Surgical Salvage of Recurrence Following Radiation Therapy for Squamous Cell Carcinoma of the Oropharynx

Surgical Salvage of Recurrence Following Radiation Therapy for Squamous Cell Carcinoma of the Oropharynx

Poster Viewing E367 Volume 96  Number 2S  Supplement 2016 cGy). The median time from surgery to RT start was 43 days and the overall TPT was 85 day...

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Poster Viewing E367

Volume 96  Number 2S  Supplement 2016 cGy). The median time from surgery to RT start was 43 days and the overall TPT was 85 days. There were no local failures and only two regional failures, resulting in 98.5% locoregional control at 4 years. Eight pts developed distant metastasis, without evidence of locoregional failure, for a 4-year overall survival (OS) of 85%. On UA, time from surgery to start of RT and TPT were not associated with a higher recurrence risk. Factors associated with worse OS in UA were T stage (P Z 0.03), PS (P Z < 0.001), smoking history (P Z 0.02) and delay in the interval from surgery to the start of RT > 43 days (P Z 0.03). No factors were significant on MVA. Conclusion: TLM followed by RT in favorable risk OPSCC pts results in excellent outcomes with few locoregional recurrences. Treatment time factors were not associated with a significant increase in recurrence risk. Further study in a larger cohort will help clarify the impact of treatment time. Author Disclosure: M.E. Gamez: None. S.E. Schild: None. M.Y. Halyard: None. M.L. Hinni: None. H.E. Richard: None. T.H. Nagel: None. C. Vargas: None. W.W. Wong: None. C. Rayfield: None. S.H. Patel: None.

2904 Advanced-Stage “Horseshoe” Anterior Commissure Laryngeal Cancers, Contemporary Management, and Long-Term (10-year) Outcomes F.L. Ampil, G. Caldito, M. Vora, T. Richards, C.A. Nathan, G. Mills, S. Devarakonda, N. dela Cruz, and M. Assercq; Louisiana State University Health, Shreveport, LA Purpose/Objective(s): Although treatment paradigms and modalities have changed significantly in the last two decades, total laryngectomy is still an option that is reserved for patients with primary laryngeal cancers portrayed as bulky tumor masses with extensive soft tissue or thyroid cartilage invasion on radiography. Optimal management of anterior commissure carcinoma remains a subject of discussion because of its juxtaposition to the thyroid cartilage. Few reports of advanced stage ‘horseshoe’ anterior commissure laryngeal carcinoma (HACLC) and the long-term outcome of patients after treatment exist in the literature. Herein, we present the results of a retrospective review of a 30-year experience of people treated for locally advanced HACLC using contemporary management strategies. Materials/Methods: Of 596 people diagnosed with laryngeal cancer between 1981 and 2010, 49 consecutive individuals were treated for stage III or IV HACLC. Twelve of these patients were treated by total laryngectomy alone, and 37 patients were treated with postoperative radiation therapy; five individuals in the latter group also received chemotherapy. The indications for adjuvant therapy included tumor-positive regional nodes/ resection margins, invasion of the thyroid/cricoid cartilage or subglottic region and extralaryngeal neoplastic spread to soft tissues; postoperative irradiation was generally omitted in the absence of the preceding risk factors. The median follow-up time was 65 months. The chosen endpoints were 10-year survival and relapse rates. Results: Overall, the median survival was 83 months. At 10 years, the survival rate was 37% and the recurrence rate was 16%. The local, regional and distant relapse rates were 0%, 4% and 12% respectively. Improved long-term prognosis was not observed in patients undergoing combined therapy compared to people treated with surgery alone in light of the corresponding 39% and 30% 10-year survival rates ( P Z .30). The recurrence rate was 11% in the postoperative radiation therapy group and was 33% in the laryngectomy alone cohort (P Z .09). Complications included tracheal stoma stricture (8%), hypothyroidism (4%) and esophageal stricture/carotid artery stenosis (2%). Conclusion: In advanced stage HACLC, definitive surgery followed by adjuvant radiation therapy (and chemotherapy as indicated) can potentially provide extended disease-free survival with minimal morbidity. Author Disclosure: F.L. Ampil: None. G. Caldito: None. M. Vora: None. T. Richards: None. C. Nathan: None. G. Mills: None. S. Devarakonda: None. N. dela Cruz: None. M. Assercq: None.

2905 Surgical Salvage of Recurrence Following Radiation Therapy for Squamous Cell Carcinoma of the Oropharynx K. Hitchcock,1 R.J. Amdur,1 P.T. Dziegielewski,2 and W.M. Mendenhall1; 1 Department of Radiation Oncology, University of Florida, Gainesville, FL, 2Department of Otolaryngology, University of Florida, Gainesville, FL Purpose/Objective(s): To test the hypothesis that there is a low rate of successful surgical salvage in patients with local-regional (LR) recurrence following radiation therapy for squamous cell carcinoma (SCC) of the oropharynx. Materials/Methods: Details regarding salvage surgery were recorded for all patients with local, regional, or local and regional recurrence following primary radiation therapy (with or without chemotherapy) at our institution between 1985 and 2005 for squamous cell carcinoma of the oropharynx. Patients with distant metastasis at the time of diagnosis were excluded. We chose the stop date of 2005 so that all patients would have at least 5 years of follow-up. Results: The study population is 136 patients with local and/or regional recurrence: (1) Overall salvage success rate: 12% (16/136); (2) salvage success rate with isolated local recurrence: 18% (15/83); (3) salvage success rate with isolated neck recurrence: 3% (1/36); (4) overall salvage attempt rate: 32% (43/136); and (5) overall salvage procedure success rate: 37% (16/43). Local and/or regional recurrence was symptomatic in 84% of patients. We analyzed salvage success by initial T stage, N-stage, oropharynx subsite, and other factors. Conclusion: It is uncommon for radiation therapy failures in SCC of the oropharynx to be successfully surgically salvaged. Almost all localregional recurrences are symptomatic. These data better inform the decision to offer salvage surgery and question the value of the frequent followup program that is recommended in some published guidelines. Author Disclosure: K. Hitchcock: None. R.J. Amdur: None. P.T. Dziegielewski: None. W.M. Mendenhall: None.

2906 Geometrical Changes of Parotid, Submandibular, and Thyroid Glands During Intensity Modulated Radiation Therapy for Nasopharyngeal Carcinoma W. Tan,1,2 X. Li,1 R. Xu,1 X. Wang,2 Y. Li,2 and D. HU2; 1Department of Oncology, Shenzheng People Hospital, Shenzhen, China, 2Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan, China Purpose/Objective(s): Both the tumor and organs at risk (OARs) occurred considerable changes during the intensity modulated radiation therapy (IMRT) course for nasopharyngeal carcinoma (NPC). This study aims to analyze quantitatively the geometrical variations of the parotid, submandibular gland (SMG) and thyroid as three independent OARs throughout IMRT course. Materials/Methods: Twenty NPC patients received the definitive chemoIMRT in 33 fractions within 6.5 week-long course. Each patient had a planning CT (pCT) and six weekly repeat CT (rCT) without enhanced contrast. Each rCT was rigidly registered to its pCT. The parotid, SMG and thyroid were manually delineated in the axial pCT and rCT imaging by a single radiation oncologist. When compared a contour in pCT with rCT, it was calculated the volume of each contour (V_pCT, V_rCT), the common volume (V_com) and the shortest perpendicular distance (SPD) between two contours. Each surface voxel of a contour in rCT has a SPD and the standard deviation (SD) of all the SPDs was calculated. Both the SPD and Dice similarity coefficient (DSC) calculated as 2*V_com / (V_pCT + V_rCT) were used as the surrogate of the shape variations. The displacement of center of mass as the positional shift was calculated and the mean displacement, system and random error were statistically calculated. The difference of geometrical changes among six week, the left- and right- sided OAR was compared using one-way analysis of variance or Mann-Whitney U test. Results: The mean radiation dose of the parotid, SMG, thyroid gland were 32.12  11.2 Gy, 25.46  8.62 Gy, 18.89  10.24 Gy, (mean  standard deviation) respectively. And their mean and maximal volume reduction were