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Absorbable mesh in placement of temporary implants
Int. J. Radiation
Oncology
Pergamon
??Technical Innovations
ABSORBABLE J. Departments
and Notes
MESH
PISCH,
IN PLACEMENT
M.D.,* A. M. BERSON, S. MISHRA, PH.D.* AND
of *Radiation
Biol. Phys., Vol. 28, No. 3, pp. 719-722, 1994 Copyright 0 1994 Elsevier Science Ltd Printed in the USA. All rights reserved 0360-3016/94 $6.00 + .OO
OF TEMPORARY
M.D.,*
J. C. HARVEY,
E. J. BEATTIE,
IMPLANTS M.D.,?
M.D.?
Oncology and jSurgery, Beth Israel Medical Center, New York, NY 10003
Purpose: To evaluate absorbable mesh for the suturing of afterloading chatters in patients with tumors involving the chest wall. Methods and Materials: Patients underwent thoracotomy and resection of tumor; a layer of absorbable mesh was then sutured to the tumor bed. Nylon flexiguide afterloading catheters were sutured into the mesh at about 1.5 cm distance from each other. A second layer of mesh was then sutured on top of the catheters. The chest wall was closed. Orthogonal radiographs and CT scans of the area of implants were done to verify catheter position in each patient on day 1 and on the last day of implant. Computer dosimetry by digitization of dummy sources was performed on each set of radiographs. The same seed for both sets of films was chosen as the origin of digitization. All seed coordinates were compared directly to offset for any rotation of the patient during the two sets of films. The distances were calculated from all seed positions to the origin, then tabulated and compared. Results: The distances agreed within a few millimeters (7-8 mm). The differences may be attributed to the patient’s breathing and to the localization uncertainty. The resulting dose alteration was negligible. Conclusion: This technique appears to provide adequate anchorage of catheters with resulting constant seed position and dose distribution in areas of scant tissues or in surgical beds of considerable size. Temporary implant, Absorhahle mesh, Iridium-192 (Ir-192).
mesh with temporary interstitial implant catheters, was evaluated in our department in dogs. Computer dosimetry by digitization of the dummy sources was performed on each set of orthogonal films. An average positional change of k2.0 mm in source position was found on each of two sets of orthogonal films taken 5 days apart. The resulting alteration in the dose prescription was found to be negligible (8). We felt that this was a safe way of placing catheters in areas of scant tissue or in surgical beds of considerable size.
INTRODUCTION Surgical resection of advanced tumors in the thoracic cavity, abdomen, and pelvis is often incomplete, leaving at least residual microscopic disease within the tumor bed. Incomplete surgery usually is followed with external irradiation in an attempt to sterilize the tumor bed. However, local control and function preservation is often poor due to limitations in normal tissue tolerance to optimal treatment doses. High total doses of radiation may be delivered when external beam is combined with brachytherapy because the rapid dose fall-off outside the implanted region preserves the surrounding normal tissues (2). For interstitial implants, flexible nylon afterloading catheters are placed at the time of surgery. However, there is often inadequate soft tissue within the tumor bed with which to secure the catheters. This situation may result in catheter migration and, consequently, inadequate radiation dose to the area of interest. Methods used to overcome these problems have included the use of nonabsorbable vicryl mesh in fixed pelvic or abdominal masses (6) or the gel-foam sandwich technique for permanent I- 125 implants (1). A combination of these two methods, using absorbable vicryl
Reprint requests to: Julianna Accepted
for publication
METHODS
MATERIALS
We used this method of implanting four consecutive patients with advanced lung cancer or, as in case 2, with recurrent fibrosarcoma of the chest wall. Each patient signed an informed consent before undergoing thoracotomy with resection of the gross tumor. After resection, the area of questionable margin or known residual disease was outlined with surgical clips and a layer of absorbable knitted vicryl mesh’ was sutured into the tumor bed with a 2.0 cm margin around the proposed target area. Nylon flexiguide afterloading catheters* were sewn into the layer of mesh at about 1.5 cm distance with absorbable chro-
’Vicryl woven mesh, Ethicon, Ethicon ’ Best Industries, Arlington, VA.
Pisch, M.D.
2 September
AND
1993. 719
Inc. DA5247.
1. J.
720
Radiation Oncology 0
Biology
0 Physics
Volume 2X. Number 3, I994
tered into the computer’ by digitizing the orthogonal films. The target volume was outlined and the seed positions for loading marked. Comparison of the coordinates of the corresponding seeds was made on the day of the implant removal. The same seed for both sets of films was chosen as the origin for digitization. All seed coordinates were compared directly to offset for any rotation of the patient during the two sets of films. The distances were calculated from all seed positions to the origin. then tabulated and compared.
Fig. I. Lateral views of afterloading catheters with dummy sources in place. Target volume is outlined (Case 1).
The catheters were led outside the chest mium sutures. cavity via stab wounds to a previously planned and marked skin exit area. A second layer of mesh was then sutured on top of the afterloading catheters and also to the hardy tissue. The catheters were secured to the skin with metal buttons using 00 silk. Wire cables were put into the catheters to keep them patent until the Ir-192 isotope was loaded. The chest wall was closed in the usual way with particular care to the implant. On the 3rd or 4th postoperative day, dummy sources were placed into the catheters and orthogonal radiographs and CAT scans were taken for dosimetry purposes. The orthogonal radiographs were repeated after the implant was removed for verification and comparison of spatial distribution of sources. Assessment of implant position and catheter parallelism was made from the initial postsurgical radiograph for each of the implants performed. The corresponding catheters and seeds were identified with the help of bony landmarks, markers implanted between the dummy seeds. anatomical structures, and geographic localization of metal buttons over the skin. Seed positions were then en-
Fig. 2. Photograph of CT scan of chest with afterloading catheters and dummy sources. Isodose curves superimposed on target volume (Case I ).
3 Theratronics
3-D Treatment
Planning
System-AECL.
Case I. Patient with T3N2Mo squamous cell cancer of the lung who received preoperative simultaneous chemoradiation with partial response. At surgery, the tumor was excised, but there was residual tumor remaining along the left posterior chest wall. Five flexiguide afterloading catheters, each 30 cm in length, were inserted through the skin just below the chest wall through the 10th and 1 lth intercostal spaces. The catheters were placed between a
a
Fig. 3. (a) Afterloading Hurstlayer of absorbable covered and reinforced (Case 2).
catheters positioned and sewn into the mesh (Case 2). (b) Afterloading catheters with a second layer of absorbable mesh
Temporary h-192 implant 0
J. PISCH
721
et ul.
Fig. 4. Lateral radiograph of patient #2 with dummy sources in place.
Fig. 5. Photograph of CT scan of chest with afterloading catheters and dummy sources. Isodose curves superimposed on target volume (Case 2).
folded layer of vicryl absorbable mesh and sutured in place along the chest wall. A total of 30 Gy in 3 days was given with Ir- 192. Figure I shows catheter position on day 1 for Case #I with the target volume outlined on the lateral radiograph. Figure 2 is a photograph of CAT scan with isodose curves superimposed over the target volume. Case 2. The patient was a 76-year-old man with recurrent soft tissue sarcoma of the chest wall measuring 20 X 9.5 cm. The 9th, IOth, and 1 Ith ribs were resected to achieve adequate margins. The defect was repaired with a synthetic nonabsorbable mesh. A layer of absorbable vicryl mesh was then sewn into the tumor bed with margins of 1.5 cm around the target volume. Nine afterloading catheters were sutured to the mesh. A second layer of vicryl mesh was sewn over the catheters to secure them. The catheters were passed through needle puncture wounds to the surface of the skin and sutured there, using 00 silk. Wire cables were put into the catheters to ensure their patency. This patient received 30 Gy in 76 hours with Ir-192. Figure 3A shows the catheters placed and sutured to the first layer of vicryl mesh. Figure 3B shows the catheters covered with a second layer of the same ab-
sorbable mesh, folded out. Figure 4 shows a lateral photograph of this patient with the catheters in position. Figure 5 is a photograph of a CAT scan with isodose curves superimposed over target volume. The procedure was well tolerated by all of the patients and the catheters were removed without complications.
Table Seed locations Seed no.
RESULTS The isodose curves superimposed over the CAT scans showed that the target volume was well covered. Comparison of the corresponding catheters and seeds showed that the distances agreed within a few millimeters, with no significant alteration in dose distribution. This change in seed position may be attributed to the patient’s breathing and to localization uncertainty. Tables 1 and 2 show representative seed positions before and after treatment. DISCUSSION Good dose distribution for temporary or permanent tumor bed implants depends on the even spacing of afterloading catheters. The lack of adequate tissue for an-
1. Case #l
before treatment
Seed locations
after treatment
X
Y
Z
d
X
Y
Z
d
D
1
0.0
2 3 4 5 6 7 8 9 10 II 12 13 14
0.22 -0.07 -0.18 0.11 0.03 0.33 0.44 0.07 0.24
0.87 0.55 0.21 0.11 -0.17 -0.69 - 1.03 -0.89 -2.09 -1.83 -1.47 -1.98 -2.8 1 -4.56
3.74 -0.04 -3.8 1 1.85 -1.91 4.53 0.83 -2.98 3.24 -0.49 -4.15 1.62 -2.00 -4.26
3.84 0.59 3.82 1.86 1.92 4.58 1.36 3.14 3.86 1.91 4.53 2.58 3.45 6.44
0.20 -0.24 -0.34 -0.15 -0.07 0.13 0.24 0.15 0.00 0.36 0.13 0.24 -0.07 1.42
0.76 0.58 0.44 0.08 -0.07 -0.76 - 1.oo -0.83 -2.2 1 -1.73 -2.51 -2.16 -2.76 -4.52
3.69 -0.22 -4.12 1.96 -1.92 4.51 0.58 -3.32 2.91 -1.91 -4.62 0.55 -2.31 -4.18
3.77 6.67 4.16 1.97 1.92 4.58 1.18 3.43 3.65 2.60 5.26 2.24 3.60 6.32
0.07 -0.08 -0.36 -0.1 I 0.00 0.00 0.18 0.29 0.21 -0.69 -0.73 0.34 -0.15 0.14
1.05 0.37 0.01 1.59
D = difference
in seed position:
X - Y - Z = Coordiantes;
d = Distance
of seeds from center.
722
1. J. Radiation
Oncology
0 Biology 0 Physics
Table
Seed locations Seed no.
I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17
Volume
2. Case
28, Number
3, 1994
#2
before treatment
Seed locations
after treatment
X
Y
Z
d
X
Y
Z
d
D
-0.12 0.10 3.56 1.oo 0.35 2.75 -0.91 -0.84 1.46 -1.11 3.05 0.01 -0.84 -1.06 - 1.60 1.96 -1.43
4.11 0.56 -5.33 -1.78 -0.86 -4.1 I 9.83 0.68 -3.21 5.68 -4.66 -1.10 5.75 6.06 6.08 -3.7 I 2.16
2.67 1.40 0.78 -2.68 0.41 -0.35 -6.78 -3.95 -4.78 -2.05 -1.27 -6.41 0.55 -2.96 -4.80 -3.43 -5.43
4.95 1.51 6.46 3.37 1.02 4.96 1 1.70 4.10 5.94 6.14 5.71 6.50 5.84 6.83 7.90 5.42 6.02
-0.27 0.21 3.03 0.37 0.26 1.92 0.98 -1.11 3.14 -0.38 2.38 1.59 -0.33 -1.73 -2.22 3.07 -0.63
3.54 -0.9 I -5.53 -1.27 -0.9 1 -4.03 10.87 2.44 -4.26 5.92 -4.41 -2.18 5.03 5.18 5.21 -4.53 0.73
3.01 1.75 -0.14 -2.88 0.26 -0.63 -4.15 -3.82 -3.97 -1.16 -1.66 -5.30 1.21 -3.59 -5.59 -2.99 -5.25
4.71 1.98 6.31 3.17 0.98 4.51 11.68 4.66 6.61 6.04 5.28 5.95 5.18 6.53 7.96 6.23 5.34
0.24 -0.47 0.15 0.20 0.04 0.45 0.02 -0.56 -0.67 0.10 0.43 0.55 0.66 0.30 -0.06 -0.8 I 0.68
X - Y - Z = Coordinates;
d = Distance
D = Difference
in seed position;
chorage, the irregularity of the anatomical surface, and the proximity of major neurological and vascular elements may result in suboptimal catheter placement with consequent inferior dose distribution (4, 9). To overcome these limitations, different brachytherapy techniques have been applied to a variety of clinical sites, such as intrathoracic (3, 5) head and neck (7. lo), and soft tissue sarcoma. To facilitate catheter fixation on parallel placement, nonabsorbable vicryl mesh in abdominal and pelvic tumor with superior dose distribution was used by Meerwaldt et ul. (6), but a second exploration was needed to remove the mesh. Greenblatt rf al. ( 1) stated that loose I- 125 seeds, placed in gel-foam sandwiched between vicryl absorbable mesh, is a safe and reproducible way of performing per-
of seeds from center.
manent implants, but the possibility of dose optimization renders a temporary implant more desirable than a permanent implant in some patients. The difference found in the average seed position in dogs and patients (2 mm vs. 7-8 mm) is the result of different implant sizes, translating into differing magnification due to the distance between center and periphery. This technique avoided the risk of sewing the catheters on or close to structures such as nerves, blood vessels, bronchi, pericardium or esophagus. The placement of afterloading catheters between the two layers of vicryl mesh ensured accurate spacing of catheters which then transformed into an acceptable homogeneous dose distribution in the area of interest.
REFERENCES A.; Brenner, H.; 1. Greenblatt. D. R.; Nori, D.; Tankenbaum, Anderson, L. L.; Hilaris, B. S. New brachytherapy techniques using I-125 seeds for tumor bed implants. Endocuriether. Hyperther. Oncol. 3:73-80; 1987. in the treatment of 2. Henschkc, U. Interstitial implantation primary bronchogenic carcinoma. Am. J. Roentgenol. 6: 981-987;1958. 3. Hilaris, B. S.; Gomez, J.; Nori, D.; Anderson, L. L.; Martini. N. Combined surgery, intraoperative brachytherapy and postoperative external radiation in Stage III nonsmall cell lung cancer. Cancer 55:1226-1231; 1985. 4. Hilaris, B. S.: Martini. N. The current state of intraoperative interstitial brachytherapy in lung cancer. Int. J. Radiat. Oncol. Biol. Phys. 15: 1347- 1354; 1989. 5. Hilaris, B. S.: Nori, D.; Beattie, E. J.; Martini, N. Value of perioperative brachytherapy in management of nonoat cell carcinoma of the lung. Int. J. Radiat. Oncol. Biol. Phys. 9: 1161-l 166;1983. J. H.; Wiggers, T.; Westenberg, H.; Koper. 6. Meerwaldt,
7.
8.
9.
10.
P. C. M.: Visser, A. G. Interoperative brachytherapy: Application of vicryl mats for flexible catheter implants. In: Mould, R. F., ed. Brachytherapy II. Proc. 5th Int. Selectron Users Mtg., Netherlands, 1988:952-957. Pierquin, B.; Chassagne, D. J.; Chahbazian, C. M.: Wilson, J. F. eds. Brachytherapy. St. Louis, MO: W.H. Green, Inc: 1978:93-146. Pisch, J.; Harvey, J. C.; Alfieri, A. A.: Aubrey, R.; Beattie, E. J.; Vikram, B. Utilization of absorbable mesh for afterloading HDR and LDR catheter placement in planar implant. Endocuriether. Hyperther. Oncol. 9: 127- 132; 1993. Shiu, M. H.; Turnbull, A. D.; Nori. D.; Hajdu, S.; Hilaris. B. S. Control of locally advanced extremity soft tissue sarcomas by function saving resection and brachytherapy. Cancer 53:1385-1392;1984. Vikram, B.; Strong, E.; Shah, J.; Spiro, R.; Gerold, F.; Sessions, R.: Hilaris, B. S. A nonlooping afterloading technique for base of tongue implants: Results in the first 20 patients. Int. J. Radiat. Oncol. Biol. Phys. 11:1853-1855:1985.
Oncology
Pergamon
??Technical Innovations
ABSORBABLE J. Departments
and Notes
MESH
PISCH,
IN PLACEMENT
M.D.,* A. M. BERSON, S. MISHRA, PH.D.* AND
of *Radiation
Biol. Phys., Vol. 28, No. 3, pp. 719-722, 1994 Copyright 0 1994 Elsevier Science Ltd Printed in the USA. All rights reserved 0360-3016/94 $6.00 + .OO
OF TEMPORARY
M.D.,*
J. C. HARVEY,
E. J. BEATTIE,
IMPLANTS M.D.,?
M.D.?
Oncology and jSurgery, Beth Israel Medical Center, New York, NY 10003
Purpose: To evaluate absorbable mesh for the suturing of afterloading chatters in patients with tumors involving the chest wall. Methods and Materials: Patients underwent thoracotomy and resection of tumor; a layer of absorbable mesh was then sutured to the tumor bed. Nylon flexiguide afterloading catheters were sutured into the mesh at about 1.5 cm distance from each other. A second layer of mesh was then sutured on top of the catheters. The chest wall was closed. Orthogonal radiographs and CT scans of the area of implants were done to verify catheter position in each patient on day 1 and on the last day of implant. Computer dosimetry by digitization of dummy sources was performed on each set of radiographs. The same seed for both sets of films was chosen as the origin of digitization. All seed coordinates were compared directly to offset for any rotation of the patient during the two sets of films. The distances were calculated from all seed positions to the origin, then tabulated and compared. Results: The distances agreed within a few millimeters (7-8 mm). The differences may be attributed to the patient’s breathing and to the localization uncertainty. The resulting dose alteration was negligible. Conclusion: This technique appears to provide adequate anchorage of catheters with resulting constant seed position and dose distribution in areas of scant tissues or in surgical beds of considerable size. Temporary implant, Absorhahle mesh, Iridium-192 (Ir-192).
mesh with temporary interstitial implant catheters, was evaluated in our department in dogs. Computer dosimetry by digitization of the dummy sources was performed on each set of orthogonal films. An average positional change of k2.0 mm in source position was found on each of two sets of orthogonal films taken 5 days apart. The resulting alteration in the dose prescription was found to be negligible (8). We felt that this was a safe way of placing catheters in areas of scant tissue or in surgical beds of considerable size.
INTRODUCTION Surgical resection of advanced tumors in the thoracic cavity, abdomen, and pelvis is often incomplete, leaving at least residual microscopic disease within the tumor bed. Incomplete surgery usually is followed with external irradiation in an attempt to sterilize the tumor bed. However, local control and function preservation is often poor due to limitations in normal tissue tolerance to optimal treatment doses. High total doses of radiation may be delivered when external beam is combined with brachytherapy because the rapid dose fall-off outside the implanted region preserves the surrounding normal tissues (2). For interstitial implants, flexible nylon afterloading catheters are placed at the time of surgery. However, there is often inadequate soft tissue within the tumor bed with which to secure the catheters. This situation may result in catheter migration and, consequently, inadequate radiation dose to the area of interest. Methods used to overcome these problems have included the use of nonabsorbable vicryl mesh in fixed pelvic or abdominal masses (6) or the gel-foam sandwich technique for permanent I- 125 implants (1). A combination of these two methods, using absorbable vicryl
Reprint requests to: Julianna Accepted
for publication
METHODS
MATERIALS
We used this method of implanting four consecutive patients with advanced lung cancer or, as in case 2, with recurrent fibrosarcoma of the chest wall. Each patient signed an informed consent before undergoing thoracotomy with resection of the gross tumor. After resection, the area of questionable margin or known residual disease was outlined with surgical clips and a layer of absorbable knitted vicryl mesh’ was sutured into the tumor bed with a 2.0 cm margin around the proposed target area. Nylon flexiguide afterloading catheters* were sewn into the layer of mesh at about 1.5 cm distance with absorbable chro-
’Vicryl woven mesh, Ethicon, Ethicon ’ Best Industries, Arlington, VA.
Pisch, M.D.
2 September
AND
1993. 719
Inc. DA5247.
1. J.
720
Radiation Oncology 0
Biology
0 Physics
Volume 2X. Number 3, I994
tered into the computer’ by digitizing the orthogonal films. The target volume was outlined and the seed positions for loading marked. Comparison of the coordinates of the corresponding seeds was made on the day of the implant removal. The same seed for both sets of films was chosen as the origin for digitization. All seed coordinates were compared directly to offset for any rotation of the patient during the two sets of films. The distances were calculated from all seed positions to the origin. then tabulated and compared.
Fig. I. Lateral views of afterloading catheters with dummy sources in place. Target volume is outlined (Case 1).
The catheters were led outside the chest mium sutures. cavity via stab wounds to a previously planned and marked skin exit area. A second layer of mesh was then sutured on top of the afterloading catheters and also to the hardy tissue. The catheters were secured to the skin with metal buttons using 00 silk. Wire cables were put into the catheters to keep them patent until the Ir-192 isotope was loaded. The chest wall was closed in the usual way with particular care to the implant. On the 3rd or 4th postoperative day, dummy sources were placed into the catheters and orthogonal radiographs and CAT scans were taken for dosimetry purposes. The orthogonal radiographs were repeated after the implant was removed for verification and comparison of spatial distribution of sources. Assessment of implant position and catheter parallelism was made from the initial postsurgical radiograph for each of the implants performed. The corresponding catheters and seeds were identified with the help of bony landmarks, markers implanted between the dummy seeds. anatomical structures, and geographic localization of metal buttons over the skin. Seed positions were then en-
Fig. 2. Photograph of CT scan of chest with afterloading catheters and dummy sources. Isodose curves superimposed on target volume (Case I ).
3 Theratronics
3-D Treatment
Planning
System-AECL.
Case I. Patient with T3N2Mo squamous cell cancer of the lung who received preoperative simultaneous chemoradiation with partial response. At surgery, the tumor was excised, but there was residual tumor remaining along the left posterior chest wall. Five flexiguide afterloading catheters, each 30 cm in length, were inserted through the skin just below the chest wall through the 10th and 1 lth intercostal spaces. The catheters were placed between a
a
Fig. 3. (a) Afterloading Hurstlayer of absorbable covered and reinforced (Case 2).
catheters positioned and sewn into the mesh (Case 2). (b) Afterloading catheters with a second layer of absorbable mesh
Temporary h-192 implant 0
J. PISCH
721
et ul.
Fig. 4. Lateral radiograph of patient #2 with dummy sources in place.
Fig. 5. Photograph of CT scan of chest with afterloading catheters and dummy sources. Isodose curves superimposed on target volume (Case 2).
folded layer of vicryl absorbable mesh and sutured in place along the chest wall. A total of 30 Gy in 3 days was given with Ir- 192. Figure I shows catheter position on day 1 for Case #I with the target volume outlined on the lateral radiograph. Figure 2 is a photograph of CAT scan with isodose curves superimposed over the target volume. Case 2. The patient was a 76-year-old man with recurrent soft tissue sarcoma of the chest wall measuring 20 X 9.5 cm. The 9th, IOth, and 1 Ith ribs were resected to achieve adequate margins. The defect was repaired with a synthetic nonabsorbable mesh. A layer of absorbable vicryl mesh was then sewn into the tumor bed with margins of 1.5 cm around the target volume. Nine afterloading catheters were sutured to the mesh. A second layer of vicryl mesh was sewn over the catheters to secure them. The catheters were passed through needle puncture wounds to the surface of the skin and sutured there, using 00 silk. Wire cables were put into the catheters to ensure their patency. This patient received 30 Gy in 76 hours with Ir-192. Figure 3A shows the catheters placed and sutured to the first layer of vicryl mesh. Figure 3B shows the catheters covered with a second layer of the same ab-
sorbable mesh, folded out. Figure 4 shows a lateral photograph of this patient with the catheters in position. Figure 5 is a photograph of a CAT scan with isodose curves superimposed over target volume. The procedure was well tolerated by all of the patients and the catheters were removed without complications.
Table Seed locations Seed no.
RESULTS The isodose curves superimposed over the CAT scans showed that the target volume was well covered. Comparison of the corresponding catheters and seeds showed that the distances agreed within a few millimeters, with no significant alteration in dose distribution. This change in seed position may be attributed to the patient’s breathing and to localization uncertainty. Tables 1 and 2 show representative seed positions before and after treatment. DISCUSSION Good dose distribution for temporary or permanent tumor bed implants depends on the even spacing of afterloading catheters. The lack of adequate tissue for an-
1. Case #l
before treatment
Seed locations
after treatment
X
Y
Z
d
X
Y
Z
d
D
1
0.0
2 3 4 5 6 7 8 9 10 II 12 13 14
0.22 -0.07 -0.18 0.11 0.03 0.33 0.44 0.07 0.24
0.87 0.55 0.21 0.11 -0.17 -0.69 - 1.03 -0.89 -2.09 -1.83 -1.47 -1.98 -2.8 1 -4.56
3.74 -0.04 -3.8 1 1.85 -1.91 4.53 0.83 -2.98 3.24 -0.49 -4.15 1.62 -2.00 -4.26
3.84 0.59 3.82 1.86 1.92 4.58 1.36 3.14 3.86 1.91 4.53 2.58 3.45 6.44
0.20 -0.24 -0.34 -0.15 -0.07 0.13 0.24 0.15 0.00 0.36 0.13 0.24 -0.07 1.42
0.76 0.58 0.44 0.08 -0.07 -0.76 - 1.oo -0.83 -2.2 1 -1.73 -2.51 -2.16 -2.76 -4.52
3.69 -0.22 -4.12 1.96 -1.92 4.51 0.58 -3.32 2.91 -1.91 -4.62 0.55 -2.31 -4.18
3.77 6.67 4.16 1.97 1.92 4.58 1.18 3.43 3.65 2.60 5.26 2.24 3.60 6.32
0.07 -0.08 -0.36 -0.1 I 0.00 0.00 0.18 0.29 0.21 -0.69 -0.73 0.34 -0.15 0.14
1.05 0.37 0.01 1.59
D = difference
in seed position:
X - Y - Z = Coordiantes;
d = Distance
of seeds from center.
722
1. J. Radiation
Oncology
0 Biology 0 Physics
Table
Seed locations Seed no.
I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17
Volume
2. Case
28, Number
3, 1994
#2
before treatment
Seed locations
after treatment
X
Y
Z
d
X
Y
Z
d
D
-0.12 0.10 3.56 1.oo 0.35 2.75 -0.91 -0.84 1.46 -1.11 3.05 0.01 -0.84 -1.06 - 1.60 1.96 -1.43
4.11 0.56 -5.33 -1.78 -0.86 -4.1 I 9.83 0.68 -3.21 5.68 -4.66 -1.10 5.75 6.06 6.08 -3.7 I 2.16
2.67 1.40 0.78 -2.68 0.41 -0.35 -6.78 -3.95 -4.78 -2.05 -1.27 -6.41 0.55 -2.96 -4.80 -3.43 -5.43
4.95 1.51 6.46 3.37 1.02 4.96 1 1.70 4.10 5.94 6.14 5.71 6.50 5.84 6.83 7.90 5.42 6.02
-0.27 0.21 3.03 0.37 0.26 1.92 0.98 -1.11 3.14 -0.38 2.38 1.59 -0.33 -1.73 -2.22 3.07 -0.63
3.54 -0.9 I -5.53 -1.27 -0.9 1 -4.03 10.87 2.44 -4.26 5.92 -4.41 -2.18 5.03 5.18 5.21 -4.53 0.73
3.01 1.75 -0.14 -2.88 0.26 -0.63 -4.15 -3.82 -3.97 -1.16 -1.66 -5.30 1.21 -3.59 -5.59 -2.99 -5.25
4.71 1.98 6.31 3.17 0.98 4.51 11.68 4.66 6.61 6.04 5.28 5.95 5.18 6.53 7.96 6.23 5.34
0.24 -0.47 0.15 0.20 0.04 0.45 0.02 -0.56 -0.67 0.10 0.43 0.55 0.66 0.30 -0.06 -0.8 I 0.68
X - Y - Z = Coordinates;
d = Distance
D = Difference
in seed position;
chorage, the irregularity of the anatomical surface, and the proximity of major neurological and vascular elements may result in suboptimal catheter placement with consequent inferior dose distribution (4, 9). To overcome these limitations, different brachytherapy techniques have been applied to a variety of clinical sites, such as intrathoracic (3, 5) head and neck (7. lo), and soft tissue sarcoma. To facilitate catheter fixation on parallel placement, nonabsorbable vicryl mesh in abdominal and pelvic tumor with superior dose distribution was used by Meerwaldt et ul. (6), but a second exploration was needed to remove the mesh. Greenblatt rf al. ( 1) stated that loose I- 125 seeds, placed in gel-foam sandwiched between vicryl absorbable mesh, is a safe and reproducible way of performing per-
of seeds from center.
manent implants, but the possibility of dose optimization renders a temporary implant more desirable than a permanent implant in some patients. The difference found in the average seed position in dogs and patients (2 mm vs. 7-8 mm) is the result of different implant sizes, translating into differing magnification due to the distance between center and periphery. This technique avoided the risk of sewing the catheters on or close to structures such as nerves, blood vessels, bronchi, pericardium or esophagus. The placement of afterloading catheters between the two layers of vicryl mesh ensured accurate spacing of catheters which then transformed into an acceptable homogeneous dose distribution in the area of interest.
REFERENCES A.; Brenner, H.; 1. Greenblatt. D. R.; Nori, D.; Tankenbaum, Anderson, L. L.; Hilaris, B. S. New brachytherapy techniques using I-125 seeds for tumor bed implants. Endocuriether. Hyperther. Oncol. 3:73-80; 1987. in the treatment of 2. Henschkc, U. Interstitial implantation primary bronchogenic carcinoma. Am. J. Roentgenol. 6: 981-987;1958. 3. Hilaris, B. S.; Gomez, J.; Nori, D.; Anderson, L. L.; Martini. N. Combined surgery, intraoperative brachytherapy and postoperative external radiation in Stage III nonsmall cell lung cancer. Cancer 55:1226-1231; 1985. 4. Hilaris, B. S.: Martini. N. The current state of intraoperative interstitial brachytherapy in lung cancer. Int. J. Radiat. Oncol. Biol. Phys. 15: 1347- 1354; 1989. 5. Hilaris, B. S.: Nori, D.; Beattie, E. J.; Martini, N. Value of perioperative brachytherapy in management of nonoat cell carcinoma of the lung. Int. J. Radiat. Oncol. Biol. Phys. 9: 1161-l 166;1983. J. H.; Wiggers, T.; Westenberg, H.; Koper. 6. Meerwaldt,
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P. C. M.: Visser, A. G. Interoperative brachytherapy: Application of vicryl mats for flexible catheter implants. In: Mould, R. F., ed. Brachytherapy II. Proc. 5th Int. Selectron Users Mtg., Netherlands, 1988:952-957. Pierquin, B.; Chassagne, D. J.; Chahbazian, C. M.: Wilson, J. F. eds. Brachytherapy. St. Louis, MO: W.H. Green, Inc: 1978:93-146. Pisch, J.; Harvey, J. C.; Alfieri, A. A.: Aubrey, R.; Beattie, E. J.; Vikram, B. Utilization of absorbable mesh for afterloading HDR and LDR catheter placement in planar implant. Endocuriether. Hyperther. Oncol. 9: 127- 132; 1993. Shiu, M. H.; Turnbull, A. D.; Nori. D.; Hajdu, S.; Hilaris. B. S. Control of locally advanced extremity soft tissue sarcomas by function saving resection and brachytherapy. Cancer 53:1385-1392;1984. Vikram, B.; Strong, E.; Shah, J.; Spiro, R.; Gerold, F.; Sessions, R.: Hilaris, B. S. A nonlooping afterloading technique for base of tongue implants: Results in the first 20 patients. Int. J. Radiat. Oncol. Biol. Phys. 11:1853-1855:1985.