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Potential contribution of modulated proton beam therapy to radical irradiation of para-aortic lymph nodes
Radiation Oncology 0 Biology 0 Physics
1214
September 1981, Volume 7, Number 9
for different end-points. A special beam geometry fractions, utilizing a sector of 15 beams was selected for the first treatments of patients with metastatic skin nodules. Six patients Acute skin reactions were scored and compared wizh were treated. comparable beam geometry. those from orthovoltage therapy with The RBE for IO fractions is approximately 1.5. The next steo involved treatment of patients inside water-bolus rings in preparaThe special immobilization, potion for dynamic raster therapy. and verification procedures will be described. The sitioning, plans are to treat initially patients with bladder and recta? later to proceed to head and neck, brain and abdominal cancers, focussing on the problem of pancreatic and biliary tract tumors, carcinomas.
22
POTENTIAL CONTRIBUTIOH OF MODULATED PROTON BEAM THERAPY RADICAL IRRADIATION OF PARA-AORTIC LYMPH NODES
TO
Sten Grafman, M.D., Marcia Urie, Ph.D. Lynn J. Verhey, Ph.D., John E. Munzenrider, M.D. The Department
of Radiation Medicine, Harvard fledical School,
Massachusetts General Boston, MA 02114
Hospital
Tolerance of adjacent normal tissues, especially of spinal cord, small intestine and kidneys prevents delivery of doses required for control of macroscopic metastases of adeno- and squamous cell carcinoma in the paraaortic nodes (PAN) with conventional super-voltage photon techniques. Modulated proton beams have a finite range in tissue and deposit no energy in structures situated distal to that depth. A posterior proton beam could be made to stop at the anterior margin of the PAN target volume This study and thereby totally avoid irradiating all anterior structures. was undertaken to define the potential contribution such beams could make to radical irradiation of the PAN. The PAN volume was defined in 51 patients on serial CBT scans or on lymphangiograms with known magnification. Mean distances from posterior skin to the anterior margin of PAN target volume increased progressively from the T12 to the L5 level for both men and women, ranging from 14.6 to 16.4 cm in men and 12.8 to 15.3 cm in wcnnen. The 160 Mev proton beam of the Harvard Cyclotron has a range in tissue of 16 cm and could have treated the PAN target volume (T12-L4) in 58% of men and 93:: of women studied. A 200 Mev beam would have sufficient range to treat all patients studied. CT sections at the levels of T12, L2, and L4 in a cervix cancer patient were used to calculate dose distributions for 4 treatment techniques: AP-PA and right and left lateral 16 WV x-rays, PA and right and left lateral xrays, AP-PA 160 Mev protons, and PA protons and right and left lateral xThe PAN volume was calculated to receive 60 Gy, and spinal cord dose rays. was limited to 46 Gy. Total volume integral doses were 23.3 and 22.1 kg. Gy for the x-ray plans and 13.3 and 14.3 for the 2-field p and for the 3-field X + p plans, respectively. Greater portions of stomach, gut, liver and kidneys received higher doses with the x-ray plans than with either of the proton plans. It was concluded that 60 Gy could be safely delivered to the PAN volume in that patient with either of the proton plans without exceeding tolerance of any of the normal structures studied. Small intestine tolerance would have been approached or exceeded with both x-ray only plans. Two patients with squamous cell cervical cancer metastatic to the PAN were treated to that volume with the 3-field X + p plan,receiving doses of 65 Gy (TDF 101) and 66 Gy (TDF 103), respectively. Both patients received concurrent pelvic irradiation with 25 MV x-rays. Clinical tolerance to the treatment was excellent, and both patients remain free of evident disease or of treatment-related complications 3 and 10 mo. after treatment. Representative dose distributions and area1 plots of doses structures will be presented. Follow up data on the 2 patients date will also be presented.
to normal treated to
1214
September 1981, Volume 7, Number 9
for different end-points. A special beam geometry fractions, utilizing a sector of 15 beams was selected for the first treatments of patients with metastatic skin nodules. Six patients Acute skin reactions were scored and compared wizh were treated. comparable beam geometry. those from orthovoltage therapy with The RBE for IO fractions is approximately 1.5. The next steo involved treatment of patients inside water-bolus rings in preparaThe special immobilization, potion for dynamic raster therapy. and verification procedures will be described. The sitioning, plans are to treat initially patients with bladder and recta? later to proceed to head and neck, brain and abdominal cancers, focussing on the problem of pancreatic and biliary tract tumors, carcinomas.
22
POTENTIAL CONTRIBUTIOH OF MODULATED PROTON BEAM THERAPY RADICAL IRRADIATION OF PARA-AORTIC LYMPH NODES
TO
Sten Grafman, M.D., Marcia Urie, Ph.D. Lynn J. Verhey, Ph.D., John E. Munzenrider, M.D. The Department
of Radiation Medicine, Harvard fledical School,
Massachusetts General Boston, MA 02114
Hospital
Tolerance of adjacent normal tissues, especially of spinal cord, small intestine and kidneys prevents delivery of doses required for control of macroscopic metastases of adeno- and squamous cell carcinoma in the paraaortic nodes (PAN) with conventional super-voltage photon techniques. Modulated proton beams have a finite range in tissue and deposit no energy in structures situated distal to that depth. A posterior proton beam could be made to stop at the anterior margin of the PAN target volume This study and thereby totally avoid irradiating all anterior structures. was undertaken to define the potential contribution such beams could make to radical irradiation of the PAN. The PAN volume was defined in 51 patients on serial CBT scans or on lymphangiograms with known magnification. Mean distances from posterior skin to the anterior margin of PAN target volume increased progressively from the T12 to the L5 level for both men and women, ranging from 14.6 to 16.4 cm in men and 12.8 to 15.3 cm in wcnnen. The 160 Mev proton beam of the Harvard Cyclotron has a range in tissue of 16 cm and could have treated the PAN target volume (T12-L4) in 58% of men and 93:: of women studied. A 200 Mev beam would have sufficient range to treat all patients studied. CT sections at the levels of T12, L2, and L4 in a cervix cancer patient were used to calculate dose distributions for 4 treatment techniques: AP-PA and right and left lateral 16 WV x-rays, PA and right and left lateral xrays, AP-PA 160 Mev protons, and PA protons and right and left lateral xThe PAN volume was calculated to receive 60 Gy, and spinal cord dose rays. was limited to 46 Gy. Total volume integral doses were 23.3 and 22.1 kg. Gy for the x-ray plans and 13.3 and 14.3 for the 2-field p and for the 3-field X + p plans, respectively. Greater portions of stomach, gut, liver and kidneys received higher doses with the x-ray plans than with either of the proton plans. It was concluded that 60 Gy could be safely delivered to the PAN volume in that patient with either of the proton plans without exceeding tolerance of any of the normal structures studied. Small intestine tolerance would have been approached or exceeded with both x-ray only plans. Two patients with squamous cell cervical cancer metastatic to the PAN were treated to that volume with the 3-field X + p plan,receiving doses of 65 Gy (TDF 101) and 66 Gy (TDF 103), respectively. Both patients received concurrent pelvic irradiation with 25 MV x-rays. Clinical tolerance to the treatment was excellent, and both patients remain free of evident disease or of treatment-related complications 3 and 10 mo. after treatment. Representative dose distributions and area1 plots of doses structures will be presented. Follow up data on the 2 patients date will also be presented.
to normal treated to