- Email: [email protected]
130 Interstitial radiotherapy in the treatment of cancer of the base of tongue
the insert contained ten grooves at a 36 ° angular interval that accepted the Gamma-Med plastic interstitial catheters. The second design presented a hollow plastic tube with a shape and outer diameter similar to the Shiely tracheostomy tube. Ten channels, at a 36 ° angular interval, were drilled in the applicator wall. Each channel ended with a "quick" connector. Plastic catheters (first design) or selected "active" channels (second design) were connected to the Gamma-Med source head using appropriate source guide tubes. The catheters placement (first design) or "active" channels selection (second design) were determined by a treatment planning computer (CMS, Inc). Calculation of the source motion parameters was the same for the both designs. When an applicator of the first design was used, the patient set-up started with the placement of the Shiely tracheostomy tube into the stoma. The hollow insert was then placed into the tube and the plastic catheters were placed into the grooves determined by the treatment plan. When the applicator of the second design was used, the patient set-up consisted only of insertion of the applicator into the tracheastoma. Results: A uniform dose distribution at the prescribed depth and an adequate sparing of the intact stoma surface was achieved when the distance between the peripheral catheters (or "active" channels) to the next catheter (or "active" channel) was twice the distance between intermediate catheters ("active" channels). Dose on the tracheastoma intact surface was 3 times less than dose on the tumor surface. Conclusions: The developed applicators provided adequate HDR brachytherapy of tracheastoma recurrences. The second design, although being more difficult to fabricate, is cfinically more convenient than the first design. A modified second design that includes adjustable shields may be used for conformal intraluminal brachytherapy of other organs. 129 ANALYSIS OF MAJOR COMPLICATIONSIN GUIDE GUTTER TECHNIQUEFOR EARLY ORAL TONGUEAND FLOOR OF THE MOUTH NEOPLASMS. A VOLUME STUDY.
Rovirosa A., Hernandez V., Osorio J.L.; Sanchez-Reyes A.; Bascon N.; Gtiell J.; Navalpotro B., Ldon C.; Arenas M., Verger E.; Biete A. Radiation Oncology Department, Hospital Clinic I Universitari, Barcelona, Spain Purpose: From September 1988 to December 1998 the records of patients treated by guide gutter (GG) technique and Paris system rules at Hospital Clinic of Barcelona were reviewed. Patients had T1-T2 neoplasm of mobile tongue or floor of the mouth. The goal of this study was to analyze retrospectively the major complications with GG technique relating them with the volume of the implant. Patients and methods: Forty-four patients with ages between 42 and 89 years (mean of 60 years), 33 males and 11 females. Thirty-three had a mobile tongue carcinoma and 9 a floor of the mouth carcinoma. Patients were staged as 29 T1N0, 13 T2N0 and 2 T2N 1. Treatment: Brachytherapy (BT) alone: 34 patients (dose ranged between 55 Gy and 72 Gy). BT plus external beam irradiation (EBI) in 10 cases (BT 30 Gy and EB140 Gy). LDR sources of Iridium 192 and energies from 6 MV Linac or Co60 were used. Surgery was performed for persistence or relapses. All the dosimetric records were re-evaluated using a software developed at Hospital Clinic. Volume of implants has been calculated by using the Slicer program. The volume of 65 Gy was determined in all the cases. Results: Mean-follow-up: 54 months (12-122). Specific overall survival: 85% at 2 years and 82% at 5 years. Local control was obtained in 95.6% of cases. Major complications related to treatment appeared in 3/10 (33%) if treatment was BT+EBI and in 4/34 (12%) if treatment was BT alone. They were the 10% in T1 cases (3/29) and the 26% in T2 cases (4/15). When 4 GG were used the rate of complications was 33% (4/12), but 9% (3/32) in the cases 2 or 3 GG. Volume 65 Gy: mean of 10cc, median 7.6cc and the range were between 2cc and 28cc. Volume 65 Gy in cases with complications: 1) BT alone: mean of 10.1cc, median 10.2cc and range between 6.1cc and 17cc. 2) BT+EBI: mean 15.6cc, median 12.2cc and range between 6.5cc and 28cc. Conclusions: In the present series, a higher incidence of major complications in GG technique was found when the implant volume was increased. 130 INTERSTITIALRADIOTHERAPYIN THE TREATMENTOF CANCEROF THE BASEOF TONGUE Zoltan Takacsi-Nagy, Ference Oberna, Csaba Polgar, Andras Somogyi, Tibor Major, GyOrgy NEmeth Department of Radiotherapy, National Institute of Oncology, Hungary, Budapest Purpose: The aim of this retrospective study was to present our six-year experience with interstitial therapy of the tumors of the base of the tongue and to introduce our treatment strategy, technique and results. Material and methods: Between January 1993 and May 1999 twenty-one patients with primary squamous cell cancer of the base of tongue (T13N0-2) were treated by interstitial radiotherapy (RT). 17 patients with advanced stage cancer received brachytherapy (BT) boost after 60-66 Gy teletherapy and 4 patients with early stage (T1-2N0) were managed by sole BT after tumour excision and elective neck node dissection in case of positive or very narrow margins. High-dose rate (HDR) afterqoading (ir-192) unit was used with rigid needles or flexible plastic tubes. The treatment plan was performed by PLATO 3D BT planning system. The mean dose of boost BT or sole BT was 20 Gy (12-24 Gy) and 27 Gy (24-30 Gy), respectively. All treatments were delivered on consecutive days with a twice-a-day fractionation schedule, except the rigid needle technique (n=4), where the dose was 12 Gy with a single fraction. Results: After definitive RT of advanced stage disease the rate of complete or partial remission was 65% (11/17) and 35% (6/17), respectively. At a mean follow-up time of 32 months the local tumor control for the entire patient population was 57% (12/21). Five patients (24%) died of local and/or regional failure and sixteen patients (76%) are alive (six with local and/or regional disease and 10 no evidence of disease). All of the four sole BT treated patients belong to the best group. The incidence of grade 2 or grade 3 mucositis was 48% and 52%, respectively. Conclusions: To achieve good local control with adequate doses, avoiding surgical morbidity and associated functional loss to the patients, and to minimize late radiation sequelae the combination of percutan and interstitial RT seems to be very advantageous in the treatment of the advanced tumour of the base of tongue. For patients with early stage cancer sole postoperative BT of the tumour bed - by positive or very narrow margins seems to be a feasible option. However, more patients and longer follow-up is required to define the value of sole BT.
69
Rovirosa A., Hernandez V., Osorio J.L.; Sanchez-Reyes A.; Bascon N.; Gtiell J.; Navalpotro B., Ldon C.; Arenas M., Verger E.; Biete A. Radiation Oncology Department, Hospital Clinic I Universitari, Barcelona, Spain Purpose: From September 1988 to December 1998 the records of patients treated by guide gutter (GG) technique and Paris system rules at Hospital Clinic of Barcelona were reviewed. Patients had T1-T2 neoplasm of mobile tongue or floor of the mouth. The goal of this study was to analyze retrospectively the major complications with GG technique relating them with the volume of the implant. Patients and methods: Forty-four patients with ages between 42 and 89 years (mean of 60 years), 33 males and 11 females. Thirty-three had a mobile tongue carcinoma and 9 a floor of the mouth carcinoma. Patients were staged as 29 T1N0, 13 T2N0 and 2 T2N 1. Treatment: Brachytherapy (BT) alone: 34 patients (dose ranged between 55 Gy and 72 Gy). BT plus external beam irradiation (EBI) in 10 cases (BT 30 Gy and EB140 Gy). LDR sources of Iridium 192 and energies from 6 MV Linac or Co60 were used. Surgery was performed for persistence or relapses. All the dosimetric records were re-evaluated using a software developed at Hospital Clinic. Volume of implants has been calculated by using the Slicer program. The volume of 65 Gy was determined in all the cases. Results: Mean-follow-up: 54 months (12-122). Specific overall survival: 85% at 2 years and 82% at 5 years. Local control was obtained in 95.6% of cases. Major complications related to treatment appeared in 3/10 (33%) if treatment was BT+EBI and in 4/34 (12%) if treatment was BT alone. They were the 10% in T1 cases (3/29) and the 26% in T2 cases (4/15). When 4 GG were used the rate of complications was 33% (4/12), but 9% (3/32) in the cases 2 or 3 GG. Volume 65 Gy: mean of 10cc, median 7.6cc and the range were between 2cc and 28cc. Volume 65 Gy in cases with complications: 1) BT alone: mean of 10.1cc, median 10.2cc and range between 6.1cc and 17cc. 2) BT+EBI: mean 15.6cc, median 12.2cc and range between 6.5cc and 28cc. Conclusions: In the present series, a higher incidence of major complications in GG technique was found when the implant volume was increased. 130 INTERSTITIALRADIOTHERAPYIN THE TREATMENTOF CANCEROF THE BASEOF TONGUE Zoltan Takacsi-Nagy, Ference Oberna, Csaba Polgar, Andras Somogyi, Tibor Major, GyOrgy NEmeth Department of Radiotherapy, National Institute of Oncology, Hungary, Budapest Purpose: The aim of this retrospective study was to present our six-year experience with interstitial therapy of the tumors of the base of the tongue and to introduce our treatment strategy, technique and results. Material and methods: Between January 1993 and May 1999 twenty-one patients with primary squamous cell cancer of the base of tongue (T13N0-2) were treated by interstitial radiotherapy (RT). 17 patients with advanced stage cancer received brachytherapy (BT) boost after 60-66 Gy teletherapy and 4 patients with early stage (T1-2N0) were managed by sole BT after tumour excision and elective neck node dissection in case of positive or very narrow margins. High-dose rate (HDR) afterqoading (ir-192) unit was used with rigid needles or flexible plastic tubes. The treatment plan was performed by PLATO 3D BT planning system. The mean dose of boost BT or sole BT was 20 Gy (12-24 Gy) and 27 Gy (24-30 Gy), respectively. All treatments were delivered on consecutive days with a twice-a-day fractionation schedule, except the rigid needle technique (n=4), where the dose was 12 Gy with a single fraction. Results: After definitive RT of advanced stage disease the rate of complete or partial remission was 65% (11/17) and 35% (6/17), respectively. At a mean follow-up time of 32 months the local tumor control for the entire patient population was 57% (12/21). Five patients (24%) died of local and/or regional failure and sixteen patients (76%) are alive (six with local and/or regional disease and 10 no evidence of disease). All of the four sole BT treated patients belong to the best group. The incidence of grade 2 or grade 3 mucositis was 48% and 52%, respectively. Conclusions: To achieve good local control with adequate doses, avoiding surgical morbidity and associated functional loss to the patients, and to minimize late radiation sequelae the combination of percutan and interstitial RT seems to be very advantageous in the treatment of the advanced tumour of the base of tongue. For patients with early stage cancer sole postoperative BT of the tumour bed - by positive or very narrow margins seems to be a feasible option. However, more patients and longer follow-up is required to define the value of sole BT.
69