Risk of misclassification during diagnosis of malnutrition in retroperitoneal sarcoma patients.

BACKGROUND: Retroperitoneal sarcoma (RPS) is a rare tumour that can reach exceptionally large size at diagnosis and affects body weight with its volume. We investigated the risk of nutritional status misclassification based on the Global Leadership Initiative on Malnutrition (GLIM) criteria in RPS patients. METHODS: We retrospectively analyzed the baseline data of patients with primary RPS including anthropometry, Malnutrition Universal Screening Tool (MUST) score and skeletal muscle index (SMI) calculated on preoperative CT scan. Phenotypic GLIM criteria considered were non-volitional weight loss, low-BMI and low muscle mass. MUST score, being inclusive of weight loss, was chosen as its surrogate. Reduced muscle mass was defined with SMI cut-offs <38.5-52.4 cm2/m2 for female and male respectively. RESULTS: From 2018 to 2020, 100 consecutive patients (male/female: 48/52) were included. Median age was 61 (48-68) years, median BMI 24.6 (21.5-27.4) kg/m2. Seven patients (7%) reported MUST score ≥2 and 80 (80%) score 0. Five patients (5%) were underweight, 44 (44%) overweight and obese. Sixty patients (60%) presented low SMI, of those 56 (93%) were normal or overweight, and 46 (77%) not at nutritional risk according to the MUST score. Both underweight BMI and MUST score ≥2 were not correlated with low SMI (p = 0.406, p = 0.612, respectively). No relevant discrepancy was found in the postoperative course of patients with low or normal muscle mass, although SMI was able to better characterize nutritional risk in the proportion of patents with high-grade liposarcoma and predicted worst overall survival. CONCLUSION: GLIM criteria are a useful tool for diagnosis of malnutrition. However, our analysis suggests that phenotypic criteria are not interchangeable with each other. An altered body composition is often hidden in patients with retroperitoneal sarcoma and the use of weight-based classification does not seem to be appropriate, enhancing the role of mass muscle measurement to prevent misdetections of malnourished patient.

Nutritional status and body composition assessment in patients with a new diagnosis of advanced solid tumour: Exploratory comparison of computed tomography and bioelectrical impedance analysis.

OBJECTIVE: Low skeletal muscle is a common characteristic of cancer-related malnutrition and a predictor of poorer prognosis in oncological patients. In this study we evaluated nutritional status and altered body composition using computed tomography (CT) and bioelectrical impedance analysis (BIA) in newly diagnosed patients. Our purpose was to compare the results of two available techniques to assess body composition suggested by the guidelines and some diagnostic criteria to identify malnutrition. METHODS: In a prospective study, patients with a new diagnosis of advanced solid tumour were enrolled and evaluated before starting first-line chemotherapy. Anthropometric, body composition and systemic inflammation measurements were collected and cut-off points from literature data were used for results classification. Malnutrition was expressed as weight loss (WL) in the previous 6 months >10% and underweight body mass index (BMI). Altered body composition was assessed as low index both skeletal muscle (SMI) derived by CT and fat-free mass by BIA (FFMI). Descriptive statistic was presented. Several statistical correlation analyses were performed. RESULTS: 67 patients were assessed: 40M/27F; average age 59 ± 13 years and BMI 23 ± 4; 43 (64%) upper gastrointestinal, 12 lung, 9 colorectal, 3 other cancers. Fourty-five (67%) were malnourished with WL criteria but only 8 (12%) resulted underweight. From analysis of CT images and BIA, 49 (73%) and 10 (15%) patients respectively reported lower cut-off point. Overall, 35 (52%) had both sarcopenia and WL > 10%. CONCLUSIONS: Our results suggest that prevalence data of malnutrition expressed as WL are more in agreement with those of sarcopenia recognised using CT than BIA method. Further studies are required to confirm these findings and to identify the best and easiest methods for monitoring BC during nutritional intervention and oncological therapies.

The role of baseline inflammatory-based scores and serum tumor markers to risk stratify pseudomyxoma peritonei patients treated with cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

AIMS: Inflammation-based scores such as neutrophil-lymphocyte ratio (NLR) and Onodera nutritional index (ONI) have been identified as new prognosticators in several tumors. We conducted a prognostic analysis of these markers and performed a risk stratification of PMP patients submitted to cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: 226 patients from two peritoneal surface malignancies centers participated in this study. Cox proportional modeling was used to select predictors of overall survival (OS) among baseline inflammation-based scores, serum tumor markers, clinical and surgical variables. Risk stratification was done using conditional inference tree model. RESULTS: One hundred eighty-two cases had diffuse peritoneal adenomucinosis subtype. Fifty-four cases had received previous systemic chemotherapy. The means of ONI and NLR were 51.4 (SD = 9.8) and 3.2 (SD = 2.3), respectively. Two hundred ten cases were optimally cytoreduced. Cox analysis identified completeness of cytoreduction, histological subtype, previous systemic chemotherapy, NLR, and CA 19-9 as independent prognosticators. Conditional inference tree method identified two poor prognostic subsets: NLR ≤2.7 and CA 19-9>336 (5yr-OS = 15%) and NLR >2.7 and ONI ≤42 (5yr-OS = 30%). CONCLUSIONS: NLR, ONI, and CA 19-9 are new prognosticators that contributed to improve prediction of OS in PMP patients treated by CRS and HIPEC. These markers allowed a risk stratification that could optimize therapeutic management of PMP patients.

The prognosis of incurable cachectic cancer patients on home parenteral nutrition: a multi-centre observational study with prospective follow-up of 414 patients.

BACKGROUND: The role of home parenteral nutrition (HPN) in incurable cachectic cancer patients unable to eat is extremely controversial. The aim of this study is to analyse which factors can influence the outcome. PATIENTS AND METHODS: We studied prospectively 414 incurable cachectic (sub)obstructed cancer patients receiving HPN and analysed the association between patient or clinical characteristics and surviving status. RESULTS: Median weight loss, versus pre-disease and last 6-month period, was 24% and 16%, respectively. Median body mass index was 19.5, median KPS was 60, median life expectancy was 3 months. Mean/median survival was 4.7/3.0 months; 50.0% and 22.9% of patients survived 3 and 6 months, respectively. At the multivariable analysis, the variables significantly associated with 3- and 6-month survival were Glasgow Prognostic Score (GPS) and KPS, and GPS, KPS and tumour spread, respectively. By the aggregation of the significant variables, it was possible to dissect several classes of patients with different survival probabilities. CONCLUSIONS: The outcome of cachectic incurable cancer patients on HPN is not homogeneous. It is possible to identify groups of patients with a ≥6-month survival (possibly longer than that allowed in starvation). The indications for HPN can be modulated on these clinical/biochemical indices.

Whole-brain histogram and voxel-based analyses of apparent diffusion coefficient and magnetization transfer ratio in celiac disease, epilepsy, and cerebral calcifications syndrome.

BACKGROUND AND PURPOSE: Diffusion and magnetization transfer (MT) techniques have been applied to the investigation with MR of epilepsy and have revealed changes in patients with or without abnormalities on MR imaging. We hypothesized that also in the coeliac disease (CD), epilepsy and cerebral calcifications (CEC) syndrome diffusion and MT techniques could reveal brain abnormalities undetected by MR imaging and tentatively correlated to epilepsy. MATERIALS AND METHODS: Diffusion and MT weighted images were obtained in 10 patients with CEC, 8 patients with CD without epilepsy and 17 healthy volunteers. The whole brain apparent diffusion coefficient (ADC) and MT ratio (MTR) maps were analyzed with histograms and the Statistical Parametric Mapping 2 (SPM2) software. We employed the non-parametric Mann-Whitney U test to assess differences for ADC and MTR histogram metrics. Voxel by voxel comparison of the ADC and MTR maps was performed with 2 tails t-test corrected for multiple comparison. RESULTS: A significantly higher whole brain ADC value as compared to healthy controls was observed in CEC (P = 0.006) and CD (P = 0.01) patients. SPM2 showed bilateral areas of significantly decreased MTR in the parietal and temporal subcortical white matter (WM) in the CEC patients. CONCLUSION: Our study indicates that diffusion and MT techniques are also capable of revealing abnormalities undetected by MR imaging. In particular patients with CEC syndrome show an increase of the whole brain ADC histogram which is more pronounced than in patients with gluten intolerance. IN CEC patients, voxel-based analysis demonstrates a localized decrease of the MTR in the parieto-temporal subcortical WM.

CT and MR imaging of neuroaxonal leukodystrophy presenting as early-onset frontal dementia.

CT and MR imaging showed diffuse changes of the frontal white matter and genu of the corpus callosum with minimal atrophy and no contrast enhancement in a 41-year-old woman with progressive dementia. Brain biopsy disclosed axonal spheroids and gliosis in the white matter without macrophage or inflammatory infiltration or vessel abnormalities consistent with neuroaxonal leukodystrophy. This disease can be suspected on CT and MR imaging findings but requires neuropathologic examination to be diagnosed.

Cytoreductive surgery followed by intra peritoneal hyperthermic perfusion in the treatment of peritoneal surface malignancies: morbidity and mortality with closed abdomen technique.

AIMS: The purpose of this phase II study was to analyze the morbidity and mortality of cytoreductive surgery (CRS) + intraperitoneal hyperthermic perfusion (IPHP) in the treatment of peritoneal surface malignancies. PATIENTS AND METHODS: One hundred and sixty four patients (36 ovarian cancer, 32 abdominal sarcomatosis, 34 peritoneal mesothelioma, 36 pseudomyxoma peritonei, 12 gastric cancer, 8 colon adenocarcinoma and 8 from other origins) underwent 166 procedures. Two patients underwent the intervention twice due to disease relapse. The mean follow-up was 20.6 months (range: 0.4 - 91.3). The mean age was 52 years (range: 24-76). CRS was performed with peritonectomy procedures. IPHP through Closed abdominal technique was conducted with preheated (42.5 degrees) perfusate containing cisplatin+mitomycin C or cisplatin+doxorubicin for 60/90 minutes. RESULTS: grade 3/4 morbidity rate was 12.0%. Some frequent post-operatory complications were intestinal fistulas (17), respiratory (5) and abdominal bleeding (4). Multivariate analysis with logistic regression model with the backward elimination method identified carcinomatosis extension (OR: 5.3, CI95%: 1.2-24.5) as the best predictor of morbidity grade 3/4. Four patients presented grade 3/4 toxicity. Operative mortality rate was 0.6%. CONCLUSIONS: CRS+ IPHP presented acceptable morbidity 3/4 toxicity and mortality rates what support the need to be tested in prospective phase III clinical trial.

Postoperative enteral versus parenteral nutrition in malnourished patients with gastrointestinal cancer: a randomised multicentre trial.

BACKGROUND: Although current opinion favours the use of enteral over parenteral nutrition, the clinical benefits of early postoperative nutrition in patients undergoing elective surgery have never been clearly shown. We aimed to test the hypothesis that postoperative enteral nutrition is better (fewer postoperative complications) than parenteral nutrition containing similar energy and nitrogen amounts (112 kJ kg(-1) day(-1) and 1.4 g aminoacid kg(-1) day(-1)). METHODS: We did a randomised multicentre clinical trial in patients with gastrointestinal cancer who were malnourished and candidates for major elective surgery. 159 patients were assigned to enteral nutrition and 158 to parenteral nutrition. The primary endpoint was the occurrence of postoperative complications, and secondary endpoints were length of postoperative hospital stay, adverse effects, and treatment crossover. Analysis was by intention to treat. FINDINGS: Postoperative complications occurred in 54 (34%) patients fed enterally versus 78 (49%) fed parenterally (relative risk 0.69, 95% CI 0.53-0.90, p=0.005). Length of postoperative stay was 13.4 days and 15.0 days in the enteral nutrition and parenteral nutrition groups, respectively (p=0.009). Adverse effects occurred in 56 (35%) patients fed enterally versus 22 (14%) patients fed parenterally (2.50, 1.61-3.86, p<0.0001). 14 (9%) patients on enteral nutrition had to switch to parenteral nutrition, whereas none of those fed parenterally crossed over to enteral feeding. INTERPRETATION: We conclude that early enteral nutrition significantly reduces the complication rate and duration of postoperative stay compared with parenteral nutrition, although parenteral nutrition is better tolerated than enteral nutrition.

Permanent brain damage following acute clonidine poisoning in Munchausen by proxy.

A child presented with recurrent episodes of lethargia for which he underwent several hospital admissions and investigations. A further episode culminated in respiratory arrest and hypoxic ischemic encephalopathy with permanent mental regression. Eighteen months later the mother was discovered while providing clonidine pills to the child; the mother appears to feature a Munchausen syndrome by proxy.

Effect of total parenteral nutrition on the protein kinetics of patients with cancer cachexia.

AIMS AND BACKGROUND: The question of whether TPN is able to reverse lean body mass depletion in cachectic cancer patients and, in particular, its effect on protein kinetics is a matter of some controversy. This study investigates the impact of TPN on protein kinetics in patients with gastric cancer. METHODS: The study involved three patients with 14-30% weight loss. They were administered a TPN regimen including 33-40 kcal/kg/day and 1.4-1.7 g amino acid/kg/day. The protein metabolism was studied before and during TPN using a stable amino acid isotope. RESULTS: Whole body protein turnover and breakdown did not change during TPN, whereas whole body protein synthesis increased from 3.39 +/- 1.04 to 6.05 +/- 0.48 g/kg/day (P = 0.03). However, the net balance, which was slightly negative prior to TPN, became positive during nutritional support. In the skeletal muscle compartment the synthesis improved with TPN (from 9.38 +/- 2.6 nmol/100 mL/min to 35.95 +/- 3.4 nmol/100 mL/min; P = 0.0143), whereas breakdown did not change significantly. CONCLUSIONS: TPN triggers a positive metabolic response in cachectic cancer patients. Whether this results in a clinical benefit for the patient requires further investigation.

Percutaneous gastrostomy in oncologic patients: analysis of results and expansion of the indications.

BACKGROUND: Percutaneous gastrostomy is generally performed for permanent enteral nutrition or gastric decompression. METHODS: In our series of oncologic patients, percutaneous gastrostomy was also used temporarily in some patients for enteral nutrition while awaiting functional recovery of swallowing, in preparation for surgery, or for the treatment of fistulas in the upper digestive tract. Fifty-one procedures were performed in 50 patients: 42 for feeding, eight for decompression, and one for transgastric drainage of a duodenal fistula. RESULTS: Of the 35 patients treated for permanent enteral nutrition, four are still alive, with a total survival time of 2,167 days. In three patients, gastrostomy was performed for temporary feeding and was removed once the ability to swallow was restored. In four patients, it was created to restore metabolic balance before surgery. In the patient with a duodenal fistula, healing was achieved in 19 days. The seven patients in whom the procedure was performed for decompression survived for a mean of 19.2 days. There was only one major procedure-related complication (peritonitis). CONCLUSIONS: Percutaneous gastrostomy is a safe, low-cost method that allows the patient to maintain essential nutrition without the discomfort of a nasogastic tube and therefore warrants wider and earlier use. We feel that its application should also be extended to temporary feeding of patients about to undergo long courses of chemotherapy and radiotherapy, which can lead to severe deterioration of nutritional status.

Perioperative total parenteral nutrition in malnourished, gastrointestinal cancer patients: a randomized, clinical trial.

BACKGROUND: Clinical trials investigating the potential benefits of perioperative total parenteral nutrition (TPN) for reducing the risk of surgery in malnourished cancer patients have yielded controversial results. METHODS: Ninety elective surgical patients with gastric or colorectal tumors and weight loss of 10% or more of usual body weight were randomly assigned to 10 days of preoperative and 9 days of postoperative nutrition vs a simple control group. The daily per kilogram body weight TPN regimen included 34.6 +/- 6.3 kcal nonprotein and 0.25 +/- 0.04 g nitrogen per kilogram in a volume of 42.6 +/- 7.3 mL of fluid. The glucose-to-fat calorie ratio was 70:30. Control patients did not receive preoperative nutrition but received 940 kcal nonprotein plus 85 g amino acids postoperatively. RESULTS: Complications occurred in 37% of the patients receiving TPN vs 57% of the control patients (p = .03). Noninfectious complications mainly accounted for this difference, which was 12% vs 34%, respectively (p = .02). Mortality occurred in only 5 of the control group patients (p = .05). The total length of hospitalization for TPN patients was longer than for control (p = .00), whereas the length of postoperative stay in the two groups did not differ significantly. CONCLUSIONS: This study shows that 10 days of preoperative TPN that is continued postoperatively is able to reduce the complication rate by approximately one third and to prevent mortality in severely malnourished patients with gastrointestinal cancer.

Total parenteral nutrition and tumor growth in malnourished patients with gastric cancer.

AIMS AND BACKGROUND: Evidence that total parenteral nutrition (TPN) can stimulate tumor growth in humans is scanty and contradictory. The purpose of this study was to evaluate the impact of TPN on tumor cell proliferation in malnourished patients receiving preoperative TPN. METHODS: We evaluated variations in the S-phase cell fraction, defined as 3H-thymidine labeling index (TLI), before and after 10 days of TPN or non-administration of nutritional support in 19 malnourished patients (weight loss, > or = 10%) with gastric cancer. TLI was determined on endoscopic biopsies at the time of diagnosis, and subsequently on the operative specimen or through intraoperative sampling. RESULTS: At diagnosis, a higher median TLI value was observed in the control than in the TPN group. Administration of TPN enhanced tumor cell proliferation in 50% of patients; however, at surgery there was no difference in the median TLI value of the two groups. CONCLUSIONS: The TPN regimen seems to be associated with increased tumor cell proliferation, even though this stimulating effect was moderate and at surgery the TLIs of TPN patients and controls were not different. Although the potential stimulation probably has little consequence for patients receiving short-term preoperative nutrition, it may call for further investigation in cancer patients undergoing long-term home TPN.

Artificial nutrition in cancer patients: which route, what composition?

The state of art of artificial nutrition in depleted cancer patients is reviewed in brief. Because cancer cachexia cannot be equated to simple nutrient deficiency but is due instead to complex metabolic abnormalities, the nutritional effects of total parenteral (TPN) and enteral (EN) nutrition are more limited than in starving subjects. TPN and EN usually prevent further deterioration of the nutritional status, although they are not able to fully reverse a state of depletion. There is evidence that quantitative and qualitative modulation of certain nutrients may obtain better results because of a favorable impact on host metabolism. Research in this field is fully warranted. Moreover, the effects of some substrates on tumor metabolism and tumor growth require further investigation to define a nutritional regimen able to maintain the host metabolism with minimum stimulation of tumor growth.

Effects of cachexia due to cancer on whole body and skeletal muscle protein turnover.

BACKGROUND: Data available in the literature regarding whole body protein (WBP) kinetics in patients with cachexia due to cancer are conflicting. Some authors have reported an increase of WBP synthesis and breakdown, whereas others have not found any significant changes; only a few researchers have investigated more compartments simultaneously. The main purpose of this study was to investigate WBP and skeletal muscle protein (SMP) turnover simultaneously in cachectic patients to understand better the mechanisms underlying the general wasting of the host present in cancer cachexia. METHODS: WBP and SMP synthesis and breakdown were studied in malnourished patients with advanced gastric carcinoma and in healthy volunteers. Protein turnover was evaluated in a postabsorptive state, using a model based on a primed constant infusion of L-[(2)H5] phenylalanine and L-[(2)H4]tyrosine, and by determining the isotopic enrichment and concentration in plasma during a plateau phase by gas chromatography and mass spectrometry. RESULTS: Rates of WBP synthesis and breakdown did not differ significantly between the two groups (whole body synthesis [WBS] of 4.35 +/- 0.2 g/kg/day and whole body breakdown [WBB] of 4.77 +/- 0.2 g/kg/day in the control group and WBS of 3.34 +/- 0.7 g/kg/day and WBB of 4.5 +/- 0.4 g/kg/day in the patient group). The skeletal muscle compartment of the patients showed a significantly lower synthesis compared with controls (patients, 9.6 +/- 1.8 nmol/100 mL/minute and control, 25.9 +/- 7.6 nmol/100 mL/minute; P < 0.05), whereas the breakdown was similar in the two groups. Such reduction in SMP synthesis in the gastric carcinoma patients resulted in a more negative net balance. CONCLUSIONS: Conflicting data in the literature may be accounted for by the different selection of patients and controls. Furthermore, WBP kinetics is the result of the metabolism of at least two compartments, the muscle and the nonmuscle compartments (including the tumor), which can change in opposite ways. In patients with cachexia due to cancer, the skeletal compartment appears to be the more compromised, with a significant decrease in SMP synthesis.

Nutritional support in patients with cancer of the esophagus: impact on nutritional status, patient compliance to therapy, and survival.

AIMS AND BACKGROUND: The multimodal approach to patients with esophageal squamous cell carcinoma often includes polychemotherapy combined with radiation therapy. Cancer dysphagia and drug-related anorexia, mucositis and vomiting can all lead to malnutrition. The aim of this study was to analyze the impact of the administration of enteral nutrition (EN) on the patient's nutritional status, tolerance of chemotherapy and radiotherapy, and final oncological outcome. METHODS: Fifty esophageal cancer patients who were to be submitted to chemotherapy (days 1-4 5-fluorouracil (FU) 1 g/m2/day and cisplatin (CDDP) 100 mg/m2/day 1) for two cycles plus radiotherapy (31 Gy) were referred to the Nutrition Support Unit prior to any therapy due to their malnourished status. Twenty-nine dysphagic patients received nutrition via tube (37 kcal/kg/day + 2.0 g proteins/kg/day for 34 days), while 21 others who were not dysphagic were given a standard oral diet (SD). The patients who received EN had a more severe weight loss than the SD patients (16.8% vs 12.8%, P <0.02). RESULTS: The dose of administered EN represented 86% of the planned support, and 70% of the nutritional therapy was administered in the home setting. Administration of EN support resulted in stable body weight and unchanged levels of visceral proteins, while SD patients had a decrease in body weight, total proteins and serum albumin (P <0.01). There was no difference between the two groups in terms of tolerance and response to cancer therapy, suitability for radical resection and median survival (9.5 months). CONCLUSIONS: EN in patients with cancer of the esophagus undergoing chemotherapy and radiotherapy is well tolerated, feasible even in the home setting, prevents further nutritional deterioration and achieves the same oncological results in dysphagic patients as those achieved in non-dysphagic patients.

Outcome of cancer patients receiving home parenteral nutrition. Italian Society of Parenteral and Enteral Nutrition (S.I.N.P.E.).

BACKGROUND: Indication for home parenteral nutrition (HPN) in cancer patients is controversial because intestinal failure and malnutrition are often only two of the many problems found in such patients that may deserve priority of treatment. METHODS: This was a retrospective study of 75 cancer patients from nine institutions included in the Italian HPN Registry. The patients had a mean weight loss of 12.5%, serum albumin of 3.1 g/dL, lymphocyte count of 1150/mm3, and serum total iron-binding capacity of 190 micrograms/dL. The main indication for HPN was intestinal obstruction (66%); 72% of the patients had metastatic disease. A series of demographic, oncologic, and nutritional characteristics were analyzed in an attempt to predict a possible benefit of HPN. RESULTS: A total of 9897 days of HPN were delivered to 75 cancer patients, for a median of 4 months (range 1 to 15 months) per patient. Sixty-nine patients died while receiving HPN, five had a remission of their intestinal failure, and one chose to stop the treatment. Complications related to parenteral nutrition were as follows: 19 cases of sepsis, 6 catheter occlusions, 4 catheter dislocations, and 2 metabolic imbalances. HPN preserved nutritional status and slightly improved weight, lymphocyte count, serum albumin, and Karnofsky performance status in patients who survived > 3 months. Quality of life during HPN was judged by the clinicians to have improved in only 9% of those who survived < 3 months, but in 68% of the patients who survived for > 3 months. Karnofsky performance status > 50 at the start of HPN was correlated with longer survival (p = .02). CONCLUSIONS: Our study demonstrated a positive effect of HPN on nutritional status and quality of life in patients who survived > 3 months and suggests that HPN should be avoided when Karnofsky performance status is < 50.

The influence of blood glucose levels on [18F]fluorodeoxyglucose (FDG) uptake in cancer: a PET study in liver metastases from colorectal carcinomas.

AIMS AND BACKGROUND: To study the influence of blood glucose levels on the clinical reliability of positron emission tomography (PET) with [18F]-2-fluoro-2-deoxy-D-glucose (FDG) in the detection of liver metastases from colorectal carcinomas and in the analysis of tumor uptake of FDG. METHODS: After having given their informed consent, 8 patients with 20 liver metastases (mean size, 31.5 mm; range, 10-75 mm) detected by means of CT were submitted to a first FDG-PET examination under fasting conditions and, 2 days later, to a second FDG-PET examination performed after i.v. infusion of a glucose solution (4 mg/kg/min for 2 hrs). The results of the two studies were compared in each patient, considering both the localization of the metastases and the FDG uptake in the lesions. A non-kinetic method was used, calculating the Standardized Uptake Value (SUV). RESULTS: All 20 metastases were clearly visible on FDG-PET under fasting conditions. Moreover, in 2 patients FDG-PET detected a number of unknown liver metastases. The blood glucose levels after glucose infusion were significantly higher than the levels under fasting conditions, 158 +/- 13.8 mg/100 ml (mean +/- sd) and 92.4 +/- 10.2, respectively (P < 0.001), and the quality of the FDG-PET images showed a marked deterioration. FDG-PET was unable to detect 6 of the 20 lesions and another 10 lesions were localized less clearly. Moreover, 80% of the unknown liver metastases were not detected after glucose loading. The SUVs of metastases decreased from 9.4 +/- 5.7 (mean +/- sd) under fasting conditions to 4.3 +/- 8.3 after glucose loading (P < 0.001). CONCLUSIONS: FDG-PET studies may be particularly unreliable under conditions of high levels of blood glucose. Therefore, patients entering FDG-PET studies should fast, and blood glucose concentration needs to be taken into account when evaluating FDG uptakes in follow-up studies.