Yield of Routine Image-Guided Biopsy of Renal Mass Thermal Ablation Zones: 11-Year Experience.

PURPOSE: To determine the yield of routine image-guided core biopsy of renal cell carcinoma (RCC) thermal ablation zones. METHODS: Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act-compliant quality improvement effort. Routine core biopsy of RCC ablation zones was performed 2 months postablation from July 2003 to December 2014. Routine nicotinamide adenine dinucleotide staining was performed by specialized genitourinary pathologists to assess cell viability. The original purpose of performing routine postablation biopsy was to verify, in addition to imaging, whether the mass was completely treated. Imaging was stratified as negative, indeterminate, or positive for viable malignancy. Histology was stratified as negative, indeterminate, positive, or nondiagnostic for viable malignancy. Histology results were compared to prebiopsy imaging findings. RESULTS: Routine ablation zone biopsy was performed after 50% (146/292) of index ablations (24 cryoablations, 122 radiofrequency ablations), and postablation imaging was performed more often with multiphasic computed tomography than magnetic resonance imaging (100 vs 46, p < 0.0001). When imaging was negative (n = 117), biopsy added no additional information (92% [n = 108] negative, 0.9% [n = 1] indeterminate, 7% [n = 8] nondiagnostic). When imaging was indeterminate (n = 19), 11% (n = 2) of biopsies had viable RCC and 89% (n = 17) were negative. When imaging was positive, biopsy detected viable neoplasm in only 10% (1/10) of cases; 80% (8/10) were negative and 10% (1/10) were nondiagnostic. CONCLUSION: Routine biopsy of renal ablation zones to validate postablation imaging results was not value-added and therefore was discontinued at the study institution.

Percutaneous image-guided pelvic procedures in women with gynecologic cancers: utilization, complications, and impact on patient management.

PURPOSE: Image-guided percutaneous pelvic procedures often play an important role in the management of women with gynecologic cancers. The purpose of this study is to evaluate the utilization of and indications for these procedures, and quantify their impact on patient management. METHODS: IRB-approved retrospective record review of percutaneous pelvic procedures requested by gynecologic oncology, 2005 to 2015. Descriptive statistics and logistic regression were performed. RESULTS: 392 pelvic procedures, including fluid aspiration, core biopsy, and fine needle aspiration, were performed in 225 women. Procedures were performed under sonographic guidance (303/392, 77.30%), CT guidance (87/392, 22.19%), or both (2/392, 0.51%). Pathology results included: no specimen sent (157/392, 40.05%), new cancer diagnosis (55/392, 14.03%), recurrence or metastasis of known primary cancer (107/392, 27.30%), benign tissue (67/392, 17.09%), and nondiagnostic (6/392, 1.53%). In terms of management, some procedures led to oncologic surgery, radiation, or chemotherapy (158/392, 40.31%), cessation of oncologic treatment (36/392, 9.18%), or treatment of infection (10/392, 2.55%). Many procedures were therapeutic (178/392, 45.41%), while a minority were performed for genomics (1/392, 0.26%) or did not impact clinical management (9/392, 2.30%). The number of procedures per year increased over time during the period of data collection. Date of service was a significant positive predictor of a purely therapeutic procedure (OR 1.69 [95 % CI 1.44-1.98], p < 0.0001) and a significant negative predictor of a malignant diagnosis (OR 0.72 [95 % CI 0.64-0.81], p < 0.0001), for each year later in the 10-year cycle. CONCLUSION: In this single institution study, we identified a trend toward increased utilization of image-guided percutaneous pelvic interventions in women with gynecologic cancers. The case mix has shifted over the past 10 years, with procedures for symptom management constituting a larger proportion and diagnostic procedures constituting a smaller proportion of procedures over time.

Prevalence of malignancy in thyroid nodules with an initial nondiagnostic result after ultrasound guided fine needle aspiration.

The objective of this study was to determine the rate of malignancy in thyroid nodules with an initial nondiagnostic fine needle aspiration. From October 2001 to April 2007, biopsies were performed on 1344 thyroid nodules in our practice. Biopsies were performed on nodules using 25-27 gauge needles, ultrasound guidance and multiple passes using both suction and capillary action. We retrospectively reviewed the results of these biopsies as well as any further management of nodules that received nondiagnostic results (IRB HUM00006459). Following initial biopsy, 295/1344 (21.9%) of nodules received nondiagnostic pathologic results. Of this population, 39 nodules (13.1%) were lost to follow-up. Of the remaining 256 nodules that received a repeat FNA, surgical excision, or greater than 24 months of clinical and imaging follow-up, only five cancers were detected, representing only 2% of the population that received an initial nondiagnostic biopsy result. All of these cancers were papillary neoplasms. When rigorous, ultrasound-guided, fine needle aspiration of thyroid nodules is performed, a nondiagnostic histopathologic result should not be interpreted as suspicious for thyroid cancer. Given the low rate of malignancy in this population (2%), we suggest that clinical and imaging follow-up of these nodules, opposed to repeat sampling, is warranted.

Usefulness of the twinkling artifact in identifying implanted mesh after inguinal hernia repair.

OBJECTIVES: Implanted mesh for inguinal hernia repair is often difficult to visualize with gray scale sonography and may present without the knowledge of the sonographer. We sought to evaluate the utility of the twinkling artifact produced by inguinal mesh to assist in mesh identification. METHODS: Two reviewers evaluated focused sonographic examinations of 44 inguinal regions, 24 of which had implanted inguinal mesh. The sonographic examinations consisted of static gray scale and color Doppler images with both linear and curvilinear array transducers. The presence of the twinkling artifact and visibility of the mesh were graded on a 4-point visibility scale. RESULTS: Inguinal mesh was not easily identified on gray scale imaging using either the curvilinear array (P = .5) or linear array (P = .5) transducer. The mesh was definitely seen in 3 of 24 inguinal regions using the linear array transducer and 2 of 24 inguinal regions using the curvilinear array transducer. In 79% of inguinal regions with mesh, the twinkling artifact was produced with the curvilinear array transducer only. The artifact was not elicited when using the linear array transducer. With the use of the curvilinear array transducer and the presence of the twinkling artifact, there was a significant chance of correctly identifying the presence of mesh (P < .005) in the entire study group. CONCLUSIONS: Standard gray scale imaging alone is not reliable when identifying inguinal mesh. The twinkling artifact was present in 79% of inguinal regions with mesh when evaluated with a low-frequency curvilinear array transducer.

MRI and CT characteristics of successfully ablated renal masses: Imaging surveillance after radiofrequency ablation.

OBJECTIVE: The objective of our study was to evaluate the evolution of the appearances of successfully ablated renal masses on CT and MRI. MATERIALS AND METHODS: We conducted a retrospective review of 28 solid renal masses in 25 patients who underwent percutaneous radiofrequency ablation (RFA) between July 2003 and July 2006 in whom there was no evidence of residual tumor during at least 1 year of imaging follow-up and there was postablation biopsy proof of nonviable tissue within the ablation cavity. Three radiologists assessed the size, morphology, and CT or MRI characteristics of the initial tumor and of the ablated tumor or ablation cavity at imaging follow-up 1-2, 3-5, 6-11, and 12-24 months after RFA. RESULTS: The mean initial tumor volume was 5.5 cm(3) (range, 0.3-22.3 cm(3)). Within 1-2 months, the postablation beds of small masses (< or = 3 cm(3)) were larger than the volume of the initial tumor. Large masses (> 3 cm(3)) did not show this increase in volume. At 12 months after RFA, the postablation beds had decreased in size but had not disappeared. On CT, the postablation beds did not show enhancement at any time. On MRI, the postablation beds often showed a thin rim of peripheral enhancement. Imaging follow-up often revealed local stranding in the perinephric fat adjacent to the ablation site. Exophytic tumors were more likely to separate from the renal parenchyma as they contracted toward their epicenter and were more likely to reveal a complete halo of soft-tissue attenuation in the adjacent perinephric fat, which became more apparent on the longer-term follow-up imaging studies. CONCLUSION: Successfully ablated tumors show predictable imaging features that can be used to guide interpretation of CT and MRI surveillance examinations.

Accuracy of percutaneous core biopsy in management of small renal masses.

OBJECTIVES: To determine the sufficiency and accuracy of percutaneous core needle renal biopsy in patients with small renal masses (SRMs). METHODS: A retrospective chart review was performed on those patients who had undergone image-guided 18-gauge core renal biopsy of SRMs < or = 4 cm from February 1999 to October 2006. The information obtained included the initial biopsy technique, pathologic findings, and the clinical outcome. RESULTS: A total of 110 renal biopsies were performed for masses < or = 4 cm. The average renal mass size biopsied was 2.7 cm, with a median of 4 cores taken. Of the 110 biopsies, 100 (90.9%) were sufficient for diagnosis and 10 (9.1%) were indeterminate or provided insufficient tissue. Of the 100 diagnostic biopsies, 65% were interpreted as malignant and 35% as benign. There were 8 complications (7.2%), with 2 postprocedural hematomas (1.8%). Thirty-four patients underwent surgical extirpation; the ultimate histopathologic accuracy of biopsy compared with the final surgical pathologic finding was 100% (34/34) in these patients. CONCLUSIONS: Image-guided core needle biopsy is highly accurate in SRMs, and more than one third of these lesions will be benign. With a low complication rate, core biopsy provides a histopathologic diagnosis that aids in decision-making for the growing number of incidentally detected SRMs.

Evaluation of imaging-guided core biopsy of pancreatic masses.

OBJECTIVE: The purpose of this study was to determine the sensitivity and accuracy of imaging-guided core biopsy in the diagnosis of pancreatic masses. CONCLUSION: Imaging-guided core biopsy is sensitive, safe, and accurate in the diagnosis of malignant lesions of the pancreas. Benign biopsy findings cannot be used to exclude the presence of a neoplasm, and repetition of a biopsy should be considered if there is high clinical suspicion of malignancy.

Changing role of imaging-guided percutaneous biopsy of adrenal masses: evaluation of 50 adrenal biopsies.

OBJECTIVE: Prior series of percutaneous imaging-guided biopsies of adrenal masses before the advent of dedicated CT and MRI of the adrenal glands have shown that 40-57% of adrenal masses biopsied were adenomas-benign lesions requiring no further evaluation or treatment. This study was performed to assess the effect of dedicated adrenal imaging with CT and MRI on the rate of percutaneous imaging-guided biopsies of adrenal masses. MATERIALS AND METHODS: We reviewed 50 consecutive adrenal mass biopsies performed during a 48-month period. The patient demographics, technique of biopsy, pathology results, and results of any prior dedicated adrenal imaging with MRI or CT protocols were noted. RESULTS: Only six (12%) of 50 biopsies were adenomas. Five of these six cases were preceded by dedicated adrenal CT or MRI. Thirty-five cases were metastatic disease, four were adrenal cortical carcinoma, three were pheochromocytoma, and two biopsies were nondiagnostic. Overall, 20 of 50 cases were preceded by a dedicated adrenal CT or MRI examination to exclude an adenoma; in 21 of the remaining 30 cases, the imaging characteristics before biopsy were inconsistent with the potential diagnosis of an adenoma and dedicated adrenal CT or MRI was not recommended. CONCLUSION: The number of adrenal adenomas biopsied has declined markedly with the introduction of dedicated adrenal CT and MRI for adrenal adenomas. Percutaneous imaging-guided biopsy is useful in confirming the presence and nature of suspected metastatic deposits to the adrenal gland and in diagnosing or excluding adrenal adenomas in patients with equivocal imaging characteristics.

Evaluation of sonographically guided percutaneous core biopsy of renal masses.

OBJECTIVE: Our objective was to determine the utility of sonographically guided percutaneous core biopsy to evaluate renal masses. MATERIALS AND METHODS: We conducted a retrospective analysis of our imaging-guided procedures from January 1999 to June 2001. We performed 26 sonographically guided percutaneous core biopsies of renal masses in 26 patients. From two to five specimens were obtained from a single mass in each patient using an 18-gauge automated biopsy system. We examined the patients' medical records, pathology results, and imaging studies. Core biopsy results were compared with surgical pathology (n = 6) or clinical follow-up (n = 20). RESULTS: All biopsies provided sufficient material for analysis. Biopsy findings were positive for malignancy in 19 (73%) of 26 masses. Histologic diagnoses included renal cell carcinoma were (n = 11), metastasis (n = 3), lymphoma (n = 2), and transitional cell carcinoma (n = 2). Specific cell type characterization could not be made on one biopsy, but the specimens were highly suspicious for malignancy. Biopsy revealed seven (27%) of 26 benign diagnoses: oncocytoma (n = 3), angiomyolipoma (n = 2), and fibrosis (n = 2). The average follow-up period for patients with benign diagnoses was 10 months. One case of surgically proven necrotic pyelonephritis was mischaracterized as fibrosis at core biopsy. Sonographically guided percutaneous core biopsy of renal masses showed a sensitivity of 100% and a specificity of 100% for the diagnosis of malignancy. The core specimens yielded a specific diagnosis in 92% (24/26) of masses. No immediate complications occurred after the procedure. One patient developed a pseudoaneurysm that presented 3 months after the biopsy. CONCLUSION. Sonographically guided percutaneous core biopsy is a reliable and accurate method for evaluating renal masses.