in vivo 19: 1071-1076 (2005)

Fast Cancer Uptake of 99mTc-labelled Bombesin (99mTc BN1)

F. SCOPINARO1, G. P. DI SANTO1, A. TOFANI1, R. MASSARI2, C. TROTTA2, M. RAGONE3, S. ARCHIMANDRITIS4 and A.D. VARVARIGOU5

1Department of Scienze Radiologiche and 4Faculty of Engineering, University “La Sapienza”, Rome; 2University Hospital “San Andrea”, Rome; 3Li-Tech and ISIB-CNR, Udine and Rome, Italy; 5National Research Center,"Demokritos", Athens, Greece

Abstract. In human blood, breakdown of -releasing show istant action because BN receptors (BNRs) and BNR and other bombesin-related occurs in less than subtypes (BNS) are the same in different tissues; however, 15 min. This quick enzymatic cleavage might impair the the action of the above peptides is prevented by their rapid diagnostic use of labelled bombesin (BN). 99mTc-labelled breakdown in the serum. bombesin (99mTc BN1) was injected intravenously and BN and BN-related peptides are neuro-hormones and dynamic uptake data were acquired for diagnosing 26 cancers ; the three well known human BNS show a of different origin: 15 breast, 3 prostate, 5 colo-rectal, 1 number of functions in the central nervous system (4, 5). pancreas, 2 small cell lung cancers and 1 gastrinoma. BNS is also expressed in several foetal and adult tissues, Background subtracted tumour uptake data were plotted where BN-related peptides act as releasing factors, against time and fitted with known mathematical functions. morphogens and growth factors (6-8). Finally, BN-related Twenty-three out of 26 cancers showed rapid increase of peptides, whose paracrine and autocrine production has radioactivity followed by a radioactivity plateau, with some already been mentioned, act as mitogens, growth and anti- oscillations around the average plateau value. The time to 80% apoptotic factors on several epithelial cancers, such as of max activity (T80) was the reference parameter to measure breast, prostate and small cell lung carcinomas (9-12). and to compare the uptake speeds. The slowest T80 was 7 min The rationale of labelling BN-like peptides with gamma- in one T1b breast cancer, gastrinoma reached T80 in 5 min ray-emitting radioisotopes (13, 14) is based on the intense and node-positive prostate cancers in 2 min. N+ breast overexpression of BNRs in a large variety of epithelial cancers showed T80 at 3.62±0.75 min, N– breast cancers at tumours. This fact makes labelled BN most suitable as a 5.5±0.88 min (p<0.02). When all the tumours were cancer seeking agent. Initial pilot and phase I diagnostic considered, N+ tumours showed T80 at 2.68±1.03 min and trials with the first of a series of BN-like peptides, labelled N– cancers at 5.5±0.82 min. In all the cancer types, the uptake with technetium (99mTc-BN-1), have confirmed this of 99mTc BN was faster than 10 min. This result shows the hypothesis (15-21). Rapid cleavage of BN in the serum has ability of 99mTc BN to image tumours. The faster uptake by suggested the synthesis of BN-like labelled peptides with a N+ versus N– cancers probably depends on the higher blood longer BN half-life than native in human blood (22). It is flow in N+ cancers. necessary to know if the cancer uptake of intravenously (i.v.) injected 99mTc BN-1 is fast enough for tumours to Bombesin (BN) and related peptides, which are gastrin- accumulate this radiopharmaceutical before its enzymatic releasing peptides (GRP), and (NMB) in destruction in human serum. mammalians, mainly act through their paracrine or their The tissue uptake of molecules undergoing internalisation autocrine secretion (1-3). GRP and NMB would be able to is generally faster than the uptake of molecules that only bind to membrane or extracellular structures (23) and the internalisation of small peptides is faster than the internalisation of large globulins, such as antibodies (24). Correspondence to: Francesco Scopinaro, Nuclear Medicine, However, it is well known that a small labelled peptide such University of Rome "La Sapienza", "S. Andrea" Hospital, Via di as 111In octreotide takes some hours before allowing good Grottarossa1038, 00100 Rome, Italy. e-mail: francesco.scopinaro@ quality emission tomography (25-27). uniroma1.it The main aim of the present study was to establish 99m Key Words: Bombesin, breast cancer, prostate cancer, gastrinoma, whether injected Tc BN-1 is taken up by different radiolabelled peptides. tumours before the breakdown of the peptide, whose half-

0258-851X/2005 $2.00+.40 1071 in vivo 19: 1071-1076 (2005) life is about 15 minutes in human blood. A secondary aim Table I. Summary of the results. was to assess whether or not the uptake characteristics can No. pts. Tumour type TN Nodes Best fit Time to 80% clarify the role of regional blood flow and BNR staging of max activity overexpression in cancer. 1 Breast cancer T2N1 + GU 2.5 min Patients and Methods 2 Breast cancer T2N1 + GU 4 min 3 Breastcancer T1cN1 + GU 4 min Patients. Twenty-six patients, 14 with breast cancer, 1 with exocrine 4 Breast cancer T1cN0 – GU 4 min pancreas cancer, 1 with gastrinoma, 2 with small cell lung cancer 5 Breast cancer T1bN1 – Sin GU 6 min (SCLC), 3 with prostate cancer, 2 with colon cancer and 2 with 6 Breast cancer T1bN0 – PO 5 min rectal cancer, were studied with 99mTc BN-1. Out of the 14 patients 7 Breast cancer T1cN0 – Sin GU 7 min with breast cancer, 5 patients showed T1b N0 stage, 5 were T1c N0, 8 Breast cancer T1bN0 – Sin GU 5 min 2 were T1c N1 and 2 were T2 N1. All the prostate cancers were T3 9 Breast cancer T1bN0 – Sin GU 4 min N+, 2 colon cancers were T2 N0, 1 rectal cancer T1N0, 1 T1N1 10 Breast cancer T1bN0 – PO 6 min and 1 T2 N0. 11 Breast cancer T1cN0 – Sin GU 4.5min Thin layer chromatography (TLC), with 75% methanol as the 12 Breast cancer T1cN0 – Sin GU 6 min mobile phase, was used to assess the labelling yield of 99mTc BN-1. 13 Breast cancer T1cN0 – Sin GU 6 min 14 Breast cancer T1cN0 – Sin GU 5.5 min The data were acquired with a double-headed large field of view 15 Colon cancer T2N0 – Sin GU 1.5 min gamma camera fitted with low energy, general purpose collimators. 16 Rectal cancer T1N1 + Sin GU 1.5 min Before starting the SPECT studies, a dynamic set of data was 17 Colon cancer T1N0 – GAV 4 min acquired for each patient. Dynamic studies started at the moment 18 Rectal cancer T2N1 + PO 1.5 min 99m of intravenous injection of Tc BN-1, 185 MBq (5 mCi) in bolus 19 Rectal cancer T1N0 – GAV 4.5 min and lasted 20 minutes with a rate of one frame/minute. 20 Prostate cancer T3N1 + GU 2 min The detectors were differently positioned for different anatomic 21 Prostate cancer T3N1 + GU 2.5 min situations: one detector ventral and the second dorsal to the chest 22 Prostate cancer T3N1 + Sin GU 2.5 min or to abdomen to study the lungs and, respectively, the pancreas 23 SCLC T2N1 + GAV 2 min and left and right lateral for the prostate. Mammary glands were 24 SCLC T1N1 + PO 3.5 min studied in a prone lateral view following the technique of Khalkhali 25 Gastrinoma TxN0 – GU 5 min et al. (28, 29) with two detectors positioned on each breast. Colon, 26 Exocr pancr. cancer T1N0 – PO 6 min pancreas and lung cancers were studied with detectors in anterior and, respectively, posterior view; prostate and rectal cancers were GU, general uptake; PO, polynomial; GAV, gamma variate examined with detectors on the left and right lateral view, with the patient in supine decubitus.

Images, ROIs and 99mTc bombesin curves. Regions of interest A dedicated program for automatic selection of best fit of the (ROIs) were selected by the operator on the sum of dynamic experimental data was implemented in the Windows/origin images of each dynamic dataset. Tumour and organ background environment of a personal computer. Normalised background ROIs were always selected (Figure 1); bladder ROI was selected subtracted counts against time were imported from the dedicated- only for patients with prostate or rectal cancer (Figure 2). Actually, to-gamma camera computer to the Windows /origin of a personal radioactive urine was always detectable in the bladder , although computer; counts/time plots were generated for each ROI and the continuous washing of the bladder occurred because of the best fit of experimental curves with MF established by the insertion of a three-way catheter. computer program. Data arising from ROIs were normalised for geometric Data arising from ROIs drawn on dynamic acquisitions of difference by predefined computer programs. The normalised radioactivity are generally presented as time/activity plots and the organ background curve was subtracted from the tumour curve and resulting observed curves are normally fitted with MF. Thus, some displayed on the computer screen. MF, such as straight line, exponential, gamma-variate (GAV), general uptake (GU) and polynomial (PO) functions are familiar Curve fit. The dynamic data of radioactivity arising from ROIs to nuclear medicine operators. Straight line and exponential can be plotted against time (Figure 3) showing time/activity functions are often used to describe physiological behaviours, curves, that we can also call uptake curves because of their independently from nuclear medicine; GAV, GU and PO are more b -ct starting from 0 for activity as well as time representing the i.v. specific. GAV is At=A0 a e , where At is the radioactivity administration, and reaching more or less stable maximum function of time, t is time after administration, A0 is the activity (max). In order to assess numeric parameters, such as radioactivity at time 0, e is the base of the natural logarithms and max value, time to max and time to 80% of max , these curves a, x, b and c are numeric coefficients that modulate the curve. have to be fitted with known mathematical functions (MF); this GAV is a family of curves, that show asymmetric up-slope and procedure is necessary because measurements are often affected down-slope and are particularly able to fit data with regular by a number of casual errors, partially due to the Poissonian increase and a point of max, followed by modest decrease. PO also 2 . 3 . 4 . n statistical error of radioactivity measurements, or due to small is a family of functions of general form At= A0 at bt ct … i t -Ït physiological – e.g., breath, or accidental movements of patients GU shows the form of At=A∞(1-e ) where At is the radioactivity during dynamic acquisition. at a given time t and A∞ is the maximal radioactivity theoretically

1072 Scopinaro et al: Fast Cancer Uptake of 99mTc BN1

Figure 1. Uptake data and GU fit of T2N1 breast cancer (case 1, Table I). Figure 2. Uptake data and GU fit of TxN0 gastrinoma (case 25, Table I) 2 –Ït Significant agreement (¯ =1.34) of general uptake function with The function A(t)=A∞ (1–e ), general uptake curve, is the best fit of experimental uptake data. Time to 80% of max is very fast: 2.5 min. uptake data of gastrinoma:correspondence of observed data with mathematical function is very tight with very low ¯2 and 0.98 correlation.

achievable to which the curve asymptotically tends, e is the base of neperian logarithms and Ï is the constant of uptake rate. The function At=a sin(bt)+ct /t+1 (Sin GU), where t is time, At is the radioactivity function of time and a, b and c are constant coefficients, is conceptually similar to GU because it tends to an asymptote, but it is more effective than GU in following experimental data, due to its sinusoidal modulation.

Statistics. The difference between experimental data and fit with GU function was analysed with the ¯2 test, 19 degrees of freedom. When the ¯2 value was too high for probability (p) lower than 0.05 of the zero hypothesis, the experimental data were fitted with the other functions Sin GU, GAV and PO. The Student’s t-test was used to test the difference of time to 80% of the max uptake between groups of cancers, e.g. cancers which invaded regional lymph nodes (N+) and node-negative cancers (N–). Figure 3. Uptake data and Sin GU fit of prostate cancer T3N1(case 21, Results Table I). Sin GU function is the best fit, with very fast (2.5 min) time to 80% of maximum uptake. TLC analysis showed that the labelling yield of BN-1 was always higher than 97% before i.v. injection. All the uptake curves showed an up-slope behaviour with 80% or more of max value between 4 and 6 minutes from injection time. The max value with T1c N+ breast cancer. In 16 patients, the best fit was always observed between 6 and 14 minutes. Radioactivity showing low ¯2 values between experimental data and fitting inside the tumour ROI roughly showed a plateau between 10 function with p<0.05 was obtained with the Sin GU function. and 20 minutes, though with oscillations of 5% to 10% around The best fit of the registered uptake curve was a central value in 23 of the 26 patients. In 3 patients, the represented by PO functions for 5 patients, 2 with breast radioactivity in the tumour ROI showed a mild decrease after cancer, 1 with small cell lung carcinoma, 1 with rectal cancer having reached its max value. and in the patient with exocrine pancreatic cancer. The best fit of the uptake curve was the GU in 8 patients, The best fit was obtained with the GAV function for 3 namely the patient with gastrinoma, 2 patients with prostate patients, 1 with colon cancer, 1 with rectal cancer and 1 with cancer, the 2 patients with T2 breast cancer and the 2 patients SCLC.

1073 in vivo 19: 1071-1076 (2005)

The ¯2 value showed a very significant probability (p<0.01) In our series it was noteworthy that the patient with that the GU curve was not casually fitting the experimental gastrinoma, 2 patients with prostate cancer, 3 patients with data in the patient with gastrinoma and in the patients with T2 breast cancer and 2 patients with T1c breast cancer, all T2 breast cancer. The probability was also significant (p<0.05) of whom had node metastases except the gastrinoma, for the 2 patients with prostate cancer and for the patients showed statistically significant consistency of experimental with T1c breast cancer. In 16 patients, GU did not succeed in data with the data expected from the GU fit. The GU giving a statistically significant (p>0.05) approximation of the function is characteristic of structures which only accumulate radioactivity uptake, though the GU fit was visually acceptable radioactivity: in order for the 99mTc BN-1 uptake to be in some of them. A statistically significant fit (p<0.05) was described by the GU curve, the receptor density must be so obtained with Sin GU in 11 patients and with III grade PO high that no radioactivity goes out from the tumour. The functions in the other 5. shape of the GU curve and the value of its most important Eighty percent of max uptake was achieved by N+ parameter, Ï, thus depends on the receptor density of the tumours faster than by N–. We observed 80% of max uptake target tissue and on regional blood flow; Ï only depends on after 2.68±1.03 minutes in N+ cancers and after 5.5±0.82 regional blood supply, when the GU function tightly follows minutes in N– cancers. This difference was significant the experimental data of uptake. Absence of labelled peptide (p<0.02). In this comparison, only tumours in which the in venous blood cannot be measured by external counting. best fit of the uptake curve was GU, Sin GU or PO were However, the tumours which were expected to show very included. GAV fit was not considered because of the high expression of BNRs (10, 30, 31) showed GU as best fit. presence of a descending branch, which was not present in The uptake speed is also intriguing: gastrinoma, that was the other fits. However, the inclusion of GAV fits in order probably the richest tumour in receptor density, showed to include the entire series did not affect the statistical 80% of max uptake after 5 minutes, which was fast, but not significance. GU and Sin GU were much more similar to the fastest we have observed. An initial possible each other than PO with both the preceding functions. interpretation of these results is that gastrinoma highly When tumours showing PO fit were not considered, the overexpresses BNRs and develops increased regional blood time to 80% of max was 2.87±0.99 minutes for N+ cancers flow, but this increase is not as high as the increase of blood and 5.5±0.88 minutes in N– tumours; the statistical flow that is developed by N+ prostate and breast cancers. difference was similar (p<0.02). The uptake speed, which is shown by the parameter 80% Breast cancer was the most homogeneous series both for of max uptake, was significantly faster in N+ compared to pathological findings – all the breast tumours were ductal N– tumours. Apparently this result was not dependent on infiltrating cancers – and for the technique of data the acquisition technique or curve fit or tumour origin: in acquisition. N+ breast cancers showed 80% of max uptake fact, faster uptake in N+ tumours was observed when all the after 3.62±0.75 minutes, whereas the same parameter was tumours with GU, Sin GU and PO fit were taken into shown by N0 breast cancers after 5.5±0.88 minutes, with a account, as well as when considering only breast cancers or significant (p<0.05) difference. when the PO fit was excluded. These results can be explained by the same mechanism responsible for the faster Discussion uptake of breast and prostate cancers versus gastrinoma: the angiogenetic phenotype is much more frequent in N+ than The general aim of our work was to demonstrate that in N– cancers and regional blood flow is higher in invasive 99mTc BN-1 is taken up by several epithelial tumours than in non-invasive cancers. Delivery is a prerequisite of before its plasmatic breakdown: actually, this uptake of i.v. administered radiopharmaceuticals and the radiopharmaceutical is based on a peptide with a plasma uptake speed of 99mTc BN-1 depends on the regional blood half-life of 15 minutes, thus it can be used for diagnostic flow when BNR is sufficiently overexpressed. purposes only if its uptake occurs within that time. All the GAV showed a decreasing pattern after having reached tumours studied by us showed 80% of max uptake within 7 its top value, that occurred after 5 to 8 minutes in our 3 minutes. The parameter 80% of max was used because patients. A decrease of activity would not be compatible assessment of maximal or plateau activity makes it with the most accepted theory of 99mTc BN-1 uptake: fast necessary to calculate the average among different points adhesion of the 99mTc BN-1 delivered by blood to the on the time-activity plot: as a consequence time to max specific membrane receptors, followed by internalisation, uptake can less precisely be assessed as single data than a thus by stable uptake. It has to be considered that all these fixed percentage of the average maximum. It was clearly cancers showed a common characteristic: the difficulty in shown that 99mTc BN-1 is very quickly taken up by cancers selecting ROIs and in subtracting background activity on and its use for diagnostic purposes (14-20) is based on a planar images because of the distance of the tumour from correct rationale. the detector and the abundance of blood, that means

1074 Scopinaro et al: Fast Cancer Uptake of 99mTc BN1 abundance of activity circulating, but not taken up by the 10 Chu KU, Ishizuka J, Battey JF, Uchida T, Beauchamp RD, tumour in the early minutes. All the 3 cancers were well Townsend CM Jr and Thompson JC: Mechanisms of bombesin imaged with tomographic scintigraphy, performed after 30 on growth of gastrinoma (PT) in vivo. Dig Dis Sci 41: 2180- 2186, 1996. minutes for colon and rectal cancer and after 60 minutes for 11 Vilches J, Salido M, Fernandez-Segura E and Roomans GM: SCLC, thus uptake did take place. It is possible that the , apoptosis and ion changes in prostate cancer. background subtraction was suboptimal, or that technical Methods of study and recent developments. Histol Histopathol problems affected the dynamic measurement. 19(3): 951-961, 2004. The uptake curves of the other colon and rectal cancers 12 Schally AV, Comaru-Schally AM, Nagy A, Kovacs M, were well fitted with the Sin GU curve and thus did not Szepeshazi K, Plonowski A, Varga JL and Halmos G: show the problem of cases no. 17, 18 and 19, however, the Hypothalamic hormones and cancer. Front Neuroendocrinol rectal and colon cancers showing a complete up-slope of 22: 248-291, 2001. 13 Varvarigou AD, Scopinaro F, Leondiadis L, Corleto V, Schillaci the uptake curve were large, N+ cancers, whereas the O, DeVincentis G, Sourlingas TG, Sekeri-Pataryas KE, curve fitted with GAV belonged to a small T1 colon Evangelatos GP, Leonti A, Xanthopoulos S, Delle Fave G and cancer that was diagnosed with colonoscopy plus biopsy. Archimandritis SC: Synthesis, chemical, radiochemical and The uptake by SCLC also deserves comments: both radiobiological evaluation of a new 99mTc-labelled bombesin- cancers were well imaged with SPECT, but both uptake like peptide. Cancer Biother Radiopharm 17(3): 317-326, 2002. data were not fitted with GU or Sin GU. The lung is a 14 Varvarigou A, Bouziotis P, Zikos C, Scopinaro F and De large and thick organ with a very high blood circulation, Vincentis G: Gastrin-releasing peptide (GRP) analogues for cancer imaging. Cancer Biother Radiopharm 19(2): 219-229, thus background subtraction is much more critical than in 2004. other organs. 15 Scopinaro F, Varvarigou AD, Ussof W, De Vincentis G, 99m In conclusion, tumour uptake of Tc BN-1 occurs faster Sourlingas TG, Evangelatos GP, Datsteris J and Archimandritis than 10 minutes after i.v. injection. The uptake speed SC: Technetium labeled bombesin-like peptide: preliminary depends on receptor abundance and regional blood flow. report on breast cancer uptake in patients. Cancer Biother Radiopharm 17(3): 327-335, 2002. References 16 Scopinaro F, Varvarigou A, Ussof W, De Vincentis G, Archimandritis S, Evangelatos G, Corleto V, Pulcini A, 1 Matsumoto K, Yamada K, Wada E, Hasegawa T, Usui Y and Capoccetti F, Remediani S and Massa R: Breast cancer take Wada K: Bombesin receptor subtype-3 modulates plasma up 99mTc bombesin. A preliminary report. Tumori 88(3): S25- concentration. Peptides 24(1): 83-90, 2003. 28, 2002. 2 Moody TW, Chan D, Fahrenkrug J and Jensen RT: 17 A Soluri, G De Vincentis, AD Varvarigou, A Spanu and F Neuropeptides as autocrine growth factors in cancer cells. Curr Scopinaro: 99mTc [13 Leu] bombesin and a new gamma camera, Pharm Des 9(6): 495-509, 2003. the imaging probe, are able to guide mammotome biopsy. 3 Cutitta E, Carney DN, Mulsine J, Moody TW, Fedoroko J, Anticancer Res 23: 2139-2142, 2003. Fischler A and Minna JD: Bombesin-like peptides as autocrine 18 Scopinaro F, De Vincentis G, Corazziari E, Massa R, Osti M, growth factors in human small-cell lung cancer. Nature 16: 823- Pallotta N, Covotta A, Remediani S, Di Paolo M, Monteleone 826, 1985. F and Varvarigou A: Detection of colon cancer with 99mTc- 4 Moody TW and Merali Z: Bombesin-like peptides and labeled bombesin derivative (99mTc-leu-13-BN1). Cancer associated receptors within the brain: distribution and Biother Radiopharmaceut 19(2): 245-252, 2004. behavioral implications. Peptides 25(3): 511-520, 2004. 19 Scopinaro F, De Vincentis G, Varvarigou AD, Laurenti C, Iori 5 Jennings CA, Harrison DC, Maycox PR, Crook B, Smart D and F, Remediani S, Chiarini S and Stella S: 99mTc-bombesin Hervieu GJ: The distribution of the orphan bombesin receptor detects prostate cancer and invasion of pelvic lymph nodes. Eur subtype-3 in the rat CNS. Neuroscience 120(2): 309-324, 2003. J Nucl Med Mol Imag 30(10): 1378-1382, 2003. 6 Shan L, Emanuel RL, Dewald D, Torday JS, Asokanathan N, 20 De Vincentis G, Scopinaro F, Varvarigou A, Ussof W, Schillaci Wada K, Wada E and Sunday ME: Bombesin-like peptide O, Archimandritis S, Leondiadis L, Corleto V, Longo F and receptor gene expression, regulation, and function in fetal Delle Fave G: Phase I trial of technetium [LEU 13] bombesin murine lung. Am J Physiol Lung Cell Mol Physiol 286(1): L165- as a cancer seeking agent. Possible scintigraphic guide for 173, 2004. surgery? Tumori 88(3): S28-30, 2002. 7 Beales IL: Regulation of gastric function by gastrin releasing 21 De Vincentis G, Remediani S, Varvarigou AD, Di Santo G, Iori peptide. Gut 50: 897-898, 2002. F, Laurenti C and Scopinaro F: Role of 99mTc-bombesin scan 8 Gunal O, Oktar BK, Ozcinar E, Tansuker D, Arbak S and in diagnosis and staging of prostate cancer. Cancer Biother Yegen BC: Healing-promoting effect of bombesin treatment on Radiopharmaceut 19(1): 81-84, 2004. chronic gastric ulcer in rats. Regul Pept 106: 81-88, 2002. 22 Zhang H, Chen J, Waldherr C, Hinni K, Waser B, Reubi JC 9 Reubi JC, Wenger S, Schmuckli-Maurer J, Schaer JC and and Maecke HR: Synthesis and evaluation of bombesin Gugger M: Bombesin receptor subtypes in human cancers: derivatives on the basis of pan-bombesin peptides labeled with detection with the universal radioligand (125)I-[D-TYR(6), indium-111, lutetium-177, and yttrium-90 for targeting beta-ALA(11), PHE(13), NLE(14)] bombesin(6-14). Clin bombesin receptor-expressing tumors. Cancer Res 64(18): 6707- Cancer Res 8(4): 1139-1146, 2002. 6715, 2004.

1075 in vivo 19: 1071-1076 (2005)

23 Scopinaro F, De Vincentis G, Banci M, Schillaci O, Di Loreto 29 Scopinaro F, Schillaci O, Ussof W, Nordling K, Capoferro R, M, Danieli R, Ierardi M, De Paola AM, Gianni W and Massa De Vincentis G, Danieli R, Ierardi M, Picardi V, Tavolaro R R: In vivo study of a technetium labelled anti EGFR MoAb. and Centi Colella A: A three center study on the diagnostic Anticancer Res 17: 1761-1765, 1997. accuracy of 99mTc-MIBI scintimammography. Anticancer Res 24 Signore A, Annovazzi A, Chianelli M, Corsetti F, Van De 17: 1631-1634, 1997. Wiele C, Waterhouse RN and Scopinaro F: Peptide 30 Tang C, Biemond I and Lamers CB: Expression of peptide radiopharmaceuticals for diagnosis and therapy. Eur J Nucl receptors in human endocrine tumours of the pancreas. Gut Med 28: 1555-1565, 2001. 40(2): 267-271, 1997. 25 Scopinaro F, Schillaci O, Delle Fave G, Danieli R, Materia A, 31 Bold RJ, Lowry PS, Ishizuka J, Battey JF, Townsend CM Jr Tavolaro R, Angeletti S, Marignani M, Massa R, Gualdi G, and Thompson JC: Bombesin stimulates the in vitro growth of Polettini E, Picardi V and Basso N: 111In-pentetreotide detection a human gastric cancer cell line. J Cell Physiol 161(3): 519- of gastrinoma before and after surgery. Anticancer Res 17: 1757- 525, 1994. 1760, 1997. 32 Goris ML and Briandet PA: Mathematical deivations. In: Goris 26 Schillaci O, Massa R and Scopinaro F: Indium-111-octreotide ML and Briandet PA (eds.). A Clinical and Mathematical scintigraphy in the detection of insulinomas: importance of Introduction to Computer Processing of Scintigraphic Images. SPECT imaging. J Nucl Med 41: 459-462, 2000. Raven Press, New York, pp. 73-122, 1987. 27 Schillaci O, Scopinaro F, Danieli R, Angeletti S, Tavolaro R, Annibale B, Cannas P, Marignani M, Centi Colella A and Delle Fave G: Single photon emission computerized tomography increases the sensitivity of indium-111-pentetreotide scintigraphy in detecting abdominal carcinoids. Anticancer Res 17: 1753-1756, 1997. 28 Khalkhali I, Diggles LE, Taillefer R, Vandestreek PR, Peller PJ and Abdel-Nabi HH: Procedure guideline for breast Received July 8, 2005 scintigraphy. J Nucl Med 40: 1233-1235, 1999. Accepted September 1, 2005

1076