Evaluating therapeutic efficacy of extended shelf-life 90 Y glass microspheres in transarterial radioembolization for colorectal cancer: a quantitative FDG PET/CT analysis

OBJECTIVES

There is a lack of sufficient evidence regarding the use of extended shelf-life (ExSL) Yttrium-90 ( 90 Y) glass radiomicrospheres in metastatic colorectal cancer (mCRC) patients. We aimed to investigate the efficacy of ExSL 90 Y glass radiomicrospheres with a personalized treatment approach by analyzing 18 F-FDG PET/CT quantitative parameters [metabolic tumor volume (MTV) and total lesion glycolysis (TLG)] separately before and after the treatment.

METHODS

A total of 93 radioembolization sessions involving 77 patients were included. Simplicit 90 Y software was utilized to perform multicompartmental voxel-based dosimetry. Adverse events were recorded using the CTCAE v5.0 criteria. The survival data were recorded in detail.

RESULTS

The overall disease control rate was 84.9%, with a median overall survival (OS) of 12.7 months and median progression-free survival (PFS) of 8.3 months. A statistically significant increase in treatment response rate was observed when there was an increase in absorbed tumor dose for pre-treatment unit MTV ( P  = 0.005) and TLG ( P  = 0.004) values. We didn't observe any additional side effects/vital risks that could be considered clinically significant.

CONCLUSION

Our study has provided evidence on the therapeutic effectiveness and safety in terms of dose-toxicity profile of ExSL 90 Y glass microspheres in a large cohort of mCRC patients. With a personalized treatment approach, the increase in radiation dose absorbed by the tumor has shown a significant contribution to treatment response rate, as indicated by quantitative measurements obtained through 18 F-FDG PET/CT.

18F-FDG PET/CT and 99mTc-MDP Bone Scintigraphy Findings of Multifocal Desmoid Fibromatosis

ABSTRACT

Desmoid fibromatosis, also called desmoid tumors, is a group of locally aggressive fibromatous proliferative disorders. They represent less than 3% of all soft tissue sarcoma and are multifocal in approximately 10% of cases. However, there are only a few cases in the literature describing 18F-FDG PET/CT and 99mTc-MDP bone scan features of extra-abdominal desmoid fibromas, and all were solitary bone lesions. Herein, we presented a unique case of multifocal desmoid fibromatosis of bone illustrating the prospective value of 18F-FDG PET/CT and 99mTc-MDP bone scan in the evaluation of desmoid tumors.

Combining Immunotherapy with Transarterial Radioembolization

Hepatocellular carcinoma (HCC) has a high mortality rate due to the diagnosis of patients at advanced stages and ineffective systemic therapies. Immunotherapy is considered a new treatment option for unresectable HCC alternatives to the limitations of conventional cytotoxic chemotherapy. In this case report, we reported that transarterial radioembolization and immunotherapy such as atezolizumab and bevacizumab can be used together in a manner effectively in the management of HCC treatment.

Challenges in the Management of a 7-Year-Old Child with Thyrotropin-Secreting Pituitary Adenoma and the Review of the Literature

INTRODUCTION

Thyrotropin-producing pituitary adenoma (TSHoma) is a very rare disease, representing less than 1% of the pituitary tumours and presenting with elevated thyroid hormones and normal/high TSH concentrations.

CASE PRESENTATION

A 7-year-old boy with nervousness was referred by his psychiatrist for elevated free T4, T3, and TSH levels. Initial evaluation revealed an elevated α-subunit. Pituitary magnetic resonance imaging (MRI) demonstrated a macroadenoma. The patient underwent a trans-sphenoidal tumour resection (TSS) which showed positive immunohistochemical staining for TSH, growth hormone, and prolactin in tumoral tissue. Euthyroidism was achieved for 1 year after TSS, then recurrence of tumour with elevated TSH and thyroid hormone levels necessitated a re-operation with TSS followed by gamma-knife radiosurgery. The euthyroid state was achieved and lasted for 2.5 years this time, but due to the recurrence, medical treatment had been commenced with cabergoline and octreotide. Euthyroidism was maintained for the last 4 years on monthly octreotide treatment. A repeat MRI demonstrated no pituitary mass, but a mass in the sphenoidal sinus had been detected. Removal of this mass by surgery did not achieve euthyroidism. 68Ga-DOTA-TATE positron emission tomography/computed tomography showed residual tissue extending from the pituitary region to the sphenoid sinus. The patient's bone age was advanced by 2 years at diagnosis which became 4 years in 1 year after the diagnosis and remained so throughout follow-up, leading to a final height of -3.3 SDS below his target height at the age of 16 years.

CONCLUSION

The diagnosis, treatment, and follow-up of TSHomas are challenging, and short stature due to accelerated bone maturation is a complication of paediatric TSHomas.

Prognostic significance of 18F-FDG PET/CT indices in metastatic renal cell cancer and evaluation of revised IMDC risk model by including 18F-FDG PET-CT parameters

Background

Prognostic markers in metastatic renal cell cancer (mRCC) are still insufficient. Any prognostic model objectively determines disease burden.

Purpose

To investigate the relationship between 18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters and outcomes in mRCC, and to define a revised International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model for the intermediate-risk group.

Material and Methods

A retrospective study of mRCC was conducted. To investigate the prognostic significance of 18F-FDG PET/CT parameters, maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), and metabolic tumor volume (MTV) were determined in pre-treatment images. Cutoff values were defined by ROC curve analyses and their association with outcomes was analyzed. Additionally, a TLG-adjusted IMDC model was created by stratifying intermediate-risk group patients according to TLG levels.

Results

The study included 52 patients. The disease control rate (DCR) was 61.5% and median overall survival (OS) was 18 months (95% confidence interval=9.2–25.8). In the univariate analyses, IMDC score, MTV, and TLG were prognostic factors for Disease Control Rate (DCR), and Eastern Cooperative Oncology Group (ECOG)-Performance Status (PS), IMDC score, lactate dehydrogenase (LDH), treatment option, MTV, and TLG were prognostic factors for OS ( P < 0.05 each). In the multivariate analyses, MTV was an independent prognostic factor for DCR, and ECOG-PS, LDH, IMDC score, and TLG were independent prognostic factors for OS. According to the revised-IMDC model, the intermediate-favorable group showed longer OS than the intermediate-unfavorable group.

Conclusion

Pretreatment MTV was independent prognostic factor for DCR and ECOG-PS, LDH, IMDC score, and TLG were independent prognostic factors for OS. Revised-IMDC model could identify patients with a worse prognosis among the IMDC intermediate-risk group.

Extranodal NK/T-Cell Lymphoma With Widespread Cutaneous and Subcutaneous Involvement on 18 F-FDG PET/CT

ABSTRACT

Nasal-type extranodal natural killer/T-cell lymphoma is an aggressive rare type of lymphoma that mostly affects the nasal cavity and adjacent areas. However, some patients can present with distant nodal or extranodal involvement including the Waldeyer ring, gastrointestinal tract, genitourinary organs, lung, thyroid, skin, or adrenal glands. Herein, we present a unique case of extranodal natural killer/T-cell lymphoma with widespread cutaneous and subcutaneous involvement on 18 F-FDG PET/CT.

Role of baseline 68Ga-PSMA PET/CT-derived whole-body volumetric parameters in predicting survival outcomes of metastatic castration-resistant prostate cancer patients receiving first-line treatment

OBJECTIVE

We aimed to evaluate whether baseline ⁶⁸Ga-PSMA PET/CT-derived whole-body volumetric parameters could be used as predictive biomarkers for survival in metastatic castration-resistant prostate cancer (mCRPC) patients receiving first-line treatment.

MATERIALS AND METHODS

This retrospective study included 54 mCRPC patients, who underwent baseline ⁶⁸Ga-PSMA PET/CT imaging within 1 month before starting first-line treatment. Pre-treatment prostate-specific antigen (PSA) levels and treatments were recorded. SUVmax, SUVmean, whole-body PSMA-derived tumor volume (wbPSMA-TV), and whole-body total lesion PSMA (wbTL-PSMA) were calculated for all patients. PSA response was defined as a decline of ≥ 50% from pre-treatment value at 12 weeks. Overall survival (OS) was measured from the start of the first-line treatment for mCRPC.

RESULTS

Docetaxel and abiraterone/enzalutamide were administered to 32 and 22 patients in the first-line setting, respectively. wbPSMA-TV (rho = 0.582, p = 0.004) and wbTL-PSMA (rho = 0.564, p = 0.007) showed moderate positive correlations with PSA levels. Older age (p = 0.02), higher wbPSMA-TV (p = 0.007), higher PSA (p = 0.01), higher number of bone metastases (p = 0.02), and lack of PSA response (p = 0.03) were significantly associated with an increased risk of mortality. Multivariate analysis determined wbPSMA-TV (HR: 1.003, 95% CI 1.001-1.004, p = 0.001) and PSA response (HR: 2.241, 95% CI 1.189-4.222, p = 0.01) as independent predictors of OS.

CONCLUSION

The wbPSMA-TV may be a useful tool to reflect tumor burden and predict survival outcomes in patients with mCRPC.

Corticomedullary Mixed Tumor of the Adrenal Gland with Apparent 18F-Fluorodeoxyglucose Activity But No 68GA-DOTATATE Uptake on Positron Emission Tomography/Computed Tomography

Corticomedullary mixed tumor (CMT) is a single adrenal tumor mass composed histologically by an admixture of adrenal cortical and medullary cells. It is a rare condition, with approximately 20 cases reported to date. To our knowledge, the positron emission tomography (PET) imaging findings of this mostly benign tumor have not been reported in the literature. We present a case of CMT who was evaluated with both 18F-fluorodeoxyglucose (18F-FDG) and 68Ga-DOTATATE. The hypermetabolic tumor seen on 18F-FDG PET/computed tomography scan showed no abnormal uptake by 68Ga-DOTATATE.

Brown Tumors Secondary to Tertiary Hyperparathyroidism Masquerading as Lytic or Sclerotic Skeletal Metastases on Preoperative/Postoperative 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: A Case Report

Tertiary hyperparathyroidism (TH) is a rare condition that develops from secondary hyperparathyroidism in cases when the secretion becomes autonomous. Brown tumors (BTs) are rare skeletal lesions of hyperparathyroidism that may mimic cancer metastasis. We report a case of a patient who was diagnosed with TH with multiple BTs which mimics osteolytic/osteoblastic metastases that were evaluated with two fluorodeoxyglucose positron emission tomography scans with an interval of 23 months in the preoperative and postoperative period.

POS0790 18F-FLUORODEOXYGLUCOSE (FDG) PET-CT IMAGING OF SALIVARY GLANDS IN PRIMARY SJÖGREN’S SYNDROME AND ITS CORRELATION WITH ULTRASONOGRAPHIC SCORES AND SALIVARY FLOW RATE COMPARED TO HEALTHY CONTROLS

Background

The use of salivary gland imaging modalities in patients with primary Sjögren’s syndrome (pSS) has been increasing recently. The contribution of each imaging method in terms of diagnosis or disease activity differs from each other. Although ultrasound and MRI are the most commonly used imaging modalities, the role of PET-CT for diagnosing pSS and determining glandular and extraglandular involvement has largely been neglected.

Objectives

This study aimed to compare the sizes and metabolic activities of the major salivary glands in patients with pSS and healthy controls (HC). Correlation of the 18F-FDG PET-CT uptake characteristics with ultrasound scores and salivary flow rates of the patients and HC was also determined.

Methods

22 patients with pSS and 10 age/sex-matched HC were included in the study. The sizes and FDG uptakes of the parotid and submandibular glands of pSS patients and HC were assessed by PET-CT. The maximum standardized uptake value (SUVmax) was evaluated for FDG uptakes, and each patient’s liver uptake and salivary gland uptake ratio were calculated. In addition, correlations of gland sizes and FDG uptakes in PET-CT with OMERACT and Hocevar ultrasound scores, stimulated and unstimulated SFR, ESSPRI dryness scores and disease durations of pSS patients were calculated by Spearman test.

Results

The mean age (SD) of the patients was 58.6 years (10.5) versus 58.6 years (19.1) of HC; the mean (SD) disease duration was 8.96 (8.77) years. ANA was positive in all patients, anti-SSA positivity was present in 82.6%, and 30.4% of patients experienced ≥1 parotid swelling episode.

Compared to HCs, the mean size of both submandibular glands (p=0.006 for left and p=0.032 for right) and SUVmax of the left submandibular gland (p=0.044) were significantly smaller in patients with pSS. In pSS patients, both right and left parotid sizes were smaller and SUVmax uptake was greater than in HC; these differences however did not reach statistical significance.

When the PET-CT involvement characteristics of the patients were compared with the salivary gland ultrasonography scores, there was a statistically significant negative correlation between the left parotid gland size in PET-CT and the ultrasonographic inhomogeneity of Hocevar score and OMERACT score. There was a statistically significant negative correlation between right parotid gland size measured on PET-CT with ultrasonographic inhomogeneity, hyperechoic foci, parenchymal echogenicity, Hocevar total score, and OMERACT score. No statistically significant correlation was found between SUVmax scores detected by PET-CT and ultrasound scores in both parotid glands and submandibular glands.

A statistically significant positive correlation was found between the total gland size measured in PET-CT and the unstimulated salivary flow rate (p=0.038, r=0.604). There was a negative correlation between total gland size and ESSPRI dryness scores and symptom duration, which did not reach statistical significance.

Conclusion

PET-CT SUVmax measurements do not provide sufficient information for pSS-related involvement of the major salivary glands. Secondly, size measurement of the parotid glands by PET-CT is associated with OMERACT ultrasound scores, and also the sizes of both submandibular and parotid glands are smaller than HC.

Table 1.

Correlations of gland sizes and ultrasonographic scores

GlandOMERACT ScoreParenchymalHomogeneityHypoechoic AreasHiperechoicVisibility of Gland BorderParenchymal InhomogenicityTotalSize (PET/CT)EchogenityFociR-Parotisr-.699*-.717*-.704*-0,598-.656*-0,368-.758**-.645*p0,0170,0130,0160,0520,0280,2660,0070,032L-Parotisr-.699*-.717*-.704*-0,598-.656*-0,368-.758**-0,482p0,0170,0130,0160,0520,0280,2660,0070,134R-Submr-0,0110.118-0,011-0,2700,203-0,0060,2470.024p0,9720.7140,9720,3970,5260,9860,4390.942L-Submr0,2450,3060,2450,0710,3270,1180,3060,435p0,4430,3330,4430,8260,3000,7140,3330,158

Disclosure of Interests

None declared

Proposal and Validation of a Novel Scoring System for Hepatocellular Carcinomas Beyond Curability Borders

Optimal scoring system for clinical prognostic factors in patients with unresectable hepatocellular carcinoma (HCC) is currently uncertain. We aimed to develop and externally validate an easy to use tool, particularly for this population, and named it the "unresectable hepatocellular carcinoma prognostic index" (UHPI). We evaluated the data of patients with treatment-naive unresectable HCC who were diagnosed in the training center from 2010 to 2019 (n = 209). A simple prognostic model was developed by assigning points for each covariate in proportion to the beta coefficients in the Cox multivariable model. Predictive performance and distinction ability of the UHPI were further evaluated in an independent European validation cohort (n = 147) and compared with 11 other available models. A simple scoring system was derived, assigning 0.5/1/2 scores for six independent covariates including, the Child-Pugh score, Eastern Cooperative Oncology Group performance status, maximum tumor size, vascular invasion or extrahepatic metastasis, lymph node involvement, and alpha-fetoprotein. The UHPI score, ranging from 0 to 6, showed superior performance in prognosis prediction and outperformed 11 other staging or prognostic models, giving the highest homogeneity (c-index, 6-month and 1-year area under the receiver operator characteristic curves), lowest Akaike information criterion, and -2 log-likelihood ratio values. The UHPI score allocated well the risk of patients with unresectable HCC for mortality within the first year, using two cut-off values (low-risk, <0.5; intermediate-risk, 0.5-2; high-risk, >2). Conclusion: The UHPI score can predict prognosis better than other systems in subjects with unresectable HCC and can be used in clinical practice or trials to estimate the 6-month and 1-year survival probabilities for this group.

68Ga-PSMA PET/CT to Distinguish Brain Metastasis of Renal Cell Carcinoma From Radiation Necrosis After Stereotactic Radiosurgery

ABSTRACT

Renal cell carcinoma (RCC) is the most common primary malignancy of the kidney. Approximately 35% of patients of RCC presents with distant metastasis at initial evaluation. CT and MRI are the mainstay imaging modalities. Distinguishing radiation necrosis from tumor progression after stereotactic radiosurgery is challenging. Herein, we present a case of a 43-year-old man with RCC who was treated with stereotactic radiosurgery for brain metastases. We want to emphasize the potential value of 68Ga-PSMA PET/CT imaging in the differential diagnosis and follow-up of tumor progression from radiation necrosis in RCC patients.

Petrous Apex Cholesterol Granuloma Showing 68Ga-DOTATATE Uptake

ABSTRACT

The importance of 68Ga-DOTATATE PET/CT in the evaluation of neuroendocrine tumors is well established. However, false-positive results can occur due to inflammatory pathologies. We report a 47-year-old man who was diagnosed with a neuroendocrine tumor of the stomach. Initial 68Ga-DOTATATE PET/CT showed intense 68Ga-DOTATATE uptake in the petrous apex. Histopathological confirmation could not be obtained, thus the asymptomatic patient was followed with periodic clinical/radiologic examinations for more than 2.5 years. Therefore, this lesion was diagnosed as a cholesterol granuloma of the temporal bone. These results suggested that an initial wait-and-scan approach is a feasible management strategy for similar presentations.

Porta Hepatic Schwannoma on FDG PET/CT

ABSTRACT

Schwannomas are benign tumors that arise from Schwann cells of neural sheath. They can occur in any part of the body. However, the most common locations are the head, neck, spinal cord, and extremities. Schwannoma in the porta hepatis is extremely rare. Herein, we describe a case of porta hepatic schwannoma in a 36-year-old woman who presented with abdominal pain for a month.

FDG-Avid Erythema Nodosum Lesions of Behçet Disease Demonstrated on FDG PET/CT

ABSTRACT

Behçet disease is a rare multisystemic vasculitis that can affect all sizes and types of blood vessels. Recurrent painful erythematous nodular lesions called erythema nodosum are the most common skin lesions of Behçet disease. Herein, we present 18F-FDG PET/CT images of erythema nodosum lesions in a patient with Behçet disease.

Central Nervous System Complications of Erdheim-Chester Disease: FDG PET/CT Findings

ABSTRACT

Erdheim-Chester disease is an uncommon non-Langerhans cell histiocytosis. The diagnosis depends on imaging and histological criteria. The most common presentation is the multiple bone lesions with involvement of at least 1 more organ. We present the FDG PET/CT findings of a 19-year-old man who presented with central nervous system symptoms such as progressive polyuria, polydipsia, gait disturbances, and eye pain and was later diagnosed with Erdheim-Chester disease.

The value of parathyroid scintigraphy on lesion detection in patients with normocalcemic primary hyperparathyroidism

OBJECTIVE

Primary hyperparathyroidism (PHPT) is one of the most frequent endocrine diseases. Most of the patients with PHPT are asymptomatic, and only 20% of them become symptomatic with increasing levels of calcium. It has been reported that normocalcemic primary hyperparathyroidism (NPHPT) may be the incipient period of PHPT where calcium (Ca) levels are in normal range, and it may advance to overt PHPT. Early diagnosis of PHPT is important in order to prevent its complications. In this retrospective study, we aimed to evaluate the role of 99mTc-MIBI parathyroid scintigraphy on lesion detection in patients with NPHPT.

MATERIAL AND METHODS

The parathyroid scintigraphy database was reviewed retrospectively in patients with PHPT. 117 patients who underwent 99mTc-MIBI scintigraphy were recruited to the study. Serum calcium level above 10.5mg/dl was considered as hypercalcemia.

RESULTS

A total of 117 patients' (female/male:98/19) mean serum PTH levels (mean±SD) were 149±97 pg/ml in normocalcemic group (Ca:9.6±0.6mg/dL, n:38) and 189±135 pg/ml in hypercalcemic group (Ca:11.4±0.6mg/dL, n:79) (p:0.072). The sex and ages were not different between the scintigraphy positive and negative groups, but the lesion detection rates with parathyroid scintigraphy were 42% in normocalcemic group and 81% in hypercalcemic group (p<0.0001).

CONCLUSIONS

Several factors including serum Ca, the imaging protocol, existence of multiglandular disease, the size and MIBI biokinetics of the adenoma may influence lesion detectability in parathyroid scintigraphy. Although high serum Ca level is an important parameter in predicting its success, parathyroid scintigraphy remains a valuable diagnostic method even in patients with NPHPT.

Calcified Adrenal Metastasis of High-Grade Osteosarcoma on FDG PET/CT

ABSTRACT

Classic type of high-grade osteosarcoma is the most common type of skeletal malignancy in children and adolescents. Metastasis of osteosarcoma frequently occurs in the lung. Adrenal metastasis of osteosarcoma is extremely rare, with only few reported case in the literature. Herein, we present the case of a 13-year-old boy with adrenal metastasis of high-grade osteosarcoma, which was seen as a solitary calcified hypermetabolic adrenal lesion on FDG PET/CT.

FDG-Avid Lung Nodule Formation by the Use of Hemostatic Powder: A Potential Cause of False-Positive FDG PET/CT

ABSTRACT

FDG PET/CT is used in the diagnosis and follow-up of various malignant tumors and changes patient management in routine clinical practice. However, inflammatory, infectious, physiological, and technical causes and benign pathological conditions may lead to false-positive FDG uptake. We report a case of a 59-year-old man who was considered having a false-positive FDG-PET pulmonary nodular lesion in favor of metastasis, which was formed by the use of hemostatic powder.

Endotracheal metastasis of colon cancer on FDG PET/CT

Although tracheal involvement of lung cancer is frequently seen, endotracheal metastasis of colon cancer is a rare entity. Since endotracheal lesion gives no symptom until tracheal lumen nearly occluded, the diagnosis of endotracheal metastasis could be challenging. F-18 fluorodeoxyglucose positron emission tomography/computed tomography may be crucial to detect this unusal distant metastasis of colon cancer. Herein, we report FDG avid endotracheal lesion that was confirmed as metastasis from colon cancer in 56-year-old female patient.

Differences in PET/CT standardized uptake values involvement and survival compared to histologic subtypes of lung adenocarcinoma

PURPOSE

Lung adenocarcinoma is histologically diverse but has distinct histologic growth patterns. There is no consensus on the clinical benefit of this histologic model. We aimed to evaluate the differences in the distribution of the preoperative primary tumor positron emission tomography (PET)/computed tomography (CT) standardized uptake values (SUVs) and survival in the lung adenocarcinoma subtypes.

METHODS

We retrospectively evaluated the data of 107 patients with resected lung adenocarcinoma who had preoperative PET/CT between 2005 and 2017 in a single center. Patients had lepidic, acinar, papillary, micropapillary, and solid histologic subtypes. We compared fluorodeoxyglucose SUVs and survival data of histologic subtypes.

RESULTS

The median age of the patients was 62 years (40-75), 76.4% were male, the median SUVmax was 9.4 (1-36.7), and the median follow-up time was 29 months (3-135 months). The median overall survival (OS) was 71 months and the median progression-free survival (PFS) was 33 months. SUVmax was significantly different in histologic subtypes: values for papillary, micropapillary, solid, acinar, and lepidic subtypes were 9.7, 8, 12, 9.1, and 3.9, respectively (p = 0.000). Solid predominant adenocarcinoma had significantly higher SUVmax than the other subtypes (p = 0.001). Lepidic predominant adenocarcinoma had significantly lower SUVmax than the other subtypes (p = 0.000). There was no significant difference in OS between histologic subtypes (p = 0.66), but PFS was significantly different between the groups (p = 0.017), and the solid subtype had a shorter PFS than the other histologic subtypes.

CONCLUSION

Lung adenocarcinoma consists of a diverse group of diseases. Different SUVmax values are seen in different histologic subtypes of nonmetastatic lung adenocarcinoma. Solid predominant types have high SUVmax values while lepidic predominant types have lower SUVmax values. The solid subtype had a shorter PFS than the other histologic subtypes.

Unexpected radiation pneumonitis after SIRT with significant decrease in DLCO with internal radiation exposure: a case report

Background

In the last years, Selective Internal Radiation Therapy (SIRT), using biocompatible Yttrium-90 (90Y) labeled microspheres have emerged for the treatment of malignant hepatic tumors. Unfortunately, a significant part of 90Y-labeled microspheres may shunt to the lungs after intraarterial injection. It can be predictable by infusing technetium-99 m-labeled macro-aggregated albumin particles through a catheter placed in the proper hepatic artery depending on the lobe to be treated with performing a quantitative lung scintigraphy. Radiation pneumonitis (RP) can occur 1 to 6 months after the therapy, which is a rare but severe complication of SIRT. Prompt timing of steroid treatment is important due to its high mortality rate. On the other hand, pulmonary diffusion capacity measured by carbon monoxide (DLCO) is an excellent way to measure the diffusing capacity because carbon monoxide is present in minimal amount in venous blood and binds to hemoglobin in the same manner as oxygen. Some authors reported that the most consistent changes after radiation therapy (RT) are recorded with this quantitative reproducible test. The relationship between the proportional reductions in DLCO and the severity of RP developing after this therapy may prove to be clinically significant.

Case presentation

We herein present a patient who developed RP after SIRT that could be quantified using DLCO. To the best of our knowledge, this case is the first who developed unexpected RP after SIRT with significant decrease in DLCO with internal radiation exposure.

Conclusions

RP is a very rare complication and may lead to a fatal outcome. Decline in DLCO could be a valuable parameter for follow-up and to identify potential candidates for RP and could be also another trigger for administration of steroid therapy with prompt timing in this patient group.

VEGF-VEGFR pathway seems to be the best target in hepatic epithelioid hemangioendothelioma: A case series with review of the literature

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor originating from endothelial cells. Clinical aspect of the disease covers a wide spectrum from a low-grade tumor to a fatal cancer. Most common sites of EHE are reported as lung, liver and bone. Hepatic EHE (HEHE) is a clinical form with an incidence of less than 1 person in a million. Due to rarity of the disease, there is no standard therapy established. Surgery and liver transplantation still seem to be the best approach if possible. However, most of the patients present with unresectable or metastatic disease. Many conventional chemotherapeutic agents and antiangiogenic drugs have been reported previously in the literature with inconsistent outcomes. Here we report 4 cases of HEHE, who benefit distinctly from anti-VEGF treatments in different settings. While combination of paclitaxel and bevacizumab resulted in partial response in 3 patients, one of them also achieved long-term disease stabilization with bevacizumab maintenance with no adverse event. Two of the patients had clear benefit from pazopanib during the course of disease. One patient was treated with thalidomide for 18 months with stable disease, and is still being followed without any treatment. Although targeting VEGF-VEGFR pathway seems to be the best approach in HEHE, randomized studies are urgently needed to support these findings.

Recurrent 99mTc Sestamibi Emboli in the Lungs Revealed on Consecutive Rest and Stress Single-Photon Emission Computed Tomography/Computed Tomography Myocardial Perfusion Images

Many causes of incidental focal uptake on raw data images using myocardial perfusion imaging, including malignant diseases, metastatic processes, benign pathologies, and physiological conditions, have been reported in the literature. However, iatrogenic ^99mTc sestamibi emboli have not yet been reported. Herein, we demonstrated iatrogenic ^99mTc sestamibi embolization on consecutive rest and stressed myocardial perfusion images at different locations.

Change in standardized uptake values in delayed 18F-FDG positron emission tomography images in hepatocellular carcinoma

Delayed 18F-2-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography (PET) imaging has been associated with improved diagnostic yield in several malignancies; however, data on the use of delayed imaging in patients with hepatocellular carcinoma (HCC) is scarce. This study aimed to examine tumoral and background standardized uptake value (SUV) alterations in dual-phase F-FDG PET/computed tomography (CT) imaging.Fifty-two HCC cases underwent dual-time-point F-FDG PET/CT examination where early and delayed images were obtained. The maximum and mean SUVs (SUVmax and SUVmean) of the tumor were determined for both time points. Similarly, the average SUVmean were also determined for background (liver, soft tissue, and spleen). Changes in tumoral and background SUV between early and delayed images were examined.The mean age was 62.0 ± 12.9 years (range, 20-88 years) and the majority of the patients were men (86.5%). Tumor SUVs, both tumor SUVmean and tumor SUVmax, significantly increased at delayed images when compared to early images. In contrast, the average SUVmean for the liver, soft tissue, and spleen significantly decreased at delayed images.A significant increase in tumor SUV in delayed images in contrast to a significant decrease in background SUVs suggests that delayed images in HCC may contribute to diagnostic performance through a potential increase in the contrast between the tumor and background. However, further studies with larger sample sizes including patients with benign lesions and different grades of the disease are warranted to better elucidate the diagnostic contribution as well as the association of delayed imaging values with prognosis.

Effect of PET/CT standardized uptake values on complete response to treatment before definitive chemoradiotherapy in stage III non-small cell lung cancer

PURPOSE

The standard treatment for patients with stage III non-small cell lung cancer (NSCLC), unsuitable for resection and with good performance, is definitive radiotherapy with cisplatin-based chemotherapy. Our aim is to evaluate the effect of the maximum value of standardized uptake values (SUVmax) of the primary tumor in positron emission tomography-computed tomography (PET/CT) before treatment on complete response (CR) and overall survival.

METHODS

The data of 73 stage III NSCLC patients treated with concurrent definitive chemoradiotherapy (CRT) between 2008 and 2017 and had PET/CT staging in the pretreatment period were evaluated. ROC curve analysis was performed to determine the ideal cut-off value of pretreatment SUVmax to predict CR.

RESULTS

Median age was 58 years (range 27-83 years) and 66 patients were male (90.4%). Median follow-up time was 18 months (range 3-98 months); median survival was 23 months. 1-year overall survival (OS) rate and 5-year OS rate were 72 and 19%, respectively. Median progression-free survival (PFS) was 9 months; 1-year PFS rate and 5-year PFS rate were 38 and 19%, respectively. The ideal cut-off value of pretreatment SUVmax that predicted the complete response of CRT was 12 in the ROC analysis [AUC 0.699 (0.550-0.833)/P < 0.01] with a sensitivity of 83%, and specificity of 55%. In patients with SUVmax < 12, CR rate was 60%, while, in patients with SUV ≥ 12, it was only 19% (P = 0.002). Median OS was 26 months in patients with pretreatment SUVmax < 12, and 21 months in patients with SUVmax ≥ 12 (HR = 2.93; 95% CI 17.24-28.75; P = 0.087). CR rate of the whole patient population was 26%, and it was the only factor that showed a significant benefit on survival in both univariate and multivariate analyses.

CONCLUSION

Pretreatment SUVmax of the primary tumor in PET/CT may predict CR in stage III NSCLC patients who were treated with definitive CRT. Having clinical CR is the only positive predictive factor for prolonged survival.

The effect of selective internal radiation therapy with yttrium-90 resin microspheres on lung carbon monoxide diffusion capacity

Background

Selective internal radiation therapy (SIRT) with embolization of branches of the hepatic artery is a valuable therapeutic tool for patients with hepatic malignancies; however, it is also associated with lung injury risk due to shunting. Diffusion capacity of the lungs for carbon monoxide (DLCO) is a clinically significant lung function test, and worsening in DLCO is suggested to reflect a limited gas exchange reserve caused by the potential toxicity of chemoradiotherapy or it may be a marker of related lung injury. This study aimed to examine the changes in DLCO during SIRT with resin microspheres in newly treated and retreated patients. Forty consecutive patients who received SIRT for a variety of malignant conditions were included. All subjects were treated with Yttrium-90 labelled resin microspheres. DLCO tests were performed after the procedures. In addition, patients were specifically followed for radiation pneumonitis.

Results

The mean DLCO did not significantly change after the first (82.8 ± 19.4 vs. 83.1 ± 20.9, p = 0.921) and the second treatments (87.4 ± 19.7 vs. 88.6 ± 23.2, p = 0.256). Proportion of patients with impaired DLCO at baseline was not altered significantly after the first (37.5 vs. 45.0%, p = 0.581) and the second treatments (27.3 vs. 27.3%, p = 1.000). Also, percent change in DLCO values did not correlate with radiation dose, lung shunt fraction, or lung exposure dose (p > 0.05 for all comparisons). None of the patients developed radiation pneumonitis.

Conclusions

Our results suggest that no significant change in DLCO in association with SIRT occurs, both after the first or the second treatment sessions. Further larger studies possibly with different protocols are warranted to better delineate DLCO changes after SIRT in a larger spectrum of patients.

Patients with Takayasu's arteritis having persistent acute-phase response usually have an increased major vessel uptake by 18F-FDG-PET/CT

OBJECTIVES

Although not uniformly accepted, an increased uptake by 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in large vessels is accepted to be a sign of active disease in Takayasu's arteritis (TAK). We aimed to investigate the value of 18F-FDG-PET/CT for clinical assessment in a subset of TAK patients having a persistent acute-phase response (APR) without any signs or symptoms of clinical disease activity.

METHOD

We studied 14 patients (mean age: 38.6 ± 13.9 years, Female/Male: 11/3, and disease duration: 5.7 ± 5 years). Patients were clinically inactive (according to the definition of activity by Kerr et al.), while categorized as having "persistent" disease activity by physician's global assessment due only to APR. 18F-FDG uptake was graded using a four-point scale from grade 0 (no uptake present) to grade 3 (high grade: uptake higher than that of liver). Any uptake in major vessels with a grade ≥ 2 was accepted to be "active."

RESULTS

Mean erythrocyte sedimentation rate was 50.8 ± 13.2 mm/hour and mean C-reactive protein level was 28.5 ± 22.1 mg/L. Active vasculitic lesions were observed by 18F-FDG-PET/CT in 9 of 14 (64.3%) patients. The median number of active vascular lesions was 2 (range: 1-5). A step-up treatment change was decided in 8 patients according to 18F-FDG-PET/CT results.

CONCLUSION

We observed increased 18F-FDG uptake in the majority of TAK patients with an increased APR, but clinically silent disease. 18F-FDG-PET/CT showed the presence and localization of active inflammation in the aorta and its branches. Although specificity for observed lesions is not clear, 18F-FDG-PET/CT imaging may influence physician's assessment of clinical activity and treatment choices in TAK.

False Positive FDG PET/CT Resulting from Fibrous Dysplasia of the Bone in the Work-Up of a Patient with Bladder Cancer: Case Report and Review of the Literature

Fibrous dysplasia of the bone (FDB) is a common, genetic, developmental disorder with a benign course. FDB can be seen anywhere throughout the skeleton. It is usually asymptomatic and found incidentally on imaging studies that are performed for other purposes. Although whole body 18 F-flourodeoxyglucose PET/CT (FDG PET/CT) is widely used in tumor imaging, infections and benign pathologies like FDB may cause false positive results. Herein we report the case of a 48-year-old FDB patient with transitional cell carcinoma of the urinary bladder. Restaging FDG PET/CT showed multiple mild to moderate hypermetabolic bone lesions which were initially misinterpreted as bone metastases. In this case report, we aimed to guide physicians in evaluating bone lesions in cancer patients with FDB in the light of the literature.

Initial mini-mental state and cerebral perfusion in Alzheimer's disease

PURPOSE

The relationship between the initial mini-mental state examination (MMSE) score and cerebral perfusion was evaluated in patients with Alzheimer's disease (AD).

METHODS

In the study single photon emission computed tomography (SPECT) images of the brains of 40 AD patients were compared with the brain scans of 10 healthy controls. Each patient underwent MMSE analysis at initial evaluation as well as Tc-99 m hexamethylpropyleneamine oxine (HMPAO) brain SPECT. The patients were followed up for at least 42 months.

RESULTS

The regional cerebral blood flow (rCBF) values for patients were found to be significantly decreased for all cerebral lobes compared to the control subjects and p-values were calculated to be less than 0.001 except for occipital lobes. The most statistically significant correlation between the MMSE scores and rCBF values was determined for the left temporal lobe (p < 0.0001). A significant correlation was also found for the right temporal lobe (p < 0.005). A minimal statistically significant correlation was found for the frontal lobes and the left parietal lobe (p < 0.05).

CONCLUSIONS

The overall cerebral perfusion was decreased except in the occipital lobes in AD cases with low initial MMSE scores and there was a significant relationship between the decrease in perfusion of the temporal/frontal lobes and the left parietal lobe with the decrease in the initial MMSE scores. The most significant relationship between the decrease in the initial MMSE scores and the rCBF values was determined for the temporal lobes (especially for the left temporal lobe). It was also found that the left frontal lobe was affected from the beginning of the disease.