F-18 FDG PET/CT in pulmonary artery sarcoma: clinical vignette

Pulmonary artery sarcomas (PAS’s) are extremely rare malignant tumors that arise from the endothelial lining of the pulmonary arteries. On CT scans PAS’s appear as intraluminal filling defects in the pulmonary arteries, mimicking pulmonary embolism (PE). Due to the similarities in radiographic features as well as in clinical presentation, PAS’s are usually misdiagnosed as pulmonary embolism. Since PASs are F-18 FDG avid, F-18 FDG PET/CT scan is a useful imaging tool for differentiating between these two conditions, as shown in this case report. We report a case of a 60-year-old woman presented with a 6-month history of chest pain, dyspnea on exertion, non-productive cough and weight loss. The initial CT pulmonary artery angiography showed extensive intraluminal mass in the pulmonary trunk and left pulmonary artery, diagnosed as massive pulmonary embolism. Since there was no clinical improvement after anticoagulant therapy, CT pulmonary angiography was repeated, and with no change observed in the intraluminal filling defect in pulmonary trunk, the possibility of tumor was raised. For further evaluation of a possible malignancy, F-18 FDG PET/CT was performed. It showed increased FDG uptake, suspicious for an aggressive tumor, in the intraluminal lesion of the pulmonary trunk and along the wall of the left pulmonary artery. There was no extrathoracic abnormality seen on PET/CT scan. Histopathological finding after complete pulmonary artery resection showed high grade undifferentiated pleomorphic sarcoma. F-18 FDG PET/CT is a useful tool for differentiating between pulmonary embolism and malignant intraluminal mass, and at the same time it enables the proper staging of the malignancy. < /p

The nonspecific lymph node uptake of 18F-choline in patients with prostate cancer — a prospective observational study

BACKGROUND: The aim of this study was to observe and characterize the nonspecific 18F-choline lymph node uptake in patients with prostate cancer. MATERIAL AND METHODS: In this single center, prospective observational study which was done in University Hospital Center Zagreb between December 2012 and October 2014, 69 patients (median age 71 years; range 50–92) with prostate cancer were included. Patients underwent 18F-choline PET/CT for staging or restaging of prostate cancer. The mean follow-up period was 11.5 months. Kruskal-Wallis test was used to find out if the differences between SUV values of specific and nonspecific accumulation of the tracer are statistically significant. RESULTS: Nonspecific accumulation of 18F-choline in lymph nodes was found in 36 patients (52.7%). Most of these findings (n = 24) were nonspecific accumulation of the tracer in mediastinal lymph nodes. Other sites of nonspecific tracer uptake were pulmonary hila (n = 20), inguinal lymph nodes (n = 15), and axillary lymph nodes (n = 10). Mean SUV values for mediastinal lymph nodes, pulmonary hila, axillary and inguinal lymph nodes were 4.8, 4.3, 3.1 and 4.1, respectively. Mean SUV value of nonspecific sites of tracer accumulation was lower (not significantly; (p = 0.2) than tracer uptake values measured in metastases sites (bone metastases mean SUVmax value — 13.2, metastatic lymph nodes mean SUVmax value — 9.2). CONCLUSIONS: 18F-choline PET/CT is a valuable and an established functional diagnostic imaging method for staging and restaging prostate cancer. However, nonspecific uptake of the tracer can often be seen in lymph nodes not related to primary disease. Patient history, clinical examination, laboratory tests and correlation with other imaging methods, must be taken into consideration when interpreting 18F-choline PET/CT findings

F-18 FDG PET/CT in pulmonary artery sarcoma: clinical vignette

Pulmonary artery sarcomas (PAS's) are extremely rare malignant tumors that arise from the endothelial lining of the pulmonary arteries. On CT scans PAS's appear as intraluminal filling defects in the pulmonary arteries, mimicking pulmonary embolism (PE). Due to the similarities in radiographic features as well as in clinical presentation, PAS's are usually misdiagnosed as pulmonary embolism. Since PASs are F-18 FDG avid, F-18 FDG PET/CT scan is a useful imaging tool for differentiating between these two conditions, as shown in this case report. We report a case of a 60-year-old woman presented with a 6-month history of chest pain, dyspnea on exertion, non-productive cough and weight loss. The initial CT pulmonary artery angiography showed extensive intraluminal mass in the pulmonary trunk and left pulmonary artery, diagnosed as massive pulmonary embolism. Since there was no clinical improvement after anticoagulant therapy, CT pulmonary angiography was repeated, and with no change observed in the intraluminal filling defect in pulmonary trunk, the possibility of tumor was raised. For further evaluation of a possible malignancy, F-18 FDG PET/CT was performed. It showed increased FDG uptake, suspicious for an aggressive tumor, in the intraluminal lesion of the pulmonary trunk and along the wall of the left pulmonary artery. There was no extrathoracic abnormality seen on PET/CT scan. Histopathological finding after complete pulmonary artery resection showed high grade undifferentiated pleomorphic sarcoma. F-18 FDG PET/CT is a useful tool for differentiating between pulmonary embolism and malignant intraluminal mass, and at the same time it enables the proper staging of the malignancy.

Gigantocelularni aortitis dijagnosticiran PET/CT-om – paraneoplastički sindrom? [Giant cell aortitis diagnosed with PET/CT - paraneoplastic syndrome?]

Vasculitides are heterogenic group of autoimmune connective tissue diseases which often present difficulties in early diagnosing. Giant cell arteritis is vasculitis of large and medium arteries. It predominantly presents with symptoms of affection of the external carotid artery branches. Furthermore, the only symptoms can be constitutional. In clinical practice, vasculitides are sometimes considered as paraneoplastic, but no definite association with malignancies has been established and the mechanisms are still debated. The gold standard for diagnosing giant cell arteritis is a positive temporal artery biopsy, but the results can often be false negative. Additionally, more than half of the patients have aorta and its main branches affected. Considering aforementioned, imaging studies are essential in confirming large-vessel vasculitis, amongst which is highly sensitive PET/CT. We present the case of a 70-year-old female patient with constitutional symptoms and elevated sedimentation rate. After extensive diagnostic tests, she was admitted to our Rheumatology unit. Aortitis of the abdominal aorta has been confirmed by PET/CT and after the introduction of glucocorticoids the disease soon went into clinical and laboratory remission. Shortly after aortitis has been diagnosed, lung carcinoma was revealed of which the patient died. At the time of the comprehensive diagnostics, there was no reasonable doubt for underlying malignoma. To the best of our knowledge, there are no recent publications concerning giant cell arteritis and neoplastic processes in the context of up-to-date non-invasive diagnostic methods (i.e. PET/CT). In the light of previous research results, we underline that the sensitivity of PET/CT is not satisfactory when estimating cancer dissemination in non-enlarged lymph nodes and that its value can at times be overestimated

Korelacija scintigrafije pluća Ga-67 s RTG pluća i testovima plućne funkcije u oboljelih od sarkoidoze

In order to assess the usefulness of Ga-67 scintigraphy in the evaluation of sarcoidosis activity, 44 patients including 14, 20 and 10 patients with radiologic stage I, II and III, respectively, were examined. Control group consisted of 22 subjects with healthy lungs who underwent Ga-67 scintigraphy for extrathoracic disease. An objective method of quantitative computer analysis was used on scintigram interpretation. Results were expressed as mean impulse count per pixel of the given area in the left and right hilar region, left and right lung, and in the area of focal accumulation if present. In sarcoidosis patients, the mean impulse count was statistically significantly higher in all regions than in the control group (p<0.0001 for left hilum, right hilum and right lung; and p<0.001 for left lung). The mean impulse count showed correlation with pathologic finding. Pathologic accumulation of Ga-67 in the hilar region was evident in 37 (84.1%) patients, and in the region of pulmonary parenchyma in 31 (70.5%) patients, and showed statistically significant correlation with radiologic staging of sarcoidosis (p<0.01). However, scintigraphy supplemented radiologic staging by providing additional information on the disease extent. In 35.7% of patients with X-ray stage I sarcoidosis, scintigraphy revealed pathologic accumulation of Ga-67 also in pulmonary parenchyma, whereas in as many as 70% of patients with X-ray stage III sarcoidosis the pathologic accumulation of Ga-67pointed to the disease activity in the lymph nodes of the hilum. Only three (6.7%) patients were free from any form of pathologic Ga-67 accumulation. The patients with pathologic Ga-67 accumulation in the lung parenchyma (n=31) had a more severe form of the disease with lower values of pulmonary function tests, i.e. forced vital capacity (FVC), forced expiratory volume in first second (FEV 1), diffusion capacity for carbon monoxide (DLCO) and arterial blood partial oxygen pressure (pO 2). Forced vital capacity as an indicator of ventilation restrictive impairments was statistically significantly lower in the group of patients with pathologic accumulation of Ga-67 in pulmonary parenchyma as compared with the group of patients without it (p<0.01). The decrease in diffusion capacity correlated statistically significantly with the increase in the pathologic accumulation of Ga-67 in pulmonary parenchyma (p<0.01). Thus, lung Ga-67scintigraphy was found to be a highly sensitive marker of the extent and activity of sarcoidosis, however, due to the low specificity of the method its use in good clinical practice should be reserved for diagnostically and therapeutically vague cases, with due consideration of the irradiation dose and cost.Radi procjene značenja scintigrafije pluća s Ga-67 u oboljelih od sarkoidoze ispitana su 44 bolesnika, i to 14 u I., 20 u II. i 10 u III. radiološkom stadiju bolesti. Kontrolnu skupinu činile su 22 osobe sa zdravim plućima u kojih je scintigrafija s Ga-67 rađena zbog ekstratorakalne bolesti. Pri tumačenju scintigrama rabljena je objektivna metoda kvantitativne kompjutorske analize gdje se rezultat izražava kao prosječan broj impulsa po kvadrantu zadane regije u području lijevog i desnog hilusa, lijevog i desnog pluća, te u području žarišnog nakupljanja ako je ono izraženo. U oboljelih od sarkoidoze prosječan broj impulsa za svaku regiju bio je statistički značajno viši od onoga u kontrolnoj skupini (p<0,0001 za lijevi hilus, desni hilus i desno pluće, te p<0,001 za lijevo pluće). Prosječan broj impulsa pratio je radiološki nalaz. Patološko nakupljanje Ga-67 u području hilusa bilo je očito u 37(84,1%) bolesnika, a u području plućnog parenhima u 31 (70,5%) bolesnika, uza statistički značajnu korelaciju s radiološkim stadijem sarkoidoze (p<0,01). Međutim, scintigrafija je dopunila radiološko određivanje stadija bolesti pruživši dodatne informacije o proširenosti bolesti. Tako je kod 35,7% bolesnika u I. rtg stadiju bolesti patološko nakupljanje Ga-67 bilo očito i u plućnom parenhimu, dok je u čak 70% bolesnika s III. rtg stadijem patološko nakupljanje Ga-67 upućivalo na aktivnost procesa i u limfnim čvorovima hilusa. Samo troje (6,7%) bolesnika nije imalo patološko nakupljanje Ga-67 u bilo kojem obliku. Bolesnici s patološkim nakupljanjem Ga-67 u plućnom parenhimu (n=31) imali su teži oblik bolesti s nižim vrijednostima testova plućnih funkcija, tj. forsiranog vitalnog kapaciteta, forsiranog ekspiracijskog volumena u prvoj sekundi, difuzijskog kapaciteta za ugljični monoksid i parcijalnog tlaka kisika u arterijskoj krvi. Forsirani vitalni kapacitet kao pokazatelj restriktivnih smetnja ventilacije bio je statistički značajno niži u skupini bolesnika s patološkim nakupljanjem Ga-67 u plućnom parenhimu u usporedbi sa skupinom bez patološkog nakupljanja (p<0,01). Pad difuzijskog kapaciteta je statistički značajno korelirao s porastom patološkog nakupljanja Ga-67 u plućnom parenhimu (p<0,01). Dakle, scintigrafija pluća s Ga-67 vrlo je osjetljiv biljeg proširenosti i aktivnosti kod sarkoidoze, međutim, ima nisku specifičnost, pa ovu metodu u dobroj kliničkoj praksi treba rabiti u dijagnostički i terapijski dvojbenim slučajevima, vodeći pritom računa o dozi ozračivanja i cijeni

Korelacija scintigrafije pluća Ga-67 s RTG pluća i testovima plućne funkcije u oboljelih od sarkoidoze

In order to assess the usefulness of Ga-67 scintigraphy in the evaluation of sarcoidosis activity, 44 patients including 14, 20 and 10 patients with radiologic stage I, II and III, respectively, were examined. Control group consisted of 22 subjects with healthy lungs who underwent Ga-67 scintigraphy for extrathoracic disease. An objective method of quantitative computer analysis was used on scintigram interpretation. Results were expressed as mean impulse count per pixel of the given area in the left and right hilar region, left and right lung, and in the area of focal accumulation if present. In sarcoidosis patients, the mean impulse count was statistically significantly higher in all regions than in the control group (p<0.0001 for left hilum, right hilum and right lung; and p<0.001 for left lung). The mean impulse count showed correlation with pathologic finding. Pathologic accumulation of Ga-67 in the hilar region was evident in 37 (84.1%) patients, and in the region of pulmonary parenchyma in 31 (70.5%) patients, and showed statistically significant correlation with radiologic staging of sarcoidosis (p<0.01). However, scintigraphy supplemented radiologic staging by providing additional information on the disease extent. In 35.7% of patients with X-ray stage I sarcoidosis, scintigraphy revealed pathologic accumulation of Ga-67 also in pulmonary parenchyma, whereas in as many as 70% of patients with X-ray stage III sarcoidosis the pathologic accumulation of Ga-67pointed to the disease activity in the lymph nodes of the hilum. Only three (6.7%) patients were free from any form of pathologic Ga-67 accumulation. The patients with pathologic Ga-67 accumulation in the lung parenchyma (n=31) had a more severe form of the disease with lower values of pulmonary function tests, i.e. forced vital capacity (FVC), forced expiratory volume in first second (FEV 1), diffusion capacity for carbon monoxide (DLCO) and arterial blood partial oxygen pressure (pO 2). Forced vital capacity as an indicator of ventilation restrictive impairments was statistically significantly lower in the group of patients with pathologic accumulation of Ga-67 in pulmonary parenchyma as compared with the group of patients without it (p<0.01). The decrease in diffusion capacity correlated statistically significantly with the increase in the pathologic accumulation of Ga-67 in pulmonary parenchyma (p<0.01). Thus, lung Ga-67scintigraphy was found to be a highly sensitive marker of the extent and activity of sarcoidosis, however, due to the low specificity of the method its use in good clinical practice should be reserved for diagnostically and therapeutically vague cases, with due consideration of the irradiation dose and cost.Radi procjene značenja scintigrafije pluća s Ga-67 u oboljelih od sarkoidoze ispitana su 44 bolesnika, i to 14 u I., 20 u II. i 10 u III. radiološkom stadiju bolesti. Kontrolnu skupinu činile su 22 osobe sa zdravim plućima u kojih je scintigrafija s Ga-67 rađena zbog ekstratorakalne bolesti. Pri tumačenju scintigrama rabljena je objektivna metoda kvantitativne kompjutorske analize gdje se rezultat izražava kao prosječan broj impulsa po kvadrantu zadane regije u području lijevog i desnog hilusa, lijevog i desnog pluća, te u području žarišnog nakupljanja ako je ono izraženo. U oboljelih od sarkoidoze prosječan broj impulsa za svaku regiju bio je statistički značajno viši od onoga u kontrolnoj skupini (p<0,0001 za lijevi hilus, desni hilus i desno pluće, te p<0,001 za lijevo pluće). Prosječan broj impulsa pratio je radiološki nalaz. Patološko nakupljanje Ga-67 u području hilusa bilo je očito u 37(84,1%) bolesnika, a u području plućnog parenhima u 31 (70,5%) bolesnika, uza statistički značajnu korelaciju s radiološkim stadijem sarkoidoze (p<0,01). Međutim, scintigrafija je dopunila radiološko određivanje stadija bolesti pruživši dodatne informacije o proširenosti bolesti. Tako je kod 35,7% bolesnika u I. rtg stadiju bolesti patološko nakupljanje Ga-67 bilo očito i u plućnom parenhimu, dok je u čak 70% bolesnika s III. rtg stadijem patološko nakupljanje Ga-67 upućivalo na aktivnost procesa i u limfnim čvorovima hilusa. Samo troje (6,7%) bolesnika nije imalo patološko nakupljanje Ga-67 u bilo kojem obliku. Bolesnici s patološkim nakupljanjem Ga-67 u plućnom parenhimu (n=31) imali su teži oblik bolesti s nižim vrijednostima testova plućnih funkcija, tj. forsiranog vitalnog kapaciteta, forsiranog ekspiracijskog volumena u prvoj sekundi, difuzijskog kapaciteta za ugljični monoksid i parcijalnog tlaka kisika u arterijskoj krvi. Forsirani vitalni kapacitet kao pokazatelj restriktivnih smetnja ventilacije bio je statistički značajno niži u skupini bolesnika s patološkim nakupljanjem Ga-67 u plućnom parenhimu u usporedbi sa skupinom bez patološkog nakupljanja (p<0,01). Pad difuzijskog kapaciteta je statistički značajno korelirao s porastom patološkog nakupljanja Ga-67 u plućnom parenhimu (p<0,01). Dakle, scintigrafija pluća s Ga-67 vrlo je osjetljiv biljeg proširenosti i aktivnosti kod sarkoidoze, međutim, ima nisku specifičnost, pa ovu metodu u dobroj kliničkoj praksi treba rabiti u dijagnostički i terapijski dvojbenim slučajevima, vodeći pritom računa o dozi ozračivanja i cijeni

GIANT CELL AORTITIS DIAGNOSED WITH PET/CT – PARANEOPLASTIC SYNDROME?

Vaskulitisi se ubrajaju u skupinu sistemskih autoimunosnih bolesti vezivnog tkiva i često se teško pravodobno dijagnosticiraju. Gigantocelularni arteritis zahvaća velike i srednje velike krvne žile. Najčešće se očituje simptomima vezanim uz zahvaćanje temporalne arterije, a može se prezentirati i općim simptomima. U kliničkoj praksi vaskulitisi se u ­nekim slučajevima smatraju paraneoplastičkim sindromom, no dokaz povezanosti ovih entiteta ostaje tema rasprave. Zlatni standard u postavljanju dijagnoze gigantocelularnog arteritisa jest biopsija temporalne arterije. U praksi je pak rezultat pretrage često lažno negativan, a u više od polovice bolesnika zahvaćeni su aorta i njezini glavni ogranci. Važnu ulogu u dijagnosticiranju vaskulitisa velikih krvnih žila imaju neinvazivne slikovne metode, među kojima se PET/CT pokazao ­visoko osjetljivim. Prikazan je slučaj 70-godišnje pacijentice koja je zbog općih simptoma i upalnih parametara, nakon u nekoliko navrata učinjene opsežne obrade, ponovo hospitalizirana. PET/CT-om verificiran je abdominalni aortitis te je uz terapiju glukokortikoidima brzo došlo do kliničke i laboratorijske remisije bolesti. Kratko nakon postavljene dijagnoze aortitisa verificiran je malignom zbog kojeg je bolesnica preminula, a za koji u vrijeme ekstenzivne dijagnostičke obrade nije bilo dokaza. Prema našim saznanjima, nema novijih radova koji su u kontekstu mogućnosti suvremene neinvazivne dijagnostike (tj. PET/CT-a) promatrali povezanost gigantocelularnog arteritisa i neoplazma. Nadalje, skrećemo pozornost na činjenicu da osjetljivost PET/CT-a ne zadovoljava ako je riječ o diseminaciji malignoma u nepovećane limfne čvorove te da se vrijednost ove pretrage u kliničkoj praksi nerijetko precjenjuje.Vasculitides are heterogenic group of autoimmune connective tissue diseases which often present difficulties in early diagnosing. Giant cell arteritis is vasculitis of large and medium arteries. It predominantly presents with symptoms of affection of the external carotid artery branches. Furthermore, the only symptoms can be constitutional. In clinical practice, vasculitides are sometimes considered as paraneoplastic, but no definite association with malignancies has been established and the mechanisms are still debated. The gold standard for diagnosing giant cell arteritis is a positive temporal artery ­biopsy, but the results can often be false negative. Additionally, more than half of the patients have aorta and its main branches affected. Considering aforementioned, imaging studies are essential in confirming large-vessel vasculitis, amongst which is highly sensitive PET/CT. We present the case of a 70-year-old female patient with constitutional symptoms and elevated sedimentation rate. After extensive diagnostic tests, she was admitted to our Rheumatology unit. Aortitis of the abdominal aorta has been confirmed by PET/CT and after the introduction of glucocorticoids the disease soon went into clinical and laboratory remission. Shortly after aortitis has been diagnosed, lung carcinoma was revealed of which the ­patient died. At the time of the comprehensive diagnostics, there was no reasonable doubt for underlying malignoma. To the best of our knowledge, there are no recent publications concerning giant cell arteritis and neoplastic processes in the context of up-to-date non-invasive diagnostic methods (i.e. PET/CT). In the light of previous research results, we underline that the sensitivity of PET/CT is not satisfactory when estimating cancer dissemination in non-enlarged lymph nodes and that its value can at times be overestimated

Primjena inhibitora kinaza u liječenju bolesnika s uznapredovalim rakom štitnjače

Although most patients with thyroid cancer have a favorable clinical course, some patients develop a more aggressive type of cancer and exhibit more rapid disease progression with worse prognosis. Those patients usually exhibit mutations of proteins such as tyrosine kinase enzymes that play a significant role in regulation of tumor proliferation and spreading. Development of targeted therapies is based on the inhibition of mutated kinases which are involved in the MAPK signaling pathway. The aim of this study was to present the initial results of clinical experience with kinase inhibitors in patients with metastatic differentiated thyroid cancer (DT C), poorly differentiated thyroid cancer (PDT C), and medullary thyroid cancer (MTC) who exhibited rapid disease progression. A total of 17 adult patients (11 women, mean age 53.3 years) managed for progressive, metastatic disease were included in the study. Twelve patients with DT C and PDT C were previously tested for BRAF mutations, of whom nine that had tumor tissue negative for the BRAF V600E mutation received sorafenib, while three patients with tumors harboring the BRAF V600E mutation were treated with vemurafenib. Patients with MTC were treated with sunitinib, vandetanib, and sorafenib. Two patients with tumors harboring the BRAF mutation treated with vemurafenib showed restoration of radioiodine uptake. Most of patients showed significant improvement in disease status but of limited duration until disease progression. Although there was an improvement in progression-free survival, future research has to achieve a greater and longer-lasting response, probably by utilizing combined targeted therapy.Iako većina bolesnika s karcinomom štitnjače ima povoljan klinički tijek, ipak neki bolesnici pokazuju agresivniji tijek bolesti s razvojem uznapredovalih formi tumora i lošijom prognozom. Razlog su vjerojatno mutacije proteina, uglavnom enzima tirozin kinaza koji imaju značajnu ulogu u proliferaciji i rastu tumora. Razvoj ciljanih terapija zasnovan je na inhibiranju mutiranih kinaza BRAF, MEK, NRAS, c-KIT koje su uključene u signalni put MAPK. U radu su predstavljeni preliminarni rezultati liječenja inhibitorima kinaza u bolesnika s metastatskim diferenciranim karcinomom štitnjače (DT C), slabo diferenciranim karcinomom štitnjače (PDT C) i medularnim karcinomom štitnjače (MTC). U izvješće je uključeno ukupno 17 odraslih bolesnika (11 žena, prosječna dob 53,3 godine) liječenih zbog progresivne, metastatske bolesti. Dvanaest bolesnika s DT C i PDT C prethodno je testirano na BRAF mutacije. Devet bolesnika kod kojih je tumorsko tkivo bilo negativno na mutaciju BRAF V600E primali su sorafenib, dok su tri bolesnika s tumorima koji nose mutaciju BRAF V600E liječena vemurafenibom u cilju rediferencijacije tumora, a u dva bolesnika došlo je do ponovne akumulacije radiojoda na scintigramu tijela. Bolesnici s MTC-om liječeni su sunitinibom, vandetanibom i sorafenibom. U većine bolesnika došlo je do pozitivnog terapijskog odgovora uz poboljšanje stanja, ali ograničenog trajanja. Buduća istraživanja bi trebala osigurati bolji i trajniji terapijski odgovor, vjerojatno primjenom kombinirane ciljane terapije