738
June 1975
TECHNICAL NOTES
mucosa of the nasal septum and turbinates is shrunk by topical application of cocaine. The afterloading applicator is introduced easily via the nares to the nasopharynx. Under fluoroscopic control, the position of the endotracheal tubes and dummy slugs is adjusted to the desired position. The cuffs are inflated with 3-5 ml of Renografin for proper radiographic identification and anchoring of the position of the tips of the tube. Overdistension may cause rotation of the cuffs. The applicators are then fastened with tape to the tip of the nose and upper lip. The separation of the sources from the nasopharyngeal wall has been found to be reliably and consistently maintained by the inflated cuffs; thus, the risk of overdosing or underdosing the adjacent structures can be minimized. The procedure is generally well tolerated and can be conveniently carried out in the simulator-treatment planning room. After
A New Calculator for Radiotherapy Treatment Planning'
•
William L. Saylor, M.S. Comparison of speed and costs of the programmable desk calculator and the minicomputer reveals that although the desk calculator is slower. most operations are simple dose and treatment time calculations in which the turnaround time is essentially immediate. Assuming a five-year equipment capitalization of the initial $24,000 cost and $1,700 per annum maintenance charge with a workload of 800 plans per year, the cost per plan is about $8.00. This does not include programmer salaries. INDEX TERMS: Computers. Dosimetry, therapeutic • Therapeutic Radiology, treatment planning
Radiology 115:738. June 1975
In a recent article in this journal, Fenn et al. (1) presented an excellent discussion ot the relative merits of four existing systems for computer-assisted radiation therapy treatment planning; telecopier, batch-processlnq, time-Sharing on a full scale computer, and a minicomputer. The purpose of this note is to bring to the attention of the radiology community a fifth system, the programmable desk calculator. One such system, manufactured by Hewlett-Packard Corporation, has been adapted to treatment planning and is in routine use at our institution. The system consists of an BK word calculator with magnetic tape storage, a high-speed line printer, an X-V plotter, and graphical (digitizer) input device. The calculator is programmable in BASIC. Software has been developed to input and plot brachytherapy plans using BRACHY I [a program quite similar to RADCOMP II (2)], teletherapy plans using SUM, irregular and "mantle" field plans using IRREG (3), and other simpler dosage calculations. When compared with the minicomputer, the calculator has the disadvantage of slower speed. This is not a problem for the majority of our calculations, which involve simple dose and treatment time calculations for x-ray, gamma-ray, and
the patient has been returned to the ward, cesium slugs are introduced into the applicators for intracavitary irradiation. 1 From the Department of Radiation Medicine, Massachusetts General Hospital, Boston, Mass., and the Department of Radiation Therapy, Harvard Medical School, Boston, Mass. Accepted for publication in December 1974. 2 Associate Professor of Radiation Therapy, Harvard Medical School, and Radiotherapist and Head, Division of Clinical Services, Department of Radiation Medicine, Massachusetts General Hospital, Boston, Mass. 02114. 3 Instructor in Radiation Therapy, Harvard Medical School, and Clinical Fellow, Department of Radiation Medicine, Massachusetts General Hospital. 4 Associate in Radiation Therapy, Harvard Medical School and Assistant in Physics, Department of Radiation Medicine, Massachusetts General Hospital. 5 National Catheter Corp., Argyle, New York 12809. shan
electron beams, gap calculations, etc. The turn-around time for these programs is essentially immediate. However the turn-around time for a "mantle" field calculation using IRREG is about 5 minutes, since the processing time in the calculator is about 3 minutes for a program of this complexity. The turnaround time (input to plot) for two wedged beams is about 30 minutes. The turn-around time for an implant of six needles in a 9 X 9-cm grid using· BRACHY is about 44 minutes: 4 minutes for input, 30 minutes for processing, and 10 minutes spent in plotting the isodose curves. A significant advantage of the calculator over the minicomputer is the cost. The calculator system, including all necessary hardware and software, is $24,000, and the maintenance contract is $1,700 per annum. Therefore, assuming a five-year equipment capitalization, and a workload of BOO plans per year, the cost per plan is about $8.00, half the perplan cost cited for the minicomputer. In the event the user wishes to reduce the turn-around time for the more complex programs, for about $1,000 the calculator can be configured as an input-output device to a remote full-scale computer. In this case, the cost per plan, using our university computer rate, would be approximately $10.50. REFERENCES 1. Fenn JO, Wallace KM, Frey GD, et al: A comparison of large and small computers for radiation therapy treatment planning. Radiology 113:429-433, Nov 1974 2. Batten GW Jr: The M.D. Anderson method for computation of isodose curves around interstitial and intracavitary radiation sources. II. Mathematical and computational sources. Am J RoentgenoI102:673-676, Mar 1968 3. Cunningham JR, Shrivastava PN, Wilkerson JM: Program IRREG-calculation of dose from irregularly shaped radiation beams. Comp Prog Biomed 2:192-199, Mar 1972
1 From the Department of Radiology (W. L. S., Assistant Professor), University of North Carolina School of Medicine, Chapel Hill, N. C. 27514. Accepted for publication in December 1974. shan
June 1975
TECHNICAL NOTES
mucosa of the nasal septum and turbinates is shrunk by topical application of cocaine. The afterloading applicator is introduced easily via the nares to the nasopharynx. Under fluoroscopic control, the position of the endotracheal tubes and dummy slugs is adjusted to the desired position. The cuffs are inflated with 3-5 ml of Renografin for proper radiographic identification and anchoring of the position of the tips of the tube. Overdistension may cause rotation of the cuffs. The applicators are then fastened with tape to the tip of the nose and upper lip. The separation of the sources from the nasopharyngeal wall has been found to be reliably and consistently maintained by the inflated cuffs; thus, the risk of overdosing or underdosing the adjacent structures can be minimized. The procedure is generally well tolerated and can be conveniently carried out in the simulator-treatment planning room. After
A New Calculator for Radiotherapy Treatment Planning'
•
William L. Saylor, M.S. Comparison of speed and costs of the programmable desk calculator and the minicomputer reveals that although the desk calculator is slower. most operations are simple dose and treatment time calculations in which the turnaround time is essentially immediate. Assuming a five-year equipment capitalization of the initial $24,000 cost and $1,700 per annum maintenance charge with a workload of 800 plans per year, the cost per plan is about $8.00. This does not include programmer salaries. INDEX TERMS: Computers. Dosimetry, therapeutic • Therapeutic Radiology, treatment planning
Radiology 115:738. June 1975
In a recent article in this journal, Fenn et al. (1) presented an excellent discussion ot the relative merits of four existing systems for computer-assisted radiation therapy treatment planning; telecopier, batch-processlnq, time-Sharing on a full scale computer, and a minicomputer. The purpose of this note is to bring to the attention of the radiology community a fifth system, the programmable desk calculator. One such system, manufactured by Hewlett-Packard Corporation, has been adapted to treatment planning and is in routine use at our institution. The system consists of an BK word calculator with magnetic tape storage, a high-speed line printer, an X-V plotter, and graphical (digitizer) input device. The calculator is programmable in BASIC. Software has been developed to input and plot brachytherapy plans using BRACHY I [a program quite similar to RADCOMP II (2)], teletherapy plans using SUM, irregular and "mantle" field plans using IRREG (3), and other simpler dosage calculations. When compared with the minicomputer, the calculator has the disadvantage of slower speed. This is not a problem for the majority of our calculations, which involve simple dose and treatment time calculations for x-ray, gamma-ray, and
the patient has been returned to the ward, cesium slugs are introduced into the applicators for intracavitary irradiation. 1 From the Department of Radiation Medicine, Massachusetts General Hospital, Boston, Mass., and the Department of Radiation Therapy, Harvard Medical School, Boston, Mass. Accepted for publication in December 1974. 2 Associate Professor of Radiation Therapy, Harvard Medical School, and Radiotherapist and Head, Division of Clinical Services, Department of Radiation Medicine, Massachusetts General Hospital, Boston, Mass. 02114. 3 Instructor in Radiation Therapy, Harvard Medical School, and Clinical Fellow, Department of Radiation Medicine, Massachusetts General Hospital. 4 Associate in Radiation Therapy, Harvard Medical School and Assistant in Physics, Department of Radiation Medicine, Massachusetts General Hospital. 5 National Catheter Corp., Argyle, New York 12809. shan
electron beams, gap calculations, etc. The turn-around time for these programs is essentially immediate. However the turn-around time for a "mantle" field calculation using IRREG is about 5 minutes, since the processing time in the calculator is about 3 minutes for a program of this complexity. The turnaround time (input to plot) for two wedged beams is about 30 minutes. The turn-around time for an implant of six needles in a 9 X 9-cm grid using· BRACHY is about 44 minutes: 4 minutes for input, 30 minutes for processing, and 10 minutes spent in plotting the isodose curves. A significant advantage of the calculator over the minicomputer is the cost. The calculator system, including all necessary hardware and software, is $24,000, and the maintenance contract is $1,700 per annum. Therefore, assuming a five-year equipment capitalization, and a workload of BOO plans per year, the cost per plan is about $8.00, half the perplan cost cited for the minicomputer. In the event the user wishes to reduce the turn-around time for the more complex programs, for about $1,000 the calculator can be configured as an input-output device to a remote full-scale computer. In this case, the cost per plan, using our university computer rate, would be approximately $10.50. REFERENCES 1. Fenn JO, Wallace KM, Frey GD, et al: A comparison of large and small computers for radiation therapy treatment planning. Radiology 113:429-433, Nov 1974 2. Batten GW Jr: The M.D. Anderson method for computation of isodose curves around interstitial and intracavitary radiation sources. II. Mathematical and computational sources. Am J RoentgenoI102:673-676, Mar 1968 3. Cunningham JR, Shrivastava PN, Wilkerson JM: Program IRREG-calculation of dose from irregularly shaped radiation beams. Comp Prog Biomed 2:192-199, Mar 1972
1 From the Department of Radiology (W. L. S., Assistant Professor), University of North Carolina School of Medicine, Chapel Hill, N. C. 27514. Accepted for publication in December 1974. shan
