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Transrectal high-intensity focused ultrasound ablation of prostate cancer: effective treatment requiring accurate imaging
Abstracts / Clinical Imaging 32 (2008) 160–163 sensitivity and specificity. Combined MR imaging and 3D-MRSI exceed the sensitivity and specificity of sextant biopsy of the prostate. When MRS and MR imaging agree on prostate cancer presence, the positive predictive value is about 80% to 90%. Distinction between healthy tissue and prostate cancer principally is maintained after various therapeutic treatments, including hormone ablation therapy, radiation therapy, and cryotherapy of the prostate. Conclusions: Since it is noninvasive, reliable, radiation free, and essentially repeatable, combined MR imaging and 3D-MRSI of the prostate lends itself to the planning of biopsy and therapy, and to posttherapeutic follow-up. For broad clinical acceptance, it will be necessary to facilitate MRS examinations and their evaluation, and make MRS available to a wider range of institutions. Transrectal high-intensity focused ultrasound ablation of prostate cancer: effective treatment requiring accurate imaging Rouvière O, Souchon R, Salomir R, Gelet A, Chapelon J.-Y, Lyonnet D (Department of Urinary and Vascular Radiology, Pavillon P Radio, Hôpital Edouard Harriot, F-69437 Lyon Cedex 03, France). Eur J Radiol 2007;63:317–327. Transrectal HIFU ablation has become a reasonable option for the treatment of localized prostate cancer in nonsurgical patients, with 5-year disease-free survival similar to that of radiation therapy. It is also a promising salvage therapy of local recurrence after radiation therapy. These favorable results are partly due to recent improvements in prostate cancer imaging. However, further improvements are needed in patient selection, preoperative localization of the tumor foci, assessment of the volume treated, and early detection of recurrence. A better knowledge of the factors influencing the HIFU-induced tissue destruction and a better preoperative assessment of them by imaging techniques should improve treatment outcome. Whereas prostate HIFU ablation is currently performed under transrectal ultrasound guidance, magnetic resonance guidance with real-time operative monitoring
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of temperature will be available in the near future. If this technique will give better targeting and more uniform tissue destruction, its cost-effectiveness will have to be carefully evaluated. Finally, a recently reported synergistic effect between HIFU ablation and chemotherapy opens possibilities for treatment in high-risk or clinically advanced tumors. Managing the risk associated with use of contrast media for computed tomography Stacul F (Department of Radiology, Cattinara Hospital, University of Trieste, Strada di Fiume 447, I-34149, Trieste, Italy). Eur J Radiol 2007,63:533–537. Contrast agents are widely used in patients undergoing diagnostic and therapeutic imaging procedures. In recent years, there has been a significant increase in the use of iodinated contrast media (CM) due to the growing number of computed tomography procedures. Although contrast agents are generally well tolerated, some patient subsets are at an increased risk of complications from CM. Patients at risk include those with a history of adverse reactions to CM, asthma or severe allergies, impaired renal function, older age, dehydration, congestive heart failure, or concurrent use of some drugs. Although the incidence of CM-associated complications cannot be eliminated, the chances of developing severe adverse reactions can be reduced by incorporating a number of management strategies into clinical practice. Patients at risk for acute adverse reactions can undergo premedication with corticosteroids, eventually associated with antihistamines, although opinion is divided whether this prophylaxis should be used with nonionic CM. Patients who have been identified as at risk for contrastinduced nephropathy (CIN) should be well hydrated and have nephrotoxic medications withdrawn prior to CM exposure. Contrast dose should be decreased, as the risk of developing CIN is dose dependent. For patients with preexisting renal insufficiency, use of low-osmolar or iso-osmolar CM is preferable to use of high-osmolar CM. Simple strategies for preventing the risk of adverse reactions are reviewed.
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of temperature will be available in the near future. If this technique will give better targeting and more uniform tissue destruction, its cost-effectiveness will have to be carefully evaluated. Finally, a recently reported synergistic effect between HIFU ablation and chemotherapy opens possibilities for treatment in high-risk or clinically advanced tumors. Managing the risk associated with use of contrast media for computed tomography Stacul F (Department of Radiology, Cattinara Hospital, University of Trieste, Strada di Fiume 447, I-34149, Trieste, Italy). Eur J Radiol 2007,63:533–537. Contrast agents are widely used in patients undergoing diagnostic and therapeutic imaging procedures. In recent years, there has been a significant increase in the use of iodinated contrast media (CM) due to the growing number of computed tomography procedures. Although contrast agents are generally well tolerated, some patient subsets are at an increased risk of complications from CM. Patients at risk include those with a history of adverse reactions to CM, asthma or severe allergies, impaired renal function, older age, dehydration, congestive heart failure, or concurrent use of some drugs. Although the incidence of CM-associated complications cannot be eliminated, the chances of developing severe adverse reactions can be reduced by incorporating a number of management strategies into clinical practice. Patients at risk for acute adverse reactions can undergo premedication with corticosteroids, eventually associated with antihistamines, although opinion is divided whether this prophylaxis should be used with nonionic CM. Patients who have been identified as at risk for contrastinduced nephropathy (CIN) should be well hydrated and have nephrotoxic medications withdrawn prior to CM exposure. Contrast dose should be decreased, as the risk of developing CIN is dose dependent. For patients with preexisting renal insufficiency, use of low-osmolar or iso-osmolar CM is preferable to use of high-osmolar CM. Simple strategies for preventing the risk of adverse reactions are reviewed.