Cary Lynn Siegel

Prospective Study of [18F]Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography for Staging of Muscle-Invasive Bladder Carcinoma

PURPOSEnNovel imaging modalities are needed to detect occult metastatic disease in bladder carcinoma. Patients with regional lymphatic spread could be targeted for neoadjuvant chemotherapy, and patients with distant metastatic disease could be spared the unnecessary morbidity of radical cystectomy. Herein, we report a prospective study of positron emission tomography/computed tomography (PET/CT) with [(18)F]fluorodeoxyglucose (FDG) in patients undergoing radical cystectomy for cT2-3N0M0 urothelial carcinoma of the bladder.nnnMETHODSnForty-three chemotherapy-naïve patients underwent FDG-PET/CT before planned cystectomy. All had negative conventional CT and bone scintigraphy before enrollment. Positive FDG-PET/CT was confirmed by percutaneous biopsy or open surgical exploration, whereas negative FDG-PET/CT was confirmed by complete lymphadenectomy. Recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS) were described using the Kaplan-Meier method and compared using log-rank test.nnnRESULTSnMedian follow-up was 14.9 months (range, 0.4 to 46.1 months). One patient who did not undergo lymphadenectomy was excluded from the pathology data analysis (n = 42), whereas another patient who failed to return for follow-up was excluded from survival analysis (n = 42). FDG-PET/CT demonstrated a positive predictive value of 78% (seven of nine), a negative predictive value of 91% (30 of 33), sensitivity of 70% (seven of 10), and specificity of 94% (30 of 32). RFS, DSS, and OS were all significantly poorer in the patients with positive FDG-PET/CT than in those with negative FDG-PET/CT.nnnCONCLUSIONnFDG-PET/CT detected occult metastatic disease in seven of 42 patients with negative conventional preoperative evaluations. PET findings were strongly correlated with survival. As such, FDG-PET/CT may help in making treatment decisions before radical cystectomy.

RENAL MEDULLARY CARCINOMA

PURPOSEnRenal medullary carcinoma is a rare and extremely aggressive neoplasm that almost always develops in young patients with sickle cell trait. To our knowledge all cases to date have been metastatic at surgical resection. Pathological examination reveals an aggressive tumor mainly involving the renal medulla with a varied morphology. The prognosis is dismal. Mean survival from the time of resection is 15 weeks (range 2 to 52). The disease course has not been altered by surgery, radiotherapy or various regimens of chemotherapeutic agents.nnnMATERIALS AND METHODSnWe add to the literature our experience treating renal medullary carcinoma in 2 cases and review the existing literature on this disease.nnnRESULTSnBoth patients whom we treated died of the disease, as have the other 35 patients described in the literature.nnnCONCLUSIONSnA high index of suspicion may lead to earlier diagnosis and treatment, and survival of patients with renal medullary carcinoma.

Primitive neuroectodermal tumor of the kidney - Another enigma: A pathologic, immunohistochemical, and molecular diagnostic study

Primitive neuroectodermal tumor (PNET), the second most common type of sarcoma in the first two decades of life, rarely presents as an organ-based neoplasm. Rather, it is seen typically in the soft tissues of the chest wall and paraspinal region. We report a case of primary PNET of the kidney in a 17-year-old girl who presented with abdominal pain, hematuria, and an abdominal mass. Nodules and sheets of monotonous-appearing primitive round cells and the formation of rosettes focally were the principal microscopic features. The tumor cells were uniformly immunoreactive for vimentin, cytokeratin, neuron-specific enolase, and 013 (CD99). In addition, the characteristic translocation of PNET and Ewing sarcoma, t(11;22)(q24;q12), was detected by polymerase chain reaction (PCR). Eight previous examples of renal PNET have been reported in the literature in the past 2 years, but only three of these cases have had complete immunohistochemical evaluation with the demonstration of 013 positivity. To our knowledge the present case is the only one to date demonstrating the recurrent translocation t(11;22)(q24;q12) by PCR. Assuming that the previous cases in the literature are bona fide examples of PNET, the kidney may be another site of predilection for this usual soft-tissue neoplasm. We are once again confronted with the dilemma about the nature of the progenitor cell.

11C-Acetate PET/CT Before Radical Prostatectomy: Nodal Staging and Treatment Failure Prediction

Despite early detection programs, many patients with prostate cancer present with intermediate- or high-risk disease. We prospectively investigated whether 11C-acetate PET/CT predicts lymph node (LN) metastasis and treatment failure in men for whom radical prostatectomy is planned. Methods: 107 men with intermediate- or high-risk localized prostate cancer and negative conventional imaging findings underwent PET/CT with 11C-acetate. Five underwent LN staging only, and 102 underwent LN staging and prostatectomy. PET/CT findings were correlated with pathologic nodal status. Treatment-failure–free survival was estimated by the Kaplan–Meier method. The ability of PET/CT to predict outcomes was evaluated by multivariate Cox proportional hazards analysis. Results: PET/CT was positive for pelvic LN or distant metastasis in 36 of 107 patients (33.6%). LN metastasis was present histopathologically in 25 (23.4%). The sensitivity, specificity, and positive and negative predictive values of PET/CT for detecting LN metastasis were 68.0%, 78.1%, 48.6%, and 88.9%, respectively. Treatment failed in 64 patients: 25 with metastasis, 17 with a persistent postprostatectomy prostate-specific antigen level greater than 0.20 ng/mL, and 22 with biochemical recurrence (prostate-specific antigen level > 0.20 ng/mL after nadir) during follow-up for a median of 44.0 mo. Treatment-failure–free survival was worse in PET-positive than in PET-negative patients (P < 0.0001) and in those with false-positive than in those with true-negative scan results (P < 0.01), suggesting that PET may have demonstrated nodal disease not removed surgically or identified pathologically. PET positivity independently predicted failure in preoperative (hazard ratio, 3.26; P < 0.0001) and postoperative (hazard ratio, 3.07; P = 0.0001) multivariate models. Conclusion: In patients planned for or completing prostatectomy, 11C-acetate PET/CT detects LN metastasis not identified by conventional imaging and independently predicts treatment-failure–free survival.

ACR Appropriateness Criteria Staging and Follow-up of Ovarian Cancer

In the management of epithelial ovarian cancers, imaging is used for cancer detection and staging, both before and after initial treatment. The decision of whether to pursue initial cytoreductive surgery for ovarian cancer depends in part on accurate staging. Contrast-enhanced CT of the abdomen and pelvis (and chest where indicated) is the current imaging modality of choice for the initial staging evaluation of ovarian cancer. Fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT and MRI may be appropriate for problem-solving purposes, particularly when lesions are present on CT but considered indeterminate. In patients who achieve remission, clinical suspicion for relapse after treatment prompts imaging evaluation for recurrence. Contrast-enhanced CT is the modality of choice to assess the extent of recurrent disease, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT is also usually appropriate, as small metastatic foci may be identified. If imaging or clinical examination confirms a recurrence, the extent of disease and timing of disease recurrence then determines the choice of treatments, including surgery, chemotherapy, and radiation therapy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Subtypes of renal cell carcinoma: MRI and pathological features

Renal cell carcinoma (RCC) is the most common malignant tumor involving the kidney. Determining the subtypes of renal cell carcinoma is among the major goals of preoperative radiological work-up. Among all modalities, magnetic resonance imaging (MRI) has several advantages, such as inherent soft tissue contrast, detection of lipid and blood products, and excellent sensitivity to detect small amounts of intravenous contrast, which facilitate the discrimination of subtypes of RCC. In this article, we review MRI and pathological features used for determining the main histologic subtypes of RCC, including clear cell, papillary, collecting duct, chromophobe, multilocular cystic, and unclassified RCC.

ACR Appropriateness Criteria® Pretreatment Planning of Invasive Cancer of the Cervix

The prognosis of cervical cancer is linked to lymph node involvement, and this is predicted clinically and pathologically by the stage of the disease, as well as the volume and grade of the tumor. Staging of cervical cancer based on International Federation of Gynecology and Obstetrics (FIGO) staging uses physical examination, cystoscopy, proctoscopy, intravenous urography, and barium enema. It does not include CT or MRI. Evaluation of the parametrium is limited in FIGO staging, and lymph node metastasis, an important prognostic factor, is not included in FIGO staging. The most important role for imaging is to distinguish stages Ia, Ib, and IIa disease treated with surgery from advanced disease treated with radiation therapy with or without chemotherapy. This article reviews the current role of imaging in pretreatment planning of invasive cervical cancer. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

MR imaging of the penis and scrotum

Traditionally, due to its low cost, ready availability, and proved diagnostic accuracy, ultrasonography (US) has been the primary imaging modality for the evaluation of scrotal and, to a lesser extent, penile disease. However, US is limited by its relatively small useful field of view, operator dependence, and inability to provide much information on tissue characterization. Magnetic resonance (MR) imaging, with its excellent soft-tissue contrast and good spatial resolution, is increasingly being used as both a problem-solving tool in patients who have already undergone US and as a primary modality for the evaluation of suspected disease. Specifically, MR imaging can aid in differentiating between benign and malignant lesions seen at US, help define the extent of inflammatory processes or traumatic injuries, and play a vital role in locoregional staging of tumors. Consequently, it is becoming more important for radiologists to be familiar with the wide range of penile and scrotal disease entities and their MR imaging appearances. The authors review the basic anatomy of the penis and scrotum as seen at MR imaging and provide a basic protocol for penile and scrotal imaging, with emphasis on the advantages of MR imaging. Pathologic processes are organized into traumatic (including penile fracture and contusion), infectious or inflammatory (including Fournier gangrene and scrotal abscess), and neoplastic (including both benign and malignant scrotal and penile tumors) processes.

ACR Appropriateness Criteria® pretreatment evaluation and follow-up of endometrial cancer.

Endometrial cancer is the most common gynecologic and the fourth most common malignancy in women in the United States. Cross-sectional imaging plays a vital role in pretreatment assessment of endometrial cancers and should be viewed as a complementary tool for surgical evaluation and planning of these patients. Although transvaginal US remains the preferred examination for the screening purposes, MRI has emerged as the modality of choice for the staging of endometrial cancer and imaging assessment of recurrence or treatment response. A combination of dynamic contrast-enhanced and diffusion weighted MRI provides the highest accuracy for the staging. Both CT and MRI perform equivalently for assessing nodal involvement or distant metastasis. PET-CT is more appropriate for assessing lymphadenopathy in high-grade FDG-avid tumors or for clinically suspected recurrence after treatment. An appropriate use and guidelines of imaging techniques in diagnosis, staging, and detection of endometrial cancer and treatment of recurrent disease are reviewed.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR appropriateness criteria(®) on abnormal vaginal bleeding

In evaluating a woman with abnormal vaginal bleeding, imaging cannot replace definitive histologic diagnosis but often plays an important role in screening, characterization of structural abnormalities, and directing appropriate patient care. Transvaginal ultrasound (TVUS) is generally the initial imaging modality of choice, with endometrial thickness a well-established predictor of endometrial disease in postmenopausal women. Endometrial thickness measurements of ≤5 mm and ≤4 mm have been advocated as appropriate upper threshold values to reasonably exclude endometrial carcinoma in postmenopausal women with vaginal bleeding; however, the best upper threshold endometrial thickness in the asymptomatic postmenopausal patient remains a subject of debate. Endometrial thickness in a premenopausal patient is a less reliable indicator of endometrial pathology since this may vary widely depending on the phase of menstrual cycle, and an upper threshold value for normal has not been well-established. Transabdominal ultrasound is generally an adjunct to TVUS and is most helpful when TVUS is not feasible or there is poor visualization of the endometrium. Hysterosonography may also allow for better delineation of both the endometrium and focal abnormalities in the endometrial cavity, leading to hysteroscopically directed biopsy or resection. Color and pulsed Doppler may provide additional characterization of a focal endometrial abnormality by demonstrating vascularity. MRI may also serve as an important problem-solving tool if the endometrium cannot be visualized on TVUS and hysterosonography is not possible, as well as for pretreatment planning of patients with suspected endometrial carcinoma. CT is generally not warranted for the evaluation of patients with abnormal bleeding, and an abnormal endometrium incidentally detected on CT should be further evaluated with TVUS.