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373 poster Interstitial high dose rate radiotherapy of cancer of the base of tongue
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Conclusions: Concurrent cisplatin-radiaition therapy in locally advanced head and neck cancers showed high response rate, resonable Iocoregional control and survMal rate. As expected, acute toxicities were increased, but compliance to treatment was acceptable. Assessment of the effect of the combination in this setting requires further accrual and follow-up. 373
poster
Interstitial high dose rate radiotherapy of cancer of the base of tongue Z. Tak~csi-Nagy 1, F. Obema 2, C. Polg~r 1, A. Somogyi 1, T. Major 1, G. N6meth 1 1National Institute of Oncology, Radiotherapy, Budapest, Hungary 2National Institute of Oncology, Head and Neck Surgery, Budapest, Hungary Purpose: The aim of this retrospective study was to present our six-year experience with interstitial radiotherapy of the tumours of the base of the tongue and to introduce our treatment strategy, technique and results. Material and methods: Between January 1993 and May I999 twenty-one patients with primary squamous cell cancer of the base of tongue (T1-4N02) 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) after-loading (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 mucosit~s was 48 % and 52 %, respectively. Conclusions: To achieve good local control avoiding the surgical morbidity 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 (T12N0) 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. 374
poster
A neural network approach to modelling cancer survival S. Abdul Kareem 1, S. Baba 1, Y. Zubairi2, I. Abdul Wahid3 I University Of Malaya, FCSIT, Kuala Lumpur, Malaysia 2University Of Malaya, IMS, Kuala Lumpur, Malaysia 3University Of Malaya, Clinical Oncology, FOM, Kuala Lumpur, Malaysia Survival data are traditionally analysed using statistical models such as the life-table, the Kaplan-Meier method and regression models such as the Cox Proportional Hazard. However, these methods are usually used to explain the data and to model the progression of the disease rather than to make survival predictions for populations or individual patients. Recently experiments have been performed on using alternative methods for the analysis of survival data on a variety of diseases. One of these methods is the use of artificial neural network technology. Artificial neural networks have been used in medicine since the 1980s, initially as an aid to diagnosis and treatment, and lately as a tool for the analysis of survival data. An artificial neural network is an information processing system that tries to simulate biological neural networks. It consists of simple processing elements called neurons connected through directed communication links. The main advantage of neural network technology is that the internal representation and distribution of data need not be known. Although neural network has not been tested extensively for modelling survival data, it is considered a good alternative for the prediction of survival of individual patients and it offers no obstacle to handling censored data. Artificial neural network have been used in medical prognosis in areas such as breast cancer, non-small cell lung carcinoma and colon cancer. The tumour model we have chosen for our study is nasopharyngeal cancer since its occurrence is high in Malaysia especially among the Chinese population. The dataset collected from 1969 to 1996 in the University Hos-
pital, Kuala Lumpur was used to investigate this approach of modelling outcome and prognosis. To date the results obtained from this study has been encouraging. 375
poster
Concurrent chemo-radiotherapy in the consevation management of locally advanced laryngeal carcinoma. A. Badib, M. Sherif, E. EI-Nashar Faculty of medicine, Clinical Oncology, Alexandria, Egypt Purpose:To assess the efficacy of concurrent chemoradiotherapy in the conservation management of locally advanced laryngeal carcinoma. Methods:Thirty patients with T3-4, N0-3, M0 biopsy proven carcinoma of the larynx were treated with concurrent chemoradiotherapy using 5-Fluorouracil continuous i.v. infusion 1000 mg/m 2 for 3 days+Cisplatin i.v. bolus injection 100 mg/m 2 on days 1,22 and 43 starting day 1 of radiotherapy. Radiation dose was given:45 Gy/4.5 weeks to the primary and neck nodes+boost to the primary to reach total dose of 70 Gy. Results:The median disease-free surviva I(DFS) 10.7 months and the overall survival (OS) was 20 months.14 patients (46.7%)achieved complete response with laryngeal preservation in 66.7%.Tumuor and nodal stages were significant prognostic factors. The 2 year DF$ and OS ratas for patients with retained larynges were 80% and 90% compared to 50% and 77% respectively for patients who underwent surgery. Most of treament toxicities were grades 1&2 and non developed grade 4 toxicities. Conclusions:Concurrent chemoradiotherapy was well tolerated with high response rates and organ preservation without compromising overall survival in our patients with locally advanced laryngeal carcinoma. 376
poster
Physiological sensitization by unequal size fractions : conclusion from palliative radiotherapy of advanced head and neck (H&N) ca by radiotherapy, P.K. Mohanta MAMC , R. T., New Delhi, India Purpose: About one third of our stage-IV H&N Ca pts don't receive any active treatment. Those treated by conventional RT show poor outcome. To improve palliation a modification of RT was done taking into consideration clinical,logistic and radiobiological factors. Method: Three/four fraction(fr)/Week(wk) were delivered to the tumor in an increasing fr size of 130, 180, 360, 540/720 cGy on day 1, 2, 3... resulting in cumulative dose of 7-14 Gy/wk. As fr size increased portal size was decreased.After a gap of 2-4 wks response was assessed and if found satisfactory the said course was repeated and so on. The machine was Th780. From Jan 98 to Jun 98 total 50 pts (H.P.proven) were treated with palliative intent after informed consent. Age ranged between 30-75 yrs. There were six females. Primary sites were Oropharynx-21, Oral cavity-9, PUO (neck node)-8, Larynx-7, Others-5. Nine pts had relapse/residual disease. Results: Total 42/50 pts completed RT. Tumor dose(TD)ranged between 14-56 Gy/4-16 fr/1-15wks. Till May 2000 maximum FU was 28 months. Compared to a stage and age matched historical control (conventional RT & or CT) CR improved from 14% to 48%. Median survival improved from 3 months to 7 months (p=0.01). Morbidity was acceptable. Conclusions: Large tumor is rendered radio-incurable conventionally due to hypoxic and G l S phase ceils. Analysis of cell survival curves show resistance is not absolute but is sensitive at higher dose (fr size)level. Physiological sensitization was suggested by using few large fractions. Limited sucess was achieved but at the cost of unacceptable morbidity. The present modification avoided the same by using low total dose, fewer large fractions to a smaller volume over protracted overall time. In the present study there is three4old increase in CR at less than half total dose implying TRUE physiological sensitization. 377
poster
IS high dose preoperative hyperfractionated accelerated radiotherapy feasible in the treatment of advanced head and neck squamous cell carcinoma ? R. Valavaara 1, K. Aitasalo2, J. Kulmala 1, P. Lindhold 1, H. Minn 1, J. Suonp~&2 j. Laine 3, R. Grenman 2, E. Nordman 1, S. PyrhOnen 1 I University Hospital of Turku, Finland, Department of Radiotherapy and O ncology, 2Department of Otorhinolaryngology, 3Department of Dentistry Purpose: to evaluate the feasibility of high dose hyperfractionated radiotherapy (RT) administered before sophisticated radical surgery. A single institution study. Methods: 73 patients with squamous cell carcinoma in the head and neck region were treated with hyperfractionated, accelerated, split course RT
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Conclusions: Concurrent cisplatin-radiaition therapy in locally advanced head and neck cancers showed high response rate, resonable Iocoregional control and survMal rate. As expected, acute toxicities were increased, but compliance to treatment was acceptable. Assessment of the effect of the combination in this setting requires further accrual and follow-up. 373
poster
Interstitial high dose rate radiotherapy of cancer of the base of tongue Z. Tak~csi-Nagy 1, F. Obema 2, C. Polg~r 1, A. Somogyi 1, T. Major 1, G. N6meth 1 1National Institute of Oncology, Radiotherapy, Budapest, Hungary 2National Institute of Oncology, Head and Neck Surgery, Budapest, Hungary Purpose: The aim of this retrospective study was to present our six-year experience with interstitial radiotherapy of the tumours of the base of the tongue and to introduce our treatment strategy, technique and results. Material and methods: Between January 1993 and May I999 twenty-one patients with primary squamous cell cancer of the base of tongue (T1-4N02) 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) after-loading (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 mucosit~s was 48 % and 52 %, respectively. Conclusions: To achieve good local control avoiding the surgical morbidity 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 (T12N0) 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. 374
poster
A neural network approach to modelling cancer survival S. Abdul Kareem 1, S. Baba 1, Y. Zubairi2, I. Abdul Wahid3 I University Of Malaya, FCSIT, Kuala Lumpur, Malaysia 2University Of Malaya, IMS, Kuala Lumpur, Malaysia 3University Of Malaya, Clinical Oncology, FOM, Kuala Lumpur, Malaysia Survival data are traditionally analysed using statistical models such as the life-table, the Kaplan-Meier method and regression models such as the Cox Proportional Hazard. However, these methods are usually used to explain the data and to model the progression of the disease rather than to make survival predictions for populations or individual patients. Recently experiments have been performed on using alternative methods for the analysis of survival data on a variety of diseases. One of these methods is the use of artificial neural network technology. Artificial neural networks have been used in medicine since the 1980s, initially as an aid to diagnosis and treatment, and lately as a tool for the analysis of survival data. An artificial neural network is an information processing system that tries to simulate biological neural networks. It consists of simple processing elements called neurons connected through directed communication links. The main advantage of neural network technology is that the internal representation and distribution of data need not be known. Although neural network has not been tested extensively for modelling survival data, it is considered a good alternative for the prediction of survival of individual patients and it offers no obstacle to handling censored data. Artificial neural network have been used in medical prognosis in areas such as breast cancer, non-small cell lung carcinoma and colon cancer. The tumour model we have chosen for our study is nasopharyngeal cancer since its occurrence is high in Malaysia especially among the Chinese population. The dataset collected from 1969 to 1996 in the University Hos-
pital, Kuala Lumpur was used to investigate this approach of modelling outcome and prognosis. To date the results obtained from this study has been encouraging. 375
poster
Concurrent chemo-radiotherapy in the consevation management of locally advanced laryngeal carcinoma. A. Badib, M. Sherif, E. EI-Nashar Faculty of medicine, Clinical Oncology, Alexandria, Egypt Purpose:To assess the efficacy of concurrent chemoradiotherapy in the conservation management of locally advanced laryngeal carcinoma. Methods:Thirty patients with T3-4, N0-3, M0 biopsy proven carcinoma of the larynx were treated with concurrent chemoradiotherapy using 5-Fluorouracil continuous i.v. infusion 1000 mg/m 2 for 3 days+Cisplatin i.v. bolus injection 100 mg/m 2 on days 1,22 and 43 starting day 1 of radiotherapy. Radiation dose was given:45 Gy/4.5 weeks to the primary and neck nodes+boost to the primary to reach total dose of 70 Gy. Results:The median disease-free surviva I(DFS) 10.7 months and the overall survival (OS) was 20 months.14 patients (46.7%)achieved complete response with laryngeal preservation in 66.7%.Tumuor and nodal stages were significant prognostic factors. The 2 year DF$ and OS ratas for patients with retained larynges were 80% and 90% compared to 50% and 77% respectively for patients who underwent surgery. Most of treament toxicities were grades 1&2 and non developed grade 4 toxicities. Conclusions:Concurrent chemoradiotherapy was well tolerated with high response rates and organ preservation without compromising overall survival in our patients with locally advanced laryngeal carcinoma. 376
poster
Physiological sensitization by unequal size fractions : conclusion from palliative radiotherapy of advanced head and neck (H&N) ca by radiotherapy, P.K. Mohanta MAMC , R. T., New Delhi, India Purpose: About one third of our stage-IV H&N Ca pts don't receive any active treatment. Those treated by conventional RT show poor outcome. To improve palliation a modification of RT was done taking into consideration clinical,logistic and radiobiological factors. Method: Three/four fraction(fr)/Week(wk) were delivered to the tumor in an increasing fr size of 130, 180, 360, 540/720 cGy on day 1, 2, 3... resulting in cumulative dose of 7-14 Gy/wk. As fr size increased portal size was decreased.After a gap of 2-4 wks response was assessed and if found satisfactory the said course was repeated and so on. The machine was Th780. From Jan 98 to Jun 98 total 50 pts (H.P.proven) were treated with palliative intent after informed consent. Age ranged between 30-75 yrs. There were six females. Primary sites were Oropharynx-21, Oral cavity-9, PUO (neck node)-8, Larynx-7, Others-5. Nine pts had relapse/residual disease. Results: Total 42/50 pts completed RT. Tumor dose(TD)ranged between 14-56 Gy/4-16 fr/1-15wks. Till May 2000 maximum FU was 28 months. Compared to a stage and age matched historical control (conventional RT & or CT) CR improved from 14% to 48%. Median survival improved from 3 months to 7 months (p=0.01). Morbidity was acceptable. Conclusions: Large tumor is rendered radio-incurable conventionally due to hypoxic and G l S phase ceils. Analysis of cell survival curves show resistance is not absolute but is sensitive at higher dose (fr size)level. Physiological sensitization was suggested by using few large fractions. Limited sucess was achieved but at the cost of unacceptable morbidity. The present modification avoided the same by using low total dose, fewer large fractions to a smaller volume over protracted overall time. In the present study there is three4old increase in CR at less than half total dose implying TRUE physiological sensitization. 377
poster
IS high dose preoperative hyperfractionated accelerated radiotherapy feasible in the treatment of advanced head and neck squamous cell carcinoma ? R. Valavaara 1, K. Aitasalo2, J. Kulmala 1, P. Lindhold 1, H. Minn 1, J. Suonp~&2 j. Laine 3, R. Grenman 2, E. Nordman 1, S. PyrhOnen 1 I University Hospital of Turku, Finland, Department of Radiotherapy and O ncology, 2Department of Otorhinolaryngology, 3Department of Dentistry Purpose: to evaluate the feasibility of high dose hyperfractionated radiotherapy (RT) administered before sophisticated radical surgery. A single institution study. Methods: 73 patients with squamous cell carcinoma in the head and neck region were treated with hyperfractionated, accelerated, split course RT