Multi-institutional Analysis of Solitary Extramedullary Plasmacytoma of the Head and Neck Treated with Curative Radiotherapy

Proceedings of the 51st Annual ASTRO Meeting Mild chronic laryngeal edema and dysphagia were noted in 18% and 7%, respectively and one patient required a tracheostomy for severe laryngeal edema. There were 19 local failures in total with 6 occurring at the original tumor site. The 5-year and 10-year LC rates were 85% and 80.8 %, respectively. There were no local failures beyond ten years. By stage the five year LC was 94% (T1a), 82.6% (T1b), 82.4% (T2a), and 65% (T2b); the ten year LC was 87.4% (T1a), 82.6% (T1b), 82.4% (T2a), and 56.3% (T2b). On univariate analysis, LC, heavy alcohol consumption during diagnosis, anterior commissure involvement, T-Stage, lower dose, and subglottic extension were significant for poor LC (p # 0.05). On multivariate analysis analyzing stage as T1 vs. T2, only heavy alcohol use at diagnosis (p = .002) and involvement of AC (p = .02) were significant. On multivariate analysis analyzing stage T2b compared to the other 3 stage subgroups, heavy alcohol consumption at diagnosis (p = .0004), and stage T2b (p = .02) were significant for inferior LC. The five year CSS and OS was 95.9% and 76.8% for all, respectively. 22% of all patients developed a second primary cancer, with lung (28%) being the most common site. Conclusions: Radiotherapy provides excellent LC and CSS for T1–T2 glottic cancer, and yields excellent long term voice quality for most patients. The major cause of death is due to other causes including second malignancies and co-morbidities and not treatment failures. T2b tumors have inferior outcomes, and more aggressive management strategies should be explored. Author Disclosure: M.K. Khan, None; S. Koyfman, None; G.H. Hunter, None; C.A. Reddy, None; J.P. Saxton, None.

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Evaluation of Arc-based Intensity Modulated Radiotherapy for Head and Neck Cancer

1

M. Rao , W. Yang2, F. Chen1, K. Sheng2, J. Ye1, M. Vivek1, D. Shepard1, D. Cao1 1

Swedish Cancer Institute, Seattle, WA, 2University of Virginia Health Systems, Charlottesville, VA

Purpose/Objective(s): Tomotherapy and Volumetric Modulated Arc Therapy (VMAT) are two arc-based approaches to the delivery of intensity modulated radiation therapy (IMRT). The objective of this study is to compare treatment plans for head and neck (H&N) cancer using VMAT, helical tomotherapy and fixed field IMRT in terms of plan quality, delivery efficiency and accuracy. Materials/Methods: Six complex H&N cases involving multiple targets and multiple prescription levels were selected for this study. Treatment sites included 2 nasopharynx and 4 oropharynx cases. Three different treatment plans were generated for each case: (1) a 9-field IMRT plan; (2) a VMAT plan generated using the SmartArc inverse planning module in the Pinnacle3 treatment planning system and (3) a tomotherapy plan. To meet the treatment goals, two arcs were used in the VMAT plans for all 6 cases. VMAT plans were delivered on an Elekta SynergyÒ equipped with a conventional 80-leaf MLC (1 cm leaf width). Helical tomotherapy plans were delivered using a Tomotherapy HI_ART II system. An IBA MatriXX 2D ion chamber array was used for VMAT plan QA, and an ion chamber and films were used for tomotherapy plan QA. Measured and calculated dose distributions were compared using 2D gamma evaluation with 3%/3mm passing criteria. Results: Both VMAT and tomotherapy are capable of providing highly uniform target doses as compared with fixed field IMRT. On average, 98.0%, 98.4%, and 98.8% of the target volumes were covered with 95% of the prescribed dose for the fixed field, VMAT and tomotherapy plans, respectively. Tomotherapy plans achieved slightly better sparing of the parotid glands, spinal cord, brain stem, larynx, and oral cavity with an average mean organ dose that was 2.0% lower than VMAT and 5.1% lower than fixed field IMRT. The average delivery time of the VMAT plans was 4.9 minutes as compared with 7.5 minutes for tomotherapy and 12.7 minutes for fixed field IMRT. In terms of delivery accuracy, every plan in this study passed our institution’s IMRT verification criteria. Conclusions: As compared with fixed-field IMRT, VMAT and tomotherapy provide highly uniform target doses while improving the dosimetric sparing of critical structures. For complex H&N cases, VMAT technique is able to provide 35% reduction in delivery time as compared with tomotherapy. Author Disclosure: M. Rao, None; W. Yang, None; F. Chen, None; K. Sheng, None; J. Ye, None; M. Vivek, None; D. Shepard, None; D. Cao, None.

2530

Multi-institutional Analysis of Solitary Extramedullary Plasmacytoma of the Head and Neck Treated with Curative Radiotherapy

R. Sasaki1, T. Kawabe1, E. Abe2, N. Uchida3, K. Yasuda4, T. Uno5, M. Fujiwara6, Y. Shioyama7, Y. Shibamoto8, S. Yamada9 Division of Radiation Oncology, Kobe University Graduate School of Medicine, Kobe, Japan, 2Division of Radiation Oncology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan, 3Department of Radiation Oncology, Shimane University Faculty of Medicine, Izumo, Japan, 4Department of Radiology, Hokkaido University School of Medicine, Sapporo, Japan, 5Department of Radiology, Graduate School of Medicine, Chiba University, Chiba, Japan, 6Department of Radiology, Hyogo College of Medicine, Nishinomiya, Japan, 7Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 8Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan, 9Department of Radiation Oncology, Tohoku University, Sendai, Japan 1

Purpose/Objective(s): Extramedullary plasmacytomas of the head and neck regions (EMPHN) are rare plasma cell neoplasms. The objective was to define the effectiveness of radiotherapy in the treatment of patients with EMPHN, and to find a hallmark of the strategy against EMPHN. Materials/Methods: A multi-institutional retrospective review between 1983 and 2008 was performed. Sixty-four patients with EMPHN were registered from 23 Japanese institutions. There were 42 male and 22 female patients. Median age of patients was 64 years old (rang: 12–83). There were 46 patients with performance status (PS by ECOG) 0, 17 patients with PS1, and a patient with PS2. Tumor sites were nasal or paranasal cavities in 35 (55%) patients, oropharynx or nasopharynx in 14 (22%) patients, orbital in 6 (9%) patients, larynx in 3 (5%) patients, and other several sites in 6 patients. Twenty-one (33%) patients were treated with surgical resection proceeded to radiotherapy, while 43 (67%) patients were treated with radiotherapy without surgery. Median radiation dose administered was 50 Gy (range, 30–64 Gy). Chemotherapies were administered in 9 patients (14%). Survival data were calculated by the Kaplan-Meyer method. Progression-free survival was calculated by consideration of all kinds of deaths, either local or distant failure of EMPHN, and progression to multiple myelomas.

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I. J. Radiation Oncology d Biology d Physics

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Volume 75, Number 3, Supplement, 2009

Results: Median follow-up duration was 36 months. Totally, death of 14 patients were identified, including 7 (11%) patients died of the disease. Five-year, 10-year overall and cause-specific survival (OS and CSS) rates were 75%, 61% and 83%, 83%, respectively. Five-year, 10-year local control (LC) rates were 94%, 89%, while 5-year, 10-year progression-free survival (PFS) rates were 46%, 30%, respectively. There were 4 (6%), 21 (33%), and 7 (11%) patients who experienced local failures, distant metastases, and progressions to multiple myelomas, respectively. No independent factor, including total dose, surgery, tumor size, and response was identified as a significant prognostic factor for PFS. There was none who experienced more than Grade 3 acute or late toxicities by radiotherapy. Conclusions: Radiotherapy brought excellent local control in the treatment of EMPHN. However, to improve OS and PFS, strategies against systemic involvement may be considered. Author Disclosure: R. Sasaki, None; T. Kawabe, None; E. Abe, None; N. Uchida, None; K. Yasuda, None; T. Uno, None; M. Fujiwara, None; Y. Shioyama, None; Y. Shibamoto, None; S. Yamada, None.

2531

The Effect of Differential Dosing, using IMRT, on Local Control in the Treatment of Advanced Head and Neck Cancers

J. Fontanesi, P. Chen, K. Marvin, J. Akervall, R. Kiedan, J. Margolis, S. Balaramin, D. J. Krauss, I. Jaiyesimi, A. A. Martinez William Beaumont Hospital, Bloomfield Hills, MI Purpose/Objective(s): The use of IMRT has become more routine in the treatment of advanced HN cancers. Additionally more patients are being treated with primary intent radiation/chemotherapy. The addition of various chemotherapies have been postulated to enhance the radiation effects. However little attention has been paid regarding whether the dose differentials , in this setting of combined treatment , that can be seen in the primary target regions and "non clinically" affected area’s can lead to any increase on local regional failure. Materials/Methods: A retrospective review of all ST III/IV HN cancers that were treated between 1/03 and 4/07 with primary intent once daily irradiation , using IMRT , was undertaken. We identified 52 patients. There were 18 ST III and 34 ST IV. Sites included OC (8), ORO (24),HYPO (9), Lary (8) and UNK (3). 46 received CDDP based concomitant CTX with amifostine , 3 received weekly Erbitux and 3 had irradiation alone. Two patients had treatment breaks in excess of 5 days. Follow-up was recorded from completion of irradiation and ranged from 24 to 75 months (med = 38 months). Daily dose was 200 cGy to the PTV1 (primary and affected LN) and 166–171 to the PTV2 (non affected LN regions). Total dose to PTV1 was 60–72 Gy, to PTV2 it was 50–54 Gy. Results: There were 7 failures in this review that occurred between 5 – 22 months (med = 8 months) post XRT, 6 were local (11.5 %) and one nodal (1.9%). Two did not receive any CTX, both were salvaged surgically. One patient who recurred 7 months was salvaged by re-irradiation and remains locally controlled. The remaining patients have died of their disease. Local failure sites included 1 oro, 3 hypo and 2 laryngeal. The nodal failure was in a tonsillar fossa primary site where the failure was in the ipsilateral parotid LN. Conclusions: The impact of the differential dose, below that which is traditionally utilized(166–171 cGy), to the non affected LN sites, did not result in any noted increase in regional LN failure. The local/regional control rate of 85.5% is excellent in this cohort of patients. The sole regional lymph node failure in an ipsilateral parotid LN site points again to the issue regarding salivary gland sparing risk in some HN cancer sites. We are presently investigating the difference in side effects between these patients and those receiving BID IMRT CTX/irradiation and also the potential impact that the addition of amifostine may have had in this patient population. Author Disclosure: J. Fontanesi, None; P. Chen, None; K. Marvin, None; J. Akervall, None; R. Kiedan, None; J. Margolis, None; S. Balaramin, None; D.J. Krauss, None; I. Jaiyesimi, None; A.A. Martinez, None.

2532

Outcomes for N3 Squamous Cell Carcinoma of the Head and Neck Managed with Definitive Radiotherapy

M. M. Wagner, J. J. Caudell, J. A. Bonner University of Alabama Medical Center, Birmingham, AL Purpose/Objective(s): The radiotherapeutic (RT) management of locoregionally advanced squamous cell carcinoma of the head and neck (SCCHN) is more challenging in the setting of very large cervical lymphadenopathy (N3 disease). Our experience in this setting was reviewed. Materials/Methods: An institutional database of 590 patients with non-nasopharyngeal SCCHN treated with definitive RT between 1995 and 2007 was queried, and 50 patients with N3 disease were identified. Patient, tumor, and treatment factors were abstracted from chart review. Locoregional control (LRC), distant metastasis-free survival (DMFS), and overall survival (OS) were calculated using the Kaplan-Meier method and potential prognostic factors were investigated. Results: Median follow-up of patients alive at last contact was 24 months. Median age was 54 years (range, 36–69 years). Primary sites included oropharynx (n = 30, 60%), hypopharynx (n = 9, 18%), larynx (n = 9, 18%), and unknown primary (n = 2, 4%). Thirty-one patients (62%) were Tx-3, while the remaining nineteen (38%) were T4. Six (12%) patients underwent definitive RT alone. Nine (18%) patients received neoadjuvant chemotherapy; one (2%) subsequently underwent definitive RT alone after induction chemotherapy, while the remaining eight (16%) patients received chemoradiotherapy. The majority of patients (n = 43, 86%) received concurrent systemic therapy and RT. The systemic agents included cetuximab (n = 2, 4%), cisplatin and/or taxol based chemotherapy (n = 38, 76%) or tirapazamine (n = 3, 6%). Neck dissection was performed prior to RT in three (6%) patients, adjuvantly in 21 (42%) patients, and the cervical lymphatics of 26 (52%) patients were observed following RT. Median RT dose was 72 Gy (range, 60–82 Gy) to the gross disease. Twenty-one (42%) patients failed, nine (18%) locoregionally, seven (14%) distantly, and five (10%) both locoregionally and distantly. LRC, DMFS, and OS rates at 2 years were 68%, 74%, 54%, respectively. LRC was significantly improved (66 vs. 36% at 2 years, p = 0.01) for patients who received