Nivolumab-Induced Subcutaneous Fat Necrosis: Another FDG-Avid Immune-Related Adverse Event A 59-year-old woman with history of metastatic melanoma, currently on nivolumab, presents for a restaging FDG PET/CT scan. New subcutaneous hypermetabolic foci are seen in bilateral lower extremities, suggestive of recurrent melanoma. She is referred for percutaneous image-guided biopsy for definitive diagnosis of progressive disease. Ultrasound shows the subcutaneous foci to be hyperechoic (fat density), and biopsy of the right thigh nodule shows fat necrosis with no evidence of tumor. Fat necrosis, an immune-related adverse event, can be FDG-avid and mimic malignancy on PET/CT scan. Received for publication May 10, 2019; revision accepted September 23, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Peeyush Bhargava, MD, Department of Diagnostic Radiology, Unit 1476, 1400 Pressler St, Houston, TX 77030. E-mail: Peeyush_bhargava@yahoo.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Utilizing the Cholecystagogue, Ensure Plus, Results in Similar Hepatobiliary Scintigraphy Study Results and Patient Outcomes Status Post Cholecystectomy, in Comparison With Sincalide Objective To determine if use of the oral cholecystagogue, Ensure Plus (EP), in hepatobiliary scintigraphy (HBS) leads to a similar distribution of normal and abnormal gallbladder ejection fractions (GBEFs) versus other historical secondary findings of chronic biliary disease in a similar patient population compared with the conventional cholecystokinin analog, sincalide. The HBS findings analyzed included the GBEF, small bowel transit time, gallbladder fill time, and reversal of the normal gallbladder versus small bowel transit. The secondary objectives were to determine whether patient outcomes were significantly different for EP and sincalide HBS study patients following cholecystectomy, namely, the surgical pathology and patient-reported biliary-type pain. Methods We reviewed all HBS examinations over a retrospective 34-month period. Data from 446 patients who underwent sincalide or EP HBS with GBEF determination for evaluation of chronic symptoms concerning for biliary etiology met the inclusion criteria. The aforementioned HBS findings and postsurgical patient outcomes were obtained for each patient group. Results Comparing HBS examinations performed with sincalide or EP, no significant differences were noted in the major HBS findings of similar patient populations. Outcomes for the sincalide and EP groups status post cholecystectomy were assessed to determine their sensitivity, specificity, positive predictive value, and negative predictive value. The outcomes assessed were the histopathology and patient-reported amelioration of biliary-type pain. No significant differences were noted. Conclusions The sincalide and EP cholecystagogues did not lead to significantly different HBS findings for similar patient populations or postcholecystectomy outcomes. Received for publication April 23, 2019; revision accepted August 16, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Justin G. Peacock, MD, PhD, Brooke Army Medical Center, 3551 Roger Brooke Dr, San Antonio, TX 78234. E-mail: justin.g.peacock@gmail.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Hepatobiliary Scintigraphy—Role in Preliminary Diagnosis and Management of Biliary Tract Injuries Purpose This study was conducted to identify the role of hepatobiliary scintigraphy (HBS) in the management of biliary tract injuries. Methods We retrospectively studied 54 patients (28 male and 26 female patients) aged 3 to 78 years with evidence of bile leak on HBS performed between January 2015 and October 2017. Following intravenous injection of 99mTc-mebrofenin, dynamic images were acquired for 30 minutes followed by static images until 24 hours. SPECT/CT was performed in patients with suspicion of bile leak on the planar images. Patients were classified as those with free intraperitoneal or localized bile leak. Any abdominal drain output was documented, and its statistical significance was assessed using Mann-Whitney U test. Subsequent management was also documented. Results Of the 54 patients, 28 demonstrated free intraperitoneal bile leak and 26 localized leak on HBS. Thirty-four patients (24 with free intraperitoneal leak and 10 with localized leak) had an abdominal drain. Drain output was significantly higher in patients with free intraperitoneal leak compared with patients with localized leak (370 vs 78 mL/d per patient, P < 0.01). All patients with free intraperitoneal bile leak underwent interventional procedures such as endoscopic retrograde cholangiopancreatography and stenting or Roux-en-Y hepaticojejunostomy later on. Patients with localized bile leak were managed conservatively and were free of symptoms at 1-year follow-up. Conclusions Our findings indicate that, in addition to detecting biliary leak, HBS may be used to identify patients with localized bile leak (48% of patients in our study) who do not require active intervention. Received for publication January 5, 2019; revision accepted August 16, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Anish Bhattacharya, DNB, PhD, Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India 160012. E-mail: anishpgi@yahoo.co.in. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Efficacy and Safety of 177Lu-PSMA-617 Radioligand Therapy in Metastatic Castration-Resistant Prostate Cancer Patients Purpose The aim of this study was to evaluate the efficacy and safety of 177Lu-PSMA-617 radioligand therapy in metastatic castration-resistant prostate cancer (mCRPC). Methods In this prospective, single-arm, single-institutional study, 90 mCRPC patients with progressive disease (PD) on second-line hormonal therapy and/or docetaxel chemotherapy were recruited for the study. All patients underwent diagnostic 68Ga-PSMA-HBED-CC PET/CT, prior to inclusion for therapy. Included patients underwent 177Lu-PSMA-617 therapy at 8- to 12-weekly intervals. The primary end point was to assess the overall survival. The secondary and cosecondary end points included biochemical response assessment as per the Prostate Cancer Working Group 3 criteria, progression-free survival, radiological and molecular response criteria, clinical response, safety profile, and disease control rates. All the outcome parameters were evaluated in 90 patients except for the radiographic and molecular response, which was evaluated in 69 patients. Results The median age of patients was 66.5 years (range, 30–88 years). The median activity administered per cycle was 3.7 to 8 GBq ranging from 1 to 7 cycles, and patients were followed up over a median duration of 28 months. At 2- to 3-month interval after the first therapy and the end of the assessment, greater than 50% decline in prostate-specific antigen was observed in 32.2% and 45.5%, respectively. Univariate analysis did not reveal any variables such as prior therapies, laboratory parameters, concomitant hormonal therapy, and SUV patient parameters associated with prostate-specific antigen decline. Radiographic response by diagnostic CT revealed partial remission in 23% (16/69), stable disease in 54% (37/69), and PD in 23% (16/69) of patients. Molecular tumor response by PET Response Criteria in Solid Tumor 1 criteria revealed 19 (27.5%) of 69 patients with partial remission, 30 (43.5%) of 69 with stable disease, and 20 (29%) of 69 with PD. The disease control rates according to the radiographic and molecular response were 77% and 71%, respectively. The median overall survival and median progression-free survivals were 14 and 11.8 months, respectively. Toxicities related to radioligand therapy were low and transient with no serious adverse effects. Conclusions 177Lu-PSMA-617 radionuclide therapy is a safe and effective approach to the treatment of mCRPC patients. Received for publication June 7, 2019; revision accepted August 18, 2019. Conflicts of interest and sources of funding: Funded by Indian Council of Medical Research, Government of India. No conflicts of interest declared. Clinical trial registration no. CTRI/06/006998. Correspondence to: Chandrasekhar Bal, MD, Department of Nuclear Medicine, Thyroid Clinic, Room No. 59-A, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India 110029. E-mail: csbal@hotmail.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Nuclear Medicine Student Elective at the Keck School of Medicine at LAC-USC Medical Center Very few medical schools offer a nuclear medicine elective. I will share our experience with the nuclear medicine elective rotation which has been well received by our fourth-year medical students. This may be of interest to nuclear medicine physicians who work in an academic setting. Received for publication August 12, 2019; revision accepted August 19, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Heidi R. Wassef, MD, Department of Radiology, Keck School of Medicine of the University of Southern California, 1510 San Pablo St Suite 350, Los Angeles, CA 90033. E-mail: wassef@med.usc.edu. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Imaging of Prostate Cancer Recurrence in the Vas Deferens With 68Ga-PSMA PET/CT Two cases with 68Ga-PSMA–avid prostate cancer recurrence in the vas deferens are presented. These cases highlight the clinical importance of imaging the pattern of local prostate cancer recurrence and the potential difficulties that arise due to the altered anatomy in the prostate bed after prostatectomy or radiotherapy. Received for publication March 8, 2019; revision accepted August 26, 2019. Support was provided to Dr Afaq by the National Institute for Health Research, the University College London Hospitals Biomedical Research Centre, and the Cancer Research UK University College London Experimental Cancer Medicine Centre. Conflicts of interest and sources of funding: Support was provided to Dr Afaq by the National Institute for Health Research, the University College London Hospitals Biomedical Research Centre, and the Cancer Research UK University College London Experimental Cancer Medicine Centre. None declared to all other authors. Correspondence to: Dimitrios Priftakis, MD, University College London Hospitals NHS Foundation Trust, 235 Euston Rd, London NW1 2BU, United Kingdom. E-mail: dimitris.priftakis@nhs.net. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Muscle Recurrence of a Primarily Nodal Follicular Lymphoma Studied by Contrast-Enhanced 18F-FDG PET/CT We report the case of a 52-year-old woman with follicular lymphoma localized in the left inguinal region without any extranodal involvement and achieving a complete response after radiotherapy. After a 3-year disease-free interval, muscular recurrence at the left arm was shown by contrast-enhanced 18F-FDG PET/CT. Contrast-enhanced 18F-FDG PET/CT performed after immunochemotherapy documented complete disease remission. Lymphoid tissue is usually not present in the skeletal muscle, making muscular lymphomatous involvement quite unusual; muscular relapse of a primarily nodal lymphoma is even rarer. Received for publication May 15, 2019; revision accepted August 28, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Gianfranco Belmonte, MD, Università Cattolica del Sacro Cuore, Istituto di Diagnostica per Immagini, Largo Francesco Vito 1, 00168 Rome, Italy. E-mail: g.zola1989@gmail.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Comparison of Quantitative Perfusion and Function Parameters of Gated-SPECT Myocardial Perfusion Imaging in Patients With Concordant and Discordant Left Bundle-Branch Block Background Patients with left bundle-branch block (LBBB) can be classified to discordant LBBB (dLBBB) and concordant LBBB (cLBBB) according to T-wave orientation in lateral leads. This classification indicates different functional left ventricular (LV) parameters with worse prognosis in dLBBB patients. However, there are no data regarding the impact of this classification on perfusion status of the left ventricle. The aim of this study is to evaluate and compare the SPECT myocardial perfusion imaging (MPI) findings of LV perfusion and function between dLBBB and cLBBB patients. Methods All patients who were referred for SPECT MPI during an 11 months' period were evaluated. Patients with evidence of LBBB on standard baseline 12-lead ECG were included, and their demographic, medical history, and imaging data were recorded. Quantitative perfusion and function parameters of LV included summed stress score, summed rest score, summed difference score, total perfusion deficit (TPD) at both phases with delta TPD, ejection fraction, end-diastolic volume, end-systolic volume, summed motion score, summed thickening score, phase SD, and phase histogram bandwidth. All baseline ECGs were further assessed by a cardiologist to categorize patients as the cLBBB or dLBBB group according to concordance of the T wave with QRS complex in lateral leads. Results Finally, 97 patients with 46 cLBBB and 51 dLBBB cases were included. Baseline characteristics and cardiovascular risk factors including diabetes mellitus, hypertension, hyperlipidemia, history of coronary artery disease (CAD), family history of CAD, and smoking were not significantly different between the 2 groups. However, summed stress score (12.2 vs 6.7), summed difference score (4.0 vs 2.6), stress TPD (11.0 vs 6.4), and delta TPD (4.8 vs 3.9) were significantly higher in dLBBB patients. In addition, functional parameters were also significantly worse in dLBBB patients with lower ejection fraction and higher end-diastolic volume, end-systolic volume, summed motion score, and summed thickening score in these patients. Mean phase SD and phase histogram bandwidth were also significantly higher in dLBBB patients. Conclusions This study revealed that LBBB patients with discordant T wave in lateral leads have significantly higher ischemic scores and worse functional parameters with more dyssynchrony in gated SPECT MPI. Received for publication May 23, 2019; revision accepted August 29, 2019. Conflicts of interest and sources of funding: The present article was extracted from the thesis written by T.B. and was financially supported by Shiraz University of Medical Sciences, Shiraz, Iran (grant 14689). None declared to all other authors. Correspondence to: Pooyan Dehghani, MD, Cardiology Department, Namazi Hospital, Namazi Square, Zand St, Shiraz, Iran 7193613311. E-mail: P.Dehghani@gmail.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

18F-FDG Imaging of a Case of Disseminated Nocardiosis Nocardiosis is an uncommon infection caused by ubiquitous environmental aerobic gram-positive filamentous bacteria, present in soil and water. Skin and lungs are usually the main targets of localized infections. Rarely, disseminated forms can occur in immunocompromised individuals. A 63-year-old man with a history of late-onset asthma and nasal and sinus polyposis treated with oral low-dose corticosteroid regimen presented with fever, headache, myalgia, skin erythematous plaques, and pustules. Brain MRI revealed multiple abscesses and pachymeningitis. 18F-FDG PET/CT was performed to assess the extent of the infection. Cutaneous samples and sputum culture isolated Nocardia brasiliensis, confirming diagnosis of disseminated nocardiosis. Received for publication April 24, 2019; revision accepted August 31, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Margot Playe, MSc, Centre Cardiologique du Nord Saint-Denis, France. E-mail: margot.playe@gmail.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Detection of Unusual Peritoneal Metastases of Prostate Cancer With 68Ga–Prostate-Specific Membrane Antigen PET/CT Peritoneal metastasis of prostate cancer (PC) is unusual site of metastatic disease; only limited case reports are published in literature. 68Ga–prostate-specific membrane antigen (PSMA) PET/CT is recently used for detection of PC metastasis with high accuracy rates. We present a case of a 68-year-old man with disseminated peritoneal metastases and abdominal metastatic lymph nodes of PC, demonstrated in 68Ga-PSMA PET/CT with intense PSMA uptake. Received for publication May 10, 2019; revision accepted August 31, 2019. Conflicts of interest and sources of funding: none declared. Correspondence to: Duygu Has Simsek, MD, Department of Nuclear Medicine, Istanbul Faculty of Medicine, Istanbul University, 34093 Fatih, Istanbul, Turkey. E-mail: dr.duyguhas@hotmail.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.