported later in this Commentary.
Carcinoma of the uterine corpus
There were two presentations on brachytherapy for the intact uterine corpus. Dr Ian Rothwell (Cookridge Hospital, Leeds) presented the largest UK experience of 74 patients treated radically with a HDR technique and plastic applicators based on traditional Heyman's stainless steel capsules. The evolution of the dosimetric system over a 12-year period to incorporate the dose delivered to the uterine serosa was described. Dr Bleddyn Jones (Imperial College, London) described his experience of 37 patients treated radically with a combination of external beam radiotherapy and a line source HDR brachytherapy technique at the Clatterbridge Centre for Oncology, Merseyside. He also incorporated a prescription point on the serosal surface to ensure adequate dose to the whole of the corpus. Both speakers showed that satisfactory local control rates could be obtained in carcinoma of the intact uterine corpus using radiotherapy alone. In the subsequent discussion, it was suggested that perhaps more patients should be offered radiotherapy alone as a treatment option for cancer of the intact uterus.
Carcinoma of the vulva
Miss Margaret Bidmead (Royal Marsden Hospital, London) presented examples of a variety of brachytherapy techniques that can be used in the management of vulval cancer. These included LDR iridium wire interstitial implants, either as a single plane using a ring template or as a volume implant using a "hedgehog" template. She also described surface moulds implanted with afterloading catheters, for use with HDR brachytherapy. Small vaginal applicators inserted in parallel in the vagina and rectum can be used to treat disease in the rectovaginal septum with fractionated HDR brachytherapy. While brachytherapy is not commonly used for the treatment of vulval cancer in the UK, the presentation provided some options for the management of the rare patients with small vulval or vaginal recurrences not suitable for surgery.
Royal College of Radiologists' Brachytherapy Report
Dr Peter Blake (Royal Marsden Hospital, London) presented the findings of the Royal College of Radiologists' (RCR) report on "The Role and Development of Brachytherapy Services in the UK" [2] published in August 2001. The report recommended that brachytherapy services should be Cancer Network-based. Each Network should identify its most viable core activity, i.e. the malignancy for which the numbers of patients treated by brachytherapy is the greatest (currently gynaecological cancer in most Networks). For this core activity, a minimum workload of 60 patients a year is recommended for optimal resource use and to maintain staff expertise. Based on this recommendation, the report suggested that caseload and case-mix review is needed in at least 20 of the 48 Cancer Centres surveyed. For non-core activity, a minimum of 10 patients a year was suggested to maintain clinical expertise. The report recommended that those services that did not fulfil the recommended minimum workload should be linked into a larger service in another Network for the purposes of training, quality assurance and audit.
Dr Blake's presentation was followed by an open discussion on the implications of the RCR report. In general, the delegates were in agreement with the recommendations of the report. However, there were some reservations on whether the recommendations, particularly those on minimum workload figures and cross-Network links, could be enforced.
National study of radiotherapy for cervical cancer
There remains a considerable heterogeneity of radiotherapy technique and dose schedules used for the treatment of cervical cancer in the UK. Dr Bleddyn Jones, on behalf of the BIR Brachytherapy Working Party, proposed a national trial which either 1) compared a national schedule against each local schedule in a randomized controlled trial or 2) used a single agreed national schedule with detailed prospective study of outcomes and comparative quality control. He presented for discussion a comparison of the biological effective doses (BED) to the tumour and normal tissues for various combinations of external beam fractionation and brachytherapy dose schedules (both LDR and HDR).
There was widespread support for a national trial. In general, delegates seemed more in favour of a Phase 2 trial using an agreed national schedule. A questionnaire was used at the meeting to gather information on preferred dose schedules and dose limits to be used in the design of the trial. Additional questionnaires will be circulated to other oncologists involved in the treatment of cervical cancer who were not present at the meeting. Additional information about the trial can be obtained from Dr Peter Blake (Peter.Blake@rmh.nthames.nhs.uk).
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Conclusions
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The RCR Brachytherapy Report found that the use of brachytherapy in the UK is low compared with other European countries. This meeting has shown that there is still considerable interest in the use of brachytherapy in the UK, at least for the treatment of gynaecological cancers. It is hoped that the ideas presented at the meeting will help promote further developments in gynaecological brachytherapy in the UK.
Received for publication May 18, 2003.
Accepted for publication October 6, 2003.
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References
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- Pötter R, Knocke TH, Fellner C, et al. Definitive radiotherapy based on HDR brachytherapy with iridium 192 in uterine cervix carcinoma: report on the Vienna University Hospital findings (1993–1997) compared to the preceding period in the context of ICRU 38 recommendations. Cancer Radiotherapie 2000;4:159–72.
- The Role and Development of Brachytherapy Services in the United Kingdom. London: Royal College of Radiologists, 2001.
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Introduction
Conclusions
