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No longer recruiting
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Plain English Summary

Background and study aims
Atypical cartilaginous tumours (ACT) are cartilage-producing tumours that arise from the bone. They have an intermediate malignant potential, which means that the tumours do not spread (metastasise) and patients do not usually die. However, they are treated often since they have a unknown potential to transform to more malignant tumours and spread, or they have local negative effects such as weakening of the bone. Treatment is still a topic of debate, since up to two decades ago whole segments of bone were removed (en bloc resection) and nowadays some physicians suggest to only monitor these tumours. Nevertheless, research in the last decade has shown that only removal of the tumour itself and not the surrounding bone (intralesional surgery) is successful in terms of tumour eradication and patient survival. However, this treatment can still lead to burdens such as hospital admission, long rehabilitation and complications. Therefore, the aim of this study is to investigate the effect of minimal invasive treatment of these tumours by radiofrequency ablation (RFA). In RFA, a needle is used that heats the tumour leading to cell death of the tumour (ablation).

Who can participate?
Patients aged 18 and over with an ACT in the long bones that needs surgery

What does the study involve?
Participants first undergo a biopsy (to take a sample of the tumour) and RFA in the same procedure under local or general anaesthetic. Three months later, a MRI scan is taken of the bone to assess the effect of the tumour ablation. Shortly after the MRI scan, patients receive the standard care of intralesional surgery. The material retrieved during surgery is sent to the pathologist to see if the tumour has been killed sufficiently by the previous RFA procedure.

What are the possible benefits and risks of participating?
The potential benefits of RFA are that it can be done through a small incision (cut) in the skin, and after the procedure full weight-bearing on the affected leg is often possible. The number of complications is lower compared to more invasive surgery, although burning wounds and fractures have been reported occasionally.

Where is the study run from?
The Departments of Orthopaedic Surgery, Radiology and Pathology of the University Medical Center Groningen, University of Groningen (Netherlands)

When is the study starting and how long is it expected to run for?
January 2009 to December 2013

Who is funding the study?
University Medical Center Groningen (Netherlands)

Who is the main contact?
Edwin F. Dierselhuis

Trial website

Contact information



Primary contact

Mr Edwin Dierselhuis


Contact details

University Medical Center Groningen
Hanzeplein 1
9700 RB
+31 (0)503 612 802

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Radiofrequency ablation: an alternative to curettage in the treatment of atypical cartilaginous tumours in the long bones


Study hypothesis

The aim of this study is to report on progressing experience with radiofrequency ablation (RFA) as a treatment for atypical cartilaginous tumours (ACT) in the long bones.

Ethics approval

Medical Ethics Committee - University Medical Center Groningen - University of Groningen, 18/09/2009,
ref: M09.077334

Study design

A prospectively kept dataset of patients treated with RFA for ACT in the long bones is analysed. A CT-guided biopsy followed by RFA in the same session is conducted. Three months later, gadolinium-enhanced magnetic resonance imaging (Gd-MRI) will be performed to assess tumour ablation, followed within four weeks by curettage and adjuvant phenolization.

Primary study design


Secondary study design

Non randomised study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Atypical cartilaginous tumors (ACT) in the long bones


Patients are first percutaneously treated by radiofrequency ablation (RFA) (intervention), and subsequently treated by standard care (curettage) (control). As a result, they serve as their own control.

Patients undergo a CT-guided biopsy followed by RFA under locoregional or general anaesthesia in the same session. Three months later, gadolinium-enhanced magnetic resonance imaging (Gd-MRI) is performed to assess tumour ablation, followed within 4 weeks by curettage and adjuvant phenolization. The material retrieved during this procedure is sent to the pathologist to see if the tumour has been killed sufficiently by the previous RFA procedure.

Intervention type



Drug names

Primary outcome measure

1. Percentage of patients who had a complete tumour ablation on a histological level
2. Percentage of tissue necrosis on a histological level
Both measured by analysing removed tissue in the Pathology department at a single timepoint directly after surgery

Secondary outcome measures

1. Signs of residual tumour, measured using Gd-MRI at 3 months after RFA
2. Occurrence of complications, which were not recorded on specific timepoints
3. Disease-free survival after curettage, measured using at Gd-MRI at 6 months, 12 months and 24 months.
4. Functional outcome, assessed by musculoskeletal tumour society (MSTS) scores at 6 and 12 weeks after RFA and 6 and 12 weeks and 1 year after standard care

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Age 18 years and above
2. Clinical suspicion of ACT in the long bones that needs surgical intervention

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Tumour size > 50 mm
2. Tumour localised in the hand, foot, pelvis or axial skeleton
3. Presence of cognitive impairments
4. Previous treatment of the same lesion

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University Medical Center Groningen - University of Groningen
9700 RB

Sponsor information


Universitair Medisch Centrum Groningen

Sponsor details

Hanzeplein 1
9700 RB

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Universitair Medisch Centrum Groningen

Alternative name(s)

University Medical Center Groningen, UMCG

Funding Body Type

government organisation

Funding Body Subtype

Local government



Results and Publications

Publication and dissemination plan

The first results have been published (see Publication Summary field). Future plans are to publish the remaining results and follow-up in high-impact peer-reviewed journals.

IPD sharing plans
The datasets generated during and/or analysed during the current study are/will be available upon request from Mr Edwin Dierselhuis (

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

2014 results in:

Publication citations

Additional files

Editorial Notes

18/07/2017: Internal edit.