The role of thallium-201 and pentavalent dimercaptosuccinic acid for staging cartilaginous tumours

Choong, Kunisada Toshiyuki, Slavin John, Schlicht Stephen, Hicks, Hicks Rodney

Description

Heterogeneity of cartilage tumours may confound accurate diagnosis and grading resulting in under and over treatment. Improved preoperative assessment of malignancy and grade would be invaluable for developing a rational plan for treatment. We examined correlations between nuclear tracer avidity and malignancy grade in cartilage tumours. Methods Between 1996 and 2000, 92 consecutive patients with cartilaginous tumours (50 benign, 42 non-metastatic malignant) underwent nuclear scanning. Thallium-201 (TL-201) and pentavalent dimercaptosuccinic acid (DMSAV) were used as nuclear isotopes. Scanning with these agents was performed on separate days 48 hours apart. Static and SPECT images were obtained at 30 m and 4 h after injection of nuclear tracer. Pathology review was undertaken blinded to the results of the nuclear scans and correlations between histologic results and trace uptake at 4 hours examined. Results 25 patients with negative DMSAV had benign tumours. 15/17 tumours with positive TL-201 had malignant tumours. 11/13 patients with both positive DMSAV and TL-201 scans had intermediate or high grade tumours and 4 of these developed metastases. We have developed an algorithm for the management of patients with tumours that aims to avoid over treatment of low grade tumours and under treatment of high grade tumours. Conclusion Functional nuclear scanning with TL-201 and DMSAV complements other imaging modalities in the management of cartilaginous tumours.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2004
• Nombre de lectures: 84
• Langue: English

Extrait

International Seminars in Surgical
BioMed CentralOncology
Open AccessResearch
The role of thallium-201 and pentavalent dimercaptosuccinic acid
for staging cartilaginous tumours
1,5 1 3 2Peter FM Choong* , Toshiyuki Kunisada , John Slavin , Stephen Schlicht
4and Rodney Hicks
1 2Address: Department of Orthopaedics, University of Melbourne, St. Vincent's Hospital, Melbourne, Australia, Department of Medical Imaging,
3 4St. Vincent's Hospital, Melbourne, Australia, Department of Pathology, St. Vincent's Hospital, Melbourne, Australia, Department of Medical
5Imaging, Peter MacCallum Cancer Institute, Melbourne, Australia and Division of Surgical Oncology, Peter MacCallum Cancer Institute,
Melbourne, Australia
Email: Peter FM Choong* - [e-mail]; Toshiyuki Kunisada - [e-mail];
John Slavin - [e-mail]; Stephen Schlicht - [e-mail]; Rodney Hicks - [e-mail]
* Corresponding author
Published: 08 November 2004 Received: 18 August 2004
Accepted: 08 November 2004
International Seminars in Surgical Oncology 2004, 1:10 doi:10.1186/1477-7800-1-10
This article is available from: http://www.issoonline.com/content/1/1/10
© 2004 Choong et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Introduction: Heterogeneity of cartilage tumours may confound accurate diagnosis and grading
resulting in under and over treatment. Improved preoperative assessment of malignancy and grade
would be invaluable for developing a rational plan for treatment. We examined correlations
between nuclear tracer avidity and malignancy grade in cartilage tumours.
Methods: Between 1996 and 2000, 92 consecutive patients with cartilaginous tumours (50 benign,
42 non-metastatic malignant) underwent nuclear scanning. Thallium-201 (TL-201) and pentavalent
dimercaptosuccinic acid (DMSAV) were used as nuclear isotopes. Scanning with these agents was
performed on separate days 48 hours apart. Static and SPECT images were obtained at 30 m and
4 h after injection of nuclear tracer. Pathology review was undertaken blinded to the results of the
nuclear scans and correlations between histologic results and trace uptake at 4 hours examined.
Results: 25 patients with negative DMSAV had benign tumours. 15/17 tumours with positive TL-
201 had malignant tumours. 11/13 patients with both positive DMSAV and TL-201 scans had
intermediate or high grade tumours and 4 of these developed metastases. We have developed an
algorithm for the management of patients with tumours that aims to avoid over treatment of low
grade tumours and under treatment of high grade tumours.
Conclusion: Functional nuclear scanning with TL-201 and DMSAV complements other imaging
modalities in the management of cartilaginous tumours.
More recently, magnetic resonance imaging has also beenBackground
Traditionally, the determination of malignancy and its employed [4-6]. However, cartilage tumours are recog-
grade in cartilage tumours has been from the combination nized for their histologic heterogeneity [7-9] and bizarre
of history, radiographic features with or without com- physical features, such that reliance on anatomic imaging
puted tomography and histologic examination [1-3]. and accuracy of biopsy alone for interpretation of state of
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malignancy or benignity may be misleading. While the area of interest and late phase images consisted of whole
recognition of high grade malignancy is not difficult, the body imaging and SPECT over the area under investiga-
differentiation between benign and low grade (grade I) tion. A low energy high resolution, parallel-hole collima-
tumours can present a diagnostic dilemma [10,11]. Such tor was used and image acquired in a 128 × 128 matrix for
a dilemma may lead inadvertently to under-or over-treat- 5 minutes. A simple grading system was devised for late
ment of cartilage tumours. phase isotope uptake with NO UPTAKE indicating no
tumour uptake greater than background activity and
Functional nuclear scans employ isotopes that become INCREASED UPTAKE indicating definite activity greater
substrates for various cellular metabolic cycles and there- than the background level. The background level referred
fore, are useful for determining the metabolic activity in to is that of the tissue within which the tumour arose, that
these tissues [12]. Given that malignant tumours are more is, bone. We selected the late phase results for correlation
metabolically active than benign tumours, and that there with the results of histological examination of the surgical
is a relationship between grade of malignancy and meta- specimens because early uptake at 30 minutes may also
bolic activity, functional nuclear scans may help to differ- represent peritumoural inflammation or vascularity,
entiate between cartilage tumours of varying metabolic which may confound the interpretation of results. In con-
activity, which in turn, may shed some light on their state trast, late phase uptake represented true tumour uptake of
of malignancy. isotope.
TumoursWe now report our experiences with 2 radio-siotopes,
Thallium-201 (Tl-201) and pentavalent dimercaptosuc- The pathologist (JS) is the designated lead pathologist on
cinic acid (DMSAV) for determining the metabolic activity the Victorian Bone Tumour Registry. For the purpose of
of cartilage tumours, and their value in differentiating this study, assessments of surgical tissue and histologic re-
between malignant and benign cartilage tumours in 92 evaluation were conducted without prior knowledge of
consecutive cartilage tumours. We describe their role in the results of the functional nuclear scans. There were 50
the development of our current regimen for treating carti- benign tumours and these consisted of enchondromata
lage tumours. (29), osteochondromata (17), chondroblastoma (3), and
chondromyxoid fibroma (1). There were 42 malignant
tumours and these consisted of 38 central chondrosar-Methods
Patients coma and 4 dedifferentiated chondrosarcoma. Of these
Between January 1997 and December 2000, 92 consecu- malignant tumours, 22 were graded as grade I, 12 as grade
tive patients were referred to our institution for investiga- II and 8 as grade III according to.
tion and management of suspected chondral tumours.
There were 50 females and 42 males with a median age of Treatment
45 years (range 16–87 years). All tumours in this study were treated with excision. In
those tumours that were considered to be benign or grade
Tumours were located in the humerus (17), chest wall (3), 1 malignancy as based on history, examination, plain
femur (27), hand (3), knee (3), vertebra (1), scapula (7), radiography, magnetic resonance imaging and functional
tibia (16), pelvis (9), foot (4), radius (2). All patients had scanning, were treated by careful intralesional curettage,
previously unoperated tumours and no patient presented burring with a high speed dental burr, pulsatile lavage,
with metastases. chemical cautery with phenol and then the defect filled
with polymethylmethacrylate cement. In those tumours
Investigations that were considered to be clearly malignant and inter-
All patients were examined with plain radiographs, com- preted as grade 2 and higher or if the functional nuclear
puted tomography and magnetic resonance imaging. scans showed significant uptake, wide resection was
From 1997 onward, TL-201 and/or DMSAV scans were employed.
also performed on patients with suspected chondral
tumours. Because of the histologic heterogeneity of cartilage
tumours, the majority of tumours were not biopsied prior
Tl-201 and DMSAV scintiigraphy were conducted at two to definitive surgery. Biopsy was considered if there was
centers (SVH, PMCI) with similar imaging protocols. All doubt about the diagnosis, or if the anticipated treatment
studies were conducted using a gamma camera. A pre- was potentially far greater than may have been required. If
determined dose of radioisotope was administered intra- biopsy was preferred but could not be safely performed
venously and scintigraphic images obtained at 30 minutes preoperatively, for example, a periacetabular tumour, fro-
(early phase) and 3–4 hours (late phase) after injection in zen section drill biopsy would be conducted as part of the
all cases. Early phase static images were acquired over the initial surgical approach to the tumour.
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Follow-up DMSA(V). Of the 42 benign tumours, 2 had positivity for-
No patients were lost to follow-up. Patients with malig- both thallium and DMSA(V), 20 had positivity only for
nant tumours were reviewed every 3 months for the first 2 DMSA(V) and 20 had no uptake on either scan.
years and 6 monthly after that for a further 2 years with a
plan for yearly review for the following 4 years. Computed Of the 36 malignant tumours that were scanned with both
tomography of the chest was performed every