NICE guideline NG14 recommendation 1.5.2 says ‘Consider sentinel lymph node biopsy as a staging rather than a therapeutic procedure for people with stage IB–IIC melanoma with a Breslow thickness of more than 1 mm…’ This example describes the establishment of a sentinel node biopsy practice for malignant melanoma by Mr Marc Moncrieff and Dr Jennifer Garioch, our early experience, and the implications for other units considering setting up the service within the NHS.
Aims and objectives
Our aim was to set up a melanoma sentinel node biopsy service, and to audit our early experience (operative time, and impact on departmental caseload), in order to provide guidance for other units considering setting up the service within the NHS.
The American Joint Committee on Cancer (AJCC) database comprising over 60,000 patients has shown that sentinel node status is the key prognostic indicator in melanoma patients. In addition, the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1)1 demonstrated a reduction in recurrence, with a significantly improved 10-year disease-specific survival in patients with intermediate thickness primary melanomas who underwent SLNB followed by immediate completion lymphadenectomy (for those with positive nodes), compared to those who were observed with delayed lymphadenectomy if clinical disease occurred. (62.1% versus 41.5%; hazard ratio for death from melanoma=0.56 (0.37-0.84), p=0.006). This was the first randomized controlled trial to specifically study sentinel node biopsy in the context of melanoma.
Patients were randomized to undergo either a wide local excision (WLE) alone (followed by observation, and a lymphadenectomy for those with clinically apparent disease) or a WLE and SLNB. Those with a positive sentinel node underwent a completion lymph node dissection. Those with a negative sentinel node were observed for the development of clinically apparent disease.
Reasons for implementing your project
Prior to 2008, a sentinel node biopsy service existed for breast cancer patients but this did not extend to our melanoma patients. At the time that the senior author decided to set up the service, the Sentinel Lymph Node Biopsy (SLNB) technique had become accepted by many, as the gold standard in the management of patients with intermediate prognosis cutaneous melanoma in the USA, Australia, New Zealand and Europe. The Department of Health’s UK cancer reform strategy set an objective that by 2012 there should be a sentinel node biopsy service for malignant melanoma across the country.
The chain of events leading to the setting up of the service commenced when the benefits and implications of the service were discussed at the Skin Network Site Specific Group (Anglia) meetings, in order to get approval of the committee.
How did you implement the project
Setting up the service involved:
• Following consultation, consent was obtained from the departments of nuclear medicine, plastic surgery, dermatology, radiology and histopathology;
• Following this, the business case was presented to the hospital executive board and approved.
• It was then presented to the regional cancer network (Anglia Cancer Network) for consideration by its Commissioners.
• Agreement reached on regionally based criteria for consideration of SLNB;
• A pilot feasibility study was carried out for four months to test the ability of the departments of nuclear medicine, histopathology and plastic surgery to absorb the required workload.
• Finally, we negotiated with the PCTs regarding an appropriate tariff for procedure.
The advantage of setting up the SLNB within the department of nuclear medicine allowed for a seamless introduction of the new services, as SLNB for breast cancer had been performed there for a number of years. However, setting up the service within a sentinel node naïve trust would require early consultation with nuclear medicine team as the use of radioactive substances and associated equipment is highly regulated. Also there is a need to address legislative requirements relating to radioactive substance management and radiation safety requirements for both staff and patients.
Early discussion with the department of pathology is also recommended. The sentinel node service will require additional time and training for both the technicians as well as the reporting pathologists. The department will need to adopt a recognised, standardised protocol to ensure comparative data collection nationally and internationally. Surgeons & relevant staff will have to demonstrate adequate training in both imaging and resection techniques and Administration of Radioactive Substances Advisory Protection Agency (ARSAC) applicant must be supported by other health care professionals, e.g. an experienced medical physicist on nuclear medicine and pharmacist responsible for radioactive materials. ARSAC issue certificates on behalf of the Health Minister, which are site specific and procedure specific.
Equipment used including sentinel node localisation probes need to be calibrated and assessed within a formal quality assessment program. Following the setting up of the service, we reviewed all consecutive sentinel node biopsies performed in the first 19 months (this came to a total of 164 patients).
We found that the setting up of this service has had an impact on our operative time, our anaesthetic resources, the number of lymph node dissections, as well as the overall plastic surgery service demand.
It takes a median time of 5 min to find the sentinel node in each location (range 1-37 min), and 26 min for sentinel node excision (range 5-113 min). This did not alter with increased experience. On examination of our total operative time for the procedure, we found that this had almost trebled from 22 min for a simple wide local excision of the melanoma (range 8-134 min) to 65 min for the SLNB and excision of the melanoma (range 39-144 min).
Furthermore, the anaesthetic resource implications have greatly increased: all patients eligible for SLNB require a general anaesthetic (GA) according to our protocol, whereas more than half (87/150) of WLE cases were performed under local anaesthetic in the previous 19 months.
On histological assessment of the sentinel nodes, 16.4% (27/164) were found to be positive. This led to a 106% increase in the number of regional lymph node dissections (from 18 to 37), which also had a significant impact on our workload.
The service is cost neutral within the National tariff that has been set up. There is the initial cost of two gamma probes was approximately £18K in 2008; the increase in anaesthetic time (due to the GA required); the increase in histology time & consumables (to examine the additional sentinel node and completion lymphadenectomy specimens); and the increase in clinic time of 20 min per patient (this has decreased with introduction of information sheets and appointment of a clinical nurse specialist).
This was balanced by the medium and long term benefits such as reduction in complications for sentinel nodes patients with and without early completion lymph node dissection compared to those requiring delayed lymph node dissections for clinical disease, especially lymphedema.
Patients who have undergone sentinel lymph node biopsies have been shown to have a decreased rate of recurrence in regional basin, a reduced tumour burden if and when they do undergo completion lymphadenectomies (versus standard lymphadenectomies for clinically apparent disease), less extensive surgery in the inguinal region (inguinal versus ilioinguinal surgery), as well as a reduced need for adjuvant radiotherapy, and its morbidity.
Another advantage of the service is that patients get an accurate prognosis and the potential for enrolment into multi-centre and adjuvant therapy trials.
Key learning points
When considering setting up this service, we would recommend from our experience in Norwich, that one should pay particular attention to providing the following:
- Additional theatre time due to an increased number of patients requiring general anaesthetic procedures.
- Supplementary nuclear medicine space and gamma camera time, with up to 5 additional scans per fortnight for a group of 150 patients per annum. Each scanning procedure may be lengthy (up to 2 hrs), particularly if lymphatic drainage occurs to more than one region and where multiple sentinel nodes are identified.
- Additional time for the histological processing and assessment.
- Longer outpatient clinic time: approximately 20 min per patient to discuss the additional procedure and consequences of the results. This has decreased more recently with the introduction of information sheets and the appointment of clinical nurse specialists.
References: 1) Morton DL et al. Final Trial Report of Sentinel-Node Biopsy versus Nodal Observation in Melanoma NEJM 2014; 30(7): 600-9