[Detection of metastases in breast cancer patients: comparison of FDG PET with chest X-ray, bone scintigraphy and ultrasound of the abdomen]. / Nachweis von Metastasen bei Patientinnen mit Mamma - karzinom Vergleich von FDG-PET mit Röntgen-Thorax, Oberbauchsonographie und Skelett szintigraphie.

UNLABELLED: Distant metastases at primary diagnosis are a prognostic key factor in breast cancer patients and play a central role in therapeutic decisions. To detect them, chest X-ray, abdominal ultrasound, and bone scintigraphy are performed as standard of care in Germany and many centers world-wide. Although FDG PET detects metastatic disease with high accuracy, its diagnostic value in breast cancer still needs to be defined. The aim of this study was to compare the diagnostic performance of FDG PET with conventional imaging. PATIENTS, METHODS: A retrospective analysis of 119 breast cancer patients who presented for staging was performed. Whole-body FDG-PET (n = 119) was compared with chest X-ray (n = 106) and bone scintigraphy (n = 95). Each imaging modality was independently assessed and classified for metastasis (negative, equivocal and positive. The results of abdominal ultrasound (n = 100) were classified as negative and positive according to written reports. Imaging results were compared with clinical follow-up including follow-up imaging procedures and histopathology. RESULTS: FDG-PET detected distant metastases with a sensitivity of 87.3% and a specificity of 83.3%. In contrast, the sensitivity and specificity of combined conventional imaging procedures was 43.1% and 98.5%, respectively. Regarding so-called equivocal and positive results as positive, the sensitivity and specificity of FDG-PET was 93.1% and 76.6%, respectively, compared to 61.2% and 86.6% for conventional imaging. Regarding different locations of metastases the sensitivity of FDG PET was superior in the detection of pulmonary metastases and lymph node metastases of the mediastinum in comparison to chest x-ray, whereas the sensitivity of FDG PET in the detection of bone and liver metastases was comparable with bone scintigraphy and ultrasound of the abdomen. CONCLUSIONS: FDG-PET is more sensitive than conventional imaging procedures for detection of distant breast cancer metastases and should be considered for additional staging especially in patients with high risk primary breast cancer.

Comparison between positron emission tomography using 2-[fluorine-18]fluoro-2-deoxy-D-glucose, conventional imaging and computed tomography for staging of breast cancer.

BACKGROUND: The presence, extent and localization of distant metastases are key prognostic factors in breast cancer patients and play a central role in therapeutic decision making. The aim of this study was to compare the diagnostic performance of positron emission tomography using 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG-PET) with that of computed tomography (CT) and conventional imaging including chest radiography, abdominal ultrasound and bone scintigraphy. PATIENTS AND METHODS: A total of 119 consecutive patients with newly diagnosed locally advanced disease (n = 69) or previous history of breast cancer (n = 50) who had clinical suspicion of metastatic disease underwent FDG-PET, CT and conventional imaging procedures. Imaging results were retrospectively compared with histopathology and clinical follow-up which served as a reference standard. RESULTS: FDG-PET detected distant metastases with a sensitivity of 87% and a specificity of 83%. In contrast, the sensitivity and specificity of combined conventional imaging procedures were 43% and 98%, respectively. CT revealed a sensitivity of 83% and a specificity of 85%. CONCLUSIONS: In breast cancer, FDG-PET is superior to conventional imaging procedures for detection of distant metastases. Although FDG-PET and CT provided similar diagnostic accuracy, the information was often found to be complementary. With increasing availability of FDG-PET/CT, prospective studies are needed to determine whether it could potentially replace the array of conventional imaging procedures used today.

Sodium selenite is a potent radioprotector of the salivary glands of the rat: acute effects on the morphology and parenchymal function during fractioned irradiation.

In vitro studies show that sodium selenite is a potential radioprotector in normal cultural cells, but not in tumor cells. The aim of this study was to evaluate the cytoprotective potency of sodium selenite during a conventional fractioned irradiation of the salivary glands of rats. The head and neck area of male WAG/RijH rats was irradiated with (60)Co-gamma rays (60 Gy/30 fractions/6 weeks). Sodium selenite (15 microg/kg body weight) was applied through a venous port 30 min before irradiation. Rats of a control group were treated in the same manner with an equal volume of physiologic sodium chloride. In the course of treatment, the salivary glands were resected at different stages and examined histopathologically. The evaluation of gland function was performed prior to and after radiotherapy by sialoscintigraphy. The irradiation caused dose-dependent damage in the salivary glands. Intra- and intercellular edema (16 Gy), vacuolization (30 Gy), degranulation (46 Gy) and necrosis of the acinar cells (60 Gy) occurred. Sodium selenite delayed the development of the described damage; additionally, the number of necrotic acinar cells after the application of 60 Gy was reduced (control, 75% vs. sodium selenite, 30%). The sialoscintigaphical results confirmed these results: the loss in gland function in the control group was 74 vs. 44% (P < 0.05) in the sodium selenite group. Based on the morphological and sialoscintigraphical findings, a cytoprotective effect on the acute toxicity of the salivary glands of rats could be detected during irradiation with synchronous application of sodium selenite.

[Sodium selenite reduces acute radiogenic damage of the rat parotid glands during fractionated irradiation]. / Reduktion akuter radiogener Schädigungen durch Natriumselenit. Wirksamkeit unter fraktionierter Bestrahlung der Glandula parotis der Ratte.

BACKGROUND: In vitro studies show that sodium selenite is a potential radioprotector in normal cell cultures, but not tumor cells. The aim of this study was to evaluate the cytoprotective potency of sodium selenite during conventional fractionated irradiation of rat salivary glands, but also on tumor response and metastasis frequency of rhabdomyosarcomas R1H. METHOD: The head-neck area of male WAG/RijH rats and the tumor in the flank were irradiated with (60)Co-gamma-rays (60 Gy/30 fractions/6 weeks). Sodium selenite (15 microg/kg body weight) was applied through a venous port 30 min before irradiation. Rats of a control group were treated in the same manner with an equal volume of physiologic sodium chloride. In the course of treatment the salivary glands were extirpated at different stages and examined histopathologically. The evaluation of the gland function was performed prior to and after radiotherapy by sialoscintigraphy. Tumor volume was measured during irradiation and plotted in tumor-volume curves. Rat body weight was determined sequentially to estimate the general constitution of the animal during the treatment. RESULTS: Irradiation caused dose-dependent damage in the salivary glands. Intra- and intercellular edema (16 Gy), vacuolization (30 Gy), degranulation (46 Gy), and necrosis of the acinar cells (60 Gy) occurred. Sodium selenite delayed the development of the described damage, and the amount of necrotic acinar cells after the application of 60 Gy was reduced (control: 75% vs sodium selenite 30%), confirmed by the sialoscintigraphic results. The loss in gland function in the control group was 44% vs 74% (p<0.05) in the sodium selenite group. Sodium selenite had no influence on the response of R1H tumors to radiation and general constitution. CONCLUSIONS: Based on morphological and sialoscintigraphic findings, a cytoprotective effect on acute toxicity of rat salivary glands could be detected under irradiation with synchronous application of sodium selenite. In addition, no effects on tumor response and metastasis frequency were observed. The general animal constitution was not affected by additional medication with sodium selenite during irradiation.

[Histomorphologic and salivary gland scintigraphic findings in radiation-induced sialadenitis due to fractionated irradiation of the head and neck region of rats. A model for evaluating potentially radioprotective substances]. / Histomorphologische und sialoszintigraphische Befunde zur Radiosialadenitis unter fraktionierter Bestrahlung der Kopf-Hals-Region von Ratten. Ein Modell zur Evaluierung potenziell radioprotektiver Substanzen.

INTRODUCTION: The aim of this study was to correlate structural, histomorphological damage of the salivary gland with scintigraphic findings during fractioned radiotherapy. METHODS: The head and neck area of 27 WAG/RijH rats was irradiated with (60)Co-gamma-rays (60 Gy/30f/6 weeks). A port-system was implanted and (99m)Tc-pertechnetat applied at different stages of irradiation (0, 16, 30, 46, 60 Gy and 6 months post irradiation). RESULTS: After the application of 16 Gy an intra- and extra-cellular oedema developed in the salivary glands. The progressive vacuolisation (30 Gy) passed over into lipomatosis (46 Gy) and necrosis (60 Gy) in the parotid and mandibular glands. Six months after irradiation treatment, the chronic histomorphological damage corresponded to stage II according to Seifert. The corresponding loss in gland function was 13% (16 Gy); 26% (30 Gy); 57% (46 Gy); 75% (60 Gy) and 66.5% (6 months post irradiation). CONCLUSION: This animal model demonstrates the correlation between histomorphological and scintigraphic findings.

Investigation of radiosialadenitis during fractioned irradiation: sialoscintigraphical and histomorphological findings in rats.

Xerostomia is the most debilitating side effect induced by irradiation of head and neck tumours and is caused by irradiation damage to the salivary glands. The aim of this study was to correlate structural histomorphological damages and sialoscintigraphical findings during fractioned radiotherapy. The head and neck area of 27 WAG/RijH rats was irradiated with 60Co-gamma rays (60 Gy/30f 6 weeks). To evaluate salivary gland function, a port system was implanted, and 99mTc-pertechnetate was applied at different stages of irradiation (0, 16, 30, 46, 60 and 6 months post-irradiation). In the course of treatment the parotid glands were examined histopathologically. Rat salivary glands developed a dose-dependent radiosialadenitis. After a dose of 16 Gy an intra- and extra-cellular oedema developed in the salivary glands. Progressive vacuolisation (30 Gy) developed into lipomatosis (46 Gy) and necrotic changes (60 Gy) in the parotid glands. Six months after irradiation treatment, the chronic histomorphological damages corresponded to stage II according to Seifert. The corresponding loss in gland function investigated by measurement of the 99mTc-pertechnetate uptake of the salivary glands was 13% (16 Gy), 26% (30 Gy), 57% (46 Gy), 75% (60 Gy) and 66.5% (6 months post-irradiation). The presented animal model is suitable to demonstrate the correlation of histomorphological and sialoscintigraphical findings.

[Reducing late toxicity with amifostine in fractionated irradiation of the rat salivary glands]. / Reduktion der Spättoxizität durch Amifostin bei fraktionierter Bestrahlung der Rattenspeicheldrüsen.

Clinical studies show that amifostine can reduce xerostomia and mucositis during radiotherapy of head and neck cancers. The aim of this study was to evaluate the radioprotective potency of amifostine with respect to late toxicity of salivary glands of rats. The head-neck-area of 8 male WAG/RijH rats (295 +/- 7 g) were irradiated with 60Co-gamma-rays (60 Gy/30 f/6 weeks). Amifostine (250 mg/m2 body surface) was applied via a venous port 15 min before each irradiation. Rats of a control group were irradiated with the same schedule with equal volumes of physiological saline. The morphological and sialoscintigraphical findings clearly demonstrate that amifostine has a remarkable cytoprotective effect on the late toxicity of irradiated salivary glands.

[F-18 FDG positron emission tomography in diagnosis and follow-up of patients with musculoskeletal tumors]. / Stellenwert der F-18-FDG-Positronenemissionstomographie in der Diagnostik und Therapiekontrolle von Knochen- und Weichteiltumoren.

The purpose of this study was to assess the value of F-18 FDG whole body positron emission tomography in the primary and follow-up diagnosis of musculoskeletal tumors. Between May 1994 and January 2000, 79 patients [36 females, 43 males; mean age: 44 years (9-78)] suffering from different musculoskeletal tumors were additionally examined with PET. In total, 100 whole body PET examinations (48 for primary staging, 52 for follow-up) were performed using a PET scanner [ECAT EXACT 47 (921)] with an axial field of view of 16.2 cm. The tracer was 370 MBq F-18 FDG. The results were compared to those achieved with conventional diagnostic tools such as CT, MRT, bone scan, and histology. In the primary staging, PET exhibited a sensitivity of 100% and a specificity of 50% (two false-positive results). In examinations for follow-up purposes, we found a sensitivity of 88.9% and a specificity of 92.0%. In the diagnosis of skeletal and extraskeletal metastases (100 PET inspections), the sensitivity was 87.5% and the specificity 89.7%. Besides this, PET was compared with standard diagnostic tools used in the follow-up procedures of those patients who had received chemo- and/or radiotherapy. In addition, the procedure was used to search for the unknown primary tumors in cases of secondary metastases in the skeleton and compared as well.PET with F-18 FDG as tracer has become an important additional method in the diagnosis of musculoskeletal tumors. It can be used for primary staging, search for metastases, and post therapeutic control. Negative results were seen when PET was used to search for metastases when the tumor was smaller than 5 mm, in cases of inflammatory diseases, and the differentiation of low-grade malignant tumors from benign lesions.

Comparison of fluorodeoxyglucose positron emission tomography and "conventional diagnostic procedures" for the detection of distant metastases in breast cancer patients.

The presence of distant metastases is the main prognostic factor in patients with breast cancer and has a significant influence in the choice of therapy. Therefore, chest X-ray, bone scintigraphy and ultrasound of the abdomen are performed to detect distant metastases at diagnosis and follow-up. Fluorodeoxyglucose positron emission tomography (FDG PET) has been shown to provide sensitive detection of primary tumour and metastases for many tumour entities, but little information is available about the diagnostic value for breast cancer patients. This study retrospectively compared FDG PET for detection of metastatic disease with chest X-ray, bone scintigraphy and ultrasound of the abdomen, referred to as "conventional diagnostic procedures" (CDPs), in 50 breast cancer patients. Imaging procedures were analysed in a blinded fashion with the results classified as "no evidence of metastases", "equivocal" and "evidence of metastases". Clinical follow-up and the results of other imaging modalities including computed tomography and magnetic resonance imaging were used to determine if metastases were present. FDG PET identified metastatic disease with a sensitivity and specificity of 86% and 90% as compared to 36% and 95% for CDPs, respectively. Regarding "equivocal" and "evidence of metastases" as positive, the sensitivity of CDPs increased to 57% with a corresponding specificity of 81%, whereas sensitivity and specificity of FDG PET remained unchanged. Regarding different localities of metastases the sensitivity of FDG PET was superior in the detection of pulmonary metastases and especially of lymph node metastases of the mediastinum in comparison to chest X-ray, whereas the sensitivity of FDG PET in the detection of bone and liver metastases was of the same magnitude as compared with bone scintigraphy and ultrasound of the abdomen.

Multiple application of drugs in rats--a new port system.

The implantation of a small port system for repeated intravenous applications of drugs in rats is described. The system basically consists of a Teflon catheter which is inserted into the right internal jugular vein. The open end of the catheter under the right foreleg is subcutaneously carried through to the back and closed by a small port. The port then is implanted into a skin pocket on the back of the rat. The advantage of this method is that repeated intravenous injections of drugs into rats can easily be applied with high accuracy. Complications were rarely observed (7%) and could be mastered successfully in all cases.

[Prevalence of iodine- and thyroglobulin-negative findings in differentiated thyroid cancer.A retrospective analysis of patients treated from 1951 to 1998 in university hospital]. / Häufigkeit lod- und hTG-negativer Befunde beim differenzierten Schilddrüsenkarzinom. Eine retrospektive Analyse der von 1961 bis 1998 in einer Universitätsklinik behandelten Patienten.

AIM: The prevalence of iodine- and thyroglobulin-negative findings was evaluated in all patients with differentiated thyroid cancer (DTC) treated from 1961 until 1998 at the Department of Nuclear Medicine, University Hospital Hamburg-Eppendorf. METHODS: A total of 490 patients with papillary thyroid cancer (PCA) and 242 patients with follicular thyroid cancer (FCA) were analyzed retrospectively. Patients were divided into four groups: 1: no recurrence, 2: recurrent disease, 3: primary metastatic/progressive disease and 4: inconclusive follow-up. Results of iodine scan, serum-TG, and additional imaging modalities as well as histology were compared in all patients. RESULTS: 21/490 (4.3%) of patients with PCA and 16/242 (6.6%) with FCA suffered from recurrent disease. 62/490 (12.7%) of patients with PCA and 59/242 (24.4%) with FCA had primary metastatic/progressive disease. 12/21 patients with PCA and 12/16 with FCA showing up with recurrent disease had a negative iodinescan. 11/21 of patients with PCA and 4/16 with FCA and tumor recurrence had negative serum-TG levels. 14/62 patients with PCA and 14/59 with FCA presenting with primary metastatic/progressive disease had negative iodinescan. 14/62 patients with PCA and 6/59 with FCA had negative serum-TG. CONCLUSION: The prevalence of iodine-negative recurrent/metastatic disease is in accordance to the literature, whereas the prevalence of TG-negative recurrent/metastatic was noted higher than reported previously. Thus, the commonly used follow-up scheme of DTC is confirmed. However, iodine scan should be regularly performed in patients with high risk of recurrence.

FDG PET in the diagnosis of hilar cholangiocarcinoma.

Resectional surgery offers a curative intent and a survival benefit for patients with hilar cholangiocarcinoma, but is associated with high morbidity. Since morphological imaging cannot solve differential diagnosis preoperatively, in order to exclude patients inappropriate to this aggressive surgery, we evaluated the impact of functional imaging using fluorodeoxyglucose positron emission tomography (FDG PET) in the detection of cholangiocarcinoma and its usefulness in the differentiation from benign Klatskin tumour-mimicking lesions. Fifteen consecutive patients aged 47-78 years underwent standardized whole-body FDG PET with attenuation correction before potentially curative surgery using a conventional full-ring PET scanner with an axial field-of-view of 16.2 cm. FDG PET was evaluated visually and semiquantitatively using tumour-to-background ratios (T/B) ratios. All lesions were evaluated histopathologically. FDG PET presumed to be indicative for carcinoma was positive in 12 of 15 patients, true positive in 10 (T/B ratio, 3.2+/-1.9) and false positive in two of them (T/B ratios, 2.1 and 2.8) with Klatskin tumour-mimicking lesions. While all true positive PET results were seen in the tubular type of cholangiocarcinoma with a high amount of tumour cells and only low production of mucus, a false negative FDG PET in three patients was observed in mucinous adenocarcinoma. Additionally, FDG PET detected locoregional lymph nodes in two patients and distant metastases in a further three patients. Due to false positive results FDG PET does not allow the differentiation of benign from malignant lesions, and FDG PET should be avoided in patients with mucinous cholangiocarcinoma. However, FDG PET may have significant influence on the treatment strategy in as much as 20% of the patients, since it may detect distant metastases.

Long-term effects of 'ecstasy' abuse on the human brain studied by FDG PET.

The popular recreational drug, 'ecstasy', mainly contains 3,4-methylenedioxymethamphetamine (MDMA) as the psychotropic agent. MDMA is suspected of causing neurotoxic lesions to the serotonergic system as demonstrated by animal studies, examinations of human cerebrospinal fluid, and the first positron emission tomography (PET) studies using the serotonin transporter ligand [11C]-McN5652. Damage of serotonergic afferents might mediate long-lasting alterations of cerebral glucose metabolism as a secondary effect. To study a relationship between ecstasy use and long-lasting alterations, PET using 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) was performed in 93 ecstasy users and 27 subjects without any known history of illicit-drug abuse. As an index of glucose metabolism, mean normalized FDG uptake was determined in both groups using a computerized brain atlas, and was compared for a selected number of brain regions. FDG uptake was normalized in each individual by dividing local FDG uptake by the maximum FDG uptake in the individual's brain. Within the group of ecstasy users we examined the relationship between FDG uptake and cumulative ecstasy dose, time since last ecstasy ingestion at the time of PET scanning, and age at first ecstasy use, respectively. Normalized FDG uptake was reduced within the striatum and amygdala of ecstasy users when compared to controls. No statistically significant correlation of the FDG uptake and the cumulative dose of ecstasy was detected. A positive correlation was found in the cingulate between FDG uptake and the time since last ecstasy ingestion. As compared to the control group, normalized FDG uptake in the cingulate was reduced in ecstasy users who took ecstasy during the last 6 months, while it was elevated in former ecstasy users who did not consume ecstasy for more than 1 year. FDG uptake was significantly more affected in ecstasy users who started to consume ecstasy before the age of 18 years. In conclusion, ecstasy abuse causes long-lasting effects on glucose metabolism in the human brain. These effects are more severe in the case of very early abuse. However, several questions still remain to be answered, i.e. the correlation of the neuronal alterations and the history of ecstasy use (cumulative dose, and time since the last dose) and its reversibility.

Radioprotection of salivary glands by S-2-(3-aminopropylamino)-ethylphosphorothioic (amifostine) obtained in a rabbit animal model.

BACKGROUND: Impairment of salivary gland function following high-dose radioiodine treatment (HDRIT) is a well-recognized side effect of the treatment. Because differentiated thyroid cancer has an excellent prognosis, reduction of long-term side-effects is mandatory. Therefore, the aim of this study was to investigate the radioprotective effect of amifostine in a rabbit animal model. METHODS: Salivary gland scintigraphy was performed in a total of 16 New Zealand White rabbits. Uptake of 99-Tc-pertechnetate was calculated in percentage of injected activity as a quantitative measure of both salivary gland and thyroid function. Reproducibility of salivary gland scintigraphy was evaluated in one rabbit without any intervention. Fifteen rabbits were studied prior to and up to 6 months after high-dose radioiodine treatment applying 2 GBq 131I. Ten animals received 200 mg/kg amifostine prior to high-dose radioiodine therapy, and 5 served as controls. Salivary glands were examined histopathologically. RESULTS: Variation coefficient of parenchymal function was less than 3.8% in salivary glands. Prior to HDRIT, thyroid uptake was 0.417+/-0.373% and 0.421+/-0.241% in control and amifostine-treated rabbits, respectively. Four weeks after HDRIT, complete ablation of the thyroid was achieved in both groups. Prior to HDRIT, uptake of 99mTc-pertechnetate in salivary glands of five control rabbits was not significantly different from ten amifostine-treated rabbits. In control rabbits 6 months after HDRIT, parenchymal function was reduced significantly (p < 0.0001) by 75.3+/-5.3% and 53.6+/-17.4% in parotid and submandibular glands, respectively. In contrast, in amifostine-treated rabbits, parenchymal function was reduced by 10.6+/-3.4% and 6.5+/-4.3% (p > 0.05) in parotid and submandibular glands, respectively. Histopathologically, marked lipomatosis was observed in control animals but was negligible in amifostine-treated animals. CONCLUSION: Parenchymal damage in salivary glands induced by high-dose radioiodine treatment can be significantly reduced by amifostine in this rabbit animal model. This corresponds to data obtained in patients with differentiated thyroid cancer.

Salivary gland protection by S-2-(3-aminopropylamino)-ethylphosphorothioic acid (amifostine) in high-dose radioiodine treatment: results obtained in a rabbit animal model and in a double-blind multi-arm trial.

Since differentiated thyroid cancer has an excellent prognosis, reduction of long-term side effects of high-dose radioiodine treatment (HD-RIT), i.e. salivary gland impairment is important. Thus, radioprotective effects of amifostine were studied. Salivary gland function was quantified by scintigraphy both in rabbits and patients. Fifteen rabbits were studied prior to and up to 6 months after HD-RIT applying 2 GBq 131I. Ten animals received 200 mg/kg amifostine prior to HD-RIT, and five served as controls. Animals were examined histopathologically. Fifty patients with differentiated thyroid cancer were evaluated prospectively prior to and 3 months after HD-RIT with either 3 or 6 GBq 131I in a double-blind, placebo-controlled study. Twenty-five patients were treated with 500 mg/m2 amifostine intravenously prior to HD-RIT, and 25 patients receiving physiological saline solution served as controls. Complete ablation of the thyroid was achieved in all rabbits four weeks after HD-RIT. In control rabbits 6 months after HD-RIT parenchymal function was reduced significantly (p < 0.0001) by 75.3 +/- 5.3% and 53.6 +/- 17.4% in parotid and submandibular glands, respectively. In contrast, in amifostine-treated rabbits parenchymal function was not significantly reduced. Histopathologically, marked lipomatosis was observed in control animals but was negligible in amifostine-treated animals. In control patients, salivary gland function was significantly (p < 0.001) reduced by 40.2 +/- 14.1% and 39.9 +/- 15.3% in parotid and submandibular glands, respectively, three months after HD-RIT, and 11 patients developed xerostomia. In 25 amifostine-treated patients, salivary gland function was not significantly reduced (p = 0.691), and xerostomia did not occur. Thus, parenchymal damage in salivary glands induced by high-dose radioiodine therapy can be reduced significantly by amifostine. This may improve quality of life of patients with differentiated thyroid cancer.

Unit And Random Linear Models In Decision Making.

Dawes and Corrigan have asserted that linear decision rules using random or unit coefficients "yield predictions that are superior to those of human judges." Their assertion is based on the large correlations between the decisions from random or unit rules and actual decisions. This paper reports an experiment based on the scheduling production problem in which the correlations coefficient is compared with actual costs. In spite of high correlations with the optimal decision, the unit and random rules yielded much higher costs than human judgment.