Defining Locoregional Failure Sites with respect to Radiotherapy Volumes in Gastric Cancer Patients

INTRODUCTION: The primary aim of this study is to evaluate and define locoregional recurrence regions individually matching with radiotherapy (RT) plans in gastric adenocarcinoma patients treated with curative surgery and adjuvant chemoradiotherapy (CRT). The secondary aim is to present the survival results.
METHODS: 62 adult gastric adenocarcinoma patients who underwent curative resection and received adjuvant CRT at two radiation oncology centers were analyzed. The 4500-5040 cGy was delivered in 25-28 fractions. At follow-up, computed tomography, which described recurrence, was transferred to the RT planning system and defined the site of relapse according to RT isodose curves.
RESULTS: The median follow up time was 18 months, 22 patients (35%) have been relapsed. Five patients had isolated loco-regional failure. Three of these relapses were in the RT field, one was marginal recurrence and the remaining one was outside the RT field. Two nodal recurrence regions were covered by 95% and 100% isodose lines and the other nodal recurrence region was covered by 20% isodose line with respect to their initial radiotherapy volumes. One local recurrence was in the anastomosis site covered by 90% isodose line and the other was on the peritoneal surface covered by 50% isodose line. The 3 and 5-year overall survival (OS) were 71% and 55% respectively, and were better with D2 lymph node dissection without statistical significance.
DISCUSSION AND CONCLUSION: Identification of the local recurrence site may be helpful in determining the RT target volume. For this, controlled studies with more patients are needed.

Mide Kanserli Hastalarda Radyoterapi Hacimlerine Göre Lokal Bölgesel Yineleme Alanlarýnýn Tanýmlanmasý

GÝRÝÞ ve AMAÇ: Bu çalýþmanýn primer amacý, küratif cerrahi ve adjuvan kemoradyoterapi (KRT) uygulanan mide adenokarsinomlu hastalarýn lokal yineleme bölgelerini radyoterapi planlarý ile birleþtirilerek tanýmlamaktýr. Ýkincil amaç ise saðkalým sonuçlarýný sunmaktýr.
YÖNTEM ve GEREÇLER: Ýki merkezde küratif rezeksiyon yapýlan ve adjuvan KRT alan 62 eriþkin mide adenokarsinomlu hastalar retrospektif olarak incelendi. Radyoterapi 25-28 fraksiyonlarda 4500-5040 cGy olarak uygulandý. Takipte, nüksün tariflendiði bilgisayarlý tomografi RT planlama sistemine aktarýldý ve RT izodoz eðrilerine göre nüks bölgesi tanýmladý.
BULGULAR: Ortanca takip süresi 18 aydý, 22 hastanýn (% 35) hastalýðý tekrarladý. Beþ hastada izole lokal-bölgesel baþarýsýzlýk (3 nodal, 2 lokal nüks) görüldü. Bu nükslerin üçü RT alanýnda, biri marjinal nüks, kalan biri de RT alaný dýþýnda idi. Ýki nodal nüks, % 95 ve % 100 izodoz eðrisi içinde kalýrken, diðer nodal nüks ise recete edilen dozun % 20’sini oluþturduðu izodoz hattýnda idi. Bir lokal nüks, % 90 izodoz eðrisi içinde, anastomoz bölgesinde, diðeri ise % 50 izodoz eðrisi içinde, peritoneal yüzeydeydi. Üç ve beþ yýllýk genel saðkalým (GS) sýrasýyla % 71 ve % 55 olarak bulundu. D2 lenf nodu diseksiyonu yapýlan hastalarda genel sað kalým daha yüksek olup farklýlýk istatistiksel olarak anlamlý düzeyde bulunmadý.
TARTIÞMA ve SONUÇ: Lokal nüks bölgesinin tanýmlanmasý RT hedef hacmin belirlenmesinde yol gösterici olabilir. Bunun için daha fazla hasta ile yapýlan kontrollü çalýþmalara ihtiyaç bulunmaktadýr.