Limits...
Feasibility of imaging esophageal cancer with labeled somatostatin analogue.

Herlin G, Ideström L, Lundell L, Aspelin P, Axelsson R - Int J Mol Imaging (2011)

Bottom Line: Conclusion.Scintigraphic examination with (99m)Tc-depreotide is feasible for imaging esophageal cancer, but the method is not suitable neither for screening or primary diagnosis, because of methods modest sensitivity.Our first results showed high specificity which should be used with caution, as the number of patients was relatively low.

View Article: PubMed Central - PubMed

Affiliation: Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology, Karolinska Institute, 141 86 Stockholm, Sweden.

ABSTRACT
Background. While the surface of a cell normally has some amount of somatostatin receptors, these receptors are overexpressed to a very high degree in multiple neoplastic diseases. No data exist for esophageal carcinoma. Purpose. To find out whether esophageal carcinoma could be imaged using somatostatin receptor scintigraphy. Material and Methods. 34 patients with esophageal lesions were prospectively examined by (99m)Tc-depreotide scintigraphy 2 and 4 hours after injection. Quantitative evaluation of (99m)Tc-depreotide uptake was performed around the lesion (T) and in healthy lung parenchyma (B). The relative uptake was calculated as T-B/B. Scintigraphy results were compared with histopathology from surgery or biopsy specimens from endoscopic ultrasonography. Results. 21 patients had esophageal cancer, and 13 lesions were benign. Visual assessment revealed positive (99m)Tc-depreotide uptake in 16 of the 21 cancers. The 13 patients without cancer had no depreotide uptake. The Mann-Whitney U test showed a statistically significant difference (P < .005) between (99m)Tc-depreotide uptake in malignant and benign lesions, for both the 2-hour and the 4-hour measurements. Conclusion. Scintigraphic examination with (99m)Tc-depreotide is feasible for imaging esophageal cancer, but the method is not suitable neither for screening or primary diagnosis, because of methods modest sensitivity. Our first results showed high specificity which should be used with caution, as the number of patients was relatively low. Further studies are needed to determine the role of the method.

No MeSH data available.


Related in: MedlinePlus

Evaluation of scintigraphic images with 99mTc-depreotide. Region of interest (ROI) was drawn manually around the esophageal tumor on each slice, using small margins, and a background ROI was drawn in healthy lung parenchyma.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3116512&req=5

fig1: Evaluation of scintigraphic images with 99mTc-depreotide. Region of interest (ROI) was drawn manually around the esophageal tumor on each slice, using small margins, and a background ROI was drawn in healthy lung parenchyma.

Mentions: The results were evaluated both through visual assessment and through quantitative calculations in the 2-hour and 4-hour images. CT scans were used for an accurate localization of the 99mTc-depreotide uptake and for placement of the region of interest (ROI). On visual assessment, any focal 99mTc-depreotide uptake in the region of the known esophageal lesion was considered pathological. The quantitative evaluation of 99mTc-depreotide uptake was performed retrospectively on SPECT images in all 34 patients. First, an ROI was drawn manually around the esophageal tumor on each slice, using small margins. Next, a background ROI was drawn in healthy lung parenchyma (Figure 1). A volume of interest (VOI) was obtained by adding all ROIs. In-house software, originally developed for volumetric measurements in magnetic resonance images and implemented on a Hermes workstation (Hermes Medical Solution AB, Stockholm, Sweden), was used to calculate the total counts and volume of the tumor and background VOIs, thus giving a count density (counts/cm3). To produce a normalized tumor uptake, each patient was normalized to his or her own normal lung parenchyma using the formula U = (T − B)/B, where U is the normalized uptake, T is the count density in the tumor, and B is the count density in the lung parenchyma. To increase accuracy and to investigate the intraobserver variability, evaluations were performed twice, 6 months apart, by the same radiologist and the mean value of the two uptake values was used in further analysis. In addition, a second radiologist made individual evaluations in order to investigate the interobserver variability of the uptake values at 2-hour images.


Feasibility of imaging esophageal cancer with labeled somatostatin analogue.

Herlin G, Ideström L, Lundell L, Aspelin P, Axelsson R - Int J Mol Imaging (2011)

Evaluation of scintigraphic images with 99mTc-depreotide. Region of interest (ROI) was drawn manually around the esophageal tumor on each slice, using small margins, and a background ROI was drawn in healthy lung parenchyma.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3116512&req=5

fig1: Evaluation of scintigraphic images with 99mTc-depreotide. Region of interest (ROI) was drawn manually around the esophageal tumor on each slice, using small margins, and a background ROI was drawn in healthy lung parenchyma.
Mentions: The results were evaluated both through visual assessment and through quantitative calculations in the 2-hour and 4-hour images. CT scans were used for an accurate localization of the 99mTc-depreotide uptake and for placement of the region of interest (ROI). On visual assessment, any focal 99mTc-depreotide uptake in the region of the known esophageal lesion was considered pathological. The quantitative evaluation of 99mTc-depreotide uptake was performed retrospectively on SPECT images in all 34 patients. First, an ROI was drawn manually around the esophageal tumor on each slice, using small margins. Next, a background ROI was drawn in healthy lung parenchyma (Figure 1). A volume of interest (VOI) was obtained by adding all ROIs. In-house software, originally developed for volumetric measurements in magnetic resonance images and implemented on a Hermes workstation (Hermes Medical Solution AB, Stockholm, Sweden), was used to calculate the total counts and volume of the tumor and background VOIs, thus giving a count density (counts/cm3). To produce a normalized tumor uptake, each patient was normalized to his or her own normal lung parenchyma using the formula U = (T − B)/B, where U is the normalized uptake, T is the count density in the tumor, and B is the count density in the lung parenchyma. To increase accuracy and to investigate the intraobserver variability, evaluations were performed twice, 6 months apart, by the same radiologist and the mean value of the two uptake values was used in further analysis. In addition, a second radiologist made individual evaluations in order to investigate the interobserver variability of the uptake values at 2-hour images.

Bottom Line: Conclusion.Scintigraphic examination with (99m)Tc-depreotide is feasible for imaging esophageal cancer, but the method is not suitable neither for screening or primary diagnosis, because of methods modest sensitivity.Our first results showed high specificity which should be used with caution, as the number of patients was relatively low.

View Article: PubMed Central - PubMed

Affiliation: Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology, Karolinska Institute, 141 86 Stockholm, Sweden.

ABSTRACT
Background. While the surface of a cell normally has some amount of somatostatin receptors, these receptors are overexpressed to a very high degree in multiple neoplastic diseases. No data exist for esophageal carcinoma. Purpose. To find out whether esophageal carcinoma could be imaged using somatostatin receptor scintigraphy. Material and Methods. 34 patients with esophageal lesions were prospectively examined by (99m)Tc-depreotide scintigraphy 2 and 4 hours after injection. Quantitative evaluation of (99m)Tc-depreotide uptake was performed around the lesion (T) and in healthy lung parenchyma (B). The relative uptake was calculated as T-B/B. Scintigraphy results were compared with histopathology from surgery or biopsy specimens from endoscopic ultrasonography. Results. 21 patients had esophageal cancer, and 13 lesions were benign. Visual assessment revealed positive (99m)Tc-depreotide uptake in 16 of the 21 cancers. The 13 patients without cancer had no depreotide uptake. The Mann-Whitney U test showed a statistically significant difference (P < .005) between (99m)Tc-depreotide uptake in malignant and benign lesions, for both the 2-hour and the 4-hour measurements. Conclusion. Scintigraphic examination with (99m)Tc-depreotide is feasible for imaging esophageal cancer, but the method is not suitable neither for screening or primary diagnosis, because of methods modest sensitivity. Our first results showed high specificity which should be used with caution, as the number of patients was relatively low. Further studies are needed to determine the role of the method.

No MeSH data available.


Related in: MedlinePlus