Tumor-to-normal tissue (T/N) dosimetry ratios role in assessment of 90Y selective internal radiation therapy (SIRT)

2021 ◽  
Author(s):  
Karin Knešaurek ◽  
Ricardo Bello Martinez ◽  
Munir Ghesani
Keyword(s):  
Normal Tissue ◽  
Complete Response ◽  
Volume Effect ◽  
Locoregional Therapy ◽  
Dose Ratio ◽  
Pet Ct ◽  
Progression Of Disease ◽  
N Dose ◽  
The Mean

Objective: The purpose of our work is to assess the role of tumor-to-normal tissue (T/N) dosimetry ratios for predicting response in patients undergoing locoregional therapy to the liver with 90Y microspheres. Methods: 39 patients (seven femal:32 male, mean age 68.3 ± 7.6y), underwent PET/CT imaging after treatment with 90Y microspheres. For attenuation correction and localization of the 90Y microspheres, the low dose, non-diagnostic CT images from PET/CT were used. The acquisition took 15 min and the reconstruction matrix size was 200 × 200×75 mm and voxel size of 4.07 × 4.07×3.00 mm. For dosimetry calculations the local deposition method with known activity of 90Y was used. For each patient, regions-of-interest (ROIs) for tumor(s) and whole liver were manually created; the normal tissue ROI was created automatically. mRECIST criteria on MRI done at a month post treatment and subsequently every three months after90Y treatment, were used to assess response. Results: For 39 patients, the mean liver, tumor and normal tissue doses (mean ± SD) were, 55.17 ± 26.04 Gy, 911.87 ± 866.54 Gy and 47.79 ± 20.47 Gy respectively. Among these patients, 31 (79%) showed complete response (CR) and 8 (21%) showed progression of disease (PD). For patients with CR, the mean T/N dose ratio obtained was 24.91 (range 3.09–80.12) and for patients with PD, the mean T/N dose ratio was significantly lower, at 6.69 (range 0.36–14.75). Conclusion: Our data shows that patients with CR have a statistically higher T/N dose ratio than those with PD. Because, the number of PD cases was limited and partial volume effect was not considered, further investigation is warranted. Advances in knowledge: Tumor-to-normal tissue dosimetry ratios can be used for assessing response in patients undergoing locoregional therapy to the liver with 90Y microspheres.

Role of hepatologists in management of hepatocellular carcinoma in the new era of transplant oncology.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 501-501
Author(s):  
Divya Ashat ◽  
Mark Karwal ◽  
Shiliang Sun ◽  
Sandeep Laroia ◽  
Tomohiro Tanaka
Keyword(s):  
Hepatocellular Carcinoma ◽  
Multidisciplinary Approach ◽  
Complete Response ◽  
Meld Score ◽  
Locoregional Therapy ◽  
Direct Role ◽  
New Era ◽  
Tumor Boards ◽  
Median Diameter

501 Background: There have been global efforts to manage hepatobiliary malignancies such as hepatocellular carcinoma (HCC) in a multidisciplinary setting under the concept of transplant oncology. We published preliminary data of hepatology-directed treatment of HCC (Ann Hepatol 2019). However, the actual role of hepatologists in this setting is not well defined. Methods: We evaluated 107 patients with newly diagnosed HCC, undergoing locoregional therapy (LRT) as a first therapy (microwave ablation, TACE, TARE or SBRT) in our institution between 1/2017 to 2/2019 and being followed until 8/2019. Patients were divided into three groups based on referral pathways: outside referral directly to oncologists (O-group, n=24), internal referral from hepatologists to oncologists (H/O-group, n=62) and hepatologist directed HCC treatment (H-group, n=21). The hepatologist performed all microwave ablations in H-group; rest of the LRTs were performed by either interventional radiology or radiation oncology. Results: The baseline gender, etiology of liver disease, MELD score, Child-Pugh score, BCLC stage, CLIP score, AFP and proportion of patients within Milan criteria were similar between 3 groups ( p=n.s.). However, O-group included older patients (median 70 vs 63/62 y.o., p<0.01), and had larger HCC size (median diameter 41 vs 26/28mm, p<0.01). In H-group, there were more cases discussed in multidisciplinary tumor boards (77% vs 46%, p=0.012) and referrals for liver transplantation (71% versus 50%, p=0.046). Time between the diagnosis and the first procedure was shorter in H-group than others (median 53 vs 69 days, p=0.048). The rate of complete response/partial response per mRECIST criteria was highest in H-group (91 vs 66%, p=0.024). The 2-year cumulative survival was comparable among three groups (70, 74 and 76% in O-group, H/O-group and H-group, respectively, p=0.4). Conclusions: Hepatologists are often the first point of contact and can play a key (and even more direct) role in subsequent management of HCC. To further accomplish the concept of multidisciplinary approach and transplant oncology, primary/secondary care institutions might be a potential target for intervention for outreach.

scholarly journals 18-FDG PET ANALYSYS FOR DEMENTIA DIAGNOSIS- BASELINE RESULTS FROM A REFERENCE CENTER IN RECIFE, BRAZIL

2021 ◽  
Author(s):  
Júlia Xavier Ramos ◽  
Bruno Zacarias ◽  
Breno Barbosa ◽  
Simone Brandão
Keyword(s):  
Differential Diagnosis ◽  
Lewy Bodies ◽  
Diagnostic Uncertainty ◽  
Medical Evaluation ◽  
Pet Ct ◽  
Diagnosis Of Dementia ◽  
Diagnostic Hypothesis ◽  
The Mean ◽  
Near Future

Background: Positrons emission tomography associated with computed tomography- PET/CT using the 18 F-fluorodeoxyglucose is a well-established exam for the medical evaluation of dementia, mainly helping in differential diagnosis to determine the specific type of dementia. Objectives: To describe the role of the PET/CT in the differential diagnosis of dementia in patients. Methods: a single-center, descriptive and records-based analysis of patients with Dementia evaluated in a clinic of Neurology at Recife and referred to PET/ CT due to diagnosis uncertainty, between 2020-2021. Results: 29 patients were included. The mean age was 65 years-old and 62% were female. Alzheimer’s dementia was the main diagnostic hypothesis (41.3%). PET/CT was suggestive of Alzheimer’s in 24%, Frontotemporal dementia in 21% and Lewy Bodies Dementia in 17% of patients. PET/CT results disagreed from clinical hypothesis in 21% o and in 10% it was inconclusive. In 38% it corroborated the clinical suspicion. Conclusions: in this sample the use of PET/CT FDG contributed to improve diagnostic accuracy in a significant subset of patients, mostly in the scenery of diagnostic uncertainty or atypical syndromes such as earlyonset dementias. A larger sample size and the continuation of this research will give us more information in the near future.

Detection of unknown primary neuroendocrine tumors (CUP-NET) using 68Ga DOTA-NOC receptor PET/CT

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 4599-4599
Author(s):  
D. Hörsch ◽  
V. Prasad ◽  
V. Ambrosini ◽  
M. Hommann ◽  
S. Fanti ◽  
...  
Keyword(s):  
Neuroendocrine Tumours ◽  
Primary Tumour ◽  
Unknown Primary ◽  
Low Grade ◽  
Pet Ct ◽  
Pancreatic Net ◽  
The Mean ◽  
Standardised Uptake Values ◽  
F 33

4599 Background: This bi-centric study aimed at determining the role of receptor PET/CT using 68Ga-DOTA-NOC in the detection of undiagnosed primary sites of neuroendocrine tumours (NETs). Methods: Overall 59 patients (M: F 33:26, age 65±9 yr) with documented NET and unknown primary, were enrolled. PET/CT was performed after injection of approximately 100 MBq (46–260 MBq) of 68Ga-DOTA-NOC. The maximum standardised uptake values (SUVmax) were calculated and compared with SUVmax in known pancreatic NET (pNET) and ileum / jejunum / duodenum (SI-NET). The results of PET/CT were also correlated with CT alone. Results: In 35/59 (59%) of patients, 68Ga-DOTA-NOC PET/CT localised the site of the primary: ileum/jejunum (14), pancreas (16), rectum (2), lungs (2) and paraganglioma (1). CT alone (on retrospective analyses) confirmed the findings in 12/59 (20%) patients. The mean SUVmax of identified previously unknown pNET and SI-Net were 18.6 ± 9.8 (range 7.8–34.8) and 9.1± 6.0 (range 4.2–27.8), respectively. SUVmax in patients with previously known pNET and SI-NET were 26.1± 14.5 (range 8.7–42.4) and 11.3±3.7 (range 5.6- 17.9). The SUVmax of the unknown pNET and SI-NET were significantly lower (p< 0.05) as compared to the ones with known primary tumour sites. 19% of the patients had high grade, and 81% low grade NET. In 4/59 patients the primary tumour was subsequently resected (2 pancretic, one ileal and one rectal tumour). Conclusions: Our data indicate that 68Ga- DOTA-NOC PET/CT is highly superior to 111In Octreoscan (17% detection rate for CUP according to literature) and can play a major role in the management of patients with CUP-NET. No significant financial relationships to disclose.

Extramedullary Leukemia: The Role of Radiation Therapy.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4583-4583
Author(s):  
Kamal M. Patel ◽  
Luciana P. De Paula ◽  
John M. Holland ◽  
Richard T. Maziarz ◽  
Carol M. Marquez
Keyword(s):  
Overall Survival ◽  
Radiation Therapy ◽  
Radiation Dose ◽  
Dose Response ◽  
Radiation Oncology ◽  
Complete Response ◽  
Significant Prognostic Factor ◽  
Small Patient Population ◽  
The Mean

Abstract Introduction Extramedullary leukemia (EML) will develop in approximately 3% of the patients with acute leukemia. Only a few retrospective studies, and no prospective or randomized studies, have assessed the effectiveness and toxicity of radiation for EML. Here we review the EML patients treated with radiation therapy at the Oregon Health and Sciences University (OHSU) Radiation Oncology department. Methods and Materials From 1987 to 2005, 17 patients with EML underwent 20 radiation courses at the OHSU Radiation Oncology department. All patients had either biopsy-proven EML or had pre-established diagnoses of leukemia and were treated for EML as presumptive relapse. Patient data and disease history were either extracted from the patient chart or obtained from the cancer tumor registry. Variables used for analysis included patient age, gender, histological diagnosis, tumor location, radiation dose, fraction size, acute toxicities, last follow up or date of death, disease recurrence site after radiation therapy, initial symptom with presenting EML, effect of radiation on symptom(s), and time to EML. Univariate and multivariate analyses were done. Kaplan-Meier survival curves and Cox regression analyses were generated. Results The mean age of our patients was 37.5 years, with a range from 7.4 to 78.5 years. Males made up 76% of the patients population. The most common location for an EML was soft tissue (25%), followed by central nervous system (20%), and mucosal (15%). Surgical intervention was performed in only 5 of the 17 EML patients. The 17 patients received 20 treatment courses. The most frequently used radiation energy was 6 Megavoltage photons (55% of the cases), while the next most common was cobalt 60 (10%) and a mixed energy beam (10%). Radiation therapy was quite effective at relieving symptoms with a 94% response rate and 61% having a complete response. Pain was palliated in 88% of patients, while mass effect was decreased in 100% of patients. The mean radiation dose given was 21.8 Gray (range 10–39.6 Gy). We did not observe a radiation dose response to symptom palliation (Table 1). Leukemia recurrence of any type occurred at a median of 5.8 months from the last day of radiation treatment. There was a low incidence of acute grade 1 or 2 toxicities (39%) and no acute grade 3 or 4 toxicities or late toxicities. Our 17 patients had a mean and median overall survival of 20.7 months and 5.6 months, ranging from less than 1 month to 149 months. Regression and correlation models failed to show any significant prognostic factor (age, gender, quality of radiation, total radiation dose, initial presenting EML symptom, or time from diagnosis of leukemia to diagnosis to EML) influencing overall survival. Conclusions The role of radiation in EML is for symptom relief. Low dose radiation provides excellent palliation with minimal toxicity. A radiation dose response was not seen in our small patient population. Table 1 Radiation Dose response in Extramedullary Leukemia Dose # Patients # Symptoms # symptoms with a response # symptoms with a complete response 10–19.9 Gy 6 7 7 (100%) 4 (57%) 20–29.9 Gy 4 5 5 (100%) 3 (60%) 30 Gy or more 4 6 5 (83%) 4 (80%)

Role of FDG-PET CT in differentiating adenocarcinomas from squamous cell carcinomas of the lung

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Amr Muhammad Abdo Salem ◽  
Laila Hosny Hussein ◽  
Ahmed Mohamed Osman
Keyword(s):  
Lung Cancer ◽  
Squamous Cell ◽  
Fdg Pet ◽  
Treatment Plan ◽  
Standardized Uptake Value ◽  
Squamous Cell Carcinomas ◽  
Radiology Department ◽  
Pet Ct ◽  
The Mean

Abstract Background Lung cancer is the leading cause of cancer related deaths worldwide. The combination of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT) has a great impact on the diagnosis, staging, and hence on the treatment plan and follow up of lung cancer patients. Maximum standardized uptake value (SUVmax) is a semi-quantitative index which is easily performed and the most widely used quantitative parameter for the analysis of 18F-FDG PET images and for the estimation of metabolic activity. Objective to investigate the role of PET/ CT to differentiate between adenocarcinomas (AC) and squamous cell carcinomas (SCC) as the most common lung cancer by comparing their FDG uptake measured in the form of SUVmax. Methods A retrospective observational study, conducted at Ain Shams University Hospitals- Radiology Department patients diagnosed with non-small cell lung cancer (NSCLC) and histopathologically proved to be adenocarcinoma or squamous cell carcinoma. All were investigated using PET/CT scans in the period between June 2017 to September 2019. SUVmax of the lesion were measured and statistically analyzed compared with the histopathological type. Results A total of 30 patients were evaluated with the age ranging from 31 to 81 years old, the mean was 56.9 years (SD ± 11.53). Among them 25 patients (83.3%) were males and 5 patients (16.7%) were females. Out of the 30 NSCLC patients included in the study, 18 patients (60%) were histopathologically diagnosed as AC and 12 patients (40%) were histopathologically diagnosed as SCC. The mean SUVmax of the 30 NSCLC lesions was 15.02±8.4 (range: 2-32.8).The mean SUVmax of AC lesions was 12.4±7.55 (range: 2-32.8), while the mean SUVmax of SCC lesions was 18.95±8.3 (range: 3.7-30.77). The mean SUVmax of lesions in patients with SCC was significantly higher than that of patients with AC using Wilcoxon-Mann-Whitney test (P = 0.04). Conclusion SCC of the lung has higher SUVmax than AC of the lung and it can be used to differentiate between them using PET/CT.

scholarly journals Increased uptake of 68Ga-DOTA-FAPI-04 in bones and joints: metastases and beyond

2021 ◽  
Author(s):  
Chunxia Qin ◽  
Yangmeihui Song ◽  
Xi Liu ◽  
Yongkang Gai ◽  
Qingyao Liu ◽  
...  
Keyword(s):  
Bone Metastases ◽  
Bone Diseases ◽  
Bone Lesions ◽  
Benign Lesions ◽  
Osteofibrous Dysplasia ◽  
Benign Diseases ◽  
Pet Ct ◽  
Malignant Lesions ◽  
The Mean

Abstract Purpose: To describe the uptake of 68Gallium-labelled fibroblast activation protein inhibitor (68Ga-FAPI) in bones and joints for better understanding of the role of 68Ga-FAPI PET in benign and malignant bone lesions and joint diseases. Methods: All 129 68Ga-FAPI PET/MR or PET/CT scans from June 1, 2020 to February 20, 2021 performed at our PET centre were retrospectively reviewed. Foci of elevated 68Ga-FAPI uptake in bones and joints were identified. All lesions were divided into malignant and benign disease. Benign lesions included osteofibrous dysplasia, periodontitis, degenerative bone diseases, arthritis, and other inflammatory or trauma-related abnormalities. The number, locations and SUVmax of all lesions were recorded and analysed. Results: Elevated uptake of 68Ga-FAPI in/around bones and joints were found in 82 cases (63.57%). A total of 295 lesions were identified, including 94 (31.9%) malignant lesions (all were metastases) and 201 (68.1%) benign lesions. The benign lesions consisted of 13 osteofibrous dysplasia, 48 degenerative bone disease, 33 periodontitis, 56 arthritis, and 51 other inflammatory or trauma-related abnormalities. Spine, shoulder joint, alveolar ridge, and pelvis were the most commonly involved locations. Bone metastases were mainly distributed in the spine, pelvis and ribs. Among benign diseases, periodontitis and arthritis are site-specific. The mean SUVmax of bone metastases was significantly higher than that of benign diseases (7.14 ± 4.33 vs. 3.57 ± 1.60, p < 0.0001), but overlap existed. The differences in SUVmax among subgroups of benign diseases were statistically significant (p < 0.0001), with much higher uptake in periodontitis (4.45 ± 1.17). Conclusion: 68Ga-FAPI accumulated in both bone metastases and some benign diseases of bones and joints. Although the uptake of 68Ga-FAPI was often higher in bone metastases, this finding cannot be used to distinguish between benign and malignant lesions.

Potential Role of PET/CT in Evaluation of Thyroid Carcinoma Subtypes

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Yara Mohamed Fahmy ◽  
Tougan Taha Abd El Aziz ◽  
Marwa El Sayed Abd El Rahman
Keyword(s):  
Thyroid Carcinoma ◽  
Risk Stratification ◽  
Lymph Nodes ◽  
Radiology Department ◽  
University Hospitals ◽  
18Fdg Pet ◽  
Pet Ct ◽  
The Mean

Abstract Background Thyroid carcinoma is the most common endocrine malignancy. The biology of its different subtypes differ dramatically leading to different treatment approaches. Role of 18FDG PET/CT in thyroid carcinoma is still highly debated and not well established. Its indications are still being investigated in the hope of utilizing it in diagnosis, risk stratification, and follow up of thyroid carcinoma patients. Objective To explore the role of 18FDG PET/CT in the evaluation of different subtypes of thyroid carcinoma. Methods A retrospective descriptive study over the course of 9 months from July 2018 till March 2019. It included patients with pathologically proven thyroid carcinoma referred to the Radiology department, Ain Shams University Hospitals for a 18FDG PET/CT scan. Results 18FDG PET/CT scans of 16 patients were included in the study. Fourteen (87.5%) patients underwent thyroid surgery, two of whom (14.3%) displayed local operative bed recurrence. Eight patients (50%) were diagnosed with nodal disease of whom four patients (50%) had necrotic lymph nodes displaying average SUVmax of 3.7 (±1.3) compared to four patients (50%) with non-necrotic lymph nodes that achieved average SUVmax of 10.7 (±12.3). The mean SUVmax of the most metabolically active lymph nodes in patients who received chemotherapy was 3.5 compared to 7.7 in those who didn’t. On the other hand, the mean SUVmax of the most metabolically active lymph nodes in those who received radioactive iodine therapy was 3.2 compared to 14.2 in those who didn’t. Distant metastasis were detected in two (12.5%) patients. Conclusion The role of 18FDG PET/CT in thyroid malignancy remains unclear and controversial, whether in diagnosis, staging, risk stratification, follow up, or detection of recurrence. Further evaluation the role of 18FDG PET/CT in thyroid carcinoma is required. Moreover, more investigation particularly in the less common subtypes is warranted to provide a more comprehensive guideline for the use of 18FDG PET/CT in various subtypes of thyroid carcinoma.

scholarly journals The Usefulness of PET/CT In Detecting and Managing Cancers With Unknown Primary Site Depends on Histological Subtype

2021 ◽  
Author(s):  
Ella Nissan ◽  
Uri Amit ◽  
Leo Baron ◽  
Amit Zabatani ◽  
Damian Urban ◽  
...  
Keyword(s):  
Primary Site ◽  
Unknown Primary ◽  
Histological Subtype ◽  
Unknown Primary Site ◽  
Primary Tumors ◽  
Poorly Differentiated Carcinoma ◽  
Pet Ct ◽  
Poorly Differentiated ◽  
The Mean

Abstract Introduction: We assessed the role of PET/CT in identifying and managing cancer of unknown primary site (CUP). Methods: We reviewed 64 patients' PET/CT scans with CUP performed during 2012–2019. Results: The median age was 65 years. Of 138-FDG-avid lesions, the mean SUVmax was10.6±6.0. Primary tumors (PT) were detected in 28(44%) patients. Detection was positive in only one(10%) patient with squamous cell carcinoma (SCC) histology, compared to 4/14(29%) with poorly differentiated carcinoma, 4/9(44%) with adenocarcinoma, 18/30(60%) of those for whom the origin could be presumed (p= 0.034 for SCC compared to other histologies). The mean age, mean SUVmax, and the distribution of organ involvement were similar between patients with and without discovered PTs, and also between patients with SCC and with the other histologies combined. However, those with SCC were less likely than the others to present with multi-lesion involvement, p<0.001. PET/CT interpretations apparently affected treatment of 8/28(29%) patients with PT detected and in none of the 35 whose PT was not discovered, p<0.001. Conclusion: PET/CT detected PT in almost half of CUP. However, it did not appear beneficial in those with SCC histology. PET/CT showed limited overall value in guiding clinical management but benefited a subgroup with discovered PT.

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