David Groshar

Gastric Emptying is not Affected by Sleeve Gastrectomy-Scintigraphic Evaluation of Gastric Emptying after Sleeve Gastrectomy without Removal of the Gastric Antrum

BackgroundThe aim of this study is to clarify whether laparoscopic sleeve gastrectomy (LSG) to treat morbid obesity causes changes in gastric emptying.MethodsGastric emptying scintigraphy was performed before and 3xa0months after LSG, in 21 consecutive morbidly obese patients. After an overnight fast, subjects consumed a standard semi-solid meal, to which 0.5xa0mCi Tc99-labeled sulfur colloid had been added. The meal was consumed within 10xa0min. Scintigraphic imaging was performed with a gamma camera immediately after the completion of the meal as well as after 30, 60, 120, 180, and 240xa0min. Quantitative and qualitative analysis was performed by drawing a region of interest (ROI) enclosing the stomach on the anterior and the posterior images. Time 0 was considered the time of meal completion (all the ingested activity) and was defined as 100% retention. The same ROI was used on all consecutive images of the same projection for the same patient. The geometric mean of the anterior and the posterior counts for each time point is calculated and corrected for Tc99m decay. Gastric emptying curves were constructed. T 1/2 is the time interval between completion of the meal and the point at which half of the meal (by radioactivity counts) has left the stomach. Retention is expressed as the percent remaining in the stomach at each time point (half, 1, 2, 3, 4xa0h).ResultsThe mean T 1/2 raw data was 62.39u2009±u200919.83 and 56.79u2009±u200918.72xa0min (pu2009=u20090.36, tu2009=u2009−0.92, NS) before and 3xa0months after LSG, respectively. The T 1/2 linear was 103.64u2009±u20099.82 and 106.92u2009±u200914.55, (pu2009=u20090.43, tu2009=u2009−0.43, NS), and the linear fit slope 0.48u2009±u20090.04 and 0.47u2009±u20090.05 (pu2009=u20090.48, tu2009=u20090.7, NS).ConclusionsLSG with antrum preservation as performed in this series has no effect on gastric emptying.

Early prediction of histopathological response of rectal tumors after one week of preoperative radiochemotherapy using 18 F-FDG PET-CT imaging. A prospective clinical study

BackgroundPreoperative radiochemotherapy (RCT) is standard in locally advanced rectal cancer (LARC). Initial data suggest that the tumor’s metabolic response, i.e. reduction of its 18u2009F-FDG uptake compared with the baseline, observed after two weeks of RCT, may correlate with histopathological response. This prospective study evaluated the ability of a very early metabolic response, seen after only one week of RCT, to predict the histopathological response to treatment.MethodsTwenty patients with LARC who received standard RCT regimen followed by radical surgery participated in this study. Maximum standardized uptake value (SUV-MAX), measured by PET-CT imaging at baseline and on day 8 of RCT, and the changes in FDG uptake (ΔSUV-MAX), were compared with the histopathological response at surgery. Response was classified by tumor regression grade (TRG) and by achievement of pathological complete response (pCR).ResultsAbsolute SUV-MAX values at both time points did not correlate with histopathological response. However, patients with pCR had a larger drop in SUV-MAX after one week of RCT (median: -35.31% vs −18.42%, pu2009=u20090.046). In contrast, TRG did not correlate with ΔSUV-MAX. The changes in FGD-uptake predicted accurately the achievement of pCR: only patients with a decrease of more than 32% in SUV-MAX had pCR while none of those whose tumors did not show any decrease in SUV-MAX had pCR.ConclusionsA decrease in ΔSUV-MAX after only one week of RCT for LARC may be able to predict the achievement of pCR in the post-RCT surgical specimen. Validation in a larger independent cohort is planned.

Comparison of 11C-choline with 18F-FDG in positron emission tomography/computerized tomography for staging urothelial carcinoma: a prospective study.

PURPOSEn11C-choline was postulated to provide better diagnostic capabilities than other tracers used in positron emission tomography/computerized tomography for staging urothelial carcinoma. We compared the value of using 11C-choline with the well investigated 18F-FDG tracer in this setting.nnnMATERIALS AND METHODSnThe study group included 20 consecutive patients with bladder cancer who underwent evaluation for local and metastatic disease using 11C-choline and 18F-FDG positron emission tomography/computerized tomography. Patients were treated with radical cystectomy with lymph node dissection, radiation therapy or chemotherapy independent of positron emission tomography/computerized tomography results. The histopathological findings (when available), followup positron emission tomography and radiological imaging served as the reference standard. Using the paired t test we compared the maximum standardized uptake and lesion-to-background ratio of the tracers. The positive predictive values were determined.nnnRESULTSnA total of 51 lesions showed abnormal tracer activity. The positive predictive value for all detected lesions was 84.7% for 11C-choline positron emission tomography/computerized tomography and 90.7% for 18F-FDG positron emission tomography/computerized tomography. The corresponding positive predictive values for extravesical lesions were 79.4% and 88.2%, respectively. Discrepant findings between the tracers were noted at 11 sites. 18F-FDG positron emission tomography/computerized tomography correctly identified 4 extravesical metastases missed by choline positron emission tomography/computerized tomography in the absence of a contrary observation. Mean maximum standardized uptake and lesion-to-background ratio at extravesical sites were significantly higher for FDG.nnnCONCLUSIONSnWithin the limitations of a relatively small number of patients and partial histopathological analysis, 11C-choline positron emission tomography/computerized tomography appears to have no advantage compared to 18F-FDG positron emission tomography/computerized tomography in the detection of metastatic bladder cancer. 18F-FDG positron emission tomography/computerized tomography has a tendency toward greater accuracy.

[18F]FDG-PET/CT for the diagnosis of patients with fever of unknown origin

BACKGROUND AND AIMSnThe diagnosis of patients with fever of unknown origin (FUO) remains a challenging medical problem. We aimed to assess the diagnostic contribution of 18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET)/computed tomography (CT) for the evaluation of FUO.nnnMETHODSnWe performed a 4-year retrospective single-center study of all hospitalized patients that underwent FDG-PET/CT for evaluation of FUO. The final diagnosis of the febrile disease was based on clinical, microbiological, radiological and pathological data available at the final follow-up. Predictors for a contributory exam were sought.nnnRESULTSnOne hundred and twelve patients underwent FDG-PET/CT for the investigation of FUO in the years 2008-2012 and were included in the study. A final diagnosis was determined in 83 patients (74%) and included: infectious disease in 49 patients (43%), non-infectious inflammatory disease in 17 patients (16%), malignancies in 15 patients (14%), other diagnoses in 2 patients (1.7%), FUO resolved with no diagnosis and no evidence of disease during a 6-month follow-up in 23 patients (20%), and death with fever and with no diagnosis in 6 patients (5%). Seventy-four FDG-PET/CT studies (66%) were considered clinically helpful and contributory to diagnosis (46% positive contributory value and 20.5% contributory to exclusion of diagnosis). PET/CT had a sensitivity of 72.2%, a specificity of 57.5%, a positive predictive value (PPV) of 74.2% and a negative predictive value (NPV) of 53.5%. On multivariable analysis, significant predictors of a positive PET/CT contributory to diagnosis were a short duration of fever and male gender.nnnCONCLUSIONSnPET/CT is an important diagnostic tool for patients with FUO.

Survival Prognostic Value of Morphological and Metabolic variables in Patients with Stage I and II Non-Small Cell Lung Cancer

AbstractBackgroundThe prognosis of patients with non-small cell lung cancer (NSCLC) is important, as patients with resectable disease and poor prognostic variables might benefit from neoadjuvant therapy. The goal of this study is to evaluate SUVmax, SUVmax ratio, CT volume (CTvol), metabolic tumour volume (MTV) and total lesion glycolisis (TLG) as survival prognostic markers. In addition, we defined two variables; MTV x SUVmax (MTVmax) and CTvol x SUVmax (CTvolmax) and assessed whether they can be used as prognostic markers.MethodsPatients with stage I-II NSCLC who underwent 18xa0F FDG PET/CT and surgery were evaluated. Cox proportional-hazard model was used to determine the association between variables and survival. Similar analysis was performed in cases with no lymph node (LN) involvement.ResultsOne hundred and eighty-one patients were included (at the end of the study, 140 patients were alive). SUVmax with a cut-off value of 8.2 was significant survival prognostic factor regardless of LN involvement (Pu2009=u20090.012). In cases with no LN involvement, SUVmax and CTvol (≥7.1xa0ml) were significant survival prognostic factors with Pu2009=u20090.004 and 0.03, respectively.ConclusionsSUVmax may be a useful prognostic variable in stage I-II NSCLC while morphologic tumour volume might be useful in cases with no lymph node involvement.Key Points• Identifying variables that predict the prognosis of patients with NSCLC is important.n • SUVmax in primary lung tumour is a useful independent prognostic variable.• (CTvol) is an independent prognostic variable if no lymph nodes are involved.

The Role of 18F-FDG PET/CT on Staging and Prognosis in Patients with Small Cell Lung Cancer

AbstractBackgroundWe evaluated 18F-FDG PET/CT in small cell lung cancer (SCLC) staging and assessed metabolic (SUVmax, MTV and TLG) and morphologic (CTvol) variables as predictors for overall survival (OS) and progression-free survival (PFS).MethodsPatients with newly diagnosed, histopathology-confirmed SCLC, who underwent 18F-FDG PET/CT were evaluated. A Cox proportional hazard model was used to determine the association between the primary tumour SUVmax, MTV, TLG and CTvol with OS and PFS. Similar evaluations were performed when hilar/mediastinal lymphadenopathy was included [total SUVmax (TSUVmax), total MTV (TMTV) and total TLG (TTLG)].Results55 patients were included. 18F-FDG PET/CT changed staging in 6/55 (10.9%) patients who were upstaged to extensive disease. TTLG (>443.8) was a significant variable for OS with HR=2.1 (CI 1.14–3.871, p=0.017). Patients with TTLG>443.8 had a median OS of 13.4 months compared to 25.7 months in patients with TTLG<443.8 (p=0.018). TMTV (>72.4) was significant for PFS with HR=2.3 (CI 1.11-4.8, p=0.025). A median PFS of 12.1 and 26.2 months was found with TMTV greater and less than 72.4, respectively (p=0.005).Conclusions18F-FDG PET/CT improved staging of patients with SCLC, and TTLG and TMTV can be used as prognostic variables for OS and PFS, respectively.Key Points• Identifying variables that predict the prognosis of patients with SCLC is important.n • 18F-FDG PET/CT influences staging of patients with SCLC.n • Metabolic parameters could be used as predictors for PFS and OS.

The role of 18F-FDG PET/CT for the diagnosis of infections in patients with hematological malignancies and persistent febrile neutropenia

We assessed the performance of PET/CT for diagnosis and management of infections in high-risk hematological cancer patients with persistent febrile neutropenia in a prospective study. (18)F-FDG PET/CT with contrast-enhanced CT was performed on day 5-7 of persistent fever. Between 2008 and 2011, 91 PET/CT examinations were performed for different episodes in 79 patients, resulting in 117 diagnoses. The sensitivity of the PET/CT was 79.8% (71/89) compared to 51.7% (46/89) with chest/sinus CT alone. Specificities were 32.14% (9/28) vs. 42.85% (12/28), respectively. PET/CT resulted in a change from the pre-test diagnosis in 63/91 (69%) of episodes and in modification of patients management in 46/91 (55%). PET/CT was beneficial in diagnosing abdominal infections. PET/CT has a potential role in the diagnostic evaluation of patients with persistent febrile neutropenia.

A novel continuous breath test versus scintigraphy for gastric emptying rate measurement.

Background Gastric scintigraphy (GS) is considered the gold standard for gastric emptying rate (GER) measurement; however, it requires expensive equipment and special licensing for radioactive substances. Aim To compare a new nonradioactive, real-time, continuous breath test (CBT) method with GS for the GER measurement. Methods Simultaneous GER analysis by both GS and CBT was carried out on 8 dyspeptic patients and 6 healthy controls. After a 14 hour fast, participants ate a standard meal of 250 Kcal double labeled with 1 mCi of Tc-99m and 100 &mgr;g of C-13 labeled octanoic acid. The participants underwent simultaneous GS for 120 minutes on single-detector &ggr; camera and CBT carried out by attaching the nasal cannula of the system (Oridion, BreathID, Israel), which automatically and continuously collected and analyzed breath samples with real time display. A linear fit model was used to calculate gastric empting half-time. A half-time of more than 100 minutes for GS and 80 minutes for CBT were considered pathologic. The GS and CBT were compared by &kgr; test of agreement in normal/abnormal results. Results Good correlation was found for GER measurements between GS and the CBT methods with a linear correlation coefficient of R=0.74. The &kgr; test indicated excellent agreement with value of 0.86 for the qualitative determination of pathologic and normal results. Conclusions The novel CBT provides reliable and reasonably accurate data for on-line GER estimate, in a simple manner suitable for medical clinics or bedside setting, without the use of radioactive substances.

Blind spots at oncological CT: lessons learned from PET/CT.

Abstract Improved accuracy in oncological computed tomography (CT) could lead to a decrease in morbidity and improved survival for oncology patients. Visualization of metabolic activity using the glucose analogue [18F]fluorodeoxyglucose (FDG) in combination with the high anatomic resolution of CT in an integrated positron emission tomography (PET)/CT examination has the highest sensitivity and specificity for the detection of primary and metastatic lesions. However, PET/CT costs are high and patient access is limited; thus CT remains the primary imaging modality in oncology patients. We have noted that subtle lesions are more easily detected on CT by radiologists with PET/CT experience. We aimed to provide a brief review of the literature with comparisons of multi-detector computed tomography (MDCT) and PET/CT in primary and metastatic disease with an emphasis on findings that may be overlooked on MDCT in cancer of the breast, lung, colon, and ovaries, and in melanoma, as well as thrombosis in oncology patients. We further reviewed our experience for illustrative comparisons of PET/CT and MDCT studies. Experience in interpreting conventional CT scans alongside PET/CT can help the reader develop an appreciation for the subtle appearance of some lesions on CT that might otherwise be missed. This could improve detection rates, reduce errors, and improve patient management.

Phase II organ‐preservation trial: Concurrent cisplatin and radiotherapy for advanced laryngeal cancer after response to docetaxel, cisplatin, and 5‐fluorouracil–based induction chemotherapy

The optimal treatment for locally advanced laryngeal cancer remains controversial. The purpose of this trial was to determine if the response to induction chemotherapy could select patients for organ preservation protocols, and improve larynx‐preservation rates without compromising overall survival (OS).