Affiliations of authors: K. Pacak (Pediatric and Reproductive Endocrinology Branch, National Institute of Child Health and Human Development), T. Fojo, J. Abraham (Medicine Branch, National Cancer Institute), D. S. Goldstein, G. Eisenhofer (Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke), M. M. Walther, W. M. Linehan (Urologic Oncology Branch, National Cancer Institute), L. Bachenheimer (Department of Anesthesiology, Clinical Center), B. J. Wood (Department of Radiology, Clinical Center), National Institutes of Health, Bethesda, MD.
Correspondence to: Karel Pacak, M.D., Ph.D., D.Sc., National Institutes of Health, Bldg. 10, Rm. 10N236, 10 Center Dr. MSC-1583, Bethesda, MD 208921583 (e-mail: karel{at}mail.nih.gov).
About 10%15% of pheochromocytomas eventually develop metastases (1). Few patients with metastatic pheochromocytoma are suitable candidates for surgical resection of the tumor.
This correspondence introduces radiofrequency ablation (RFA) as an alternate treatment modality in pheochromocytoma. RFA is a safe, predictable, and effective method for local tumor destruction in primary and metastatic carcinomas (27). We report on a patient with metastatic pheochromocytoma with a rapidly growing bone metastasis who was treated with RFA.
The patient, a 42-year-old man, first presented with episodes of hematuria, hypertension, and palpitations. A 24-hour urine collection demonstrated elevated levels of catecholamines and metanephrines. Computed tomography (CT) scan revealed a 5.5 x 7.5 x 8.0-cm pheochromocytoma invading the posterior urinary bladder wall. His tumor was considered unresectable. The patient was treated with radiotherapy and six cycles of chemotherapy, with 80% tumor shrinkage followed by cystectomy. CT scans 5 years later showed lung metastases and a 0.5-cm third lesion on the right rib. The lesion grew gradually, then rapidly to 3 cm in diameter, with marked elevations in the levels of plasma norepinephrine (6974 pg/mL), free normetanephrine (3516 pg/mL), urinary norepinephrine (707 µg/24 hours), total metanephrines (6090 µg/24 hours), and vanillylmandelic acid (18.2 µg/24 hours). 6-[18F]Fluorodopamine positron emission tomography (Fig. 1) and [131I]metaiodobenzylguanidine scintigraphy confirmed that the rib lesion was metastatic pheochromocytoma. To treat the rib lesion, we chose RFA after we considered the limitations, side effects, and time commitments of radiotherapy, chemotherapy, and surgical resection. Because RFA disrupts cells by heat, marked catecholamine release was anticipated. Therefore, beginning 2 weeks before the procedure, the patient received phenoxybenzamine, atenolol, and
-methyl-para-tyrosine (DemserTM; Merck Sharp & Dohme, West Point, PA). The adequacy of the adrenergic blockade was assessed by a provocative glucagon test 2 days before the RFA. Glucagon increased the patient's blood pressure, and phenoxybenzamine was increased to 80 mg and DemserTM to 1.5 g once a day.
|
This case illustrates that RFA can be used safely to ablate rapidly growing pheochromocytoma. In pheochromocytoma, where cells release contents in response to stimuli, it was unclear whether RFA would be safe. However, oral phenoxybenzamine, atenolol, and DemserTM with intravenous labetelol and nitroprusside provided adequate control of acute hypertension. On the basis of this experience, we propose that RFA be evaluated further in patients with primary or metastatic pheochromocytoma as an alternative to surgery, chemotherapy, or radiotherapy. 6-[18F]Fluorodopamine positron emission tomography scan provides a valuable tool to evaluate the effects of the ablation; it can be used as an alternative to CT and magnetic resonance imaging, in conjunction with measurements of levels of plasma catecholamines and metanephrines.
REFERENCES
1 Manger W, Gifford R. Clinical and experimental pheochromocytoma. Cambridge (MA): Blackwell Science; 1996.
2
Seki T, Tamai T, Nakagawa T, Inoue K. Percutaneous radiofrequency (RF) ablation therapy for hepatocellular carcinoma: difficulty in removing the expandable RF needle electrode. AJR Am J Roentgenol 2000;174:2645.
3
Dupuy DE, Zagoria RJ, Akerley W, Mayo-Smith WW, Kavanagh PV, Safran H. Percutaneous radiofrequency ablation of malignancies in the lung. AJR Am J Roentgenol 2000;174:579.
4 Zlotta AR, Djavan B, Matos C, Noel JC, Peny MO, Silverman DE, et al. Percutaneous transperineal radiofrequency ablation of prostate tumour: safety, feasibility and pathological effects on human prostate cancer. Br J Urol 1998;81:26575.[Medline]
5
Jeffrey SS, Birdwell RL, Ikeda DM, Daniel BL, Nowels KW, Dirbas FM, et al. Radiofrequency ablation of breast cancer: first report of an emerging technology. Arch Surg 1999;134:10648.
6 Wood BJ, Fojo A, Gomez-Jorge J, Chang R, Spies J. Radiofrequency ablation of adrenocortical carcinoma: early experience. Scientific paper at Society for Cardiovascular and Interventional Radiology 25th Annual Scientific Meeting. J Vasc Interv Radiol 2000;11S:2245.
7
Wood BJ, Levy EB, Gomez-Jorge J, Chang R, Spies J. Radiofrequency ablation of renal tumors. Scientific paper at Society for Cardiovascular and Interventional Radiology 25th Annual Scientific Meeting. J Vasc Interv Radiol 2000;11S:225.
This article has been cited by other articles in HighWire Press-hosted journals:
![]() |
||||
|
Oxford University Press Privacy Policy and Legal Statement |