FMISO-Based Adaptive Radiotherapy in Head and Neck Cancer.

Concurrent chemoradiotherapy represents one of the most used strategies in the curative treatment of patients with head and neck (HNC) cancer. Locoregional failure is the predominant recurrence pattern. Tumor hypoxia belongs to the main cause of treatment failure. Positron emission tomography (PET) using hypoxia radiotracers has been studied extensively and has proven its feasibility and reproducibility to detect tumor hypoxia. A number of studies confirmed that the uptake of FMISO in the recurrent region is significantly higher than that in the non-recurrent region. The escalation of dose to hypoxic tumors may improve outcomes. The technical feasibility of optimizing radiotherapeutic plans has been well documented. To define the hypoxic tumour volume, there are two main approaches: dose painting by contour (DPBC) or by number (DPBN) based on PET images. Despite amazing technological advances, precision in target coverage, and surrounding tissue sparring, radiation oncology is still not considered a targeted treatment if the "one dose fits all" approach is used. Using FMISO and other hypoxia tracers may be an important step for individualizing radiation treatment and together with future radiomic principles and a possible genome-based adjusting dose, will move radiation oncology into the precise and personalized era.

18F-FDG PET/CT and 99mTc-HMPAO-WBC SPECT/CT effectively contribute to early diagnosis of infection of arteriovenous graft for hemodialysis.

OBJECTIVE: An arteriovenous graft (AVG) is indicated in hemodialysis patients with failed arteriovenous access. Early treatment of AVG infection is important because an advanced prosthetic infection leads to the removal of the prosthesis. The aim of this study was to evaluate the benefits of 18F-FDG PET/CT and 99mTc-HMPAO-WBC SPECT/CT in early detection of AVG infections. SUBJECTS AND METHODS: Fifty-one AVGs were evaluated. 18F-FDG PET/CT and 99mTc-HMPAO-WBC SPECT/CT studies were performed at intervals of 10, 20-30, and 40-50 weeks after AVG insertion. Agreement between the imaging methods and reference parameters (i.e. clinical presentation, C-reactive protein and microbiological findings on the hemodialysis cannula extracted after hemodialysis from AVG) was evaluated. RESULTS: The study results showed that focal accumulation of the radiopharmaceuticals can be considered a sign of AVG infection. At 10 weeks after AVG implantation, the focal 18F-FDG findings showed the best agreement with the reference parameters (agreement coefficients AC1 - clinical status: 0.693, CRP: 0.605, cannula microbiology: 0.518, respectively). At 20 to 30 weeks after AVG implantation, the diagnostic value of focal 99mTc-HMPAO-WBC accumulation increased (AC1 coefficients: 0.658, 0.658, 0.408) and was similar to that of focal 18F-FDG uptake (AC1s: 0.656, 0.570, 0.409). Between 40 and 50 weeks since AVG implantation, the diagnostic significance of focal 99mTc-HMPAO-WBC accumulation (AC1 coefficients: 0.771, 0.811, 0.611) slightly exceeded the diagnostic value of focal 18F-FDG accumulation (AC1 coefficients: 0.524, 0.456, 0.569). CONCLUSION: 18F-FDG PET/CT and 99mTc-HMPAO-WBC SPECT/CT can both serve as important tools contributing to early diagnosis of AVG infection.

Additional value of the coronary artery calcium score in patients for whom myocardial perfusion imaging is challenging.

BACKGROUND Determination of prognosis based on ischemia detection, using single­photon emission computed tomography myocardial perfusion imaging (SPECT­MPI), can be challenging in patients with multiple affected coronary arteries. AIMS The aim of the study was to examine the outcomes of SPECT­MPI combined with the coronary artery calcium score (CACS) to identify predictors of adverse cardiac events (ACEs) in patients for whom ischemia detection may be difficult using SPECT­MPI. METHODS The study group included 195 patients with a history of chronic kidney disease, suspected ischemic cardiomyopathy, or left bundle branch block. All patients underwent SPECT­MPI and CACS evaluation. During the follow­up, ACEs were recorded. Perfusion and functional parameters as well as the CACS were analyzed to find the predictors of ACEs. RESULTS The ACEs were recorded in 58 individuals (29.7%) and were significantly associated with ischemia (P <0.001), abnormal functional parameters (P = 0.04), and higher CACSs (P <0.001). The optimal cutoff value of the CACS to predict an ACE was 530. Cox proportional hazards models revealed that age, mild and severe ischemia, functional abnormalities, and a CACS of 530 or higher were significant predictors of ACEs. In the subgroup of individuals without ischemia, a CACS of 530 or higher was significantly associated with poor outcome, while we recorded only 3 ACEs in these patients when the CACS was lower than 530. CONCLUSIONS The addition of the CACS to SPECT­MPI improves the identification of patients at higher risk for ACEs, even in individuals for whom SPECT­MPI is challenging.

Immunotherapy in mucosal melanoma: a case report and review of the literature.

BACKGROUND: Mucosal melanoma is a rare form of melanoma presenting variably as sores or unexplained bleeding located mainly in the head and neck region, anorectal region or female genital tract. Mucosal melanoma is usually diagnosed at an advanced stage and is characterized by an aggressive behavior. Surgery represents the mainstay of treatment for early stage melanomas, but for advanced disease there have been until recently very limited treatment options. Ipilimumab, a human monoclonal antibody directed against the cytotoxic T lymphocyte antigen 4, was the first treatment modality to demonstrate survival benefit in advanced malignant melanoma. METHOD: Description of a new case and review of the literature. RESULTS: We present here a patient with mucosal melanoma with aggressive biological behavior and documented late response to ipilimumab. CONCLUSIONS: Ipilimumab represents an effective treatment option in selected patients with mucosal melanoma.

Current diagnostic imaging of pheochromocytomas and implications for therapeutic strategy.

The topic of pheochromocytomas is becoming increasingly popular as a result of major advances in different medical fields, including laboratory diagnosis, genetics, therapy, and particularly in novel advances in imaging techniques. The present review article discusses current clinical, biochemical, genetic and histopathological aspects of the diagnosis of pheochromocytomas and planning of pre-surgical preparation and subsequent surgical treatment options. The main part of the paper is focused on the role of morphological imaging methods (primarily computed tomography and magnetic resonance imaging) and functional imaging (scintigraphy and positron emission tomography) in the diagnosis and staging of pheochromocytomas.

Prognostic Influence of Internal Mammary Node Drainage in Patients with Early-stage Breast Cancer.

BACKGROUND: The management of internal mammary nodes (IMNs) during multidisciplinary treatment of breast cancer has been debated for the last four decades without unequivocal conclusion. PATIENTS AND METHODS: We retrospectively reviewed patients with breast cancer who underwent sentinel lymph node biopsy at our center from 2008 until 2012. IMN drainage was assessed as a potential risk factor for local and distant disease recurrence. RESULTS: We identified 712 patients, with incidence of drainage to IMNs of 18.4%. No detrimental effect of the pattern of drainage to IMNs was found after a median follow-up of 58 months. A similar outcome was observed when drainage to IMNs was evaluated as a risk factor for patient survival. The potential risk factors for drainage to IMNs during sentinel lymph node biopsy were younger age (p=0.002) and tumor location in lower-outer, lower-inner, and upper-inner versus upper-outer quadrant (p<0.0001). CONCLUSION: The drainage to IMNs is unlikely to have a detrimental effect on patient outcome.

The benefit of personalized hybrid SPECT/CT pulmonary imaging.

Hybrid pulmonary imaging in the present day has seen a fusion of various uses of CT scans, including angiography (CTAG), diagnostic CT, low dose CT (LDCT), and perfusion or ventilation scintigraphy in tomographic or planar imaging. Determining the most effective individualized test for the complete diagnostics of patients with pulmonary symptoms for various groups of patients is a major issue. The aim of the present study was to assess the effectiveness of the implementation of hybrid imaging in current methods of nuclear medicine in differential diagnostics of pulmonary embolism (PE). 326 patients were examined for symptomatology of PE. Patients were initially examined with SPECT perfusion scintigraphy. SPECT finding without sub-segmental or segmental defects was considered unproven PE but the finding of more segments or sub-segments in various lung parts was considered nearly proven PE. In the case of unclear findings, LDCT was added and in the case of a higher suspicion of PE, a ventilation examination was applied. It was possible to determine 83% of patients with the occurrence or exclusion of PE only on the basis of the perfusion SPECT examination and an X-ray or LDCT. LDCT was determined with 26% of the patients. With 41% of them, the use of LDCT resulted in an alternative diagnosis, explaining perfusion abnormalities. The research proved that use of SPECT/LDCT for differential diagnosis of lung symptoms brings about improvement in the diagnosis of pulmonary embolism or the identification of other lung diseases when lung perfusion abnormalities are recorded.

SPECT/CT imaging in breast cancer - current status and challenges.

BACKGROUND: The increasing incidence of breast cancer worldwide raises the importance of improving imaging techniques for disease stratification after early lesion detection. SPECT/CT imaging is now widely available but its diagnostic potential is not fully utilized for more specific purposes including breast cancer patient stratification. METHODS AND RESULTS: A Pubmed search for both original and review articles related to the value of SPECT/CT in breast cancer patients and comparison to other diagnostic methods. 62 articles were found using the key words SPECT/CT, Fusion Image and Breast Cancer. Development of a new generation of SPECT/CT systems and their introduction into practice has changed the old diagnostic algorithm. The increasing importance of SPECT/CT in the detection of bone metastases is confirmed. The diagnostic accuracy of new SPECT/CT instruments in the diagnostics of bone metastases is nearly comparable to PET/CT scans. SPECT/CT is more widely available and costs less than PET. It is able not only to identify a sentinel lymph nodes in atypical localizations but also to detect sentinel lymph nodes non visualized on previous planar scans. SPECT/CT offers precise anatomic localization of sentinel lymph nodes, thereby facilitating surgery. Knowledge of precise sentinel lymph node localization can also be applied in radiotherapy. CONCLUSIONS: The role of hybrid SPECT/CT imaging in breast cancer patients is changing. It is a powerful modality for skeletal and nodal staging in breast cancer patients with important impact on therapy.

Can renal ultrasonography and DMSA scintigraphy be used for the prediction of irreversible histological lesions of the upper pole in duplex system with ureteroceles or ectopic ureters?

AIM: To assess of the role of renal ultrasonography (US) and DMSA renal scintigraphy in the prediction of irreversible histological lesions of the upper pole in duplex system. METHODS: A prospective cohort study based on data collected between 2005 and 2012 at our institution. The cohort consisted of 23 patients with ureteroceles and 28 patients with ectopic ureters who underwent upper pole nephrectomy. Preoperative recordings from ultrasound and nuclear renal scans were compared with the histological findings. Histological irreversible lesions were defined as the presence of dysplasia and/or severe chronic interstitial nephritis (CIN) in ≥ 90% of the specimen. ROC (Receiver Operating Characteristic) curves were used to investigate thresholds in order to identify irreversible lesions using various differential functions. The histology was correlated with the results of imaging. RESULTS: Pathological findings were found in all histological samples. Histological lesions were irreversible in 20/23 patients (87.0%) with ureteroceles and in 14/28 patients (50.0%) with ectopic ureters. The model is able to predict irreversible lesions if an upper pole differential function is ≤ 3% in patients with ureteroceles, and ≤ 2% in the presence of ectopic ureters. Weak association between parenchymal thinning on ultrasonography and irreversible lesions was found in patients with ectopic ureters. CONCLUSION: DMSA renal scintigraphy provides a useful tool for the prediction of irreversible lesions in the upper pole. Low differential function (≤ 3% and ≤ 2%, respectively) indicates irreversible lesions, favoring heminephrectomy. Higher differential function indicates greater remaining biological potential of the parenchyma, favoring reconstruction of the upper pole.

Prognostic value of myocardial perfusion imaging and coronary artery calcium measurements in patients with end-stage renal disease.

OBJECTIVE: Coronary artery disease (CAD) is highly prevalent in patients with end-stage renal disease (ESRD), owing to clustering of traditional and uremic-specific risk factors. However, in this population asymptomatic course of CAD is common and it has been reported that myocardial perfusion imaging (MPI) with single-photon emission tomography (SPET) has lower sensitivity. In the current study, we assessed the value of MPI gated-SPET and its combination with coronary artery calcium (CAC) score measurements in risk stratification of ESRD patients. MATERIALS AND METHODS: MPI gated-SPET was performed with dual-headed SPET camera and CAC score measured by multi-detector computed tomography (MDCT) system.There were tested 77 ESRD individuals. During the follow-up study, cardiac events (CE) defined as cardiac death or nonfatal myocardial infarction (MI) or the necessity for coronary revascularization were recorded. Univariate and stepwise multivariable Cox proportional hazards-models were used to identify the predictors of CE. RESULTS: Eighteen CE were recorded during the follow-up. They were significantly associated with higher summed stress scores on MPI, higher percentage of ischaemic myocardium, higher occurrence of defects in multiple territories and higher CAC score (all with P<0.05). Univariate Cox proportional hazard-models showed that severe perfusion abnormalities as well as CAC score ≥1000 were significantly associated with cardiac events (P<0.0001, P=0.0056). In stepwise Cox proportional hazards-models considering age, gender, history of diabetes mellitus, post-stress left ventricular stunning, the degree of perfusion abnormality and CAC score, only severe perfusion abnormalities and CAC score ≥1000 were independent predictors of CE. There was no CE in patients with normal perfusion, normal function and zero CAC score. CONCLUSION: This study suggests that combined evaluation of MPI and CAC can predict the outcome in ESRD individuals, while severe perfusion abnormality on gated-SPET and high CAC score ≥1000 are predictors of future cardiac events.

Diagnosis of high-risk patients with multivessel coronary artery disease by combined cardiac gated SPET imaging and coronary calcium score.

OBJECTIVE: The added value of coronary artery calcium (CAC) to SPET for identification of multivessel CAD has not been studied yet. The aim of this original study was to investigate CAC as an adjunct to gated single photon emission tomography (GSPET) in the detection of multivessel coronary artery disease (CAD). SUBJECTS AND METHODS: The study group consisted of 164 prospectively recruited patients without known CAD-123 (75%) men and 60 (37%) women, having diabetes type II, renal insufficiency, left ventricular dilatation and other cardiac problems (arrhythmia, necessity of pharmacological stress test, etc.). The mean age of these patients was 61±12 years (range 34-85 years). All these patients underwent GSPET imaging, CAC score measurement, and coronary angiography. The percentage of ischaemic myocardium, stress and rest left ventricular ejection fraction (LVEF), and transient ischaemic dilation (TID) ratio were measured. RESULTS: Patients with multivessel CAD had more frequently reversible defects in multiple territories, severe ischaemia ≥10% of the left ventricle, stress worsening of the LVEF ≥5%, TID ratio ≥1.17, and CAC score >1000. In the detection of multivessel CAD, the sensitivity of combined assessment of perfusion, function, and CAC (i.e., multiple and/or ≥10% ischaemia, and/or worsening of the LVEF ≥5%, and/or TID ratio ≥1.17, and/or CAC score >1000) was significantly higher than the sensitivity of perfusion alone or perfusion and function alone (81% vs. 55% and 65%, respectively, P<0.05). Sensitivity of only CAC was low (41%). CONCLUSION: Sensitivity of combined assessment of myocardial perfusion, function, and CAC was significantly higher than sensitivity of perfusion alone or perfusion and function alone, suggesting better identification of high-risk patients with CAD.

Prognostic value of stress-only and stress-rest normal gated SPECT imaging: higher incidence of cardiac hard events in diabetic patients who underwent full stress-rest imaging.

BACKGROUND: The European procedural guidelines for cardiac gated SPECT imaging demonstrate considerable variability in recommended administered radiopharmaceutical activity and imaging protocols. This study compared stress-only and stress-rest protocols to evaluate the safety of stress-only imaging, and to identify characteristics of patients who need full stress-rest imaging. METHODS: Patients referred for a chest pain were scheduled for stress-rest gated SPECT imaging. If the stress images were interpreted as normal according to the perfusion and left ventricular function, the examination of patients was finished and patients did not undergo the rest imaging. A total number of 1063 patients was included (mean age 61 ± 11 years). These patients have been followed for hard cardiac events, i.e. cardiac deaths or nonfatal myocardial infarction. RESULTS: During a follow-up of 3.2 ± 2.5 years, hard events occurred in 12 patients with normal SPECT and 59 with abnormal SPECT had hard events (0.7 vs. 3.6% /year, P < 0.001). Among the 536 patients with normal study, there was no significantly lower incidence of hard events in the subgroup of patients with stress-only imaging (0.6 vs. 0.8% /year, P = 0.641). Diabetes mellitus was an independent predictor of hard events in patients with normal SPECT (1.3 vs. 0.5%/year, P < 0.001). We found a higher incidence of hard events in diabetic patients with normal study with the necessity of full stress-rest imaging in comparison with those with stress-only imaging (1.7 vs. 0.7% /year, P < 0.001). CONCLUSIONS: Our results support the good prognosis of normal stress-only study. Diabetes mellitus was an independent predictor of hard events in patients with normal SPECT. Diabetic patients with normal results who required additional rest imaging had significant adverse outcome.

Predictive parameters for internal mammary node drainage in patients with early breast cancer.

INTRODUCTION: Breast cancer treatment currently represents one of the biggest challenges in clinical oncology. The gold standard for axillary lymph node management is to perform sentinel node biopsy to avoid axillary dissection and its sequelae. The detection of radiocolloid flow outside the axillary nodes is a diagnostic and therapeutic challenge. METHODS: A database search at the Department of Oncology of Palacky University, Olomouc, Czech Republic, identified 127 patients who underwent breast cancer resection with a sentinel node procedure and had radiocolloid flow into the internal mammary nodes. Sentinel node lymphoscintigraphy was performed after intraparenchymal injection. Clinical and pathological data were collected to identify possible risk factors. RESULTS: Ten clinical and pathological parameters including age, tumor histology, axillary lymph node status, estrogen receptor expression, progesterone receptor expression, tumor grade, Ki-67 expression, Her-2 status, tumor size and tumor location were analyzed with regard to internal mammary node drainage. A cohort of 127 patients with detected drainage into the internal mammary nodes was compared with 135 patients without such drainage. Six significant risk factors, including age <50 years ( P <0.0313), tumor location in central and inner quadrants (P <0.012), larger tumor size (P <0.017), positive Her-2 status (P <0.025), progesterone receptor expression (P <10-4) and axillary lymph node involvement (P <0.01) were found to predict radiocolloid flow into the internal mammary nodes. CONCLUSION: Six parameters (patient age, tumor location, hormone receptor status, tumor size, Her-2 status and axillary lymph node status) should be considered in the management of breast cancer patients and help in the selection of patients for locoregional procedures encompassing the internal mammary nodes.

Bone SPECT image reconstruction using deconvolution and wavelet transformation: development, performance assessment and comparison in phantom and patient study with standard OSEM and resolution recovery algorithm.

PURPOSE: The aim of this work was to introduce a new algorithm for image reconstruction in bone SPECT and to compare its performances with a commercially available standard OSEM and resolution recovery (RR) reconstruction. MATERIALS AND METHODS: The algorithm was built applying the Lucy-Richardson deconvolution adn logarithmic image processing to the projections. A modification of the coefficients of wavelet decomposition was used to suppress the noise. The comparison with vendor software was performed both in a phantom study, using Signal-to-Noise ratio (SNR), Signal-to-Background ratio (SBR), spatial resolution and in clinical studies, by visual assessment of changes in contrast, spatial resolution and lesion detectability. RESULTS: A change in the SNR (from -4 to 40%), an increase in the SBR (from 19 to 40%), a minor improvement in spatial resolution and a similar noise level were observed in the phantom study in comparison to the standard OSEM. A decrease in the SNR, a worse spatial resolution, but only a 3 to 13 % lower SBR were achieved in comparison with the vendor supplied RR algorithm. The proposed algorithm creates patient images with better contrast and lesion detectability compared to clinically used OSEM. Compared to RR, more than half of obtained images showed better contrast and nearly half of them have better lesion detectability. CONCLUSION: The proposed algorithm compares favorably with the standard OSEM. Although less favorable, the comparison with RR and noise suppression algorithms, suggests that it can be used with only a slight decrease in the SBR.

Nuclear medicine training and practice in the Czech Republic.

Nuclear medicine in the Czech Republic is a full specialty with an exclusive practice. Since the training program was organized and structured in recent years, residents have had access to the specialty of nuclear medicine, starting with a two-year general internship (in internal medicine or radiology). At present, nuclear medicine services are provided in 45 departments. In total, 119 nuclear medicine specialists are currently registered. In order to obtain the title of Nuclear Medicine Specialist, five years of training are necessary; the first two years consist of a general internship in internal medicine or radiology. The remaining three years consist of training in the nuclear medicine specialty itself, but includes three months of practice in radiology. Twenty-one physicians are currently in nuclear medicine training and a mean of three specialists pass the final exam per year. The syllabus is very similar to that of the European Union of Medical Specialists (UEMS), namely concerning the minimum recommended numbers for diagnostic and therapeutic procedures. In principle, the Czech law requires continuous medical education for all practicing doctors. The Czech Medical Chamber has provided a continuing medical education (CME) system. Other national CMEs are not accepted in Czech Republic.

Adrenal disease: a clinical update and overview of imaging. A review.

AIM: The aim of this article is to provide an overview of the most frequent clinically significant adrenal diseases and to describe the latest trends in their diagnostics, particularly by means of imaging techniques. METHODS: The authors reviewed standard textbooks and subsequently conducted a search using the PubMed (Public/Publisher MEDLINE) electronic database by the year 2013 with the following search terms: adrenal masses, adrenal adenoma, phaeochromocytoma, adrenocortical carcinoma, metastases, incidentalomas, hypercortisolism, hyperaldosteronism. RESULTS: If adrenal disease is clinically suspected, hormone tests are performed to detect adrenal hyperfunction and imaging studies are used to assess the nature of adrenal lesion. The most frequent syndromes include hypercortisolism, primary hyperaldosteronism, and phaeochromocytoma. The clinically most significant pathologies of the adrenal glands are adenomas and adrenal hyperplasia, adrenocortical carcinomas, phaeochromocytomas, and metastases. Given the availability and improved quality of imaging techniques, adrenal incidentalomas are detected increasingly often. In these cases, it is necessary to rule out hormonal activity and malignancy. Incidentalomas can be associated with clinical syndromes of adrenal hormone overproduction. In most cases, they are clinically silent. In some cases, the definitive diagnosis can be determined as early as during the initial examination with an imaging technique (most frequently, a CT scan). If the finding is inconsistent, other imaging techniques can be used: CT contrast washout analysis, MRI, SPECT or PET/CT. CONCLUSION: In the case of adrenal gland disorders, correct interpretation of the results of laboratory tests and imaging studies is essential for further management of these patients.

Internal mammary node management in breast cancer. A review.

BACKGROUND: Internal mammary nodes visualized during sentinel node biopsy for breast cancer, remain an unresolved management issue. Further, both internal mammary node (IMN) radiotherapy and biopsy have attendant risks and hence should be used with caution. The purpose of this review is to highlight the available data and evidence. METHODS AND RESULTS: A PubMed database from 1960 to 2012 using key words: internal mammary nodes, breast cancer radiotherapy planning, adjuvant radiotherapy, sentinel node biopsy in breast cancer and selected publications on the significance of internal mammary nodes in breast cancer treatment, published data and approaches used. We found 14513 relevant papers and we selected 30 that clearly investigated the management of internal mammary nodes during sentinel node search. We focused on the incidence of IMN metastasis (6 papers), risk factors associated with IMN drainage (9 reports), management of IMN and the impact on disease free and overall patient survival (15 papers). CONCLUSIONS: The evidence for breast cancer axillary nodes management is good but the data for other draining nodes such as internal mammary nodes are far less conclusive and further research is needed.

Unused arteriovenous grafts as a source of chronic infection in haemodialysed patients with relevance to diagnosis of Fluorodeoxyglucose PET/CT examination.

INTRODUCTION: Clotted arteriovenous grafts (AVG) for haemodialysis which are not used (silent grafts) can serve as a potential source of chronic bacterial infection in patients on dialysis programs. In some cases, the local finding is unclear. The patient only suffers from repeated metastatic infection and the detection of AVG infection is difficult. Nuclear medicine methods have the potential to uncover AVG infection. In this study, we correlated the positron emission tomography (PET)/ computed tomography (CT) findings of the AVG examination with the microbiological findings from removed grafts. The aim was to evaluate the relevance of the Fluorodeoxyglucose (FDG) PET/CT method in detecting clotted graft infection. MATERIAL AND METHODS: A cohort of 13 patients with clotted grafts were followed-up. Four patients had overall symptoms of infection and 9 patients were asymptomatic. In all cases, the PET CT examination and microbiological examination of the removed graft were provided. RESULTS: Only one mismatch-negative PET CT finding and positive microbiological culture was recorded in the 13 followed-up patients. CONCLUSION: In patients with silent grafts and recurrent infection of equivocal aetiology, PET CT examination can contribute to the diagnosis of AVG infection and, subsequently, to prevent further infectious complications, if the AVG infection is treated appropriately and the graft is removed.

The value of ¹8F-FDG PET/CT in assessment of metabolic response in esophageal cancer for prediction of histopathological response and survival after preoperative chemoradiotherapy.

AIM: To evaluate the ability of hybrid 18F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) to predict histopathological response and overall survival (OS) after preoperative neoadjuvant chemoradiotherapy (CRT) in patients with the esophageal carcinoma. METHODS: 73 patients with locally advanced esophageal carcinoma were included in the study. All were treated with CRT and 34 subsequently underwent surgical resection of the esophagus. (18)F-FDG PET/CT was carried out prior to (PET/ CT1) and 6 weeks after (PET/CT2) completion of the CRT. RESULTS: PET/CT2-determined complete metabolic response (CMR) was achieved in 6 (17.6%) out of 34 operated patients, the metabolic response was incomplete (NCMR) in 28 (82.4%) patients. A histopathological complete response (CR) to CRT was discovered in 7 patients (20.6%). The median OS in operated patients was 17.1 months, 95% CI:12.9-23.3 months. In a group of 39 non-operated patients, CMR after neoadjuvant CRT was achieved in 12 patients (30.8%), while NCMR was found in 28 (82.4%). The median OS was 13.5 months in this group, 95% CI: 4.4-22.7 months. CONCLUSION: No statistically significant correlation was found between the (18)F-FDG metabolic response after the neoadjuvant CRT and histopathological response. Presently, the contribution of (18)F-FDG PET/CT as a marker of the potential result of CRT cannot be considered definite. Another study with a larger sample of patients and standardized algorithms for the examining protocols would be necessary for reaching definitive conclusions.