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1.
Recent Results Cancer Res ; 216: 359-404, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32594393

RESUMO

Molecular imaging enables both spatial and temporal understanding of the complex biologic systems underlying carcinogenesis and malignant spread. Single-photon emission tomography (SPECT) is a versatile nuclear imaging-based technique with ideal properties to study these processes in vivo in small animal models, as well as to identify potential drug candidates and characterize their antitumor action and potential adverse effects. Small animal SPECT and SPECT-CT (single-photon emission tomography combined with computer tomography) systems continue to evolve, as do the numerous SPECT radiopharmaceutical agents, allowing unprecedented sensitivity and quantitative molecular imaging capabilities. Several of these advances, their specific applications in oncology as well as new areas of exploration are highlighted in this chapter.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32296882

RESUMO

PURPOSE: The purpose of this study was to investigate the prognostic value of whole-body metabolic tumor volume (MTV) and other metabolic tumor parameters, obtained from baseline and first restaging 18F-FDG PET/CT scans in melanoma patients treated with immune checkpoint inhibitors (ICIs). METHODS: Eighty-five consecutive melanoma patients (M, 57; F, 28) treated with ICIs who underwent PET/CT scans before and approximately 3 months after the start of immunotherapy were retrospectively enrolled. Metabolic tumor parameters including MTV for all melanoma lesions were measured on each scan. A Cox proportional hazards model was used for univariate and multivariate analyses of metabolic parameters combined with known clinical prognostic factors associated with overall survival (OS). Kaplan-Meier curves for patients dichotomized based on median values of imaging parameters were generated. RESULTS: The median OS time in all patients was 45 months (95% CI 24-45 months). Univariate analysis demonstrated that MTV obtained from first restaging PET/CT scans (MTVpost) was the strongest prognostic factor for OS among PET/CT parameters (P < 0.0001). The median OS in patients with high MTVpost (≥ 23.44) was 16 months (95% CI 12-32 months) as compared with more than 60 months in patients with low MTVpost (< 23.44) (P = 0.0003). A multivariate model including PET/CT parameters and known clinical prognostic factors revealed that MTVpost and the presence of central nervous system lesions were independent prognostic factors for OS (P = 0.0004, 0.0167, respectively). One pseudoprogression case (1.2%) was seen in this population and classified into the high MTVpost group. CONCLUSION: Whole-body metabolic tumor volume from PET scan acquired approximately 3 months following initiation of immunotherapy (MTVpost) is a strong prognostic indicator of OS in melanoma patients. Although the possibility of pseudoprogression must be considered whenever evaluating first restaging PET imaging, it only occurred in 1 patient in our cohort.

3.
J Nucl Med ; 61(4): 533-539, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31562226

RESUMO

PET using radiolabeled prostate-specific membrane antigen (PSMA) is now being more widely adopted as a valuable tool to evaluate patients with prostate cancer (PC). Recently, 3 different criteria for interpretation of PSMA PET were published: the European Association of Nuclear Medicine (EANM) criteria, the Prostate Cancer Molecular Imaging Standardized Evaluation criteria, and the PSMA Reporting and Data System. We compared these 3 criteria in terms of interreader, intrareader, and intercriteria agreement. Methods: Data from 104 patients prospectively enrolled in research protocols at our institution were retrospectively reviewed. The cohort consisted of 2 groups: 47 patients (mean age, 64.2 y old) who underwent Glu-NH-CO-NH-Lys-(Ahx)-[68Ga(HBED-CC)] (68Ga-PSMA11) PET/MRI for initial staging of biopsy-proven intermediate- or high-risk PC, and 57 patients (mean age, 70.5 y old) who underwent 68Ga-PSMA11 PET/CT because of biochemically recurrent PC. Three nuclear medicine physicians independently evaluated all 68Ga-PSMA11 PET/MRI and PET/CT studies according to the 3 interpretation criteria. Two of them reevaluated all studies 6 mo later in the same manner and masked to the initial reading. The Gwet agreement coefficient was calculated to evaluate interreader, intrareader, and intercriteria agreement based on the following sites: local lesion (primary tumor or prostate bed after radical prostatectomy), lymph node metastases, and other metastases. Results: In the PET/MRI group, interreader, intrareader, and intercriteria agreement ranged from substantial to almost perfect for any site according to all 3 criteria. In the PET/CT group, interreader agreement ranged from substantial to almost perfect except for judgment of distant metastases based on the PSMA Reporting and Data System (Gwet agreement coefficient, 0.57; moderate agreement), in which the most frequent cause of disagreement was lung nodules. Intrareader agreement ranged from substantial to almost perfect for any site according to all 3 criteria. Intercriteria agreement for each site was also substantial to almost perfect. Conclusion: Although the 3 published criteria have good interreader and intrareader reproducibility in evaluating 68Ga-PSMA11 PET, there are some factors causing interreader disagreement. Further work is needed to address this issue.

4.
J Nucl Med ; 61(4): 546-551, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31628216

RESUMO

18F-DCFPyL (2-(3-{1-carboxy-5-[(6-18F-fluoropyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid) is a promising PET radiopharmaceutical targeting prostate-specific membrane antigen (PSMA). We present our experience with this single-academic-center prospective study evaluating the positivity rate of 18F-DCFPyL PET/CT in patients with biochemical recurrence (BCR) of prostate cancer (PC). Methods: We prospectively enrolled 72 men (52-91 y old; mean ± SD, 71.5 ± 7.2) with BCR after primary definitive treatment with prostatectomy (n = 42) or radiotherapy (n = 30). The presence of lesions compatible with PC was evaluated by 2 independent readers. Fifty-nine patients had scans concurrent with at least one other conventional scan: bone scanning (24), CT (21), MR (20), 18F-fluciclovine PET/CT (18), or 18F-NaF PET (14). Findings from 18F-DCFPyL PET/CT were compared with those from other modalities. Impact on patient management based on 18F-DCFPyL PET/CT was recorded from clinical chart review. Results: 18F-DCFPyL PET/CT had an overall positivity rate of 85%, which increased with higher prostate-specific antigen (PSA) levels (ng/mL): 50% (PSA < 0.5), 69% (0.5 ≤ PSA < 1), 100% (1 ≤ PSA < 2), 91% (2 ≤ PSA < 5), and 96% (PSA ≥ 5). 18F-DCFPyL PET detected more lesions than conventional imaging. For anatomic imaging, 20 of 41 (49%) CT or MRI scans had findings congruent with 18F-DCFPyL, whereas 18F-DCFPyL PET was positive in 17 of 41 (41%) cases with negative CT or MRI findings. For bone imaging, 26 of 38 (68%) bone or 18F-NaF PET scans were congruent with 18F-DCFPyL PET, whereas 18F-DCFPyL PET localized bone lesions in 8 of 38 (21%) patients with negative results on bone or 18F-NaF PET scans. In 8 of 18 (44%) patients, 18F-fluciclovine PET had located the same lesions as did 18F-DCFPyL PET, whereas 5 of 18 (28%) patients with negative 18F-fluciclovine findings had positive 18F-DCFPyL PET findings and 1 of 18 (6%) patients with negative 18F-DCFPyL findings had uptake in the prostate bed on 18F-fluciclovine PET. In the remaining 4 of 18 (22%) patients, 18F-DCFPyL and 18F-fluciclovine scans showed different lesions. Lastly, 43 of 72 (60%) patients had treatment changes after 18F-DCFPyL PET and, most noticeably, 17 of these patients (24% total) had lesion localization only on 18F-DCFPyL PET, despite negative results on conventional imaging. Conclusion: 18F-DCFPyL PET/CT is a promising diagnostic tool in the work-up of biochemically recurrent PC, given the high positivity rate as compared with Food and Drug Administration-approved currently available imaging modalities and its impact on clinical management in 60% of patients.

5.
J Nucl Med ; 60(7): 882-891, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30850504

RESUMO

The diagnosis and subsequent therapy of neuroendocrine neoplasms (NENs) have long relied on somatostatin receptor (SSTR) expression. The field of theranostics now uses newer SSTR-based PET imaging with 68Ga-DOTATATE or 68Ga-DOTATOC as a prerequisite for the administration of peptide receptor radionuclide therapy (PRRT). In the United States, Food and Drug Administration approval of 177Lu-DOTATATE, a form of PRRT, in 2018 for use in gastroenteropancreatic NENs was obtained on the basis of prolonged progression-free survival versus high-dose octreotide long-acting release in a phase III clinical trial of well-differentiated midgut NENs. Well-differentiated grade 1 and grade 2 NENs have a low proliferation index (Ki-67 < 20%) and longer overall survival (>10 y), whereas higher-grade (grade 3 [G3]) NENs have a high Ki-67 (>20%) and shorter overall survival (<1 y). Here, we present a review on the role of SSTR-based imaging and PRRT in G3 NENs, including a discussion of well-differentiated G3 NENs, the newest histologic classification. Some studies suggest that G3 NENs are less likely to be positive on SSTR-based imaging (but more likely on 18F-FDG PET) than are well-differentiated NENs, but these data are limited. We found only 13 studies mentioning the use of PRRT in G3 NENs and a total of only 151 patients across these studies in whom radiologic response was measured. Of these 151 patients, 99 (66%) demonstrated at least stable disease or a partial response, indicating that some G3 NENs can be responsive to PRRT. We suggest that patients with G3 NENs should receive both 18F-FDG PET and SSTR-based imaging to aid in both diagnosis and treatment selection, as positivity on SSTR-based imaging helps with patient identification for PRRT and discordance may suggest important clues to tumor biology and prognosis. However, prospective studies are needed to fully understand the role of PRRT in G3 NENs, especially in well- versus poorly differentiated G3 disease.


Assuntos
Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/terapia , Medicina Nuclear/métodos , Humanos , Gradação de Tumores , Tumores Neuroendócrinos/patologia
6.
Radiol Case Rep ; 13(2): 464-467, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29682136

RESUMO

Solitary fibrous tumor/hemangiopericytomas (SFT/HPC) are soft tissue tumors that can arising from the abomen, pleura, head and neck, or extremities. We report an unusual case of recurrent hemangiopericytoma in a 67-year-old female presenting with a painless and palpable mass within her right posterior neck. Eight years after initial resection of the mass, a follow-up MRI showed multiple enlarging calvarial lesions. A whole body FDG-PET/CT revealed not only hypermetabolic calvarial lesions but also numerous hypermetabolic axillary node and osseous metastases. Though the majority of these soft tissue tumors exhibit benign behavior and carry a favorable prognosis, patients with these slow growing tumors are at risk for local recurrence and distant metastases which demonstrate substantial FDG avidity. Additional studies are needed to clarify the role of whole body FDG-PET/CT in the surveillance of SFT/HPC to detect recurrent or metastatic lesions.

7.
J Clin Imaging Sci ; 6: 31, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27625897

RESUMO

We present a case of a 69-year-old patient who underwent ascending aortic aneurysm repair with aortic valve replacement. On postsurgical day 12, he developed leukocytosis and low-grade fevers. The chest computed tomography (CT) showed a periaortic hematoma which represents a postsurgical change from aortic aneurysm repair, and a small pericardial effusion. The abdominal ultrasound showed cholelithiasis without any sign of cholecystitis. Finally, a fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT examination was ordered to find the cause of fever of unknown origin, and it showed increased FDG uptake in the gallbladder wall, with no uptake in the lumen. FDG-PET/CT can diagnose acute cholecystitis in patients with nonspecific clinical symptoms and laboratory results.

8.
World J Nucl Med ; 15(1): 44-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26912978

RESUMO

Many patients with hepatorenal syndrome (HRS) end up receiving a combined liver and kidney transplant (CKLT) with preservation of native kidneys, specially type 1 HRS since is characterizes by a very rapid deterioration of renal function. Eventually, most of the patients regain renal function, but it is unknown if this is due to the transplanted kidney, the recovery of native renal function, or both. The aim of this study is to evaluate if there is recovery of native renal function in patients with HRS following CKLT. 22 patients (16 men; 6 women) with history of HRS and status post CKLT were studied. Mercapto-acetyltriglycine-3 renograms in the anterior and posterior views with the three kidneys in the field of view were simultaneously acquired. The renograms were analyzed by creating regions of interest around the transplanted and native kidneys. Relative contribution to the renal function, clearance, and effective renal plasma flow for the transplanted and native kidneys were obtained. 1/22 (4.5%) patients presented with a very poor functioning transplanted kidney, in 15/22 (68%) cases the combined native renal function was markedly poorer than the transplanted renal function and in 6/22 (27%) native kidneys showed a contribution to the renal function similar to the transplanted kidney. In conclusion, our series show that around 32% of the HRS patients recovered their native renal function after CKLT. Identification of common factors that affect recovery of native renal function may help to avoid unnecessary renal transplants, significantly reducing morbidity and cost, while facilitating a reallocation of scarce donor resources.

10.
Nucl Med Mol Imaging ; 49(4): 331-2, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26550056
11.
World J Nucl Med ; 14(3): 222-4, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26420998

RESUMO

The patient was a 46-year-old Asian male diagnosed with lynch syndrome associated colon adenocarcinoma in the right ascending colon. A presurgical staging 18-fluoro-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) found increased metabolic activity in the cervical, axillary, mediastinal, supraclavicular, para-aortic and mesenteric lymph nodes. This pattern of metastasis was very unusual for lynch syndrome associated colon adenocarcinoma and the involvement of those lymph nodes resembles the pattern of spread of lymphoma. He underwent right hemicolectomy and he was subsequently treated with 12 cycles of folinic acid (leucovorin), fluorouracil (5-FU), irinotecan. A restaging FDG-PET/CT at the end of the chemotherapy showed interval decrease in size and metabolic activity in the affected lymph nodes. FDG-PET/CT is a useful imaging modality in following-up the treatment response in colon adenocarcinoma.

12.
J Clin Imaging Sci ; 5: 35, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26180658

RESUMO

Our patient was a 36-year-old female diagnosed with Grade II ER+/PR-/Her-2 - ductal carcinoma in situ (DCIS) in the left breast. She underwent left lumpectomy and received treatment with tamoxifen and radiotherapy. Three years later, she presented with multiple diffused skin nodules on the chest and upper left arm. 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) exam showed widespread metastasis in the chest, upper left arm, left axillary lymph nodes, and left suprascapular muscle. FDG-PET/CT imaging of breast carcinoma en cuirasse is very rare. FDG-PET/CT is useful in detecting recurrent breast cancer.

13.
World J Nucl Med ; 14(2): 128-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26097424

RESUMO

Primary retroperitoneal seminoma is a very rare entity. We present a case of 39-year-old male with primary retroperitoneal seminoma with staging and surveillance by means of F-18 fluoro-2-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). The case demonstrates that primary retroperitoneal seminoma can be easy to identify with FDG-PET/CT and potential follow-up on recurrence, or metastatic disease can be performed using this technique.

14.
J Clin Imaging Sci ; 5: 22, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25973286

RESUMO

Squamous cell carcinoma (SCC) of the rectum is extremely rare with a reported incidence of only 0.025-0.1% of all colorectal tumors. The patient was a 68-year-old man who presented with fatigue, dry cough, shortness of breath, and unintentional weight loss. A chest CT revealed a left suprahilar mass suspected to be lung cancer and an initial diagnosis of primary lung cancer was made. However, fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) exam revealed an intensely hypermetabolic rectal mass which turned out to be rectal squamous cell carcinoma. This is the first report that shows FDG-PET/CT images of rectal squamous cell carcinoma metastasis to the skin, muscle, bone, and lung. Use of PET/CT in the initial diagnosis of non-resectable rectal cancers may avoid unnecessary surgery.

15.
Abdom Imaging ; 40(6): 1432-40, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25820755

RESUMO

OBJECTIVE: To evaluate a simultaneous PET/MRI approach to imaging patients with neuroendocrine tumor using a combination of (68)Ga-DOTA-TOC as a PET contrast agent and gadoxetate disodium as a hepatobiliary MRI contrast agent. MATERIALS AND METHODS: Ten patients with neuroendocrine tumor with known or suspected hepatic disease were imaged using a (68)Ga-DOTA-TOC PET/CT immediately followed by a 3.0T time-of-flight PET/MRI, using a combined whole body and liver specific imaging. The presence of lesions and DOTA-TOC avidity were assessed on CT, PET from PET/CT, diffusion weighted imaging, hepatobiliary phase imaging (HBP), and PET from PET/MRI. Maximum standardized uptake values (SUVmax) in hepatic lesions and nodal metastases were compared between PET/CT and PET/MRI, as were detection rates using each imaging approach. RESULTS: A total of 101 hepatic lesions were identified, 47 of which were DOTA-TOC avid and able to be individually measured on both PET/CT and PET/MRI. HBP imaging had a higher sensitivity for detection of hepatic lesions compared to CT or PET (99% vs. 46% and 64%, respectively; p values <0.001). There was a strong correlation between SUVmax of liver lesions obtained with PET/CT compared to PET/MR imaging (Pearson's correlation = 0.91). For nodal disease, CT had a higher sensitivity compared to whole body MRI (p = 0.015), although PET acquired from PET/MRI detected slightly more lesions compared to PET from PET/CT. CONCLUSIONS: A simultaneous PET/MRI using both (68)Ga-DOTA-TOC and gadoxetate disodium was successful in whole body staging of patients with neuroendocrine tumor. HBP imaging had an increased detection rate for hepatic metastases.


Assuntos
Gadolínio DTPA , Neoplasias Hepáticas/diagnóstico , Imagem por Ressonância Magnética , Tumores Neuroendócrinos/diagnóstico , Octreotida/análogos & derivados , Compostos Organometálicos , Tomografia por Emissão de Pósitrons , Adulto , Idoso , Meios de Contraste , Diagnóstico Diferencial , Feminino , Radioisótopos de Gálio , Humanos , Aumento da Imagem , Fígado/diagnóstico por imagem , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Imagem Corporal Total
16.
World J Nucl Med ; 14(1): 25-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25709541

RESUMO

Focal (18)F-fluorodeoxyglucose (FDG) colonic activity can be incidentally seen in positron emission tomography/computed tomography (PET/CT) scans. Its clinical significance is still unclear. The purpose of this study was to assess the significance of focal FDG activity in PET/CT scans by correlating the imaging findings to colonoscopy results, and come up with some guidelines for recommendation of follow-up colonoscopy. A total of 133 patients who underwent both (18)F-FDG PET/CT for different oncological indications and colonoscopy within 3 months were retrospectively studied. Imaging, colonoscopy and pathology results were analyzed. Of the 133 FDG-PET/CT scans, 109/133 (82%) did not show focal colonic FDG activity, and 24/133 (18%) did. Of the 109/133 PET/CTs without focal colonic FDG activity, 109/109 (100%) did not have evidence of colon cancer after colonoscopy and histology. Of the 24/133 PET/CTs with focal colonic FDG activity, 10/24 (42%) had pathologic confirmation of colon cancer and 14/24 (58%) did not have evidence of colon cancer after colonoscopy and histological analysis. Sensitivity was 10/10 (100%), specificity 109/123 (89%), positive predictive value (PPV) 10/24 (42%) and negative predictive value (NPV) 109/109 (100%). Incidental focal (18)FDG activity in PET/CT imaging shows a high sensitivity, specificity and NPV for malignancy, with a not so high PPV of 42%. Although some people would argue that a 42% chance of malignancy justifies colonoscopy, this maybe is not possible in all cases. However, the high sensitivity of the test does not allow these studies to be overlooked. We provide our recommendations as per when to send patients with focal FDG colonic activity to have further characterization with colonoscopy.

17.
World J Nucl Med ; 14(1): 36-40, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25709543

RESUMO

Positron emission tomography (PET) is currently the most advanced technique of metabolic imaging available for tumor diagnosis and follow-up. The aim of this study was to examine the versatility and accuracy of fluorodeoxyglucose (FDG) PET/computed tomography (CT) in the metastasis detection of renal cell carcinoma (RCC). We also compared our findings to other similar studies from the literature. This is the biggest study so far to examine the sensitivity and specificity of FDG PET/CT in the management of RCC. A retrospective review was carried out on all the FDG PET/CT studies done from January 1999 to January 2014 at our institution. Biopsy results were considered the gold standard. For our patients (n = 315) with biopsy results, FDG PET/CT studies exhibited 100% sensitivity, 100% specificity. Our results were better than results achieved by other studies. The use of FDG PET/CT in restaging and metastasis detection of RCC has many advantages, in addition to high accuracy. This imaging technique has great potential in influencing treatment decisions. We recommend the incorporation of FDG PET/CT in routine standard protocols for RCC.

19.
J Clin Imaging Sci ; 4: 51, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25337437

RESUMO

We present the case of a 69-year-old male with chromophobe renal cell carcinoma (RCC). Chromophobe RCC accounts for only 4% of renal cancers and it is the least aggressive type. Omental nodular deposits due to RCC metastasis are very rare and it is reported only in more aggressive forms of RCC. This is the first report that shows FluoroDeoxyGlucose - Positron Emission Tomography/Computed Tomgraphy (FDG-PET/CT) images of omental nodular deposits from chromophobe RCC. FDG-PET/CT is becoming very useful in restaging RCC with distant metastases.

20.
J Clin Imaging Sci ; 4: 54, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25337440

RESUMO

OBJECTIVES: Nonreal-time Positron Emission Tomography/Computed Tomography (PET/CT) biopsies that use the image co-registration of a prior PET with an intra-procedural CT have been reported. The aim of this study was to report the initial experience of performing real-time intra-procedural PET/CT-guided biopsies. MATERIALS AND METHODS: All patients (n = 4) had a prior PET/CT examination of the concerning lesion and no significant CT correlate. On the day of the biopsy, 5 mCi of 18F-fluorodeoxyglucose (FDG) or NaF18 was intravenously injected. After 60 min of biodistribution of the molecular probe, PET/CT images were obtained in a limited one bed position over the region of the concerning lesion to be biopsied. RESULTS: One patient had a mesenteric mass and the other three had bone lesions, one located in the rib and two in the iliac bone. The pathology report revealed that two lesions (50%) were malignant and two lesions (50%) were benign. The results of the biopsy changed management in all cases. There was 0% complication rate. CONCLUSIONS: No additional software or hardware is required to perform real-time intra-procedural PET/CT-guided biopsies. It can optimize the yield, especially in cases where there are no anatomical abnormalities. Real-time intra-procedural PET/CT biopsy may have benefits over conventional biopsy techniques in terms of accuracy.

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