Factors predictive of local disease control after intra-arterial concomitant chemoradiation (RADPLAT)

Abstract

Objectives: To determine the relative risk of prognostic factors for local disease control following RADPLAT.

Study design: Prospective study, academic medical center.

Methods: Analyses of nine categories of risk factors among 240 patients with Stage II-IV carcinoma consecutively treated with RADPLAT (cisplatin 150 mg/m IA and sodium thiosulfate 9 g/m IV, weekly x4; radiotherapy 2 Gy/fraction/d, 5x weekly, 68-74 Gy over 6 to 7 weeks). Median follow-up: 58 months (range, 12-96 mo).

Results: The percentage of patients who had local disease control was 87.5%. Univariant analysis showed T classification (P =.01), laterality of neck disease (P =.026), number of neck levels involved (P =.008), total dose of radiation greater versus less than 60 Gy (P =.027), and presence of pathologically positive lymph nodes following chemoradiation (P =.01) to be significant. Logistic regression analysis showed total dose of radiation (P =.03) and the presence of pathologically positive lymph nodes following chemoradiation (P =.05) to be significant. For Kaplan-Meier estimates of local disease control at 5 years, T classification (P =.038), number of levels with nodal disease (P =.006), and total dose of radiation therapy (P =.0001) were significant. The log-rank test identified as significant the total dose of radiation therapy (P <.0001), the presence of pathologically positive lymph nodes following chemoradiation (P =.005), and the number of neck levels with positive nodes (P =.006). The Cox regression model showed significance for the total dose of radiation (P =.001), the presence of pathologically positive lymph nodes following chemoradiation (P =.007), and the T classification (P =.029).

Conclusion: Risk factors significantly associated with local disease control after RADPLAT appears to differ from more traditional therapy and is suggestive of a paradigm shift.