Intensity Modulated Radiation Therapy for T1 Glottic Cancer: Initial Clinical Outcomes. P.R. Sevak,1 M.J. Awan,2 G.B. Gunn,2 D.I. Rosenthal,2 and C.D. Fuller2;.
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International Journal of Radiation Oncology Biology Physics
and 69 pts with stage N0 and N+, respectively. ALB and CRP were indicated in serum before treatment (0) and immediately after the treatment completion (1). Additionally, in case of every patient GPS value has been calculated on basis of CRP 0 and ALB 0 and NRI on the basis of ALB 0 and the weight of the patient before and after the treatment. Early outcome of the treatment was defined at 6th month of follow-up as complete remission of the tumor (CR) or treatment failure (no complete remission, NCR). Mann-Whitney U test was used for analysis of correlation between protein concentration and indicators (GPS, NRI) in CR and NCR patients. Wilcoxon signed rank test was used to compare protein concentrations in two groups of patientseCR and NCR. Results: The rates of CR and NCR were respectively in 71% and 29%. There were clear differences between concentrations of both proteins before and after the treatment: ALB 0 vs ALB 1 (p Z 0.0001) and CRP 0 vs CRP 1 (p Z 0.0001). For all patients there was a significant increase of CRP and decrease of ALB concentration after RT. ALB 0 was lower in NCR than in CR group (p Z 0.01). Also NRI rate was lower in NCR patients than in CR (p Z 0.004). Despite no significant difference found in CRP 0 comparing CR and NCR groups the GPS was higher in NCR group than in CR (p Z 0.01). Conclusions: Pretreatment concentration of ALB and CRP seems to have an influence on early RT outcome in HNC patients. Low concentration of ALB (and consecutively low NRI and high GPS rates) is possible negative prognostic factors indicating higher risk of RT failure. ALB determination before the RT suggests contribution of this protein in cancer progression, alteration of inflammatory proteins during radiation therapy is probably related to acute mucosal reaction intensity. Author Disclosure: J.J. Mrochem-Kwarciak: None. T. Rutkowski: None. A. Wygoda: None. A. Chmura: None. A. Hajduk: None. Z. Kołosza: None. B. Masłyk: None. P. Widłak: None. K. Składowski: None.
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2657 Intensity Modulated Radiation Therapy for T1 Glottic Cancer: Initial Clinical Outcomes P.R. Sevak,1 M.J. Awan,2 G.B. Gunn,2 D.I. Rosenthal,2 and C.D. Fuller2; 1 University of Texas Medical Branch School of Medicine, Galveston, TX, 2 University of Texas MD Anderson Cancer Center, Houston, TX Purpose/Objective(s): T1 glottic cancer is highly curable with definitive RT. Traditional radiation techniques result in high radiation doses to the carotid arteries that accelerates atherosclerosis, and increases the risk for ischemic stroke in a dose-dependent fashion. We review our clinical outcomes for T1 larynx cancer patients treated with IMRT. Dosimetric in silico comparisons were performed between virtual conventional opposed lateral and delivered IMRT plans in terms of dosimetric correlates for RT sequelae. Materials/Methods: Twenty-eight patients with T1 glottic cancer were treated with IMRT. Non-target structures, including left and right carotid arteries, middle pharyngeal constrictor (MPC), and inferior pharyngeal constrictor (IPC) were contoured. We then evaluated plans using generalized equivalent uniform dose and dose-volume parameters. Results: Mean prescription dose was 63.93 +/- 1.69 Gy given over 29 +/- 2 fractions. Median follow-up time after radiation therapy was 20.27 months. There were two local recurrences at 4 and 12 months post-radiation therapy. One patient underwent a salvage larynx preservation surgery, and the other underwent a salvage partial laryngectomy. Both had no evidence of disease at last follow-up. We were able to achieve a mean carotid V35 and V50 of 8% and 3% respectively. The IPC in our patients received a mean dose of 61.57 Gy, and the MPC 24.2 Gy. The generalized effective uniform dose of the carotid arteries ranged from 2.55-14.77 Gy. Conclusions: IMRT significantly reduces carotid artery RT dose without compromising tumor control. The dose to the MPC was also significantly lower with IMRT, but due to the location of the IPC, sparing may affect CTV coverage. The use of IMRT for early glottic cancer may offer benefits, however longer follow-up is needed for confirmation. Author Disclosure: P.R. Sevak: None. M.J. Awan: None. G.B. Gunn: None. D.I. Rosenthal: None. C.D. Fuller: None.
Toxicities of Radiation Therapy for the Definitive Treatment of Early-Stage Glottic Carcinoma Comparing Conventionally and Hypofractionated Regimens M.T. Scott, A.R. Dosch, and M.A. Samuels; University of Miami and Jackson Memorial Hospital, Miami, FL Purpose/Objective(s): The traditional approach to treatment of stage I squamous cell cancer of the glottis has been to deliver 66-70 Gy in 33-35 fractions of 2 Gy once daily. A randomized trial from Japan in 2006 compared hypofractionated radiation therapy (RT) at 2.25 Gy daily to 56.25 Gy for “minimal” T1 and 63 Gy for larger T1 tumors to 60-66 Gy in 2 Gy fractions. Local control was higher in the 2.25 Gy arm and toxicity was reported as extremely low in both arms, leading to wide adoption of the hypofractionated regimen. However, many U.S. institutions have modified this regimen to deliver a higher total dose (63 Gy for all T1 and 65.25 Gy for T2), potentially resulting in higher levels of acute toxicity. The dose range for comparable conventionally fractionated patients is higher than in Japan, possibly improving local control for these patients. Our clinical experience has indicated that patients may experience greater toxicity, possibly without added efficacy in terms of local control, on the United States hypofractionated regimen compared to the traditional approach. Materials/Methods: Between 2003 and 2011, 71 patients with histologically-proven early stage (T1-T2) squamous cell carcinoma of the larynx were treated with RT at our institution. Median age was 65 years (range, 33-94 years). Fifty-five patients had T1 tumors and 16 patients had T2 tumors. Forty-five patients in conventional RT arm received 2 Gy daily, and 26 patients in hypofractionated arm received 2.25 Gy daily. The median RT dose was 66 Gy (range, 54-74 Gy) for conventional RT, and 63 Gy (range, 49.5-67.5 Gy) for hypofractionated RT. Toxicity was graded using the CTCAE, v 4.0. Statistics were calculated by a two-tailed t-test. Results: Patients treated with conventional RT had lower rates of Grade 3 hoarseness [0% vs 26% (n Z 7), p Z 0.02] and showed trend of requiring less administration of narcotics [53% (n Z 25) vs 70% (n Z 19), p Z 0.14] acutely during the course of treatment. The rates of Grade 3 dysphagia [0% vs 6% (n Z 3), p Z 0.84] and weight loss (2.5% vs 4.8%, p Z 0.33) acutely during treatment were comparable in both arms. Complete response to treatment was 87% (n Z 41) in the conventional RT arm and 89% (n Z 24) in the hypo-fractionated arm (p Z 0.86). There were 4 local recurrences (9%) in patients receiving conventional RT doses and 1 local recurrence (4%) in patients receiving hypofractionated RT (p Z 0.38). Conclusions: Our preliminary retrospective data suggest that patients receiving hypofractionated RT may experience higher rates of Grade 3 hoarseness with a trend toward increased narcotic use without significant improvement in local control rates. Further patient data and follow-up of the hypofractionated arm is required to validate these results. Author Disclosure: M.T. Scott: None. A.R. Dosch: None. M.A. Samuels: None.
2659 Voice Rehabilitation After Total Laryngectomy and Postoperative Radiation Therapy N. Bhandare, C.G. Morris, and W.M. Mendenhall; Department of Radiation Oncology, College of Medicine, University of Florida, Gainesville, FL Purpose/Objective(s): To evaluate the type and success rate of voice rehabilitation techniques after laryngectomy and postoperative radiation therapy (RT) for patients with carcinoma of the larynx and hypopharynx. Materials/Methods: The medical records of 225 patients with advanced squamous cell carcinoma of the larynx and hypopharynx who underwent total laryngectomy and postoperative RT at the University of Florida were retrospectively reviewed. The median follow-up time was 40 months (range, 3 to 192 months). Five patients were lost to follow-up from 4 to 60 months after treatment. Voice rehabilitation was stratified into the following categories: tracheoesophageal, artificial larynx, esophageal,
