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The usefulness of ultrasonography in intracavitary radiotherapy using selectron applicators
Int J Rodrarion Oncology RioI Phys Vol. Printed in the U.S.A. All nghts reserved.
19, pp. 471-482
0360-3016/90 $3.00 + .Xl Copyright 0 1990 Pergamon Press plc
??Technical Innovations and Notes
THE USEFULNESS OF ULTRASONOGRAPHY RADIOTHERAPY USING SELECTRON
IN INTRACAVITARY APPLICATORS
M.D., F.R.C.P. (C)* AND SHAMIM BHIMJI, M.B.CH.B.,
FRANCES WONG,
F.R.C.P.
(C)t
A. Maxewell Evans Clinic, Cancer Control Agency of British Columbia, 600, West 10th Avenue, Vancouver, British Columbia, V5Z 4E6 Canada Uterine perforation can occur during the procedure of intracavitary insertions for the treatment of carcinoma of the cervix. If radiation treatment proceeds in the situation of inadvertent perforation, severe complication may result. The ultrasonographic studies of five patients with metal intrauterine applicators in situ are described. The applicator appeared as a linear echogenic density within the uterine cavity. The thickness of the uterine wall and the fundus could be clearly identified in a normal insertion. In the presence of uterine perforation, the applicator was seen traversing the myometrium necessitating alteration of the treatment plan. Uterus, perforation; Uterus, ultrasonography; Therapeutic radiology, intracavitary; Uterine neoplasms, therapeutic radiology.
cific type of tandem was not described. To our knowledge, the normal or abnormal appearance of the uterus with the modern remote controlled after-loading metallic intrauterine applicator in situ has not been described in the literature.
INTRODUCTION Afterloading
intracavitary
radiotherapy
for carcinoma
of
To minimize staff exposure, remote control (after-loading equipment has become popularized (9). At times, cervical stenosis or uterine malpositioning may result in difficulty of the insertion procedure. In one study, uterine perforation has been noted in 1.75% of the in:sertions (4), and in another, routine CT scanning revealed unexpected perforation in 3% of the “straight forward” insertions (6). Inadvertent uterine perforation can lead to overdose and serious injury of the adjacent organs. Investigations should therefore be carried out to ensure intrauterine applicator positioning prior to the initiation of treatment. While computerized tomography (CT) scanning has been demonstrated to be useful for accurate localization of the applicators and dosimetry calculation (2, 5, 6, 9), heavy hospital demands on the scanner limit its availability for routine use after insertion. Hemostatic clips could be placed on the serosal surface of the uterine wall for visualization of the uterine contour in the localization films (7). This would only be feasible for patients undergoing pretreatment laparotomies. Ultrasonography has been described for assessing the in situ position of intrauterine tandems ( 1, 3). However, the spethe cervix
is well established
(8).
METHODS
AND MATERIALS
A low dose rate remote after-loading applicator system* was used for all of the patients. The procedure was performed under anesthesia. One metallic intrauterine tube and two ovoids were placed in each patient and secured with vaginal gauze packing. A foley catheter was inserted and the balloon inflated with 10 ml of diluted contrast. After recovery from the anesthesia, each patient was taken to the ultrasound department. The bladder was inflated with direct instillation of 200 to 300 ml normal saline through the foley catheter. Longitudinal and transverse scans of the pelvis area were then obtained using 3.5 and 5.0 MHz transducers.+ RESULTS Case 1 demonstrates the desired positioning of the intrauterine tube. Figures la and 1b show the proximal wall
tributions from Dr. B. Acker, Dr. E. McMurtrie,
* Department of Radiatllon Oncology.
and Dr. P. Hassell. Accepted for publication 22 February * Selectron, Nucletron manufacturing. + G.E. 3600.
+ Department of Radiology. Reprint requests to: Dr. Frances Wong. Acknowledgements-The authors wish to acknowledge the technical assistance of Ms. Diane McEwen, and the clinical con-
477
1990.
Dr. H. Mueller,
I. J. Radiation Oncology 0
478
Biology
0 Physics
August
1990. Volume
19. Number
2
(b) Fig. 1. (a) Longitudinal scan a = anterior wall of uterus, catheter balloon, o = ovoid applicator. a = anterior wall
of Case 1 with the intra-uterine applicator in desirable position. f = fundus 01Futerus, p = posterior wall of uterus, ap = intra-uterine applicator, b = bladder, c = foley applicator. (b) Transverse scan of Case 1 through the uterus with the intra -uterine of uterus, p = posterior wall of uterus, ap = intra-uterine applicator, b = bla Idder.
Ultrasonography in intracavitary radiotherapy 0 F. WONG
AND S. BHIMJI
479
Fig. 2. Longitudinal scan of Case 2 with the applicator tip penetrating into the fundal myometrium. f = fundus of uterus, a = anterior wall of uterus, p = nosterior wall of uterus, ap = intra-uterine applicator, b = bladder, c = foley catheter balloon.
and even portions of the posterior wall of the applicator as a linear echogenic density in the uterine cavity. The applicator is located approximately equidistant from the anterior and posterior wall of the uterus with a definite identifiable thickness of the fundus beyond the applicator tip. One cervical applicator is shown on the anterior side of the intrauterine applicator and the other can be easily identified by examination from other angles. Case 2 underwent two insertions 1 week apart. Clinical sounding of the uterus was difficult due to severe cervical stenosis. Uterine perforation was noted during the first insertion. However, the fundus of the uterus could be appreciated clinically and the treatment was carried out. The intrauterine applicator is seen clearly within the uterine cavity on ultrasound, with the tip of the applicator abutting the fundus indicating penetration through the fundal myometrium (Fig. 2). The second insertion remained difficult. On the ultrasound study (Fig. 3a), the uterine applicator is shown to enter the endocervical canal, but then traversed through the anterior myometrium. This was confirmed on CT scan examination with the tip of the applicator shown between the bladder and uterus (Fig. 3b). Case 3 also had severe cervical stenosis. Dilatation was performed by a consultant gynecologist. The ultrasound study, post insertion, shows a similar finding as in Case 2 (Fig. 4a) with the intrauterine applicator perforating the uterus anteriorly. The CT scan confirmed the perforation (Fig. 4b).
Case 4 had a previous cone biopsy resulting in great distortion of the appearance of the exocervix and the cervical OS was not readily apparent at the time of insertion. Despite the clinical appreciation of the uterine fundus, the ultrasound finding revealed anterior perforation through the myometrial wall (Fig. 5).
DISCUSSION Uterine perforations are reported to occur in 3% of the patients undergoing intracavitary radiotherapy. With normal positioning, the proximal wall of the intracavitary applicators could be easily identified on ultrasound as a linear echogenic density within the uterine cavity. Since the applicator is metallic to its tip and is strongly echogenie, the tip can be identified easily. On the longitudinal and transverse scans, a finite thickness of the fundus could be appreciated from the tip of the applicator which should be equidistant from the anterior and the posterior wall of the uterus. Despite its echogenicity, the applicator does not completely attenuate the beam and does allow the posterior wall of the uterus to be identified as demonstrated in these cases. This information was verified with CT scan findings. In order to visualize the applicator and the uterus, a filled bladder acting as a window is necessary. Since the applicator system is rigid, even if filling the bladder may displace the entire uterine applicator system, the relationship between the applicator and the uterus
480
I. J. Radiation
Oncology
0 Biology 0 Physics
August 1990, Volume
19. Number
2
(b) Fig. 3. (a) Longitudinal scan of Case 2 with anterior perforation and the applicator tip abutting the I p = posterior wall of uterus, ap = intra-uterine applicator, b = bladder, c = foley catheter balloon. (b) CT scan of Case 2 with anterior perforation. a = anterior wall of uterus, p = posterior wall of uterus, ap = intra. -uterine applicator, b = bladder.
Ultrasonography in intracavitary radiotherapy 0 F.
481
WONG AND S. BHIMJI
(4
03 Fig. 4. ($4 7‘ramverse scan of Case 3 with anterior perforation. f = fundus of uterus, ap = intra-uterine b= blal ddel ., c = catheter, (b) CT scan of Case 3 with anterior perforation. a = anterior wall of uterus, p wall I of uter us, apl = intra-uterine applicator, b = bladder.
cator, jterior
482
I. J. Radiation
Fig. 5. Transverse ap = intra-uterine
Oncology
0 Biology 0 Physics
scan of Case 4 with the applicator applicator, b = bladder.
remains intact. Uterine perforations were seen with the applicator transversing the myometrium either at the fundus or through the anterior wall of the uterus. The procedure of ultrasonographic study was easy and safe. The treatments were discontinued with immediate removal of the applicators in those cases with demonstrated
August
within
1990. Volume
the anterior
19. Number
myometrium.
2
f = fundus
of uterus,
perforation. Although our patients were scanned post-operatively, the scan could easily be performed intra-operatively as guidance during the time of insertion. This would reduce the 3% of inadvertent uterine perforations, rendering the insertion procedure an even safer treatment for patients.
REFERENCES 1. Brascho, D. J.; Kim, R. Y.; Wilson, E. E. Use of ultrasonography in planning intracavitary radiotherapy of endometrial carcinoma. Radiology 129: 163- 167; 1978. 2. Coltart, R. S.; Nethersell, B. W.; Thomas, S.; Dixon, A. K. A CT based dosimetry system for intracavitary therapy in carcinoma of the cervix. Radiother. Oncol. 10:295-305; 1987. H.; 3. Granai, C. 0.; Allee, P.; Doherty, F.; Madoc-Jones, Curry, S. L. Ultrasound used for assessing the in situ position of intrauterine tandems. Gynecol. Oncol. 18:334-338; 1984. 4. Kim, R. Y.; Levy, D. S.; Brascho, D. J.; Hatch, K. D. Uterine perforation during intracavitary application. Radiology 147: 249-251; 1983. 5. Lee, K. R.; Mansfield, C. M.; Dwyer, S. J. III; Cox, H. L.; Levine, E.; Templeton, A. W. CT for intracavitary radiotherapy planning. AJR 135:809-8 13; 1980.
6. Makin. W. P.; Hunter, R. D. CT scanning in intracavitary therapy: unexpected findings in “straightforward” insertions. Radiother. Oncol. I3:253-255; 1988. 7. Matsuyama, T.: Tsukamoto, N.; Matsukuma, K.; Kamura, T.; Jingu, K. Uterine perforation at the time of brachytherapy for the carcinoma of the uterine cervix. Gynecol. Oncol. 23:205-2 I 1; 1986. H.; Wollin, M.; Kagan, A. R. 8. Reddi, P. R.; Nussbaum, Treatment of carcinoma of the cervox uteri with special reference to radium system. Obstet. Gynecol. 43:238-247; 1974. 9. Wilkinson, J. M.; Moore, C. J.; Notley, H. M.; Hunter, R. D. The use of Selectron afterloading equipment to simulate and extend the Manchester system for intracavitary therapy of the cervix uteri. Br. J. Radiol. 56:409-4 14; 1983.
19, pp. 471-482
0360-3016/90 $3.00 + .Xl Copyright 0 1990 Pergamon Press plc
??Technical Innovations and Notes
THE USEFULNESS OF ULTRASONOGRAPHY RADIOTHERAPY USING SELECTRON
IN INTRACAVITARY APPLICATORS
M.D., F.R.C.P. (C)* AND SHAMIM BHIMJI, M.B.CH.B.,
FRANCES WONG,
F.R.C.P.
(C)t
A. Maxewell Evans Clinic, Cancer Control Agency of British Columbia, 600, West 10th Avenue, Vancouver, British Columbia, V5Z 4E6 Canada Uterine perforation can occur during the procedure of intracavitary insertions for the treatment of carcinoma of the cervix. If radiation treatment proceeds in the situation of inadvertent perforation, severe complication may result. The ultrasonographic studies of five patients with metal intrauterine applicators in situ are described. The applicator appeared as a linear echogenic density within the uterine cavity. The thickness of the uterine wall and the fundus could be clearly identified in a normal insertion. In the presence of uterine perforation, the applicator was seen traversing the myometrium necessitating alteration of the treatment plan. Uterus, perforation; Uterus, ultrasonography; Therapeutic radiology, intracavitary; Uterine neoplasms, therapeutic radiology.
cific type of tandem was not described. To our knowledge, the normal or abnormal appearance of the uterus with the modern remote controlled after-loading metallic intrauterine applicator in situ has not been described in the literature.
INTRODUCTION Afterloading
intracavitary
radiotherapy
for carcinoma
of
To minimize staff exposure, remote control (after-loading equipment has become popularized (9). At times, cervical stenosis or uterine malpositioning may result in difficulty of the insertion procedure. In one study, uterine perforation has been noted in 1.75% of the in:sertions (4), and in another, routine CT scanning revealed unexpected perforation in 3% of the “straight forward” insertions (6). Inadvertent uterine perforation can lead to overdose and serious injury of the adjacent organs. Investigations should therefore be carried out to ensure intrauterine applicator positioning prior to the initiation of treatment. While computerized tomography (CT) scanning has been demonstrated to be useful for accurate localization of the applicators and dosimetry calculation (2, 5, 6, 9), heavy hospital demands on the scanner limit its availability for routine use after insertion. Hemostatic clips could be placed on the serosal surface of the uterine wall for visualization of the uterine contour in the localization films (7). This would only be feasible for patients undergoing pretreatment laparotomies. Ultrasonography has been described for assessing the in situ position of intrauterine tandems ( 1, 3). However, the spethe cervix
is well established
(8).
METHODS
AND MATERIALS
A low dose rate remote after-loading applicator system* was used for all of the patients. The procedure was performed under anesthesia. One metallic intrauterine tube and two ovoids were placed in each patient and secured with vaginal gauze packing. A foley catheter was inserted and the balloon inflated with 10 ml of diluted contrast. After recovery from the anesthesia, each patient was taken to the ultrasound department. The bladder was inflated with direct instillation of 200 to 300 ml normal saline through the foley catheter. Longitudinal and transverse scans of the pelvis area were then obtained using 3.5 and 5.0 MHz transducers.+ RESULTS Case 1 demonstrates the desired positioning of the intrauterine tube. Figures la and 1b show the proximal wall
tributions from Dr. B. Acker, Dr. E. McMurtrie,
* Department of Radiatllon Oncology.
and Dr. P. Hassell. Accepted for publication 22 February * Selectron, Nucletron manufacturing. + G.E. 3600.
+ Department of Radiology. Reprint requests to: Dr. Frances Wong. Acknowledgements-The authors wish to acknowledge the technical assistance of Ms. Diane McEwen, and the clinical con-
477
1990.
Dr. H. Mueller,
I. J. Radiation Oncology 0
478
Biology
0 Physics
August
1990. Volume
19. Number
2
(b) Fig. 1. (a) Longitudinal scan a = anterior wall of uterus, catheter balloon, o = ovoid applicator. a = anterior wall
of Case 1 with the intra-uterine applicator in desirable position. f = fundus 01Futerus, p = posterior wall of uterus, ap = intra-uterine applicator, b = bladder, c = foley applicator. (b) Transverse scan of Case 1 through the uterus with the intra -uterine of uterus, p = posterior wall of uterus, ap = intra-uterine applicator, b = bla Idder.
Ultrasonography in intracavitary radiotherapy 0 F. WONG
AND S. BHIMJI
479
Fig. 2. Longitudinal scan of Case 2 with the applicator tip penetrating into the fundal myometrium. f = fundus of uterus, a = anterior wall of uterus, p = nosterior wall of uterus, ap = intra-uterine applicator, b = bladder, c = foley catheter balloon.
and even portions of the posterior wall of the applicator as a linear echogenic density in the uterine cavity. The applicator is located approximately equidistant from the anterior and posterior wall of the uterus with a definite identifiable thickness of the fundus beyond the applicator tip. One cervical applicator is shown on the anterior side of the intrauterine applicator and the other can be easily identified by examination from other angles. Case 2 underwent two insertions 1 week apart. Clinical sounding of the uterus was difficult due to severe cervical stenosis. Uterine perforation was noted during the first insertion. However, the fundus of the uterus could be appreciated clinically and the treatment was carried out. The intrauterine applicator is seen clearly within the uterine cavity on ultrasound, with the tip of the applicator abutting the fundus indicating penetration through the fundal myometrium (Fig. 2). The second insertion remained difficult. On the ultrasound study (Fig. 3a), the uterine applicator is shown to enter the endocervical canal, but then traversed through the anterior myometrium. This was confirmed on CT scan examination with the tip of the applicator shown between the bladder and uterus (Fig. 3b). Case 3 also had severe cervical stenosis. Dilatation was performed by a consultant gynecologist. The ultrasound study, post insertion, shows a similar finding as in Case 2 (Fig. 4a) with the intrauterine applicator perforating the uterus anteriorly. The CT scan confirmed the perforation (Fig. 4b).
Case 4 had a previous cone biopsy resulting in great distortion of the appearance of the exocervix and the cervical OS was not readily apparent at the time of insertion. Despite the clinical appreciation of the uterine fundus, the ultrasound finding revealed anterior perforation through the myometrial wall (Fig. 5).
DISCUSSION Uterine perforations are reported to occur in 3% of the patients undergoing intracavitary radiotherapy. With normal positioning, the proximal wall of the intracavitary applicators could be easily identified on ultrasound as a linear echogenic density within the uterine cavity. Since the applicator is metallic to its tip and is strongly echogenie, the tip can be identified easily. On the longitudinal and transverse scans, a finite thickness of the fundus could be appreciated from the tip of the applicator which should be equidistant from the anterior and the posterior wall of the uterus. Despite its echogenicity, the applicator does not completely attenuate the beam and does allow the posterior wall of the uterus to be identified as demonstrated in these cases. This information was verified with CT scan findings. In order to visualize the applicator and the uterus, a filled bladder acting as a window is necessary. Since the applicator system is rigid, even if filling the bladder may displace the entire uterine applicator system, the relationship between the applicator and the uterus
480
I. J. Radiation
Oncology
0 Biology 0 Physics
August 1990, Volume
19. Number
2
(b) Fig. 3. (a) Longitudinal scan of Case 2 with anterior perforation and the applicator tip abutting the I p = posterior wall of uterus, ap = intra-uterine applicator, b = bladder, c = foley catheter balloon. (b) CT scan of Case 2 with anterior perforation. a = anterior wall of uterus, p = posterior wall of uterus, ap = intra. -uterine applicator, b = bladder.
Ultrasonography in intracavitary radiotherapy 0 F.
481
WONG AND S. BHIMJI
(4
03 Fig. 4. ($4 7‘ramverse scan of Case 3 with anterior perforation. f = fundus of uterus, ap = intra-uterine b= blal ddel ., c = catheter, (b) CT scan of Case 3 with anterior perforation. a = anterior wall of uterus, p wall I of uter us, apl = intra-uterine applicator, b = bladder.
cator, jterior
482
I. J. Radiation
Fig. 5. Transverse ap = intra-uterine
Oncology
0 Biology 0 Physics
scan of Case 4 with the applicator applicator, b = bladder.
remains intact. Uterine perforations were seen with the applicator transversing the myometrium either at the fundus or through the anterior wall of the uterus. The procedure of ultrasonographic study was easy and safe. The treatments were discontinued with immediate removal of the applicators in those cases with demonstrated
August
within
1990. Volume
the anterior
19. Number
myometrium.
2
f = fundus
of uterus,
perforation. Although our patients were scanned post-operatively, the scan could easily be performed intra-operatively as guidance during the time of insertion. This would reduce the 3% of inadvertent uterine perforations, rendering the insertion procedure an even safer treatment for patients.
REFERENCES 1. Brascho, D. J.; Kim, R. Y.; Wilson, E. E. Use of ultrasonography in planning intracavitary radiotherapy of endometrial carcinoma. Radiology 129: 163- 167; 1978. 2. Coltart, R. S.; Nethersell, B. W.; Thomas, S.; Dixon, A. K. A CT based dosimetry system for intracavitary therapy in carcinoma of the cervix. Radiother. Oncol. 10:295-305; 1987. H.; 3. Granai, C. 0.; Allee, P.; Doherty, F.; Madoc-Jones, Curry, S. L. Ultrasound used for assessing the in situ position of intrauterine tandems. Gynecol. Oncol. 18:334-338; 1984. 4. Kim, R. Y.; Levy, D. S.; Brascho, D. J.; Hatch, K. D. Uterine perforation during intracavitary application. Radiology 147: 249-251; 1983. 5. Lee, K. R.; Mansfield, C. M.; Dwyer, S. J. III; Cox, H. L.; Levine, E.; Templeton, A. W. CT for intracavitary radiotherapy planning. AJR 135:809-8 13; 1980.
6. Makin. W. P.; Hunter, R. D. CT scanning in intracavitary therapy: unexpected findings in “straightforward” insertions. Radiother. Oncol. I3:253-255; 1988. 7. Matsuyama, T.: Tsukamoto, N.; Matsukuma, K.; Kamura, T.; Jingu, K. Uterine perforation at the time of brachytherapy for the carcinoma of the uterine cervix. Gynecol. Oncol. 23:205-2 I 1; 1986. H.; Wollin, M.; Kagan, A. R. 8. Reddi, P. R.; Nussbaum, Treatment of carcinoma of the cervox uteri with special reference to radium system. Obstet. Gynecol. 43:238-247; 1974. 9. Wilkinson, J. M.; Moore, C. J.; Notley, H. M.; Hunter, R. D. The use of Selectron afterloading equipment to simulate and extend the Manchester system for intracavitary therapy of the cervix uteri. Br. J. Radiol. 56:409-4 14; 1983.