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Transoral Laser Microsurgery (TLM) Followed by Radiation Therapy (RT) for Oropharyngeal Tumors
S472
International Journal of Radiation Oncology Biology Physics
2672
underwent TLM with neck dissection. Adjuvant radiation therapy was given after TLM. Thirty seven (46%) pts received concurrent adjuvant cisplatin or cetuximab chemotherapy . The primary outcome measured was locoregional control. Results: Median follow up was 32.9 months (range 6.5-117.6). The median radiation dose was 60 Gy (range 50-70 Gy). The 3-year locoregional control, recurrence free survival, and overall survival rates were 98.3% (95% CI 88-100%), 90% (95% CI 79-95%), and 93% (95% CI 8297%), respectively. There were a total of 11 deaths and 5 treatment failures, 1 regional and 4 distant. Thirty three percent of the pts underwent neck only radiation therapy with exclusion of the primary site and had no locoregional recurrences. Twenty five percent of pts had grade 3 dysphagia during RT and 6.3% of pts required use of a PEG tube at 1 year. Conclusions: TLM followed by RT for locally advanced oropharyngeal cancer results in very promising locoregional control rates. A prospective study examining patient reported outcomes and the exclusion of the primary site in the radiation field is being planned. Author Disclosure: S.H. Patel: None. W. Wong: None. M. Hinni: None. R. Hayden: None. M. Zarka: None. A.C. Dueck: None. K. Curtis: None. M. Halyard: None.
Dosimetric Effect of Sparing the Primary Site for Oropharyngeal Squamous Cell Carcinoma After Transoral Laser Microsurgery D. Fried, M. Lehman-Davis, T. Hackman, M. Kostich, J. Lian, K. Burkhardt, and B. Chera; University of North Carolina at Chapel Hill, Chapel Hill, NC Purpose/Objective(s): To quantify the effect of sparing the primary site after transoral laser microsurgery (TLM) for oropharyngeal squamous cell carcinoma (OPSCC). Materials/Methods: We reviewed five patients who were treated with TLM and post-operative radiation. All patients were staged T1 of the base of tongue with 1 patient being N1, 3 being N2 and 1 N3. 1 patient’s tumor extended bilaterally, 3 were lateralized to the right, and 1 lateralized to the left. All patients were treated using 9-field, step-and-shoot, intensity modulated radiation therapy (IMRT) to the primary site and at risk neck(s). The prescribed dose to the high risk (HR) and standard risk (SR) planning target volumes (PTVs) was 60 Gy and 46 Gy at 2 Gy/fx, respectively. We re-planned these patients with the purpose of sparing the primary site. PTV-SR and PTV-HR were adjusted to exclude the primary site from the treatment volumes. Re-plans were performed such that the primary site was maximally spared while maintaining similar PTV coverage and normal tissue avoidance as the initial, standard treated plan. Results: Dosimetric results are shown in the table. Both plans were able to adequately (at least 95% of the target volume receives 100% of the prescribed dose) cover the PTVs and similarly spare normal tissues (spinal cord, brainstem, contralateral parotid, ipsilateral cochlea, and larynx). The mean dose to the primary site was reduced by 33% (19 Gy) and the mean dose to the oral cavity was reduced by 50% (24 Gy). The conformity index was worse when the primary site was spared. Conclusions: Reducing the mean dose delivered to oropharynx after TLM by approximately 20 Gy is feasible using 9-field, step and shoot, IMRT. Sparing the primary site post TLM may yield reductions in toxicity.
Poster Viewing Abstract 2672; Table primary included plans
Comparison of primary spared versus Primary site spared plans average [max, min]
PTV-HR volume PTV-HR conformity index PTV-SR volume PTV-SR conformity index Primary avoidance volume Mean dose to primary avoidance % Primary avoidance 60 Gy Mean dose to oral cavity Mean dose to parotid
104cc [117, 83] 2.33 [2.81, 2.12] 290cc [358, 252] 4.83 [6.34, 3.91] 107cc [138, 64] 42 Gy [47, 40] 4.1% [16, 0.2] 24 Gy [29, 18] 23 Gy [24, 21]
Primary site NOT spared plans average [max, min] 198cc [249, 115] 2.22 [3.03, 1.82] 397cc [496, 316] 4.27 [5.26, 3.74] NA 61Gy [62, 60] NA 48 Gy [56, 42] 23 Gy [25, 21]
Author Disclosure: D. Fried: None. M. Lehman-Davis: None. T. Hackman: None. M. Kostich: None. J. Lian: None. K. Burkhardt: None. B. Chera: None.
2673 Transoral Laser Microsurgery (TLM) Followed by Radiation Therapy (RT) for Oropharyngeal Tumors S.H. Patel, W. Wong, M. Hinni, R. Hayden, M. Zarka, A.C. Dueck, K. Curtis, and M. Halyard; Mayo Clinic Arizona, Scottsdale, AZ Purpose/Objective(s): To report the treatment outcomes of locally advanced oropharyngeal cancer patients (pts) treated with TLM followed by RT at MCA. Materials/Methods: An IRB approved retrospective study of 80 pts treated from January 1, 2000 through November 7, 2011 was performed. All pts had stage III or IV tonsil and/or base of tongue primary tumors and
2674 HPV-Positive Squamous Cell Carcinoma of the Oropharynx Is Adequately Treated With Radiation Therapy Alone M.L. Mierzwa,1 L.E. Imwalle,1 K.A. Casper,2 A. Dwivedi,3 Q. Zhai,4 K.P. Redmond,1 and W.L. Barrett1; 1Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, 2Department of Otolaryngology, University of Cincinnati, Cincinnati, OH, 3Center for Biostatistical Services, University of Cincinnati, Cincinnati, OH, 4Department of Pathology, University of Cincinnati, Cincinnati, OH Purpose/Objective(s): At our institution, clinicians have historically had opposing biases regarding the role of concurrent cytotoxic chemotherapy in the management of locally advanced head and neck cancer. This presents a unique opportunity to review patients treated with either definitive radiation therapy or chemoradiation therapy for squamous cell carcinoma of the oropharynx (SCCOP) in the HPV era. Materials/Methods: We retrospectively reviewed 63 consecutive patients treated from 2006-2009 for cT2N2b-T4N3 SCCOP at UC for whom p16 immunostaining was clinically performed or pathology was available for retrospective HPV analysis. Patient treatment consisted of either definitive RT consisting of EBRT to 70Gy or EBRT to 50Gy followed by brachytherapy boost, of definitive chemoradiation therapy (CRT) consisting of EBRT to 70Gy with concurrent cisplatin 100mg/m2 q 3 week. The endpoints analyzed included locoregional control (LRC), distant-metastasis free survival (DMFS), overall survival (OS) and toxicities according to RTOG criteria. The LRC, DMFS and OS were estimated from the date of completed RT till date of each event respectively or date of last follow up. Log rank test was used to compare the LRC, DMFS and OS according to cofactors. Fisher’s exact test was used to compare the variables between the treatment groups. Results: Median follow-up was 17.8 mo (range:1.8-73.4). Minimum follow up for living patients was 24 mo. 71% of patients were HPV positive by p16 analysis. 27(43%) patients underwent definitive RT, and 36 (57%) patients underwent chemoRT. Pretreatment variables including smoking status, p16, site, T and N stage were balanced between RT and CRT groups (pZ.60, 0.09, 0.26, 0.47 and .71 respectively). A total of 12 (19%) patients observed with LR, 12 (19%) patients with DM. 16 (25.4%) deaths were found in this study. The overall LRC, DMFS and OS were estimated as 81%, 81% and 79% at 1 year. For HPV+ patients, LRC, DMFS and OS at 2 years were 87%, 87% and 96% for CRT and 100%, 94% and 93% for RT (pZ0.21, 0.91, 0.50). For HPV- patients, 2 year LRC, DMFS and OS were 57%, 54% and 57% for CRT and 44%, 45% and 12% for RT pZ0.90, 0.98, 0.27). p16 status was the only independent factor associated with LR, DM and OS. There were 16 T4 tumors in this study, of these 8 were HPV+; only
International Journal of Radiation Oncology Biology Physics
2672
underwent TLM with neck dissection. Adjuvant radiation therapy was given after TLM. Thirty seven (46%) pts received concurrent adjuvant cisplatin or cetuximab chemotherapy . The primary outcome measured was locoregional control. Results: Median follow up was 32.9 months (range 6.5-117.6). The median radiation dose was 60 Gy (range 50-70 Gy). The 3-year locoregional control, recurrence free survival, and overall survival rates were 98.3% (95% CI 88-100%), 90% (95% CI 79-95%), and 93% (95% CI 8297%), respectively. There were a total of 11 deaths and 5 treatment failures, 1 regional and 4 distant. Thirty three percent of the pts underwent neck only radiation therapy with exclusion of the primary site and had no locoregional recurrences. Twenty five percent of pts had grade 3 dysphagia during RT and 6.3% of pts required use of a PEG tube at 1 year. Conclusions: TLM followed by RT for locally advanced oropharyngeal cancer results in very promising locoregional control rates. A prospective study examining patient reported outcomes and the exclusion of the primary site in the radiation field is being planned. Author Disclosure: S.H. Patel: None. W. Wong: None. M. Hinni: None. R. Hayden: None. M. Zarka: None. A.C. Dueck: None. K. Curtis: None. M. Halyard: None.
Dosimetric Effect of Sparing the Primary Site for Oropharyngeal Squamous Cell Carcinoma After Transoral Laser Microsurgery D. Fried, M. Lehman-Davis, T. Hackman, M. Kostich, J. Lian, K. Burkhardt, and B. Chera; University of North Carolina at Chapel Hill, Chapel Hill, NC Purpose/Objective(s): To quantify the effect of sparing the primary site after transoral laser microsurgery (TLM) for oropharyngeal squamous cell carcinoma (OPSCC). Materials/Methods: We reviewed five patients who were treated with TLM and post-operative radiation. All patients were staged T1 of the base of tongue with 1 patient being N1, 3 being N2 and 1 N3. 1 patient’s tumor extended bilaterally, 3 were lateralized to the right, and 1 lateralized to the left. All patients were treated using 9-field, step-and-shoot, intensity modulated radiation therapy (IMRT) to the primary site and at risk neck(s). The prescribed dose to the high risk (HR) and standard risk (SR) planning target volumes (PTVs) was 60 Gy and 46 Gy at 2 Gy/fx, respectively. We re-planned these patients with the purpose of sparing the primary site. PTV-SR and PTV-HR were adjusted to exclude the primary site from the treatment volumes. Re-plans were performed such that the primary site was maximally spared while maintaining similar PTV coverage and normal tissue avoidance as the initial, standard treated plan. Results: Dosimetric results are shown in the table. Both plans were able to adequately (at least 95% of the target volume receives 100% of the prescribed dose) cover the PTVs and similarly spare normal tissues (spinal cord, brainstem, contralateral parotid, ipsilateral cochlea, and larynx). The mean dose to the primary site was reduced by 33% (19 Gy) and the mean dose to the oral cavity was reduced by 50% (24 Gy). The conformity index was worse when the primary site was spared. Conclusions: Reducing the mean dose delivered to oropharynx after TLM by approximately 20 Gy is feasible using 9-field, step and shoot, IMRT. Sparing the primary site post TLM may yield reductions in toxicity.
Poster Viewing Abstract 2672; Table primary included plans
Comparison of primary spared versus Primary site spared plans average [max, min]
PTV-HR volume PTV-HR conformity index PTV-SR volume PTV-SR conformity index Primary avoidance volume Mean dose to primary avoidance % Primary avoidance 60 Gy Mean dose to oral cavity Mean dose to parotid
104cc [117, 83] 2.33 [2.81, 2.12] 290cc [358, 252] 4.83 [6.34, 3.91] 107cc [138, 64] 42 Gy [47, 40] 4.1% [16, 0.2] 24 Gy [29, 18] 23 Gy [24, 21]
Primary site NOT spared plans average [max, min] 198cc [249, 115] 2.22 [3.03, 1.82] 397cc [496, 316] 4.27 [5.26, 3.74] NA 61Gy [62, 60] NA 48 Gy [56, 42] 23 Gy [25, 21]
Author Disclosure: D. Fried: None. M. Lehman-Davis: None. T. Hackman: None. M. Kostich: None. J. Lian: None. K. Burkhardt: None. B. Chera: None.
2673 Transoral Laser Microsurgery (TLM) Followed by Radiation Therapy (RT) for Oropharyngeal Tumors S.H. Patel, W. Wong, M. Hinni, R. Hayden, M. Zarka, A.C. Dueck, K. Curtis, and M. Halyard; Mayo Clinic Arizona, Scottsdale, AZ Purpose/Objective(s): To report the treatment outcomes of locally advanced oropharyngeal cancer patients (pts) treated with TLM followed by RT at MCA. Materials/Methods: An IRB approved retrospective study of 80 pts treated from January 1, 2000 through November 7, 2011 was performed. All pts had stage III or IV tonsil and/or base of tongue primary tumors and
2674 HPV-Positive Squamous Cell Carcinoma of the Oropharynx Is Adequately Treated With Radiation Therapy Alone M.L. Mierzwa,1 L.E. Imwalle,1 K.A. Casper,2 A. Dwivedi,3 Q. Zhai,4 K.P. Redmond,1 and W.L. Barrett1; 1Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, 2Department of Otolaryngology, University of Cincinnati, Cincinnati, OH, 3Center for Biostatistical Services, University of Cincinnati, Cincinnati, OH, 4Department of Pathology, University of Cincinnati, Cincinnati, OH Purpose/Objective(s): At our institution, clinicians have historically had opposing biases regarding the role of concurrent cytotoxic chemotherapy in the management of locally advanced head and neck cancer. This presents a unique opportunity to review patients treated with either definitive radiation therapy or chemoradiation therapy for squamous cell carcinoma of the oropharynx (SCCOP) in the HPV era. Materials/Methods: We retrospectively reviewed 63 consecutive patients treated from 2006-2009 for cT2N2b-T4N3 SCCOP at UC for whom p16 immunostaining was clinically performed or pathology was available for retrospective HPV analysis. Patient treatment consisted of either definitive RT consisting of EBRT to 70Gy or EBRT to 50Gy followed by brachytherapy boost, of definitive chemoradiation therapy (CRT) consisting of EBRT to 70Gy with concurrent cisplatin 100mg/m2 q 3 week. The endpoints analyzed included locoregional control (LRC), distant-metastasis free survival (DMFS), overall survival (OS) and toxicities according to RTOG criteria. The LRC, DMFS and OS were estimated from the date of completed RT till date of each event respectively or date of last follow up. Log rank test was used to compare the LRC, DMFS and OS according to cofactors. Fisher’s exact test was used to compare the variables between the treatment groups. Results: Median follow-up was 17.8 mo (range:1.8-73.4). Minimum follow up for living patients was 24 mo. 71% of patients were HPV positive by p16 analysis. 27(43%) patients underwent definitive RT, and 36 (57%) patients underwent chemoRT. Pretreatment variables including smoking status, p16, site, T and N stage were balanced between RT and CRT groups (pZ.60, 0.09, 0.26, 0.47 and .71 respectively). A total of 12 (19%) patients observed with LR, 12 (19%) patients with DM. 16 (25.4%) deaths were found in this study. The overall LRC, DMFS and OS were estimated as 81%, 81% and 79% at 1 year. For HPV+ patients, LRC, DMFS and OS at 2 years were 87%, 87% and 96% for CRT and 100%, 94% and 93% for RT (pZ0.21, 0.91, 0.50). For HPV- patients, 2 year LRC, DMFS and OS were 57%, 54% and 57% for CRT and 44%, 45% and 12% for RT pZ0.90, 0.98, 0.27). p16 status was the only independent factor associated with LR, DM and OS. There were 16 T4 tumors in this study, of these 8 were HPV+; only