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Comparison of Daily versus Less-than-daily Image-guided Radiotherapy Protocols in the Treatment of Head and Neck Cancer
Proceedings of the 50th Annual ASTRO Meeting age was 56 years (range, 18-84, with 111 patients .45 years old) and male/female ratio was 4: 3. Thirty-one (22%) patients had high risk histology (12 Hurthle cell, 10 poorly differentiated, 8 tall cell, and 1 clear cell) and 81 (58%) had recurrent disease. There were 1 T1, 5 T2, 11 T3, 113 T4, and 9 Tx stage cases. Ninety-eight (71%) patients had N1 disease and 40 (29%) patients were M1. AJCC stage distribution was 1 Stage I, 2 Stage III, 134 Stage IVa-c, and not accessible in 2 cases. Extraglandular disease extension was seen in 117 (84%) cases, positive surgical margins in 43 and gross residual disease in 25. 45 (46%) of N1 patients had extracapsular extension. Radioactive iodine was given to 112 (81%) patients, while chemotherapy was given to 18 (13%). Median total EBRT dose was 60 Gy (range, 37.5-72 Gy) in 30 fractions (range, 15-40). Sixty patients were treated with IMRT technique after 7/ 2000 with a median dose of 60 Gy (range, 54-66 Gy). Median follow-up was 36 months (range, 0-134) for all patients and 44 months for surviving patients (range, 2-134). Results: At last follow-up, 97 (70%) patients were alive, and 115 (83%) patients had no evidence of locoregional disease progression. Kaplan-Meier estimates of locoregional relapse free survival (LRFS), disease specific survival, and overall survival (OS) at 4 years were 79%, 75%, and 72%, respectively. Seventy-eight of 99 M0 patients (79%) remained free of distant failure. Male gender, follicular histology, age over 45 years, M1 disease, gross residual disease, and use of chemotherapy predicted for inferior OS. Use of IMRT did not predict for differences in survival outcomes, but was associated with less late radiation morbidity. Ten (13%) patients had late morbid events requiring intervention after conventional EBRT. One (2%) patient suffered morbidity of equivalent severity following IMRT. Conclusions: Current EBRT techniques provide durable locoregional disease control for high-risk differentiated thyroid cancer. IMRT may significantly reduce chronic radiation morbidity, but requires further study to determine ideal target volumes and dosing. Author Disclosure: M.J. Lobo, None; A.S. Garden, None; W. Morrison, None; K.K. Ang, None; D.I. Rosenthal, None; C. Chao, None; D.B. Evans, None; G. Clayman, None; S. Sherman, None; D.L. Schwartz, None.
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Comparison of Daily versus Less-than-daily Image-guided Radiotherapy Protocols in the Treatment of Head and Neck Cancer
A. M. Chen, J. Perks, R. L. S. Jennelle, R. Sreeraman, A. Michaud, B. Li, S. Vijayakumar, J. A. Purdy University of California, Davis Cancer Center, Sacramento, CA Purpose/Objective(s): Using data from patients treated with daily on-board imaging for head and neck cancer, we aimed to determine if image-guided radiotherapy (IGRT) protocols utilizing less-than-daily cone-beam computed tomography (CBCT) potentially compromises patient alignment and target localization. Materials/Methods: Image registration data from 84 patients treated with daily IGRT were analyzed, resulting in a data set of 2,658 fractions during which CBCT was used for patient localization. The following hypothetical protocols were analyzed for each patient: IGRT performed with every other fraction; IGRT obtained weekly; and IGRT obtained with the first 5 fractions with the mean shifts values calculated and applied to the remaining fractions. Residual setup errors were determined for each scenario as the difference in vector displacement between the less-than-daily IGRT protocol and the actual alignments shifts obtained from daily CBCT. Results: The mean systematic setup errors were 5.0, 0.4, and 2.1 mm in the primary translational axes (anteroposterior, superoinferior, and right-left directions), respectively, when daily IGRT was used. This resulted in a mean overall shift vector (MOSV) of 8.6 mm (range, 0-49.3 mm). Residual MOSV setup errors greater than 5 mm occurred in 24%, 26%, and 21% of treatment fractions when CBCT was utilized every other day, weekly, and with the first 5 fractions, respectively. Using a 3 mm threshold, these percentages increased to 58%, 61%, and 54%, respectively. Incidentally, we also noted that in 921 scans where the translational shifts were less than 5 mm in each of the primary axes, the calculated MOSV exceeded the 5 mm tolerance in 228 (25%). The mean of the MOSV in that situation was 5.6 mm but had an absolute maximum of 8 mm. Conclusions: Although set up errors increased with decreasing frequency of imaging guidance, these data suggest that less-thandaily CBCT may still be acceptable in the utilization of IGRT for head and neck cancer provided an adequate planning margin is incorporated. The optimum protocol in this setting appeared to be the use of CBCT for the first 5 days, calculating the mean shift values, and employing them for the remainder of the treatment. Care should be taken to calculate the MOSV to ensure proper target coverage. The appropriateness of these strategies should be considered at the discretion of the treating clinician. Author Disclosure: A.M. Chen, None; J. Perks, None; R.L.S. Jennelle, None; R. Sreeraman, None; A. Michaud, None; B. Li, None; S. Vijayakumar, None; J.A. Purdy, None.
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Phase II Trial of Hyperfractionated IMRT and Concurrent Cisplatin for Stage III and IV Head and Neck Cancer: Early Quality of Life Analysis
P. D. Maguire1, C. Neal1, M. Papagikos1, M. Meyerson1, S. Hamann2 1
New Hanover Radiation Oncology, Wilmington, NC, 2Coastal Area Health Education Center, Wilmington, NC
Purpose/Objective(s): To evaluate acute quality of life (QOL) for patients with locally advanced squamous cell cancer of the head and neck (SCCHN) treated with a novel chemoirradiation regimen. Materials/Methods: Eligible patients with Stage III or IV SCCHN of oropharynx, hypopharynx or larynx (excluding N2c, N3, and M1 disease) received hyperfractionated intensity modulated radiation therapy (IMRT) with attempted sparing of contralateral parotid gland. High-risk planning target volume (PTV) was prescribed to receive 1.25 Gy bid-70 Gy. Intermediate and low-risk PTVs received 60 Gy and 50 Gy, respectively, at lower doses per fraction bid utilizing a single IMRT plan. Concurrent chemotherapy consisted of cisplatin 33 mg/meter2/week. Validated QOL tool consisted of 39 questions: 24 general, 1 overall, and 14 head and neck specific, 2 of which addressed swallowing function. Patients completed QOL questionnaires prior to treatment (PRE), at end of treatment (EOT), at month 1 (MO1) and month 3 (MO3) following completion. Worsening QOL was defined as .50% reduction in mean QOL score compared to PRE.
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2509
Comparison of Daily versus Less-than-daily Image-guided Radiotherapy Protocols in the Treatment of Head and Neck Cancer
A. M. Chen, J. Perks, R. L. S. Jennelle, R. Sreeraman, A. Michaud, B. Li, S. Vijayakumar, J. A. Purdy University of California, Davis Cancer Center, Sacramento, CA Purpose/Objective(s): Using data from patients treated with daily on-board imaging for head and neck cancer, we aimed to determine if image-guided radiotherapy (IGRT) protocols utilizing less-than-daily cone-beam computed tomography (CBCT) potentially compromises patient alignment and target localization. Materials/Methods: Image registration data from 84 patients treated with daily IGRT were analyzed, resulting in a data set of 2,658 fractions during which CBCT was used for patient localization. The following hypothetical protocols were analyzed for each patient: IGRT performed with every other fraction; IGRT obtained weekly; and IGRT obtained with the first 5 fractions with the mean shifts values calculated and applied to the remaining fractions. Residual setup errors were determined for each scenario as the difference in vector displacement between the less-than-daily IGRT protocol and the actual alignments shifts obtained from daily CBCT. Results: The mean systematic setup errors were 5.0, 0.4, and 2.1 mm in the primary translational axes (anteroposterior, superoinferior, and right-left directions), respectively, when daily IGRT was used. This resulted in a mean overall shift vector (MOSV) of 8.6 mm (range, 0-49.3 mm). Residual MOSV setup errors greater than 5 mm occurred in 24%, 26%, and 21% of treatment fractions when CBCT was utilized every other day, weekly, and with the first 5 fractions, respectively. Using a 3 mm threshold, these percentages increased to 58%, 61%, and 54%, respectively. Incidentally, we also noted that in 921 scans where the translational shifts were less than 5 mm in each of the primary axes, the calculated MOSV exceeded the 5 mm tolerance in 228 (25%). The mean of the MOSV in that situation was 5.6 mm but had an absolute maximum of 8 mm. Conclusions: Although set up errors increased with decreasing frequency of imaging guidance, these data suggest that less-thandaily CBCT may still be acceptable in the utilization of IGRT for head and neck cancer provided an adequate planning margin is incorporated. The optimum protocol in this setting appeared to be the use of CBCT for the first 5 days, calculating the mean shift values, and employing them for the remainder of the treatment. Care should be taken to calculate the MOSV to ensure proper target coverage. The appropriateness of these strategies should be considered at the discretion of the treating clinician. Author Disclosure: A.M. Chen, None; J. Perks, None; R.L.S. Jennelle, None; R. Sreeraman, None; A. Michaud, None; B. Li, None; S. Vijayakumar, None; J.A. Purdy, None.
2510
Phase II Trial of Hyperfractionated IMRT and Concurrent Cisplatin for Stage III and IV Head and Neck Cancer: Early Quality of Life Analysis
P. D. Maguire1, C. Neal1, M. Papagikos1, M. Meyerson1, S. Hamann2 1
New Hanover Radiation Oncology, Wilmington, NC, 2Coastal Area Health Education Center, Wilmington, NC
Purpose/Objective(s): To evaluate acute quality of life (QOL) for patients with locally advanced squamous cell cancer of the head and neck (SCCHN) treated with a novel chemoirradiation regimen. Materials/Methods: Eligible patients with Stage III or IV SCCHN of oropharynx, hypopharynx or larynx (excluding N2c, N3, and M1 disease) received hyperfractionated intensity modulated radiation therapy (IMRT) with attempted sparing of contralateral parotid gland. High-risk planning target volume (PTV) was prescribed to receive 1.25 Gy bid-70 Gy. Intermediate and low-risk PTVs received 60 Gy and 50 Gy, respectively, at lower doses per fraction bid utilizing a single IMRT plan. Concurrent chemotherapy consisted of cisplatin 33 mg/meter2/week. Validated QOL tool consisted of 39 questions: 24 general, 1 overall, and 14 head and neck specific, 2 of which addressed swallowing function. Patients completed QOL questionnaires prior to treatment (PRE), at end of treatment (EOT), at month 1 (MO1) and month 3 (MO3) following completion. Worsening QOL was defined as .50% reduction in mean QOL score compared to PRE.
S397