Purpose/Objective(s): The widespread use of IMRT for head and neck cancer requires ... Materials/Methods: Commercially available software was used for atlas ...
Proceedings of the 50th Annual ASTRO Meeting
2495
Timesavings for Contour Generation in Head and Neck IMRT: Multi-institutional Experience with an Atlas-based Segmentation Method
K. Hu1, A. Lin2, A. Young1, G. Kubicek2, J. W. Piper3,4, A. S. Nelson3, J. Dolan1, R. Masino1, M. Machtay2 1 4
Beth Israel Deaconess Hospital, NY, NY, 2Thomas Jefferson University, Philadelphia, PA, 3MIMvista Corp, Cleveland, OH, Department of Computer Science, Wake Forest University, Winston-Salem, NC
Purpose/Objective(s): The widespread use of IMRT for head and neck cancer requires comprehensive and consistent target delineation. Manual contouring is a major workflow obstacle for which a more rapid but accurate solution is needed. The purpose of this study is to evaluate the timesavings for initial contour generation by implementing an atlas-based segmentation (ABS) method into the clinical workflow for two different institutions. Materials/Methods: Commercially available software was used for atlas creation and automatic ABS (MIMvista Corp, Cleveland, OH). Each institution created customized atlases containing a library of previously treated patients to reflect its institutional guidelines for normal tissue and PTV delineation. Institution #1 (I1) created an atlas of oropharynx (OPX) and nasopharynx (NPX) patients with 13 subjects each. Institution #2 (I2) created an atlas of OPX and larynx (LAX) patients with 15 subjects each. Three patients for each site were randomly selected for comparison of ABS to manual contouring. For each patient, the best-fit atlas subject was automatically selected and contours were automatically deformed onto the patient’s CT scan in less than 5 minutes. The I1 attending edited the atlas contours directly and the I2 attending edited the contours after the resident edited the atlas contours. The time to manually contour the patient and subsequently edit by an attending was recorded. Results: At I1, the difference in time required for the attending physician to edit the resident’s contours and the atlas contours was not statistically significant (p = 0.33). Total I1 resident contouring timesavings using ABS was 83% for normal structures, 91% for nodal targets, 90% for primary targets (PT), and 87% overall. At I2, ABS followed with editing by a resident and attending physician saved 62% and 50% compared with manual contouring for OPX and LAX patients, respectively. Three of the prospectively contoured patients at I2 were T1-2 and these patients had less complex contours, especially in terms of primary targets. Considering only normal structures and nodal targets, the timesavings were 79% for OPX, 56% for LAX, and 68% for all patients. Conclusions: ABS was shown at I1 to be nearly as helpful to the attending physician as resident contours. Overall time savings using ABS was found to be 87% at I1 and a 68% reduction in contouring time for nodal targets and normal structures and 25% for primary targets at I2. Greater timesavings were experienced for complex patients and additional timesavings are expected as the atlases increase in size. Author Disclosure: K. Hu, None; A. Lin, None; A. Young, None; G. Kubicek, None; J.W. Piper, MIMvista Corp, A. Employment; MIMvista Corp, E. Ownership Interest; A.S. Nelson, MIMvista Corp, A. Employment; MIMvista Corp, E. Ownership Interest; J. Dolan, None; R. Masino, None; M. Machtay, None.
2496
Radiotherapy with Humidification in Head and Neck Cancer: A Pilot Study 1
A. Macann , D. Hay1, H. Krawitz1, V. Thomson1, C. Fraser Browne1, C. Gerard2, R. Morton1 1 Auckland Regional Head and Neck Cancer Service, Auckland City Hospital, Auckland, New Zealand, 2Fisher and Paykel Healthcare, Auckland, New Zealand
Purpose/Objective(s): The principle of moist wound care is well established to prevent dessication and facilitate healing through mechanisms such as enhanced epithelial cell migration. Previously we had demonstrated that the Fisher and Paykel Healthcare MR880 humidifier (nasal prong interface; flow rate 35 liters / min) moisturizes both the pharynx and oral cavity mucosa improving radiotherapy (RT) associated patient (pt) quality of life outcomes. We report a pilot study using home based humidification during RT of head and neck cancer recording both objective and functional mucositis endpoints. Materials/Methods: Pts with stage IV oropharynx, nasopharynx cancers receiving definitive RT to circumferential pharyngeal volumes were encouraged to use the humidifier overnight plus maximally during the day. CTCAE v 3.0 clinical (clin) mucositis, functional mucositis, and dysphagia scores were recorded at baseline and weekly thereafter to week 12. Nutritional mode evaluating nutritional status and feeding tube use was also recorded. Humidification commenced on day 1 of RT and continued until resolution of clin mucositis grade 2 to #1, or at week 12. Compliance was recorded electronically by the flow source. Results: Of 7 pts on study, total dose was 70 Gy (6 pts) and 66 Gy (1 pt); 5 received concurrent Cisplatin. Total duration of humidification ranged from 66 - 91 days. Total number of days of humidifier use for more than 4 hours / day ranged from 0 - 74 days (mean 32.9). The average number of hours / day humidifier use for all days ranged from 0.2 - 11.3 hours (median 3.5; mean 5.1). Analysis of mucositis endpoints for correlation (Mann Whitney) by separation into compliers (average humidification of .5 hours / day: 3 pts) / non compliers (4 pts) identified duration grade 3 clin mucositis as a significant differentiator between the groups (p 0.031). This endpoint scores 0 if clin mucositis grade \3 which could explain a signal of efficacy for effective moisturization with low pt numbers. Conclusions: These findings demonstrate the practicality of home based humidification during RT. Patient education is essential to promote compliance. The hypothesis that effective moisturization of the mucosa can modulate the natural history of mucositis is worth evaluation. The Trans Tasman Radiation Oncology Group (TROG) has activated a randomized phase III trial to evaluate the impact of humidification on acute and long term toxicities experienced with RT for head and neck cancer using the MR880 humidifier. Author Disclosure: A. Macann, None; D. Hay, None; H. Krawitz, None; V. Thomson, None; C. Fraser Browne, None; C. Gerard, Fisher and Paykel Healthcare, A. Employment; R. Morton, None.
2497
Is Chemotherapy Necessary for N1 and N2 Head and Neck Cancer of Unknown Primary?
A. Shoushtari, K. Kerr, K. Sheng, P. Read University of Virginia, Charlottesville, VA Purpose/Objective(s): The optimal treatment of head and neck cancer of unknown primary (HNCUP) continues to be controversial and undefined. This study analyzed outcomes of patients with HNCUP treated at The University of Virginia with
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I. J. Radiation Oncology d Biology d Physics
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Volume 72, Number 1, Supplement, 2008
predominantly preoperative Intensity Modulated Radiation Therapy (IMRT). Concurrent chemotherapy and radiation is commonly used to treat stage III and IV squamous cell carcinoma of the head and neck, but its role in HNCUP is not defined as control rates of the T0 primary are extremely high with radiation alone. Materials/Methods: Records from 22 patients with HNCUP from 2002-2007 were reviewed and analyzed retrospectively. All patients received IMRT, 10 were treated with a Linear Accelerator and 12 were treated with Helical Tomotherapy. All patients received radiation to the gross nodal disease, uninvolved bilateral cervical lymphatics, and pharyngeal axis. The mean preoperative dose to gross disease, pharyngeal axis, and uninvolved bilateral cervical nodes was 57.7 Gy, 53.2 Gy, and 51.1, respectively. Nodal staging distribution was as follows: 5 with N1; 7 with N2a; 3 with N2b; 2 having N2c; and 5 patients with N3. Fourteen patients underwent neck dissection after radiation completion, 3 underwent neck dissection prior to radiation, and 5 were deemed inoperable. Four patients received chemotherapy; 2 of whom were inoperable with N2b and N3 disease, 1 with N2a disease and extracapsular extension, and 1 with lymphoepithelioma histology and bulky N2c disease. Results: Follow-up was a mean of 24 months (range, 4-64 months). Thirty-two percent (6/19) had a complete clinical response to radiation treatment. Of those that had a neck dissection after radiation, 64% (9/14) had a complete pathologic response. Two patients developed local nodal recurrence, and one developed distant metastasis. All three of these patients had N3 disease. One patient died of an unknown cause but did not have any evidence of disease at 13 month follow-up. The 2 year actuarial overall survival, disease-free survival, and nodal control were 88%, 81%, and 85%. Actuarial nodal control at 2 years for N1 and N2 disease was 100%, while the actuarial nodal control for N3 disease was 52% at 2 years. Conclusions: IMRT for HNCUP has comparable survival rates to conventional radiotherapy. By treating gross disease, bilateral uninvolved cervical lymphatics and pharyngeal axis with radiation and no chemotherapy, followed by post-radiation neck dissection, high overall survival, disease free survival, and nodal control can be achieved for those with T0N1 or nonbulky T0N2 disease without extracapsular spread. Patients with T0N3 disease may benefit from the addition of more aggressive chemotherapy, biologic, and or accelerated radiation regimens. Author Disclosure: A. Shoushtari, None; K. Kerr, None; K. Sheng, None; P. Read, None.
2498
Determination of Tumor Growth Rate in Head and Neck Cancer, Correlation with Possible Prognostic Parameters in the Diagnostic Biopsy
C. H. J. Terhaard1,2, L. W. van Bockel1,2, G. M. Verduyn1,2, F. A. Pameier1,3, J. A. Kummer1,4 1 University Hospital Utrecht, Utrecht CX, Netherlands, 2Department of Radiotherapy, Utrecht, Netherlands, 3Department of Radiology, Utrecht, Netherlands, 4Department of Pathology, Utrecht, Netherlands Purpose/Objective(s): Fast proliferating squamous cell carcinomas of the H&N may benefit from more aggressive (accelerated) treatment without delay, resulting in improved tumor control. To determine the rate of volume increase of the primary tumor and neck nodes, we observed tumor growth in the time between a diagnostic and planning CT in oropharyngeal and laryngeal cancer. We searched for markers in the diagnostic biopsy to predict this observed rate of tumor growth. Materials/Methods: Tumor volume was delineated on a diagnostic and second, planning-CT scan made just before the start of radiotherapy, by three observers in 13 patients with oropharyngeal cancer and 40 with stage T2- T4a laryngeal cancer. The mean time between the first and second CT-scan was 34 days and 32 days, respectively. The tumor volume doubling time (TVDT) was calculated from the volume increase and the time interval between both CT-scans. In the biopsy of 9 out of 13 oropharyngeal cancer (all moderately differentiated) the percentage of cells stained with antibodies against Ki67, cyclin A (proliferation markers), and active caspase 3 (apoptosis marker) was measured, and correlated with TVDT. Results: On the diagnostic CT-scan, tumors of the oropharynx showed a mean volume of 28 cm3, significant larger compared to tumors of the larynx (5.9 cm3). The mean percentage of volume increase of the primary tumor was 70% (13-235%) for the oropharynx, and 41% (0-145%) for the larynx. The volume increase of positive lymph nodes was equal (70%) for both sites. The TVDT was \50 days in 38% and 23%, and .100 days in 28% and 58%, for oropharyngeal and laryngeal cancer, respectively. Cyclin A was significantly correlated with TVDT in the 9 oropharynx cases, however, Ki67 and active caspase 3 were not. A significant cutoff point was found for a fraction of cyclin A stained cells of 22%. TVDT was more than 50 days for all tumors with a cyclin A fraction of #22 % (4/4), and TVDT was less than 50 days for all tumors with a cyclin A fraction of .22% (5/5), p = 0.003. Conclusions: This study showed that actually observed TVDT was shorter for primary tumors of the oropharynx, compared to the larynx, but equal for positive neck nodes. Determination of percentage cyclin A stained cells in the diagnostic biopsy could identify patients with fast proliferating oropharyngeal cancer, for which a more aggressive treatment should be considered. Author Disclosure: C.H.J. Terhaard, None; L.W. van Bockel, None; G.M. Verduyn, None; F.A. Pameier, None; J.A. Kummer, None.
2499
High Negative Predictive Value of FDG-PET/CT in Assessment of Tumor Response Following RT of SCCHN
D. Wang, M. Michel, B. Campbell, B. Massey, J. Blumin, S. Wong, C. Schultz Medical College of Wisconsin, Milwaukee, WI Purpose/Objective(s): There is no reliable means for evaluating tumor response to RT of SCCHN. Recent studies suggest that PET has significant advantages over CT alone in identifying unknown primary lesions, pathologic lymph nodes, distant metastases, and recurrent neoplasm. The purpose of this study is to evaluate a value of integrated PET/CT 4-6 mo post RT in assessing tumor response following definitive RT or RT-Chemo. Materials/Methods: From July 2002 through March 2006 a total of 51 patients (mean age of 56 years) with localized primary SCCHN underwent PET/CT at 4-6 mos following definitive RT (13) or RT-Chemo (38). Five patients had T4a and 21 had T3 disease while 24 had N2-N3 and 11 had N1 disease. The PET/CT scans were initially reviewed as routine diagnostic procedures.
