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Purpose Currently, most centres use 2-D planar lymphoscintigraphy when performing dynamic sentinel lymph node biopsy in penile cancer patients with clinically impalpable inguinal nodes. This study aimed to investigate the role of SPECT/CT following 2-D planar lymphoscintigraphy (dynamic and static) in the detection and localization of sentinel lymph nodes in the groin. Methods A qualitative (visual) review was performed on planar followed by SPECT/CT lymphoscintigraphy in 115 consecutive patients (age 28–86 years) who underwent injection of 99mTc-nanocolloid followed by immediate acquisition of dynamic (20 min) and early static scans (5 min) initially and further delayed static (5 min) images at 120 min followed by SPECT/CT imaging. The lymph nodes detected in each groin on planar lymphoscintigraphy and SPECT/CT were compared. Results A total of 440 and 467 nodes were identified on planar scintigraphy and SPECT/CT, respectively. Overall, SPECT/CT confirmed the findings of planar imaging in 28/115 cases (24%). In the remaining 87 cases (76%), gross discrepancies were observed between planar and SPECT/CT images. SPECT/CT identified 17 instances of skin contamination (16 patients, 13%) and 36 instances of in-transit lymphatic tract activity (24 patients, 20%) that had been interpreted as tracer-avid lymph nodes on planar imaging. In addition, SPECT/CT identified 53 tracer-avid nodes in 48 patients (42%) that were not visualized on planar imaging and led to reclassification of the drainage basins (pelvic/inguinal) of 27 tracer-avid nodes. Conclusions The addition of SPECT/CT improved the rate of detection of true tracer-avid lymph nodes and delineated their precise (3-D) anatomic localization in drainage basins.

Ectopic thoracic kidney is an extremely rare condition caused by the abnormal location of one or both kidneys in the thoracic cavity. They are usually discovered incidentally on routine imaging. Although commonly asymptomatic, thoracic kidneys are at a risk of malrotation, pelviureteric junction obstruction, and subsequent obstructive nephropathy, by virtue of their long pedicle. We present a case report of an incidental thoracic kidney, for which a 99mtechnetium-mercaptoacetyltriglycine (99mTc-MAG3) renogram was performed to assess the baseline renal function. Although few reports are published in the literature using 99mTc-MAG3 renogram for this indication, we demonstrate a safe and feasible study to establish a baseline assessment of renal function in this group of patients.

The cause of low back pain due to lumbosacral transitional vertebra (LSTV) still remains a debated topic. Functional imaging with bone scintigraphy has been a valuable adjunct in its assessment; however, in recent years, the additional utility of single-photon emission tomography with computed tomography (SPECT/CT) is evolving as the imaging modality of choice in identifying range of complex lower back pain sources, leading to the provision of suitable treatment options. We present a case demonstrating a variant type of LSTV as a source of pain localized and delineated on hybrid SPECT/CT imaging treated by minimally invasive microendoscopic resection of the pseudoarticulations.

Sentinel lymph node studies using radiotracer techniques with pre-operative lymphatic mapping image and intra-operative gamma probe localization decrease surgical time, patient’s morbidity and improve staging accuracy. This in turn leads to improved treatment, quality of life and higher long-term survival rates. Surgeons, pathologist and nuclear medicine physicians need to work synergistically to explore and exploit the full benefits offered by this technique. The purpose of this article is to provide the reader with a concise overview on the applications and implications of sentinel lymph node biopsy procedure since its introduction into clinical practice approximately 25 years ago, but with main focus on recently consolidated areas and also the potential new areas for future expansion of this simple yet exquisite technique. The literature search included all relevant sentinel lymph node studies (reviews, meta-analysis, original articles, feasibility and case reports) utilizing radioisotopes in the areas discussed herewith from PubMed and Cochrane library.

Purpose To define the anatomical location of sentinel lymph nodes (SLN) in penile cancer patients based on Daseler's original zonal description using a combination of single photon emission computed tomography-computed tomography (SPECT-CT), cross sectional imaging and lymphoscintigraphy and characterise the limits of Zone V. Materials and methods Patients with primary penile cancer ≥T1G2 were included in the study. A total of 113 groins with impalpable inguinal lymph nodes (cN0) underwent planar lymphoscintigraphy and SPECT-CT. The sentinel lymph nodes were mapped on cross sectional imaging according to Daseler's anatomical description. Using measurements from fixed anatomical landmarks, a custom-made software program mapped the SLNs. SLNs were mapped to the previously undefined Zone V using 3 approaches to avoid observational bias: (a) as perceived by the uroradiologist, (b) limiting Zone V to a 5 mm radius from the sapheno-femoral junction or (c) using a 10 mm radius from the sapheno-femoral junction. Results Using SPECT-CT, drainage to the groins was seen in 109 of the 113 cN0 groins (96.5%). The majority of the SLNs were located in the central and superior quadrants with 38.2% lying within Zone I, 45% in Zone II and 13% in Zone V. More importantly, sentinel lymph nodes were still localised to the inferior zones with 3% located in Zone III and 0.8% in Zone IV. Conclusions Using a hybrid of SPECT-CT, cross sectional imaging and lymphoscintigraphy we have demonstrated that SLNs may be located in the inferior zones. We also define the limits of Zone V as an area of 5 mm radius from the sapheno-femoral junction.

Patients diagnosed with penile cancer and clinically impalpable inguinal lymph nodes (cN0), normally undergo dynamic sentinel lymph node biopsy (DSNB) at the same time as the primary penile surgery. The aim of this study is to investigate the diagnostic accuracy and clinical outcomes of performing DSNB in patients who have already undergone surgery for the primary penile cancer. Ninety-two patients with unilateral or bilateral impalpable inguinal lymph nodes (LNs) who had already undergone primary resection of the penile tumour (stage ≥ T1G2) were included in this study. All patients underwent a preoperative USS of the groin(s) with fine needle aspiration cytology (FNAC). Provided that the FNAC was clear, DSNB was performed. Radical inguinal lymphadenectomy was performed if the histological analysis of the SLN confirmed the presence of micrometastatic disease. DSNB was undertaken in 165 groins with a nonvisualisation rate of 4.8 % (8/165 groins). The SLN was positive for micrometastatic disease in nine groins (5.5 %) from a total of eight patients (8.7 %). One patient developed regional recurrence in a prepubic LN after excision of bilateral negative SLN (1.1 %). The three-year disease-specific survival for patients with negative and positive SLN was 98.8 and 87.5 %, respectively (p = 0.042). Using DSNB, occult LN metastases in penile cancer can be detected with a sensitivity of 88.9 % and specificity of 100 %. We have demonstrated that DSNB is feasible as a delayed procedure to localise the SLN. Surgical resection of the primary penile lesion does not appear to change the lymphatic drainage.

The aim of the study was to evaluate the value of single-photon emission computerized tomography/computed tomography (SPECT/CT) in the clinical assessment of painful knee prostheses.Between 2009 and 2011 we identified 105 patients who had undergone Tc-hydroxydiphosphonate SPECT/CT for painful knee prosthesis. Complete follow-up data were available for 69 patients (50 women and 19 men; mean age, 71 years) with painful knee prostheses (59 total, nine unicompartmental, one patellofemoral) and clinical suspicion of infection or loosening. The imaging test report in conjunction with the clinical data from the patient's notes was used to gauge how useful the test had been in terms of patient management.SPECT/CT confirmed the suspected clinical diagnosis of loosening in nine patients (13%) and of infection in two (2.9%) and identified other causes in 43 patients (62.3%). In 85.5% of patients, SPECT/CT was clinically useful (both positive and negative results), whereas in 14.5% it had no clinical impact on patient management. Revision surgery was performed in 24/69 (34.8%) patients and confirmed the SPECT/CT diagnosis in 21 patients (seven loosening, one infection, two subchondral fractures, two postoperative inflammation and nine patellofemoral osteoarthritis).SPECT/CT is a useful tool for the evaluation of painful knee prosthesis in 85.5% of cases and helps in confirming mechanical loosening and in excluding other causes such as infection and patellofemoral osteoarthritis.

With the recent introduction of PET/MRI, we investigated whether diffusion-weighted imaging (DWI) can complement PET for predicting local treatment response in Hodgkin lymphoma.This retrospective study included 39 patients selected from a hospital database with a histological diagnosis of Hodgkin lymphoma undergoing whole-body MRI (supplemented by DWI) and PET/CT before and after two cycles of vincristine, etoposide, prednisolone and doxorubicin (OEPA). The pretreatment volume, MRI apparent diffusion coefficient (ADC) and PET maximum standardized uptake value (SUV(max)) of the largest nodal mass were determined quantitatively for evaluation of the local response following two cycles of OEPA. Quantitative pretreatment imaging biomarkers (disease volume, ADC, SUV(max)) were compared between sites with an adequate and those with an inadequate response using Fisher's exact test and Mann Whitney statistics. Multivariate models predictive of an inadequate response based on demographic/clinical features, pretreatment disease volume and SUV(max) without (model 1) and with (model 2) the addition of ADC were derived and crossvalidated. The ROC area under curve (AUC) was calculated for both models using the full dataset (training) and the crossvalidation (test) data.Sites with an adequate response had a significantly lower median pretreatment ADC (1.0 × 10(-3)mm(2)s(-1)) than those with an inadequate response (1.26 × 10(-3)mm(2)s(-1); p 0.01). There were no significant differences in patient demographic/clinical parameters, pretreatment SUV(max) or pretreatment nodal volume between sites with inadequate and adequate response. The ROC-AUCs for prediction of an inadequate response for the training and test data for model 1 were 0.90 and 0.53, and for model 2 were 0.84 and 0.71, respectively.DWI complements PET for prediction of site-specific interim response to chemotherapy.

A 47-year-old gentleman was diagnosed with diffuse B cell lymphoma. His initial presentation was skin lesions. He was then referred for patch test with a diagnosis of periorbital eczema. Later, patient developed varicose veins and skin lesions in the right leg which was operated upon with poor healing and subsequent skin biopsy of the lesions demonstrated diffuse large B cell lymphoma (DLBCL). The bone marrow biopsy proved marrow involvement. He had no B symptoms. His past medical history includes brain abscess aged 9 …

R. Weissleder, B.D. Ross, A. Rehemtulla, and S.S. Gambhir Shelton, CT: People's Medical Publishing House–USA, 2010, 1357 pages, $189 The field of molecular imaging has seen spectacular advances in chemistry, engineering, and biochemical applications in recent years. Comprehensive molecular