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How much could the radiotherapy dose be altered for individual patients based on a predictive assay of normal-tissue radiosensitivity?
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Vol. 21, No. 2, pp. 113-114, 1996 Association of Medical Dosimetrists Printed in the USA. All rights reserved 09X3947/96 $15.00 + .OO
0958-3947(96)00044-l
ELSEVIER
l
Medical Dosimetry, 0 1996 American
Selected Abstracts
From the journal Radiotherapy and Oncology Eighty-five bladder cancers were treated at the Urology Clinic of Nancy and the Centre Alexis Vautrin from 1975 to 1992 with short course preoperative radiation therapy (3 X 3.5 Gy ) , conservative surgery and brachytherapy by iridium192. The tumours were classified according to the 1979 UICC pTNM classification. There were 27 pT1, 3 1 pT2 and 22 pT3, two pT4 and three pTx. The pTl-pT2 cases received only one brachytherapy (50 Gy at least) after the short course preoperative irradiation. The pT3 cases received only 30 Gy of brachytherapy and an external irradiation boost (generally 40 Gy to the node areas and 30 Gy to the tumour, but the dose varied during the time course). Surgery was often preceded by an endoscopic resection consisting of a tumoral resection or a partial cystectomy according to the localisation. The plastic vector tubes were put into place at the time of partial cystectomy. Until 1983 the radioactive wires were loaded into the vector tubes on the day following surgery, thereafter it was done one week later. The 85 patients were classified into two groups: 63 patients who were untreated previously and 22 patients who had received one or more endoscopic resections for recurrences. The median follow-up was 84 months. The local controls at 5 years were 78% in the first group versus 56% in the second group (p = 0.005) with an overall survival of 73 and 65%, respectively. The local control did not vary according to the differentiation (grade l/2 vs. grade 3). The local control for pT1, pT2, pT3 was 85, 64 and 70% with a specific survival of 85, 76 and 72%, and an overall survival of 78, 66 and 66%. Among early complications, delay in healing of the bladder wall with subsequent vesico-cutaneous fistula depends mainly on the loading time of radioactive wires after surgery and is rare if the loading is delayed by one week. The late complications depend mostly on dosimetric factors. We found 24 grade 1, three grade 2, four grade 3 and one grade 4. The following factors are significant: the surface treated ( > 14 cm2), a distance between the sources of more than 2 cm and, especially. activity of the wires of more than 2 mCi/ cm (this factor was found in the five complications of grade 3 and 4)) the other factors were not significant in univariate analyses.
HOW MUCH COULD THE RADIOTHERAPY DOSE BE ALTERED FOR INDIVIDUAL PATIENTS BASED ON A PREDICTIVE ASSAY OF NORMAL-TISSUE RADIOSENSITIVITY? Susan L. Tucker,” Fady B. Geara,b Lester J. Peters,< William A. Brockd “Department of Biomathematics, Box 237, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA bDepartment of Radiotherapy, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA ‘Division of Radiation Oncology, Peter MacCallum Cancer Institute, Smorgon Family Bldg., St. Andrew’s Place, East Melbourne, Victoria 3002, Australia dDepartment of Experimental Radiotherapy, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd.. Houston, Texas 77030, USA Vol. 38. 1996 pp. 103-113 Key words: Normal tissue; Late reaction; Complication probability; Fibroblast radiosensitivity; Doseresponse; Predictive assay Predictive assays are presently being developed to identify the patients at highest risk for developing severe late normaltissue complications. If such patients could be identified prior to treatment, then the doses to those patients could be reduced to lower their complication rate. In addition, patients identified as being relatively radioresistant could receive higher doses without an increase in complications. The aim of the present study was to estimate the magnitude of the dose adjustments that could potentially be made if radiotherapy doses were tailored to the individual patient using a predictive assay of normal-tissue radiosensitivity. The dose adjustments were estimated by reanalyzing data from an earlier study [ 13 ] to determine the influence of dose and in vitro fibroblast radiosensitivity on the incidence of severe late normal-tissue complications. Although the dose estimates are preliminary and based on limited data, the results of this study support the concept that a significant therapeutic gain could be achieved for a subset of patients from the use of a predictive assay of normal-tissue radiosensitivity.
SSDI 0167-8140(95)01669-8
SSDI 0167-8140(95)01669-8 RADIATION MALIGNANT
COMBINED SURGERY AND BRACHYTHERAPY IN THE TREATMENT OF SOME CANCERS OF THE BLADDER (PARTIAL CYSTECTOMY AND INTERSTITIAL IRIDIUM- 192 ) M. Pemot,” J. Hubert,b F. Guillemin,” A. Six,” S. Hoffstetter.” D. Peiffert,” J. Verhaeghe,” E. Luporsi” “Centre Alexis Vautrin, 54511 Vandoeuvre les Nancy, Nancy Cedex, France bClinique Urologique (CHU), 545 11 Vandoeuvre les Nancy, Nancy Cedex, France Vol. 38, 1996. pp. 115-120 Key words: Bladder cancer; Surgery; Brachytherapy
THERAPY OF INTRACRANIAL MELANOMA
Olli-Pekka Isokangas. Timo Muhonen, Seppo Pyrhijnen Department of Oncology, Hospital, Haartmaninkatu
Mikael
Kajanti,
Helsinki University Central 4, FIN-00290 Helsinki, Finland
Vol. 38, 1996. pp. 139-144 Key words: Melanoma: Normalized Sixty-four melanoma 113
Brain involvement; Radiotherapy; total dose; (r/p ratio
consecutive patients with intracranial malignant were irradiated between January 1980-March
Vol. 21, No. 2, pp. 113-114, 1996 Association of Medical Dosimetrists Printed in the USA. All rights reserved 09X3947/96 $15.00 + .OO
0958-3947(96)00044-l
ELSEVIER
l
Medical Dosimetry, 0 1996 American
Selected Abstracts
From the journal Radiotherapy and Oncology Eighty-five bladder cancers were treated at the Urology Clinic of Nancy and the Centre Alexis Vautrin from 1975 to 1992 with short course preoperative radiation therapy (3 X 3.5 Gy ) , conservative surgery and brachytherapy by iridium192. The tumours were classified according to the 1979 UICC pTNM classification. There were 27 pT1, 3 1 pT2 and 22 pT3, two pT4 and three pTx. The pTl-pT2 cases received only one brachytherapy (50 Gy at least) after the short course preoperative irradiation. The pT3 cases received only 30 Gy of brachytherapy and an external irradiation boost (generally 40 Gy to the node areas and 30 Gy to the tumour, but the dose varied during the time course). Surgery was often preceded by an endoscopic resection consisting of a tumoral resection or a partial cystectomy according to the localisation. The plastic vector tubes were put into place at the time of partial cystectomy. Until 1983 the radioactive wires were loaded into the vector tubes on the day following surgery, thereafter it was done one week later. The 85 patients were classified into two groups: 63 patients who were untreated previously and 22 patients who had received one or more endoscopic resections for recurrences. The median follow-up was 84 months. The local controls at 5 years were 78% in the first group versus 56% in the second group (p = 0.005) with an overall survival of 73 and 65%, respectively. The local control did not vary according to the differentiation (grade l/2 vs. grade 3). The local control for pT1, pT2, pT3 was 85, 64 and 70% with a specific survival of 85, 76 and 72%, and an overall survival of 78, 66 and 66%. Among early complications, delay in healing of the bladder wall with subsequent vesico-cutaneous fistula depends mainly on the loading time of radioactive wires after surgery and is rare if the loading is delayed by one week. The late complications depend mostly on dosimetric factors. We found 24 grade 1, three grade 2, four grade 3 and one grade 4. The following factors are significant: the surface treated ( > 14 cm2), a distance between the sources of more than 2 cm and, especially. activity of the wires of more than 2 mCi/ cm (this factor was found in the five complications of grade 3 and 4)) the other factors were not significant in univariate analyses.
HOW MUCH COULD THE RADIOTHERAPY DOSE BE ALTERED FOR INDIVIDUAL PATIENTS BASED ON A PREDICTIVE ASSAY OF NORMAL-TISSUE RADIOSENSITIVITY? Susan L. Tucker,” Fady B. Geara,b Lester J. Peters,< William A. Brockd “Department of Biomathematics, Box 237, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA bDepartment of Radiotherapy, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA ‘Division of Radiation Oncology, Peter MacCallum Cancer Institute, Smorgon Family Bldg., St. Andrew’s Place, East Melbourne, Victoria 3002, Australia dDepartment of Experimental Radiotherapy, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd.. Houston, Texas 77030, USA Vol. 38. 1996 pp. 103-113 Key words: Normal tissue; Late reaction; Complication probability; Fibroblast radiosensitivity; Doseresponse; Predictive assay Predictive assays are presently being developed to identify the patients at highest risk for developing severe late normaltissue complications. If such patients could be identified prior to treatment, then the doses to those patients could be reduced to lower their complication rate. In addition, patients identified as being relatively radioresistant could receive higher doses without an increase in complications. The aim of the present study was to estimate the magnitude of the dose adjustments that could potentially be made if radiotherapy doses were tailored to the individual patient using a predictive assay of normal-tissue radiosensitivity. The dose adjustments were estimated by reanalyzing data from an earlier study [ 13 ] to determine the influence of dose and in vitro fibroblast radiosensitivity on the incidence of severe late normal-tissue complications. Although the dose estimates are preliminary and based on limited data, the results of this study support the concept that a significant therapeutic gain could be achieved for a subset of patients from the use of a predictive assay of normal-tissue radiosensitivity.
SSDI 0167-8140(95)01669-8
SSDI 0167-8140(95)01669-8 RADIATION MALIGNANT
COMBINED SURGERY AND BRACHYTHERAPY IN THE TREATMENT OF SOME CANCERS OF THE BLADDER (PARTIAL CYSTECTOMY AND INTERSTITIAL IRIDIUM- 192 ) M. Pemot,” J. Hubert,b F. Guillemin,” A. Six,” S. Hoffstetter.” D. Peiffert,” J. Verhaeghe,” E. Luporsi” “Centre Alexis Vautrin, 54511 Vandoeuvre les Nancy, Nancy Cedex, France bClinique Urologique (CHU), 545 11 Vandoeuvre les Nancy, Nancy Cedex, France Vol. 38, 1996. pp. 115-120 Key words: Bladder cancer; Surgery; Brachytherapy
THERAPY OF INTRACRANIAL MELANOMA
Olli-Pekka Isokangas. Timo Muhonen, Seppo Pyrhijnen Department of Oncology, Hospital, Haartmaninkatu
Mikael
Kajanti,
Helsinki University Central 4, FIN-00290 Helsinki, Finland
Vol. 38, 1996. pp. 139-144 Key words: Melanoma: Normalized Sixty-four melanoma 113
Brain involvement; Radiotherapy; total dose; (r/p ratio
consecutive patients with intracranial malignant were irradiated between January 1980-March