Proceedings of the 38th Annual ASTRO Meeting 351

2150 DOES HIGH DOSE RATE IRRADIATION OF OBSTRUCTIVE INTRABRONCHIAL MALIGNANCY

JUSTIFY THE HIGH COST ? A STUDY OF 83 PATIENTS

Paul Anthony, M.D. and Kutub Khan, M.D., F.A.C.R.

Department of Radiation Oncology, St.Joseph Cancer Center, Albuquerque, New Mexico

Purwee: Over a 6 year period, 1989 through 1994.83 patients (pta) (76 pts with primary lung carcinoma (ca) and 7 pb with a solitary metastic lesion to the lung) and with bronchoscopically identified obstructive tumor, causing symptoms (ax’s) of cough, hemoptysis and/or shortness of breath (SOB) were treated with high dose rate (HDR) Ir-192 intrabronchial irradiation (XRT), and are the basis of this study. The purpose of this retrospective study is to determine the survival and relief of ax’s, compare our results to those in the classic radiation oncology lung ca literature, and determine if the improvement is suflicient to justify the high cost of adding HDR XRT to standard external beam XRT.

m 44 pts presented with de novo disease and initially received a course of external beam XRT (5000 - 6000 cGy, standard fractionation) followed by 3 HDR tx’s of 800 cGy per treatment (tx) calculated at one cm depth, separated by one week intervals, for a total HDR dose of 2400 cGy. 39 pts presented with locally recurrent disease following prior tx with external beam XRT, and they received 3 HDR tx’s, 1000 cGy per tx, one cm from the center of the catheter, separated by one week intervals, for a total dose to the tumor of 3000 cGy. All patients presented with one or more obstructive sx’s. Relief of these sx’s were determined at last follow-up (FU) or until death. All patients have been followed for a minimum of 6 months (mos).

Results: Our results show overall median survivals of 13 mos since initial diagnosis and 6 mos since treatment. In light of these results, we attempted to determine a subgroup of patients who might have a statistically significant increase in survival. The subgroups we analyzed were 1) pta with recurrent disease, 2) those treated in later years of the study, surmising we were more selective as our experience increased, 3) squamous histology with its natural history to remain localized, and 4) younger patients, age below 50. Our analysis revealed that one subgroup, recurrent disease, had a statistically significant improved survival (13 mos; 7 mos increase) from the date of diagnosis. No difference was seen from the date of tx (6 mos). Further subgroup analysis revealed a trend towards better survival in pt.a in the last 2 years of the study (2 mos increase), with squamous histology (2 mos increase) and younger pts (3 mos increase). With relief of sx’s, our results did not reveal any subgroup with improved sx relief. Overall cough was relieved in 6396, hemoptysis 81% and SOB 59%. Serious complications arose in 12% of pts; 7 pta died from exsanguination (8%) and 3 pta developed tracheoesophageal fistulas (4%).

m: When adding a new tx modality to standard tx, radiation oncologists expect to achieve one of 3 goals prior to accepting a new modality as standard tx, 1) significant improvement in survival, 2) reduction in complications and/or 3) improvement in quality of life. Comparison of our results with those from the classic radiation oncology lung ca literature showed no significant improvements regarding the above parameters. Our own practice cost analysis revealed HDR XRT doubled the cost of tx. In this era of capitated managed care, we conclude that the addition of HDR XRT to external beam XFtT in the tx of lung ca does not justify doubling the cost in the absence of significantly improved survival or sx relief. HDR XRT should not be accepted as standard tx in lung ca unless future randomized cooperative group studies can demonstrate significant improvement in tx results.

2151 STRATETEGIESAND TECHNICAL ASPECTS OF ENDOBRONCHJAL HIGH DOSE RATE IRRADIATION IN THE TREATMENT OF MALIGNANT AIRWAY OCCLUSION.

Paolo Muto, Vincenzo Rave”

1st. di Science Radiologiche Universiti degli Studi di Napoli “Federico II” *Radioterapia “Villa Del Sole” Napoli

OBJECTIVES The combination of external beam radiotherapy (EBRT) and High Dose Rate Brachytherapy (HDRBT) in a definitive approach to these patients is proposed Moreover we trie to determine the maximal acutely tolerable dose of HDRBT combined with EBRT and to search the optimal dose schedule using different fractionations MATERIAL AND METHODS From January 1992 to September 1995 we treated 165 patients with external beam radiotherapy with concomitant HDR endobronchial brachytherapy Patients selection criteria were biopsy proved histology (non small cell cancers), Stage IIIa-IIIb-IV, KPS > 60, expectance of life> 3 months, presence of cough and/or dyspnea, haemoptysis, obstructive pneumonia EBRT was performed using a 15 Mv linear accelerator and delivering 60 Gy to the tumor bed and 50 Gy for mediastinum with or without treating the supraclavicular fossae In 38 patients (Group A) we delivered, with HDRBT, 10 Gy in 1 fraction with a dose that was calculated at 1 cm from the central axis of the endobronchial catheter In 47 patients (Group B) HDRBT dose was of 7 Gy in 2 fractions always at 1 cm In 80 patients (Group C) the dose was of 5 Gy in 3 fractions In 20 patients of this group the dose was calculated at 1 cm and in 60 it was calculated at 0,5 cm from the central axis Group A treatment was performed before starting EBRT Group B received brachytherapy at the beginning and at the end of the EBRT treatment Group C was treated every 15 fractions of EBRT (timing 0.15.30) Totally our group has performed 382 treatments RESULTS Follow up is in the range of 5-36 months (with 15 l/l65 evaluable patients) Mean survival from diagnosis of 10 3 months and mean survival from last HDRJ3T of 9 5 months The symptomatic response rate is of 90% for dyspnea, 82 % for cough, 94% for emoptysis and of 90 % for obstructive pneumonia. We proved it at the 6 months bronchoscopy in 27135 patients evaluable of Group A, in22144 evaluable of Group B and in 18/62 evaluable of Group C In 12/35 of Group A, 1 l/44 of Group B and S/62 of Group C biopsy proved the presence of neoplastic cells in the bronchus The complications of the association EBRT+HDRBT were emoptysis, complications linked to the procedure of bronchoscopy, that was performed under local anaestesia, 3). bronco-oesophageal tistulas CONCLUSIONS Endoluminal brachytherapy is and effective palliative modality to relieve endoluminal obstruction that can be used alone or definitively to boost the primary site after or during a course of external irradiation. At the moment we believe that is very important to consider the importance of the prescribed dose but above all at what distance from the catheter this dose is prescribed With a reference dose of 5 Gy calculated at 1 cm from the central axis, in a standard treatment the volume that receives such dose is of 23cc The volume that receive a double dose is 7cc With the same dose calculated at I ,5 cm the volume irradiated with the prescrived dose is of 51 cc That that recieves a double dose of l8cc With the same dose calculated at 0.5 cm the volume that receive the precrived dose is of 7cc. the one that receives the double of 3cc As our experience confirms at the smallest irradiated volume correspond side effects of less importance