RG f Volume 21 ● Number 2 March-April 2001 f 519
Letter to the Editor
Recent eLetters to the Editor are available at http://radio- corresponds to the fatty changes in the marrow (7). In-
graphics.rsnajnls.org. eLetters that are no longer posted un- versely, fatty changes seen in FDG PET images, such as
der “Recent Letters” can be found as a link in the related those shown in Figure 9a, may also predict the photope-
article or by browsing through past Tables of Contents. nic appearance of corresponding vertebrae on bone scans.
It might be worthwhile for Skehan and colleagues to re-
Incidental Detection of Diminished view the bone scans of the patient in Figure 9a to examine
Bone Marrow Metabolic Activity the presence of photopenia in the thoracic spine.
with FDG PET
From: References
Wei-Jen Shih, MD 1. Skehan SF, Brown AL, Thompson M, Young EM,
Department of Diagnostic Radiology Coates G, Nahmias C. Imaging features of primary
University of Kentucky Medical Center and recurrent esophageal cancer at FDG PET. Ra-
800 Rose St dioGraphics 2000; 20:713–723.
Lexington, KY 40536 2. Meyer MA, Nathan CAO. Reduced F-18 fluorode-
e-mail: wshih0@pop.uky.edu oxyglucose uptake within marrow after external
beam radiation. Clin Nucl Med 2000; 25:279 –280.
Editor: 3. King MA, Casarett GW, Weber DA. A study of
I read with great interest the article by Skehan and col- irradiated bone: I. Histologic and physiologic
leagues in the May-June 2000 issue of RadioGraphics changes. J Nucl Med 1979; 20:1142–1149.
(1). Positron emission tomography (PET) with 2[fluo- 4. Knope WH, Blom J, Grosby WH. Regeneration of
locally irradiated bone marrow. I. Dose dependent,
rine-18]fluoro-2-deoxy-d-glucose (FDG) certainly has
long-term changes in the rat with particular empha-
a valuable role in the detection of local invasion by pri- sis upon vascular and stoma reaction. Blood 1966;
mary tumor and in the follow-up of patients who un- 28:398 – 415.
dergo radiation therapy and chemotherapy. 5. Blau M, Gonatra R, Bender MA. F-18 FDG for
The 13 figures presented by Skehan et al in their ar- bone imaging. Semin Nucl Med 1972; 2:31–37.
ticle are commendable. I had a couple of questions, how- 6. Bell EG, McAffee JG, Constable WC. Local radiation
ever, about an incidental finding that appears in Figure 9a damage to bone and marrow demonstrated by radio-
(p 720). Figure 9a, in addition to clearly demonstrating a isotopic imaging. Radiology 1969; 92:1083–1088.
tumor with increased FDG uptake in the lower esopha- 7. Shih WJ, Li CY, Coffey CW, Maruyama Y. Tho-
gus, shows photon deficiency in the vertebral bodies of racic vertebral photopenia may predict fatty
changes of the corresponding bone marrow follow-
the thoracic spine. Normally, bone marrow takes up FDG
ing irradiation. Radiation 1989; 7:32–35.
as shown in Figure 1 (p 715). The legend mentions that
the patient underwent palliative surgery; however, did the Dr Nahmias responds:
patient also undergo radiation therapy? If so, what was the My colleagues and I thank Dr Shih for his interest in our
time interval between irradiation and the PET study? article. Dr Shih correctly discusses an incidental finding in
To examine the effects of external beam radiation one of our figures. The patient in Figure 9 did undergo
therapy on the metabolism of the intravertebral marrow radiation therapy in addition to palliative surgery: 9 days
cavity, Meyer and Nathan (2) reviewed the cases of two before the PET study we showed in our article, the pa-
neurologically normal patients who had an abnormally tient began the first of four courses of 1,200 Gy delivered
low uptake of F-18 FDG in the marrow cavity and who to the esophageal area. As Dr Shih discusses, Figure 9a is
had completed a full course of radiation treatment for an example of diminished metabolic activity within irradi-
squamous cell carcinoma of the head and neck. Meyer ated marrow. We have observed this pattern in several
and Nathan concluded that diminished metabolic activity patients who underwent a course of radiation treatment,
within irradiated marrow can be detected with FDG PET and we are currently documenting the timing between
imaging (2). treatment and imaging. Unfortunately, the patient in Fig-
After 2– 6 months irradiation to vertebrae, vertebral ure 9 did not undergo bone scintigraphy, so we are unable
marrow is eventually replaced by fatty tissue and has to comment further.
fewer residual capillaries (3,4). Concomitantly, irradia-
tion-induced vasculitis and hyalinization of small vessels
Claude Nahmias, PhD
in the vertebrae result in interruption of blood supply,
Department of Nuclear Medicine and Radiology
which leads to photopenia at bone scintigraphy (5). De-
McMaster University Medical Centre
pression of metabolic activity in the bone marrow corre-
1200 Main St W
sponding to a photopenic area on a bone scan has been
Hamilton, Ontario, Canada L8N 3Z5
documented (6). Fatty changes of the bone marrow and
e-mail: nahmias@ fhs.csu.mcmaster.ca
vertebral bone injury may coexist after irradiation. Pho-
topenia of vertebrae after irradiation seen on bone scans
520 March-April 2001 RG f Volume 21 ● Number 2
Online:
Abstracted Contents of March-April
2001
Interventional Musculoskeletal Procedures
Afshin Gangi, Stephane Guth, Jean-Louis Dietemann,
Catherine Roy
Percutaneous interventional procedures for the muscu-
loskeletal system are demonstrated and explained by
means of a hypertext-based teaching file. The authors
provide an overview of different procedures, including
musculoskeletal biopsy, percutaneous periradicular in-
filtration, diskography, percutaneous cementoplasty,
percutaneous treatment of disk herniation, and percuta-
neous treatment of osteoid osteoma. The procedures are
demonstrated with detailed illustration of materials used
and computed tomographic and fluoroscopic images.
The authors guide the user through each step of the pro-
cedures, with case studies that include indications, tech-
niques, complications, and results.—Received September
10, 2000; accepted November 9. Available at http://ra-
diographics.rsnajnls.org/cgi/content/full/21/2/e1.