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Safety of Submandibular Gland-Sparing Intensity Modulated Radiation Therapy for Head-and-Neck Cancer
Volume 87 Number 2S Supplement 2013 a gradation in risk for nodal dissemination evident at presentation dependent on anatomic subsite, with maxillary sinus carrying the highest risk (20.6%), followed by frontal/sphenoid (15.4%), ethmoid (11.9%), and nasal cavity (8.5%, p < .001). Conclusions: The risk of nodal involvement in cancers of the paranasal sinus is dependent on local extension, histology and anatomic location. The issue of appropriate radiation portals in the treatment of these patients has not been entirely clear, although our data suggests that in the absence of gross neck disease that the low neck and retropharyngeal nodes do not need to be treated. Although subject to limitations of the SEER analysis, this analysis suggests criteria via which patients can be selected for elective nodal irradiation. Author Disclosure: P. Ahn: K. Stock; father.
141 Safety of Submandibular Gland-Sparing Intensity Modulated Radiation Therapy for Head-and-Neck Cancer M.F. Gensheimer, J.J. Liao, G.E. Laramore, and U. Parvathaneni; University of Washington Medical Center, Seattle, WA Purpose/Objective(s): For patients with head and neck cancer, parotid sparing IMRT is the standard of care. However, parotid saliva lacks mucins and preserving it has inconsistently translated to improvements in xerostomia. The submandibular glands (SMG) contribute to 90% of unstimulated saliva that is rich in mucins and SMG sparing has been shown to significantly improve patient-reported xerostomia. However, sparing the SMG is technically challenging due to the proximity of target volumes and the small size of the gland compared to the parotid. The feasibility and safety of SMG-sparing IMRT has not been established in a large series. Materials/Methods: We analyzed 93 consecutive patients treated with IMRT for head and neck squamous cell carcinoma between Feb. 2006 and Jul. 2012, who had at least one SMG spared (mean SMG dose < 45 Gy). SMG sparing was typically considered on the side of elective nodal treatment. Patients with recurrent disease, those receiving unilateral treatment, and those with follow-up of < 6 months were excluded. Primary sites were: oropharynx 61, oral cavity 9, hypopharynx 6, unknown primary 6, nasopharynx 5, larynx 5, and maxillary sinus 1. Ninety-eight percent had stage III/IV disease; 86% were node-positive. Sixty were treated with definitive radiation therapy and 33 were treated post-operatively. Median dose to the highest dose target was 70 Gy in 33 fractions (range, 60-72 Gy). Concurrent systemic therapy was used in 77 patients. Results: Eighty-nine patients had 1 SMG spared and 4 patients had both SMGs spared. The median of the mean spared SMG dose was 29.0 Gy (range, 15.6-44.0). Eighty-four percent of spared SMGs had mean dose < 39 Gy, a level which has been shown to reduce xerostomia. The median of the mean parotid dose on the SMG spared side was 23.3 Gy. Median follow-up in surviving patients was 23 months (range, 6-74). Disease recurrence which could be due to SMG sparing was defined as level Ib/IIa nodal failure on the spared side or primary recurrence extending to within 2 cm of the spared SMG. Two patients had recurrences meeting this definition, but on further analysis neither recurrence was felt to be due to SMG sparing. One developed a contralateral out of field oral cavity recurrence on the side of the spared SMG, with the epicenter within the oral mucosal avoidance volume. The other patient developed distant metastases followed by level IIa nodal failure located centrally within the nodal prescription isodose line. Overall, 10 patients had recurrences in the primary site, 9 in the regional nodes and 9 in distant sites. Twenty are deceased. Two-year Kaplan-Meier overall survival was 82%; 2-year locoregional control was 79%. Conclusions: To our knowledge, this is the largest reported series of SMGsparing IMRT. SMG sparing was achieved without compromising tumor control. SMG sparing should be considered in suitable patients to reduce xerostomia and improve quality of life. Author Disclosure: M.F. Gensheimer: None. J.J. Liao: None. G.E. Laramore: None. U. Parvathaneni: None.
Oral Scientific Sessions
S59
142 Gross Tumor Volume of Laryngeal/Hypopharyngeal Cancer Delineated on MRI Is Doubled Compared to Pathology C.P. Raaijmakers, E. Jager, N. Kasperts, J. Caldas-Magalhaes, F. Pameijer, M. Philippens, and C. Terhaard; University Medical Centre Utrecht, Utrecht, Netherlands Purpose/Objective(s): To compare gross tumor volume (GTV) of laryngeal and hypopharyngeal carcinoma delineated on MRI with the tumor volume determined by the pathologist on the laryngectomy specimen. Materials/Methods: From 22 patients (mean age, 62.3; range, 52 -79 years; 20 males and 2 females) with T3 (n Z 5) or T4 (n Z 17) squamous cell carcinoma of the larynx (5 transglottic-, 6 supraglottic-, 1 glottic carcinoma) or hypopharynx (n Z 10), the specimen was obtained after total laryngectomy. The sliced specimen was processed and 3-D reconstructed according to our pathology validation protocol and registered to in vivo MR-images with an accuracy of 3 mm in the cartilage skeleton. Hematoxylin-eosin (H&E) stained sections were obtained and tumor volume on these sections was delineated by two pathologists. Prior to laryngectomy, a high-resolution 1.5 Tesla MRI-scan was performed in a head-and-shoulder mask with a two-element surface receiver coil. T2w images and T1w images before and after injection of gadolinium were obtained. The mean time interval between the MRI-scan and operation was 10.8 days (range, 2-34 days). Three experienced head-and-neck specialists (2 radiation oncologists, 1 radiologist) delineated the GTV on MRI after consensus about guidelines according to delineation of the GTV in clinical practice. Results: The mean tumor volume (27.1 mL, SD 18.2) delineated by the observers were almost doubled compared to tumor volumes delineated by the pathologists (15.5 mL, SD 15.3). For all patients, the GTV of the observers exceeded the tumor volume of the pathologists. The GTVs delineated on MRI included tumor tissue as well as non-tumorous tissues (e.g.; edema and necrosis) enlarging the GTV compared to pathology. To increase accuracy in tumor delineation, evidence-based guidelines are being developed in our institute for the interpretation and delineation of head and neck cancer on MRI. Conclusions: Gross tumor volume on MRI is overestimated in clinical radiation therapy practice compared to tumor volume of the pathology. Author Disclosure: C.P. Raaijmakers: None. E. Jager: None. N. Kasperts: None. J. Caldas-Magalhaes: None. F. Pameijer: None. M. Philippens: None. C. Terhaard: None.
143 Low-Dose Radiation Therapy (2 Gy x 2) in the Treatment of NonHodgkin Lymphoma of the Ocular Adnexa C. Fasola,1 J.C. Jones,2 D. Huang,3 Q. Le,1 R.T. Hoppe,1 and S.S. Donaldson1; 1Stanford Cancer Center, Stanford, CA, 2National Cancer Institute, Bethesda, MD, 3University of California-Los Angeles Olive View, Sylmar, CA Purpose/Objective(s): Low dose radiation has become increasingly used in the management of indolent non-Hodgkin lymphoma (NHL), but has not been studied specifically for cases of ocular adnexal involvement. The objective of this study is to investigate the effectiveness of low dose radiation in the treatment of NHL of the ocular adnexa. Materials/Methods: We reviewed the records of 20 NHL patients with 27 sites of ocular adnexal involvement treated with low dose radiation consisting of 2 successive fractions of 2 Gy between 2005 and 2011. All patients had histologically proven NHL and were clinically staged according to Ann Arbor staging system. Patient characteristics, treatment details, treatment response and clinical outcomes were reviewed. Complete response (CR) is defined as resolution of disease by physical examination with or without radiographic studies. Partial response (PR) is defined as a reduction in size of the tumor by physical examination with or without radiographic studies, in the absence of CR. The primary endpoint is
141 Safety of Submandibular Gland-Sparing Intensity Modulated Radiation Therapy for Head-and-Neck Cancer M.F. Gensheimer, J.J. Liao, G.E. Laramore, and U. Parvathaneni; University of Washington Medical Center, Seattle, WA Purpose/Objective(s): For patients with head and neck cancer, parotid sparing IMRT is the standard of care. However, parotid saliva lacks mucins and preserving it has inconsistently translated to improvements in xerostomia. The submandibular glands (SMG) contribute to 90% of unstimulated saliva that is rich in mucins and SMG sparing has been shown to significantly improve patient-reported xerostomia. However, sparing the SMG is technically challenging due to the proximity of target volumes and the small size of the gland compared to the parotid. The feasibility and safety of SMG-sparing IMRT has not been established in a large series. Materials/Methods: We analyzed 93 consecutive patients treated with IMRT for head and neck squamous cell carcinoma between Feb. 2006 and Jul. 2012, who had at least one SMG spared (mean SMG dose < 45 Gy). SMG sparing was typically considered on the side of elective nodal treatment. Patients with recurrent disease, those receiving unilateral treatment, and those with follow-up of < 6 months were excluded. Primary sites were: oropharynx 61, oral cavity 9, hypopharynx 6, unknown primary 6, nasopharynx 5, larynx 5, and maxillary sinus 1. Ninety-eight percent had stage III/IV disease; 86% were node-positive. Sixty were treated with definitive radiation therapy and 33 were treated post-operatively. Median dose to the highest dose target was 70 Gy in 33 fractions (range, 60-72 Gy). Concurrent systemic therapy was used in 77 patients. Results: Eighty-nine patients had 1 SMG spared and 4 patients had both SMGs spared. The median of the mean spared SMG dose was 29.0 Gy (range, 15.6-44.0). Eighty-four percent of spared SMGs had mean dose < 39 Gy, a level which has been shown to reduce xerostomia. The median of the mean parotid dose on the SMG spared side was 23.3 Gy. Median follow-up in surviving patients was 23 months (range, 6-74). Disease recurrence which could be due to SMG sparing was defined as level Ib/IIa nodal failure on the spared side or primary recurrence extending to within 2 cm of the spared SMG. Two patients had recurrences meeting this definition, but on further analysis neither recurrence was felt to be due to SMG sparing. One developed a contralateral out of field oral cavity recurrence on the side of the spared SMG, with the epicenter within the oral mucosal avoidance volume. The other patient developed distant metastases followed by level IIa nodal failure located centrally within the nodal prescription isodose line. Overall, 10 patients had recurrences in the primary site, 9 in the regional nodes and 9 in distant sites. Twenty are deceased. Two-year Kaplan-Meier overall survival was 82%; 2-year locoregional control was 79%. Conclusions: To our knowledge, this is the largest reported series of SMGsparing IMRT. SMG sparing was achieved without compromising tumor control. SMG sparing should be considered in suitable patients to reduce xerostomia and improve quality of life. Author Disclosure: M.F. Gensheimer: None. J.J. Liao: None. G.E. Laramore: None. U. Parvathaneni: None.
Oral Scientific Sessions
S59
142 Gross Tumor Volume of Laryngeal/Hypopharyngeal Cancer Delineated on MRI Is Doubled Compared to Pathology C.P. Raaijmakers, E. Jager, N. Kasperts, J. Caldas-Magalhaes, F. Pameijer, M. Philippens, and C. Terhaard; University Medical Centre Utrecht, Utrecht, Netherlands Purpose/Objective(s): To compare gross tumor volume (GTV) of laryngeal and hypopharyngeal carcinoma delineated on MRI with the tumor volume determined by the pathologist on the laryngectomy specimen. Materials/Methods: From 22 patients (mean age, 62.3; range, 52 -79 years; 20 males and 2 females) with T3 (n Z 5) or T4 (n Z 17) squamous cell carcinoma of the larynx (5 transglottic-, 6 supraglottic-, 1 glottic carcinoma) or hypopharynx (n Z 10), the specimen was obtained after total laryngectomy. The sliced specimen was processed and 3-D reconstructed according to our pathology validation protocol and registered to in vivo MR-images with an accuracy of 3 mm in the cartilage skeleton. Hematoxylin-eosin (H&E) stained sections were obtained and tumor volume on these sections was delineated by two pathologists. Prior to laryngectomy, a high-resolution 1.5 Tesla MRI-scan was performed in a head-and-shoulder mask with a two-element surface receiver coil. T2w images and T1w images before and after injection of gadolinium were obtained. The mean time interval between the MRI-scan and operation was 10.8 days (range, 2-34 days). Three experienced head-and-neck specialists (2 radiation oncologists, 1 radiologist) delineated the GTV on MRI after consensus about guidelines according to delineation of the GTV in clinical practice. Results: The mean tumor volume (27.1 mL, SD 18.2) delineated by the observers were almost doubled compared to tumor volumes delineated by the pathologists (15.5 mL, SD 15.3). For all patients, the GTV of the observers exceeded the tumor volume of the pathologists. The GTVs delineated on MRI included tumor tissue as well as non-tumorous tissues (e.g.; edema and necrosis) enlarging the GTV compared to pathology. To increase accuracy in tumor delineation, evidence-based guidelines are being developed in our institute for the interpretation and delineation of head and neck cancer on MRI. Conclusions: Gross tumor volume on MRI is overestimated in clinical radiation therapy practice compared to tumor volume of the pathology. Author Disclosure: C.P. Raaijmakers: None. E. Jager: None. N. Kasperts: None. J. Caldas-Magalhaes: None. F. Pameijer: None. M. Philippens: None. C. Terhaard: None.
143 Low-Dose Radiation Therapy (2 Gy x 2) in the Treatment of NonHodgkin Lymphoma of the Ocular Adnexa C. Fasola,1 J.C. Jones,2 D. Huang,3 Q. Le,1 R.T. Hoppe,1 and S.S. Donaldson1; 1Stanford Cancer Center, Stanford, CA, 2National Cancer Institute, Bethesda, MD, 3University of California-Los Angeles Olive View, Sylmar, CA Purpose/Objective(s): Low dose radiation has become increasingly used in the management of indolent non-Hodgkin lymphoma (NHL), but has not been studied specifically for cases of ocular adnexal involvement. The objective of this study is to investigate the effectiveness of low dose radiation in the treatment of NHL of the ocular adnexa. Materials/Methods: We reviewed the records of 20 NHL patients with 27 sites of ocular adnexal involvement treated with low dose radiation consisting of 2 successive fractions of 2 Gy between 2005 and 2011. All patients had histologically proven NHL and were clinically staged according to Ann Arbor staging system. Patient characteristics, treatment details, treatment response and clinical outcomes were reviewed. Complete response (CR) is defined as resolution of disease by physical examination with or without radiographic studies. Partial response (PR) is defined as a reduction in size of the tumor by physical examination with or without radiographic studies, in the absence of CR. The primary endpoint is