Werkin Pregress Internauonal Journal of Nuclear Medicine and Bmlogy. pp 195 199 Pergamon Pres Prmtcd in Great Britain
1977. Vol.
4.
Modified Scintigraphic Technique for the Dynamic Study of the Esophagus (Rrcriaed
10 Frhruary
1977)
THE GAMMAGRAPHIC study of esophageal dynamics or radioesophagogram (REG) introduced by KAZEM(‘)in 1972, is a simple technique that enables the evaluation of abnormalities in the esophageal transit. In areas where cancer of the esophagus is common, a method which can be used as a screening tool and contribute to an early diagnosis of such a lesion is of undeniable value. This method was utilized in Puerto Rico, where the incidence of cancer of the esophagus is highJ2) and, in trying to improve the interpretation and evaluation of esophageal disorders by means of the radioesophagogram and the dynamic histogram as proposed by Kazem, several modifications to the original technique were introduced. These modifications constitute the basis of this study. Materials and Methods One hundred and eighty-four adults were studied to establish the normal transit time and the pattern of the dynamic histogram. NO special preparations of the subjects under study were required. ““Tc pertechnetate (20 mCi) was dissolved in a total volume of 100 ml of water containing 20g of commercial gelatin, and the solution was refrigerated until gelatinized. The dilution has an approximate activity of 0.2 mCi/ml gelatin. A teaspoon of approximately 5 cm3 gelatin, equivalent to I mCi of activity, was administered to each subject. A gamma-camera system, on line to a Video-Tape recorder was used. The detector surface of the gamma camera is adjusted to vertical position, covering from the cervical region of the esophagus down to the fundus of the stomach. With the Video-Tape system on, the person under study is instructed to swallow the gelatin bolus, and the passage of radioactive material is observed on the monitor scope until it reaches the stomach. The information recorded in the Video-Tape is reproduced by playing back the tape. and the study is photographed in a 35 mm film at a rate of 0.4 sec of exposure. The procedure is performed in anterior standing position and repeated with the subject. arms lowered, standing in left lateral position. Observing the monitor scope during the play-back of the data, the region of activity corresponding to the esophagus is easily identified and selected, excluding the stomach. The esophageal region is then subdi-
vided into two segments of equal length, upper and lower. A histogram is then traced for each of the two segments and photographed with a Polaroid camera. The histograms represent the accumulation of counts through 100 channels. at a pre-set time interval of 0.4 sec/channel.
Results Norm1
REG
In the normal radioesophagogram, two definite stages of the passage of the radioactive bolus were identified in the serial scintiphotos. The bolus passes the pharnygo-esophageal junction and rapidly runs down to the lower third of the esophagus. The transit time of the first stage has a duration of 1-3 sec. There is a delay in the transit at the leve1 of the esophagogastric junction corresponding to the time interval required for the bolus to enter the stomach. Thr duration of this second stage ranges between 1 and 5 sec. The overall transit time in normal subjects varied from 3.0 to 8.6 sec, with an average of 5.9 k 0.07 sec (Fig. 1. A-E). The dynamic histogram of the upper segment is characterized by a sharp tise and fa11of the activity. resulting in a curve with a distinct narrow peak. The lower segment generates a wider angle. or a smaller plateau, due to the temporary physiologic detention of the radioactive bolus at the leve1 of the cardias (Fig. 1F). Ahnord
REG
In patients with esophageal obstruction, either extrinsic or intrinsic, a partial or complete detention of the bolus is obscrved. The transit time wil1 vary according to the degree of obstruction. In the abnormal histogram. a widening of the curve peak is observed at the leve1 of the lesion (Fig. 2). A complete detention of radioactive material is represented by a characteristic plateau at the leve1 of the obstructed segment where the lesion lies. resulting in a very distinct pattem from the normal histogram. Discussion Following the original technique as described by KAZEM.(” some difficulties were encountered, which allowed equivocal interpretation of the results. In view that this tracer method for studying the esophagus proved to be of great clinical value in the detection and diagnosis of esophageal lesions, it seemed worthwhile to present and to discuss the rationale for modifying the original technique.
On administering an aqueous solution of “““Tc pertechnetate in a volume of 10 20 cm3, such a quantity of liquid resulted in more than one swallow for the majority of subjects under study. giving images of repeated activity and generating an apparently abnormal histogram. When multiple spikes appear in the histogram, they are due to more than one swallow, each of which adds a spike of radioactivity to a histogram, thus making difficult the interpretation of the results in such a case. A gelatin bolus ingested in a single swallow overcomes such difficulty and the resultant histogram shows a single spike in normal subjects. and a plateau in cases with obstruction. Since gelatin is a common nutrient containing mostly water, the test may stil1 be considered as physiologic as when water is used as the tracer medium. The gelatin radioactive bolus is compact and travels from the pharynx to the lower esophagus as a single mass, giving better photographic images of the transit, and its detention at any certain point is better observed, whereas water usually flows through and the differente between normal and abnormal transit is manifested only as a minimal delay in time, except in cases with severe degrees of obstruction. Figure 3 shows a radioesophagogram done using water as a test medium which gave doubtful images of a possible obstructive lesion at the leve1 of the middle third of the esophagus, but a normal histogram. Performing the study with gelatin on the same patient (Fig. 4). a frank detention of the radioactive bolus was observed at the middle third of the esophagus, with an abnormal histogram. A barium swallow roentgenogram was done and reported negative, but on esophagoscopy, a lesion was found in the middle third of the esophagus, biopsy was done, and histologie confirmation of squamous cell carcinoma was obtained. The tracing of a single histogram as described by KAZEN”) includes the radioactivity in the gastric region, which invariably gives an image of a plateau in the curve obtained in both normal and abnormal cases. If the stomach is excluded and the csophageal region selected, the plateau wil1 be present only in cases with obstruction. If the esophagus is further subdivided into two equal segments. each of the corresponding histograms wil1 have a characteristic pattern, allowing for a more precise localization of the site of obstruction when present. The study is done in both anterior and lateral positions, since sometimes one gives better or additional information than the other. The lateral view is useful in the detection of esophago-bronchial fistulae, and for delineating lesions in the anterior or posterior esophageal walls (Fig. 5). The lateral view is also useful as a repetition of the procedure, to definitively ascertain the presence of true abnormalities, which should show in both views. If present in only one view, the abnormality is possibly due to a transitory state such as spasm. or hypermotility.
The radioesophagogram has been found to bc a relatively inexpensive and safe procedure, the estlmated radiation dose delivered to the whole body ranging from 5 to 6 mrads.13’ This simple technique for studying esophageal dynamics is a valuable screening tool, especially in areas of high incidence of esophageal cancer. It is, furthermore, useful in the fellow-up of patients with esophageal disorders. The data obtained from this functional test should be supplemented by radiographic and endoscopic studies which are of unquestionable clinical value in the diagnosis of esophageal lesions. Summary
The radioesophagogram (REG) is a simple technique which enables the dynamic study of the esophageal transit. The average normal transit time was established as 5.9 + 0.07 sec and individual values ranged from 3 to 8.6 sec. In order to facilitate the results, the following modifications were introduced to the technique as originally described by Kazem: (1) replacing the aqueous medium by a gelatin bolus; (2) excluding the stomach when tracing the dynamic histogram; (3) subdividing the esophageal region into upper and lower segments thus obtaining two corresponding histograms; and (4) performing the study in both anterior and lateral positions. Reasons for the modifications are discussed. Acknowledgement-This work was supported in part by the National Cancer Institute Wisconsin Clinical Cancer Center Grant (CA-14520). ANMNIO BOSCH* RENE DIETRICHP ALDO E. LANARO~ ZENAIDA FRIAS$
*$Divisìon of Radìatìon Oncology, University of Wixonsin Hospitals, 1300 University Avenue, Madison, Wisconsin 53706, U.S.A. t$Nuclear Medicine Division, Puerto Rico Nuclear Center, San Juan, Puerto Rico 00935, U.S.A. References
1. KAZEM 1. Am. J. Roentg. Radiother. nucl. Med. 115, 681 (1972). 2. MARTINEZ1. Cancer 17, 1279 (1964). 3. Protection of the Patient in Radionuclide lnvestiga; tions, ICRP Pub]. 17. Pergamon Press, Oxford (1971).
FIG. 1. Normal REG after swallowing gelatin bolus containing 1 mCi 99”‘Tc pertechnetate: (a) immediately; (b) at 0.8 sec; (c) at 1.6 sec; (d) at 2.8 sec and (e) at 3.2sec. (f) Dynamic histogram corresponding to the upper and lower segments.
FIG. 2. Abnormal REG due to obstruction in the upper third of the esophagus: (a) at 0.8 sec; (b) at 2.0 sec; (c) at 3.2 sec; (d) at 10 sec, most of the radioactive bolus remains at the leve1 of the obstruction. (e) The histogram shows mounting plateau in the upper segment due to obstruction of the upper esophagus.
Fto. 3. REG after swalkxving 10cm’ of water containing 1 mCi 99”Tc pertechnetate. (c) and (d) scintiphotos at 3.2 and 4.0 sec show a doubtful image of obstruction; however, the transit time and the histograms were within normal limits.
FIG. 4. REG on the same patient as Fig. 3, done with gelatin 99”TC bolus. (c) and (d) scintiphotos at 4.4 and 5.6 sec, show a frank detention of the radioactive material in the middle third of the esophagus and (e) an abnormal histogram.
199
FIG. 5. REG in the left lateral position of a patient with Ca of the esophagus and esopha tgobror xhial fistula. We observe retention of radioactive material in the middle third of the esophagus and the arrow shows activity in the lung region that sugpests the fìstula.
1977. Vol.
4.
Modified Scintigraphic Technique for the Dynamic Study of the Esophagus (Rrcriaed
10 Frhruary
1977)
THE GAMMAGRAPHIC study of esophageal dynamics or radioesophagogram (REG) introduced by KAZEM(‘)in 1972, is a simple technique that enables the evaluation of abnormalities in the esophageal transit. In areas where cancer of the esophagus is common, a method which can be used as a screening tool and contribute to an early diagnosis of such a lesion is of undeniable value. This method was utilized in Puerto Rico, where the incidence of cancer of the esophagus is highJ2) and, in trying to improve the interpretation and evaluation of esophageal disorders by means of the radioesophagogram and the dynamic histogram as proposed by Kazem, several modifications to the original technique were introduced. These modifications constitute the basis of this study. Materials and Methods One hundred and eighty-four adults were studied to establish the normal transit time and the pattern of the dynamic histogram. NO special preparations of the subjects under study were required. ““Tc pertechnetate (20 mCi) was dissolved in a total volume of 100 ml of water containing 20g of commercial gelatin, and the solution was refrigerated until gelatinized. The dilution has an approximate activity of 0.2 mCi/ml gelatin. A teaspoon of approximately 5 cm3 gelatin, equivalent to I mCi of activity, was administered to each subject. A gamma-camera system, on line to a Video-Tape recorder was used. The detector surface of the gamma camera is adjusted to vertical position, covering from the cervical region of the esophagus down to the fundus of the stomach. With the Video-Tape system on, the person under study is instructed to swallow the gelatin bolus, and the passage of radioactive material is observed on the monitor scope until it reaches the stomach. The information recorded in the Video-Tape is reproduced by playing back the tape. and the study is photographed in a 35 mm film at a rate of 0.4 sec of exposure. The procedure is performed in anterior standing position and repeated with the subject. arms lowered, standing in left lateral position. Observing the monitor scope during the play-back of the data, the region of activity corresponding to the esophagus is easily identified and selected, excluding the stomach. The esophageal region is then subdi-
vided into two segments of equal length, upper and lower. A histogram is then traced for each of the two segments and photographed with a Polaroid camera. The histograms represent the accumulation of counts through 100 channels. at a pre-set time interval of 0.4 sec/channel.
Results Norm1
REG
In the normal radioesophagogram, two definite stages of the passage of the radioactive bolus were identified in the serial scintiphotos. The bolus passes the pharnygo-esophageal junction and rapidly runs down to the lower third of the esophagus. The transit time of the first stage has a duration of 1-3 sec. There is a delay in the transit at the leve1 of the esophagogastric junction corresponding to the time interval required for the bolus to enter the stomach. Thr duration of this second stage ranges between 1 and 5 sec. The overall transit time in normal subjects varied from 3.0 to 8.6 sec, with an average of 5.9 k 0.07 sec (Fig. 1. A-E). The dynamic histogram of the upper segment is characterized by a sharp tise and fa11of the activity. resulting in a curve with a distinct narrow peak. The lower segment generates a wider angle. or a smaller plateau, due to the temporary physiologic detention of the radioactive bolus at the leve1 of the cardias (Fig. 1F). Ahnord
REG
In patients with esophageal obstruction, either extrinsic or intrinsic, a partial or complete detention of the bolus is obscrved. The transit time wil1 vary according to the degree of obstruction. In the abnormal histogram. a widening of the curve peak is observed at the leve1 of the lesion (Fig. 2). A complete detention of radioactive material is represented by a characteristic plateau at the leve1 of the obstructed segment where the lesion lies. resulting in a very distinct pattem from the normal histogram. Discussion Following the original technique as described by KAZEM.(” some difficulties were encountered, which allowed equivocal interpretation of the results. In view that this tracer method for studying the esophagus proved to be of great clinical value in the detection and diagnosis of esophageal lesions, it seemed worthwhile to present and to discuss the rationale for modifying the original technique.
On administering an aqueous solution of “““Tc pertechnetate in a volume of 10 20 cm3, such a quantity of liquid resulted in more than one swallow for the majority of subjects under study. giving images of repeated activity and generating an apparently abnormal histogram. When multiple spikes appear in the histogram, they are due to more than one swallow, each of which adds a spike of radioactivity to a histogram, thus making difficult the interpretation of the results in such a case. A gelatin bolus ingested in a single swallow overcomes such difficulty and the resultant histogram shows a single spike in normal subjects. and a plateau in cases with obstruction. Since gelatin is a common nutrient containing mostly water, the test may stil1 be considered as physiologic as when water is used as the tracer medium. The gelatin radioactive bolus is compact and travels from the pharynx to the lower esophagus as a single mass, giving better photographic images of the transit, and its detention at any certain point is better observed, whereas water usually flows through and the differente between normal and abnormal transit is manifested only as a minimal delay in time, except in cases with severe degrees of obstruction. Figure 3 shows a radioesophagogram done using water as a test medium which gave doubtful images of a possible obstructive lesion at the leve1 of the middle third of the esophagus, but a normal histogram. Performing the study with gelatin on the same patient (Fig. 4). a frank detention of the radioactive bolus was observed at the middle third of the esophagus, with an abnormal histogram. A barium swallow roentgenogram was done and reported negative, but on esophagoscopy, a lesion was found in the middle third of the esophagus, biopsy was done, and histologie confirmation of squamous cell carcinoma was obtained. The tracing of a single histogram as described by KAZEN”) includes the radioactivity in the gastric region, which invariably gives an image of a plateau in the curve obtained in both normal and abnormal cases. If the stomach is excluded and the csophageal region selected, the plateau wil1 be present only in cases with obstruction. If the esophagus is further subdivided into two equal segments. each of the corresponding histograms wil1 have a characteristic pattern, allowing for a more precise localization of the site of obstruction when present. The study is done in both anterior and lateral positions, since sometimes one gives better or additional information than the other. The lateral view is useful in the detection of esophago-bronchial fistulae, and for delineating lesions in the anterior or posterior esophageal walls (Fig. 5). The lateral view is also useful as a repetition of the procedure, to definitively ascertain the presence of true abnormalities, which should show in both views. If present in only one view, the abnormality is possibly due to a transitory state such as spasm. or hypermotility.
The radioesophagogram has been found to bc a relatively inexpensive and safe procedure, the estlmated radiation dose delivered to the whole body ranging from 5 to 6 mrads.13’ This simple technique for studying esophageal dynamics is a valuable screening tool, especially in areas of high incidence of esophageal cancer. It is, furthermore, useful in the fellow-up of patients with esophageal disorders. The data obtained from this functional test should be supplemented by radiographic and endoscopic studies which are of unquestionable clinical value in the diagnosis of esophageal lesions. Summary
The radioesophagogram (REG) is a simple technique which enables the dynamic study of the esophageal transit. The average normal transit time was established as 5.9 + 0.07 sec and individual values ranged from 3 to 8.6 sec. In order to facilitate the results, the following modifications were introduced to the technique as originally described by Kazem: (1) replacing the aqueous medium by a gelatin bolus; (2) excluding the stomach when tracing the dynamic histogram; (3) subdividing the esophageal region into upper and lower segments thus obtaining two corresponding histograms; and (4) performing the study in both anterior and lateral positions. Reasons for the modifications are discussed. Acknowledgement-This work was supported in part by the National Cancer Institute Wisconsin Clinical Cancer Center Grant (CA-14520). ANMNIO BOSCH* RENE DIETRICHP ALDO E. LANARO~ ZENAIDA FRIAS$
*$Divisìon of Radìatìon Oncology, University of Wixonsin Hospitals, 1300 University Avenue, Madison, Wisconsin 53706, U.S.A. t$Nuclear Medicine Division, Puerto Rico Nuclear Center, San Juan, Puerto Rico 00935, U.S.A. References
1. KAZEM 1. Am. J. Roentg. Radiother. nucl. Med. 115, 681 (1972). 2. MARTINEZ1. Cancer 17, 1279 (1964). 3. Protection of the Patient in Radionuclide lnvestiga; tions, ICRP Pub]. 17. Pergamon Press, Oxford (1971).
FIG. 1. Normal REG after swallowing gelatin bolus containing 1 mCi 99”‘Tc pertechnetate: (a) immediately; (b) at 0.8 sec; (c) at 1.6 sec; (d) at 2.8 sec and (e) at 3.2sec. (f) Dynamic histogram corresponding to the upper and lower segments.
FIG. 2. Abnormal REG due to obstruction in the upper third of the esophagus: (a) at 0.8 sec; (b) at 2.0 sec; (c) at 3.2 sec; (d) at 10 sec, most of the radioactive bolus remains at the leve1 of the obstruction. (e) The histogram shows mounting plateau in the upper segment due to obstruction of the upper esophagus.
Fto. 3. REG after swalkxving 10cm’ of water containing 1 mCi 99”Tc pertechnetate. (c) and (d) scintiphotos at 3.2 and 4.0 sec show a doubtful image of obstruction; however, the transit time and the histograms were within normal limits.
FIG. 4. REG on the same patient as Fig. 3, done with gelatin 99”TC bolus. (c) and (d) scintiphotos at 4.4 and 5.6 sec, show a frank detention of the radioactive material in the middle third of the esophagus and (e) an abnormal histogram.
199
FIG. 5. REG in the left lateral position of a patient with Ca of the esophagus and esopha tgobror xhial fistula. We observe retention of radioactive material in the middle third of the esophagus and the arrow shows activity in the lung region that sugpests the fìstula.
