The equivalence of definitive radiotherapy with combined surgery and postoperative radiotherapy for advanced squamous cell carcinoma of the oropharynx

Radiation Oncology, Biology, Physics Volume 27, Supplement 1

248

POSTER MONDAY,

OCTOBER

12:OO NOON

11,

SESSIONS WEDNESDAY,

1993

12:30

1:OO p.m.

-

OCTOBER

p.m. -

2:00

13,

1993

p.m.

1001 CONCOMITANT BOOST RADIOTHERAPY FOR ADVANCED AND UNRESECTABLE HEAD AND NECK SQUAMOUS CELL CARCINOMA: PRELIMINARY RESULTS Giuseppe Sanguineti,Renso Corvo, Vito Vitale, Giacomo Garaventa", Marco Scala, Marco Barbieri*,Almalina Bacigalupo, Marina Guenzi, Felice Scasso§', Monica Cavallari, Tindaro Scolaro Department of Radiotherapy, National Institute for Cancer Research, Genoa; Head and Neck Surgery Depts,'S.Martino Hospital,§Celesia Hospital, *University of Genoa Conventional radiotherapy offers unsatisfactory results in advanced, inoperable squamous cell carcinoma of the head and neck (HN-SCC).For improving the prognosis of these tumors, since 1989 we have been testing the concomitant boost strategy developed at the University of Texas,M.D.Anderson Cancer Center.It allows to shrink overall treatment time by l-2 weeks without a reduction in total dose, delivering the boost treatment phase during the basic field course. Matherials and Methods: From May 1989 through February 1993 we enrolled 55 previous untreated patients affected by advanced, unresectable HN-SCC from various primary site. Out of 55, 38 patients with a minumum follow-up of 12 months are evaluable. Sites of primary tumors were: oral cavity (7), oropkarynx (12), nasopharynx (4),larynx (12) and hypopharynx (3). Thirteen(34%) patients were in stage III and 25 (66%) in stage IV. Patients were planned to receive a total dose of 75 Gy in 40 fractions over 40 days. The basic course was given as a daily dose of 2 Gy, five times a week, for six weeks. The concomitant boost encompassing only the macroscopic tumor was given as a second daily dose 1.5 Gy per fraction, five times a week, during the last two weeks of the basic treatment. The interval between the two daily fractions was six hours at least. Only four patients delayed the treatment due to radiation-related complications. Twelve (32%) patients showed patchy mucositis and 26 (68%) patients showed confluent mucositis. Four patients needed nasogastric tube feeding. Results: We obtained 31/38 (81%) complete responses, 12/13 (93%) for stage III patients and 19/25 (76%)for stage IV ones. At a median follow-up of 24 months (12-45 months) the actuarial loco-regional control rate and the overall survival rate are 45% and 64% respectively. Conclusionr We conclude that the preliminary results are satisfactory in terminal of loco-regional control and acute toxicity. In March 1992.we started, in advanced inoperable PIN-SCC, a randomized multicenter trial to compare the efficacy of the concomitant boost schedule versus a alternating chemo-radiotherapy regimen which, in our previous trial, demonstrated to be superior to conventional fractionated radiotherapy.

POSTER

NUMBER

1002 HAS BEEN WITHDRAWN

1003 THE EQUIVALENCE OF OEFlNlTlVE RADIOTHERAPY WITH COMBINED SURGERY AND POSTOPERATIVE RADIOTHERAPY FOR ADVANCED SQUAMOUS CELL CARCINOMA OF THE OROPHARYNX Christopher

R. Johnson,

M.D.,

David T. Huang, M.D.,

Department

of Radiation Oncology,

Ph.D.,

Rupert Schmidt-Ullrich,

Medical College of Virginia,

Richmond,

M.D.

Virginia

PURPOSE: Combined surgery and postoperative radiotherapy rather than radiotherapy alone are often advocated for advanced oropharyngeal squamous cell carcinomas. This report will compare the local tumor control rates of patients managed by radical resection and standard postoperative radiotherapy with a similar cohort of patients managed with a definitive accelerated hyperfractionated radiotherapy schedule.

Proceedings of the 35th Annual ASTRO Meeting

249

MATERIALS AND METHODS: This study examines a group of 50 patients treated for stage III and IV squamous cell carcinoma of the oropharvnx. Twenty five patients were managed with surgery and postoperative radiotherapy WITI between 1982 and 1988 and 25 were managed with definitive radiotherapy (RT) between 1985 and 1991. Minimum followup is :2 years. The RT group was managed with an accelerated hyperfractionated schedule (1.8+ 1.6 Gy/day) using concomitant boost with a dose range of 68.4-73.8 Gy (70.2 Gy median). The SRT group received standard daily fractionation (1.8-2.0 Gy/day) with doses ranging from 50-70 Gy (54 Gy median). There are 4 females in the RT group and 3 females in the SRT group. Forty eight percent (12/25) of the RT group are tongue base primaries versus 72% (18/25) in the SRT group. Thirty two percent (8/25) of the RT group are tonsillar region primaries versus 24% (6/25) of the SRT group. Forty percent of the RT group are AJCC T4 and 32% are T3 versus 26% T4 and 40% T3 in the SRT group. AJCC N stage distributions are approximately equivalent . RESULTS: Actuarial local-regional control at 36 months is 52% and 53% respectively for the RT and SRT groups (log rank p = n.s.1. Multivariate analysis using the Cox regression model tested treatment method (RT vs. SRT), T stage, N stage and prilmary site. T stage was the only significant independent variable to be identified by stepwise analysis (p = .006). CONCLUSION: In this study, local tumor control is equivalent between the definitive radiotherapy and combined modality groups managed for stage III and IV oropharyngeal squamous cell carcinoma. Statistical adjustment for baseline patient characteristics fails to demonstrate a difference between the two treatment groups. This study fails to demonstrate a superiority of local tumor control with combined surgery and postoperative radiotherapy over that achieved with radical radiotherapy alone.

1004 RADIOTHERAPY

FOR IOASOPHARYNGEAL CARCINOMA: AN ANALYSIS OF THE SITE OF FAILURE

David Raben, M.D., John Lee, and Ding-Jen Lee, M.D., Ph.D. Division of Radiation Oncology, The Johns Hopkins Hospital, Baltimore, MD 21287

Objective: nasopharyngeal

To ev,aluate

the

site

of failure

following

a course

of definitive

radiotherapy

for

carcinoma.

From 1976 to 1991 56 consecutive patients with previously untreated Materials and Hethods: nasopharyngeal carcinoma received a course of definitive radiotherapy. All patients received a course of external beam irradiation (median dose: 7020 cGy, range: 6480 to 7380 cGy). Twenty-eight patients received intracavitary brachytherapy boost with a median mucosal dose Most of them had initial bulky of 1000 cGy (range 600 to 2000 cGy) 2 to 3 weeks later. Nine patients with palpable mucosal disease with or without extra-nasopharyngeal extension. residual disease in the neck at the end of external beam irradiation also received a boost The median with interstitial brachytherapy (median dose: 2240 cGy, range: 1000 to 3500 cGy). follow up is 5 years with a range of 1.5 to 15 years.

Results: In terms of the site of failure, 1 of 21 patients with Tl/TZ disease failed in the Among 35 patients with T3/T4 disease, 3 failed in the none in the skull base. nasopharynx, nasopharynx only, 8 failed in the skull base only and 6 failed in the nasopharynx as well as skull base. Only 3 of 56 patients (5%) (17 patients had NO, 3 had Nl, 26 had N2 and 10 had In 12 patients (21%) the first site of failure was distant N3 disease) faile!d in the neck. metastasis. The corrected 5 year disease free actuarial survival is 40%. The results indicate that the external beam irradiation plus brachytherapy can Conclusion: A 95% overall local control in the neck achieve excellent local control for Tl/TZ disease. However, local failure for T3/T4 disease and has demonstrated the efficacy of our approach. distant metastasis remain the major cause of patient's demise.