BRIEF REPORT 3.0T MR-Guided Laser Ablation of a Prostate Cancer Recurrence in the Postsurgical Prostate Bed David A. Woodrum, MD, PhD, Lance A. Mynderse, MD, Krzysztof R. Gorny, PhD, Kimberly K. Amrami, MD, Roger J. McNichols, PhD, and Matthew R. Callstrom, MD, PhD ABSTRACT Biochemical recurrence of prostate cancer after definitive therapy with radical prostatectomy occurs in 25%-30% of cases. The first known case of magnetic resonance (MR) imaging– guided ablation using laser interstitial thermal therapy (LITT) for locally recurrent prostate cancer after radical prostatectomy is presented. Using 3.0T MR guidance, two laser applicators were placed via a transperineal approach. Laser ablation was performed using MR thermometry to determine the ablation endpoint and lesion coverage. Dynamic contrast-enhanced MR imaging after the procedure showed no definitive abnormal enhancement. The patient had no change in continence or potency after the procedure. ABBREVIATIONS DCE = dynamic contrast enhancement, LITT = laser interstitial thermal therapy (LITT), PRF = proton resonance frequency, PSA = prostate-specific antigen Prostate cancer is the most common malignant tumor in men in the United States and second among tumors leading to death (1). Prostate cancer recurrence after definitive therapy can be 25% after 15 years (2–4). Local recurrences of prostate cancer are associated with a significant risk of disease progression (5). One retrospective analysis found an 18% death rate from prostate cancer over a median fol- low-up of 6 years status after biochemical recurrence (6). In the same study, it was found that salvage radiotherapy administered after 2 years from the point of biochemical recurrence provided no significant increase in prostate can- cer–specific survival, emphasizing the need for early ther- apy (6). The current standard of therapy for biochemical recurrence is radiation therapy. However, the failure rate of radiation therapy for local tumor control of a palpable recurrence is 42% (7). Laser interstitial thermal therapy (LITT) is a minimally invasive ablation technique that uses laser light to deposit high-energy photons locally in tissue causing tissue de- struction through rapid heating. Because the fiberoptic wave guides and laser energy are inherently compatible with magnetic resonance (MR) imaging, LITT is ideally suited for MR-guided ablation therapy. MR-guided LITT has the advantage of superior anatomic tissue visualization provided by MR imaging for better lesion visualization and more precise placements of fiberoptic laser applicators for treatment. Additionally, MR thermometry, based on proton resonance frequency (PRF) shift, offers real-time monitor- ing and visualization of tissue ablation, which is paramount from the perspective of patient safety and treatment effi- cacy. We describe a technique using MR-guided LITT ablation to treat recurrent prostate cancer in the prostate bed. CASE REPORT Institutional review board approval was granted for this retrospective case review. A 59-year-old man presented with a history of radical prostatectomy in 2004 for a Glea- son 4 + 3 adenocarcinoma with a minor component of Gleason 5; pathologic stage was pT2cN0MX with tetrap- From the Departments of Radiology (D.A.W., K.R.G., K.K.A., M.R.C.) and Urology (L.A.M.), Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905; and BioTex, Inc. (R.J.M.), Houston, Texas. Received November 19, 2009; final revision received February 15, 2011; accepted February 22, 2011. Address correspondence to D.A.W.; E-mail: woodrum. david@mayo.edu From the SIR 2010 Annual Meeting. R.J.N. is an employee of and equity owner in Visualase, Inc. None of the other authors have identified a conflict of interest. © SIR, 2011 J Vasc Interv Radiol 2011; 22:929 –934 DOI: 10.1016/j.jvir.2011.02.039