224
TECHNICAL NOTES
•
Problems of PosteriOr Fields 1
October1975
•
Sameer Raila, M.D., Ph.D. and Flkry Meleka, M.D. Problems arising with the use of posterior fields can be solved by the undertouch technique. Treatment couches with a large window covered with transparent Mylar polyester (D) film can support the patient and do not interfere with the supervoltage beam. INDEX TERM:
Therapeutic radiology, apparatus and equipment
Radiology 117:224, October 1975
• Use of the posterior field in radiotherapy raises problems, particularly in those patients who cannot lie in the prone position. Treatment delivered by inverting the tube, the so-called "under-couch technique," answers or solves many of these problems, but it is impossible to mark the patient on the back in this situation except when the treatment couch has a completely removable section. Such an arrangement may result in sagging of the particular anatomical structure and gross inaccuracies of the set-up. Some of the recent couches have a large window with a transparent Mylar polyester (O) film. Mylar polyester is the condensation polymer resulting from the esterification reaction between ethylene glycol and terephthalic acid (1). Its tensile strength is such that it can support the weight of a patient using only a very thin gauge which would not interfere with the skin-sparing effects of the supervoltage beam. After a satisfactory simulation of the treatment volume with the beam situated under couch, the gantry is then reversed and the port of entry is marked on the anterior aspect of the patient. During the treatment set-up, this process is reversed. REFERENCE 1. Amborski LE, Flierl OW: Physical properites of polyethylene terephthalate films. Ind Eng Chern 45:2290-2294, Oct 1953
•
Incompatibility of Diphenhydramine Hydrochloride (Benadryl) with Meglumine lodipamide (Cholografih) 1 Jeffrey S. Stevens, M.D. 2
Diphenhydramine hydrochloride (Benadryl) and rneqlumine iodipamide (Cholografin) were mixed in varying proportions and found to consistently form a dense amorphous precipitate. This is riot mentioned in the package insert of either agent. All physicians who administer these compounds should be aware of this phenomenon. INDEX TERMS:
Contrast media • Drugs
Radiology 117:224-225, October 1975
• Diphenhydramine hydrochloride (Benadryl, Parke-Davis) is frequently administered for adverse reactions during intravenous cholangiography. We have observed precipitate formation when it and meglumine iodipamide (Cholografin, Squibb) are mixed, and think that all physicians who administer these compounds should be aware of this phenomenon, because of its potential danger.
Fig. 1.
Mylar window as seen mounted on the treatment table of Lineac 4.
1 From the Radiotherapy Department, The Methodist Hospital, 506 Sixth Street, Brooklyn, N. Y. 11215. Accepted for publication in May 1975. dk
During infusion intravenous cholangiography hives developed in a patient and a syringe containing 50 mg of diphenhydramine hydrochloride was introduced into the intravenous tubinq, Upon aspiration into the syringe prior to injection, a dense white precipitate formed within the syringe. The infusion was immediately discontinued and the biliary tree radiographed without incident. This incident prompted us to mix meglumine iodipamide and diphenhydramine hydrochloride under various conditions, each time resulting in the immediate formation of an amorphous, white, putty-like precipitate. The diphenhydramine hydrochloride was added in doses ranging from 5 mg (0.1 ml) to 50 mg (1 ml) to meglumine iodipamide, both undiluted and diluted 20 to 250 ml of normal saline. The pH of both agents was 7. Fifty milligrams (1 ml) of diphenhydramine hydrochloride was added to 5 ml of a number of angiographic and urographic contrast agents containing meglumine diatrizoate, sodium diatnzoate, and meglumine iothalamate in various commercial concentrations. No precipitate formation was detect-
ed. The only apparent significant difference among these agents is the presence of the iodipamide radical in the cholangiographic agent. Warning of the possible occurrence of this phenomenon is not contained in the package insert for either agent.
•
225
TECHNICAL NOTES
Vol. 117
An Afterloading Applicator for Intracavitary Vaginal Irradiation 1
Technical Notes
1 From the Department of Radiology, Division of Nuclear Medicine, Martin Luther King, Jr. General Hospital, 12021 South Wilmington Avenue, Los Angeles, Calif. 90059. Accepted for publication in May 1975. 2 Present address: Department of Radiology, Portland Adventist Hospital, 6040 S.E. Belmont, Portland, Ore. 97215. dk
• I
I
I
I
o
1
2
3
Scale (em)
C. C. Wang, M.D. An afterloadlng applicator for intracavitary vaginal irradiation that employs 137CS sources in a T-shaped irradiator is described.
A Therapeutic radiology, apparatus and equipment. Therapeutic radiology, interstitial and intracavitary INDEX TERMS:
Radiology 117:225, October 1975
•
•
An afterloading applicator employing T-shaped cesium-137 sources for vaginal irradiation for carcinoma of the uterus and currently in use at the Department of Radiation Medicine at the Massachusetts General Hospital is herein described. The applicator is made of a nylon cylinder into which two tunnels, each connected with stainless steel tubing, are carved (Fig. 1). The central tunnel can accommodate two 15-mg radium-equivalent 137CS slugs in tandem. (The physical and active lengths of each slug are 21 and 15 mm, respectively.) Between the central linear source and the surface of the applicator, a second tunnel which ends in a semicircular "well" is used to accommodate a third 15-mg radium-equivalent 137CS slug, hinged to a stiff wire (identical source for afterloading ovoid in treatment of carcinoma of the cervix). The third source can be made perpendicular to the central linear source at the end of the applicator, thus forming aT-shaped irradiator during intracavitary treatment. Detailed measurements of the applicator are shown in Figure 2. Figure 3 shows the isodose curves which were generated
Fig. 1. Photograph of the applicator (lid removed to show the groove and "well") and the cesium-137 dummy slugs and caps.
Fig. 2. Diagram of the applicator showing (A) the removable lid and screws and (B) the detailed structural measurements.
Scale (em)
[t Fig. 3. PC-12 computer-generated isodose curves in coronal (right) and sagittal (left) projections. Speckled area is the contour of the applicator.
on a PC-12 computer. Rounding off of radiations at the vaginal apex is achieved. Intracavitary implant procedure is carried out under local anesthesia and consists of insertion of a Foley catheter for drainage and the vaginal applicator which is held in place by a stitch in the vulva. After the patient has returned to the ward, cesium-137 sources are introduced into the applicator at the appropriate time. A dose of 4000-4500 rad in 45 hours to the mucous membrane of the entire vaginal tube is given for elective irradiation following total abdominal hysterectomy for Stage I, well-differentiated adenocarcinoma of the uterus. This has been found to be highly effective in reducing vaginal recurrences without radiation complications.
1 From the Department of Radiation Medicine, Massachusetts General Hospital, and the Department of Radiation Therapy, Harvard Medical School, Boston, Mass. 02114. Accepted for publication in May 1975. dk
TECHNICAL NOTES
•
Problems of PosteriOr Fields 1
October1975
•
Sameer Raila, M.D., Ph.D. and Flkry Meleka, M.D. Problems arising with the use of posterior fields can be solved by the undertouch technique. Treatment couches with a large window covered with transparent Mylar polyester (D) film can support the patient and do not interfere with the supervoltage beam. INDEX TERM:
Therapeutic radiology, apparatus and equipment
Radiology 117:224, October 1975
• Use of the posterior field in radiotherapy raises problems, particularly in those patients who cannot lie in the prone position. Treatment delivered by inverting the tube, the so-called "under-couch technique," answers or solves many of these problems, but it is impossible to mark the patient on the back in this situation except when the treatment couch has a completely removable section. Such an arrangement may result in sagging of the particular anatomical structure and gross inaccuracies of the set-up. Some of the recent couches have a large window with a transparent Mylar polyester (O) film. Mylar polyester is the condensation polymer resulting from the esterification reaction between ethylene glycol and terephthalic acid (1). Its tensile strength is such that it can support the weight of a patient using only a very thin gauge which would not interfere with the skin-sparing effects of the supervoltage beam. After a satisfactory simulation of the treatment volume with the beam situated under couch, the gantry is then reversed and the port of entry is marked on the anterior aspect of the patient. During the treatment set-up, this process is reversed. REFERENCE 1. Amborski LE, Flierl OW: Physical properites of polyethylene terephthalate films. Ind Eng Chern 45:2290-2294, Oct 1953
•
Incompatibility of Diphenhydramine Hydrochloride (Benadryl) with Meglumine lodipamide (Cholografih) 1 Jeffrey S. Stevens, M.D. 2
Diphenhydramine hydrochloride (Benadryl) and rneqlumine iodipamide (Cholografin) were mixed in varying proportions and found to consistently form a dense amorphous precipitate. This is riot mentioned in the package insert of either agent. All physicians who administer these compounds should be aware of this phenomenon. INDEX TERMS:
Contrast media • Drugs
Radiology 117:224-225, October 1975
• Diphenhydramine hydrochloride (Benadryl, Parke-Davis) is frequently administered for adverse reactions during intravenous cholangiography. We have observed precipitate formation when it and meglumine iodipamide (Cholografin, Squibb) are mixed, and think that all physicians who administer these compounds should be aware of this phenomenon, because of its potential danger.
Fig. 1.
Mylar window as seen mounted on the treatment table of Lineac 4.
1 From the Radiotherapy Department, The Methodist Hospital, 506 Sixth Street, Brooklyn, N. Y. 11215. Accepted for publication in May 1975. dk
During infusion intravenous cholangiography hives developed in a patient and a syringe containing 50 mg of diphenhydramine hydrochloride was introduced into the intravenous tubinq, Upon aspiration into the syringe prior to injection, a dense white precipitate formed within the syringe. The infusion was immediately discontinued and the biliary tree radiographed without incident. This incident prompted us to mix meglumine iodipamide and diphenhydramine hydrochloride under various conditions, each time resulting in the immediate formation of an amorphous, white, putty-like precipitate. The diphenhydramine hydrochloride was added in doses ranging from 5 mg (0.1 ml) to 50 mg (1 ml) to meglumine iodipamide, both undiluted and diluted 20 to 250 ml of normal saline. The pH of both agents was 7. Fifty milligrams (1 ml) of diphenhydramine hydrochloride was added to 5 ml of a number of angiographic and urographic contrast agents containing meglumine diatrizoate, sodium diatnzoate, and meglumine iothalamate in various commercial concentrations. No precipitate formation was detect-
ed. The only apparent significant difference among these agents is the presence of the iodipamide radical in the cholangiographic agent. Warning of the possible occurrence of this phenomenon is not contained in the package insert for either agent.
•
225
TECHNICAL NOTES
Vol. 117
An Afterloading Applicator for Intracavitary Vaginal Irradiation 1
Technical Notes
1 From the Department of Radiology, Division of Nuclear Medicine, Martin Luther King, Jr. General Hospital, 12021 South Wilmington Avenue, Los Angeles, Calif. 90059. Accepted for publication in May 1975. 2 Present address: Department of Radiology, Portland Adventist Hospital, 6040 S.E. Belmont, Portland, Ore. 97215. dk
• I
I
I
I
o
1
2
3
Scale (em)
C. C. Wang, M.D. An afterloadlng applicator for intracavitary vaginal irradiation that employs 137CS sources in a T-shaped irradiator is described.
A Therapeutic radiology, apparatus and equipment. Therapeutic radiology, interstitial and intracavitary INDEX TERMS:
Radiology 117:225, October 1975
•
•
An afterloading applicator employing T-shaped cesium-137 sources for vaginal irradiation for carcinoma of the uterus and currently in use at the Department of Radiation Medicine at the Massachusetts General Hospital is herein described. The applicator is made of a nylon cylinder into which two tunnels, each connected with stainless steel tubing, are carved (Fig. 1). The central tunnel can accommodate two 15-mg radium-equivalent 137CS slugs in tandem. (The physical and active lengths of each slug are 21 and 15 mm, respectively.) Between the central linear source and the surface of the applicator, a second tunnel which ends in a semicircular "well" is used to accommodate a third 15-mg radium-equivalent 137CS slug, hinged to a stiff wire (identical source for afterloading ovoid in treatment of carcinoma of the cervix). The third source can be made perpendicular to the central linear source at the end of the applicator, thus forming aT-shaped irradiator during intracavitary treatment. Detailed measurements of the applicator are shown in Figure 2. Figure 3 shows the isodose curves which were generated
Fig. 1. Photograph of the applicator (lid removed to show the groove and "well") and the cesium-137 dummy slugs and caps.
Fig. 2. Diagram of the applicator showing (A) the removable lid and screws and (B) the detailed structural measurements.
Scale (em)
[t Fig. 3. PC-12 computer-generated isodose curves in coronal (right) and sagittal (left) projections. Speckled area is the contour of the applicator.
on a PC-12 computer. Rounding off of radiations at the vaginal apex is achieved. Intracavitary implant procedure is carried out under local anesthesia and consists of insertion of a Foley catheter for drainage and the vaginal applicator which is held in place by a stitch in the vulva. After the patient has returned to the ward, cesium-137 sources are introduced into the applicator at the appropriate time. A dose of 4000-4500 rad in 45 hours to the mucous membrane of the entire vaginal tube is given for elective irradiation following total abdominal hysterectomy for Stage I, well-differentiated adenocarcinoma of the uterus. This has been found to be highly effective in reducing vaginal recurrences without radiation complications.
1 From the Department of Radiation Medicine, Massachusetts General Hospital, and the Department of Radiation Therapy, Harvard Medical School, Boston, Mass. 02114. Accepted for publication in May 1975. dk
