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A Dosimetric Evaluation of Oral Tongue Sparing to Reduce Dysgeusia in Head and Neck Cancers
Poster Viewing Abstracts S507
Volume 90 Number 1S Supplement 2014 analysis showed that the radiological nodal extension was an only significant factor for the OS; the 3-year OS rate in patients with and without nodal extension was 41% and 79%, respectively (P Z 0.0013). Although all of the post-treatment variables were significant factors by univariate analysis, in contrast, multivariate analysis confirmed that CCRT effect, multiple nodes, and nodal extension were independent predictors (Table); the 3-year OS rate in patients with and without nodal extension was 9% and 82%, respectively. Conclusions: The radiological and pathological nodal extensions based on the lymph node levels are important prognostic factors in patient with advanced oral cancer.
Scientific Abstract 2748; Table variables Pathological variables CCRT effect Node positive Multiple nodes Contralateral node Nodal extension
Multivariate analysis of post-treatment Overall survival
Hazard ratio
95% confidence interval
P
2.5419 Not applicable 3.0745 Not applicable 3.7066
1.1535 - 5.6011
.0213
1.3098 - 7.2166
.0103
1.4681 - 9.3579
.0058
CCRT effect Z pathological effect of preoperative concurrent chemoradiation therapy on the primary tumor. Nodal extension Z nodal extension to the levels Ia, III, IV, and/or V.
Author Disclosure: R. Murakami: None. N. Kai: None. Y. Fujita: None. R. Toya: None. T. Hirai: None. H. Nakayama: None. Y. Yamashita: None. M. Shinohara: None.
2749 A Dosimetric Evaluation of Oral Tongue Sparing to Reduce Dysgeusia in Head and Neck Cancers Z.P. Nicholas, S. Ahmad, T. Herman, and C.L. Matthiesen; Stephenson Cancer Center, Oklahoma City, OK Purpose/Objective(s): Radiotherapy for head and neck malignancies continues to be an area of research and quality improvement. Dysgeusia is a significant acute and long term toxicity experienced by patients receiving head and neck radiotherapy. Unlike other acute effects of esophagitis, mucositis, and xerostomia, dysgeusia has no significant medical intervention available. At this time, the only believed therapy is to minimize dose to the tongue, however this is often difficult due to close tumor volumes, and or the later effects of sparing other structures such as the salivary glands. This study aims to investigate the possibility of reducing dose to the oral tongue to reduce clinical dysgeusia without compromising PTV coverage and other normal structure preservation. Materials/Methods: Ten patients were retrospectively selected from our institutional database that were previously planned and treated with IMRT for head and neck cancer. Five patients had a unilateral T1-T2 tonsillar cancer with N1-2B neck lymph nodes (LN), and 5 patients had supraglottic cancers of similar stage. Exclusion criteria included bilateral gross disease in the LN or primary, extension of the primary to the oral tongue or a positive level I LN. The oral tongue was defined as the anterior 2/3rds of the tongue. Any primary lesion that extended to the base of the tongue had 5mm cropped out of the oral tongue structure from the high dose PTV margin without violating the border of the oral tongue. The plans were then re-optimized to evaluate the ability to reduce the dose of the contoured oral tongue to a target mean dose of 2000cGy. Results: All plans were normalized to the 95% isodose line without exception. Regarding the pre-study dosimetry, the mean dose to the target PTV was 7462 cGy, and the mean dose to the oral tongue was 4033 830 cGy. Following study re-optimization, the mean dose to the target PTV was consistent at 7471 cGy and the mean dose to the tongue was reduced
to 2210 239 cGy for all plans (P Z <0.001). This represents an average decrease in mean oral tongue dose of 1823cGy per plan or (45%). As a consequence of this re-optimization, the mean increase to the ipsalateral parotid was not significant (19 cGy, P Z 0.98). The mean PTV maximum dose increased by 29cGy and the mean PTV minimum dose decreased by 131cGy both were also insignificant. Conclusions: This study suggests that select head and neck cancers with unilateral gross disease can achieve significant tongue sparing. This was done without a significant compromise of target PTV coverage or increase in normal structure dosing in an attempt to improve acute and long term dysgeusia. The optimal dose reduction to improve clinical dysgeusia remains unknown, and warrants further investigation. Author Disclosure: Z.P. Nicholas: None. S. Ahmad: None. T. Herman: None. C.L. Matthiesen: None.
2750 Evaluation of Primary Treatment Technique for Squamous Cell Carcinoma of the Buccal Mucosa: A Single-Center Experience E.D. Scher, E. Handorf, J.A. Ridge, R. Mehra, M.N. Lango, B. Burtness, J.C. Liu, and T.J. Galloway; Fox Chase Cancer Center, Philadelphia, PA Purpose/Objective(s): Squamous cell carcinoma of the buccal mucosa is an uncommon oral cancer with a high rate of local recurrence. The purpose of this analysis is to review an institutional policy favoring primary radiation for thick/advanced tumors on functional and cosmetic grounds. Materials/Methods: We retrospectively reviewed the charts of patients treated for buccal mucosa cancer with curative intent at a single tertiary care cancer center between January 1990 and April 2013 under an IRB approved protocol. Patients were assessed using univariate and multivariate analyses. Local regional control (LRC), progression-free survival (PFS), and overall survival (OS) were analyzed utilizing the Kaplan-Meier method. Results: Fifty-five patients met the inclusion criteria, 32 (58%) of whom were treated with primary surgery. Twenty-three (42%) were treated initially with radiation therapy (RT). Neither age (p Z 0.30), stage (p Z 0.99), 10-pack year smoking history (p Z 0.44), nor use of chronic mouth irritants (betel nut/alcohol use > 7 drinks a week/smokeless tobacco) differed (p Z 0.78) among treatment groups. Half (n Z 16, 50%) of patients treated with primary surgery received adjuvant radiation (median 60, range 34 - 68.25 Gy) according to conventional indications. Patients treated with primary radiation with curative intent received a median dose of 70 (range 34 - 70) Gy, with radiosensitizing systemic therapy (n Z 9, 39%), interstitial brachytherapy (n Z 4, 17%), or external beam radiation alone (n Z 10, 44%). LRC was not significantly influenced by treatment modality (primary surgery: 65%, primary radiation: 50%; p Z 0.30), 10-pack year smoking history (p Z 0.99), stage (p Z 0.16), chronic mouth irritants (p Z 0.40) or age (p Z 0.55). By contrast, treatment with primary surgery had a significant PFS (p Z 0.0024) and OS benefit (p Z 0.05). Earlier stage had a similar PFS (p Z 0.0003) and OS benefit (p Z 0.0003). On multivariate analysis, the PFS benefit of treatment with primary surgery (p Z 0.019) and for early stage tumors persisted (p Z 0.003). The benefit of surgery was largely confined to patients with stage I/II disease, with a PFS of 100% at two years (p Z 0.016). By contrast, the two year PFS of patients managed with primary surgery for stage III/IV tumors (33%), primary radiation for stage I/II tumors (46%), and primary radiation for stage III/IV tumors (18%) was poor. Most recurrences were local (24/26, 92%). Thirteen patients submitted to salvage surgery for recurrence survived 1.8 years (range 0.29 - 4.56). Conclusions: Select T1-T2 N0 buccal mucosa cancers do well when managed with primary surgery. By contrast, advanced tumors (Stage III/ IV) requiring combined modality therapy and Stage I/II tumors managed with primary RT did not do well. Author Disclosure: E.D. Scher: None. E. Handorf: None. J.A. Ridge: None. R. Mehra: None. M.N. Lango: None. B. Burtness: None. J.C. Liu: None. T.J. Galloway: None.
Volume 90 Number 1S Supplement 2014 analysis showed that the radiological nodal extension was an only significant factor for the OS; the 3-year OS rate in patients with and without nodal extension was 41% and 79%, respectively (P Z 0.0013). Although all of the post-treatment variables were significant factors by univariate analysis, in contrast, multivariate analysis confirmed that CCRT effect, multiple nodes, and nodal extension were independent predictors (Table); the 3-year OS rate in patients with and without nodal extension was 9% and 82%, respectively. Conclusions: The radiological and pathological nodal extensions based on the lymph node levels are important prognostic factors in patient with advanced oral cancer.
Scientific Abstract 2748; Table variables Pathological variables CCRT effect Node positive Multiple nodes Contralateral node Nodal extension
Multivariate analysis of post-treatment Overall survival
Hazard ratio
95% confidence interval
P
2.5419 Not applicable 3.0745 Not applicable 3.7066
1.1535 - 5.6011
.0213
1.3098 - 7.2166
.0103
1.4681 - 9.3579
.0058
CCRT effect Z pathological effect of preoperative concurrent chemoradiation therapy on the primary tumor. Nodal extension Z nodal extension to the levels Ia, III, IV, and/or V.
Author Disclosure: R. Murakami: None. N. Kai: None. Y. Fujita: None. R. Toya: None. T. Hirai: None. H. Nakayama: None. Y. Yamashita: None. M. Shinohara: None.
2749 A Dosimetric Evaluation of Oral Tongue Sparing to Reduce Dysgeusia in Head and Neck Cancers Z.P. Nicholas, S. Ahmad, T. Herman, and C.L. Matthiesen; Stephenson Cancer Center, Oklahoma City, OK Purpose/Objective(s): Radiotherapy for head and neck malignancies continues to be an area of research and quality improvement. Dysgeusia is a significant acute and long term toxicity experienced by patients receiving head and neck radiotherapy. Unlike other acute effects of esophagitis, mucositis, and xerostomia, dysgeusia has no significant medical intervention available. At this time, the only believed therapy is to minimize dose to the tongue, however this is often difficult due to close tumor volumes, and or the later effects of sparing other structures such as the salivary glands. This study aims to investigate the possibility of reducing dose to the oral tongue to reduce clinical dysgeusia without compromising PTV coverage and other normal structure preservation. Materials/Methods: Ten patients were retrospectively selected from our institutional database that were previously planned and treated with IMRT for head and neck cancer. Five patients had a unilateral T1-T2 tonsillar cancer with N1-2B neck lymph nodes (LN), and 5 patients had supraglottic cancers of similar stage. Exclusion criteria included bilateral gross disease in the LN or primary, extension of the primary to the oral tongue or a positive level I LN. The oral tongue was defined as the anterior 2/3rds of the tongue. Any primary lesion that extended to the base of the tongue had 5mm cropped out of the oral tongue structure from the high dose PTV margin without violating the border of the oral tongue. The plans were then re-optimized to evaluate the ability to reduce the dose of the contoured oral tongue to a target mean dose of 2000cGy. Results: All plans were normalized to the 95% isodose line without exception. Regarding the pre-study dosimetry, the mean dose to the target PTV was 7462 cGy, and the mean dose to the oral tongue was 4033 830 cGy. Following study re-optimization, the mean dose to the target PTV was consistent at 7471 cGy and the mean dose to the tongue was reduced
to 2210 239 cGy for all plans (P Z <0.001). This represents an average decrease in mean oral tongue dose of 1823cGy per plan or (45%). As a consequence of this re-optimization, the mean increase to the ipsalateral parotid was not significant (19 cGy, P Z 0.98). The mean PTV maximum dose increased by 29cGy and the mean PTV minimum dose decreased by 131cGy both were also insignificant. Conclusions: This study suggests that select head and neck cancers with unilateral gross disease can achieve significant tongue sparing. This was done without a significant compromise of target PTV coverage or increase in normal structure dosing in an attempt to improve acute and long term dysgeusia. The optimal dose reduction to improve clinical dysgeusia remains unknown, and warrants further investigation. Author Disclosure: Z.P. Nicholas: None. S. Ahmad: None. T. Herman: None. C.L. Matthiesen: None.
2750 Evaluation of Primary Treatment Technique for Squamous Cell Carcinoma of the Buccal Mucosa: A Single-Center Experience E.D. Scher, E. Handorf, J.A. Ridge, R. Mehra, M.N. Lango, B. Burtness, J.C. Liu, and T.J. Galloway; Fox Chase Cancer Center, Philadelphia, PA Purpose/Objective(s): Squamous cell carcinoma of the buccal mucosa is an uncommon oral cancer with a high rate of local recurrence. The purpose of this analysis is to review an institutional policy favoring primary radiation for thick/advanced tumors on functional and cosmetic grounds. Materials/Methods: We retrospectively reviewed the charts of patients treated for buccal mucosa cancer with curative intent at a single tertiary care cancer center between January 1990 and April 2013 under an IRB approved protocol. Patients were assessed using univariate and multivariate analyses. Local regional control (LRC), progression-free survival (PFS), and overall survival (OS) were analyzed utilizing the Kaplan-Meier method. Results: Fifty-five patients met the inclusion criteria, 32 (58%) of whom were treated with primary surgery. Twenty-three (42%) were treated initially with radiation therapy (RT). Neither age (p Z 0.30), stage (p Z 0.99), 10-pack year smoking history (p Z 0.44), nor use of chronic mouth irritants (betel nut/alcohol use > 7 drinks a week/smokeless tobacco) differed (p Z 0.78) among treatment groups. Half (n Z 16, 50%) of patients treated with primary surgery received adjuvant radiation (median 60, range 34 - 68.25 Gy) according to conventional indications. Patients treated with primary radiation with curative intent received a median dose of 70 (range 34 - 70) Gy, with radiosensitizing systemic therapy (n Z 9, 39%), interstitial brachytherapy (n Z 4, 17%), or external beam radiation alone (n Z 10, 44%). LRC was not significantly influenced by treatment modality (primary surgery: 65%, primary radiation: 50%; p Z 0.30), 10-pack year smoking history (p Z 0.99), stage (p Z 0.16), chronic mouth irritants (p Z 0.40) or age (p Z 0.55). By contrast, treatment with primary surgery had a significant PFS (p Z 0.0024) and OS benefit (p Z 0.05). Earlier stage had a similar PFS (p Z 0.0003) and OS benefit (p Z 0.0003). On multivariate analysis, the PFS benefit of treatment with primary surgery (p Z 0.019) and for early stage tumors persisted (p Z 0.003). The benefit of surgery was largely confined to patients with stage I/II disease, with a PFS of 100% at two years (p Z 0.016). By contrast, the two year PFS of patients managed with primary surgery for stage III/IV tumors (33%), primary radiation for stage I/II tumors (46%), and primary radiation for stage III/IV tumors (18%) was poor. Most recurrences were local (24/26, 92%). Thirteen patients submitted to salvage surgery for recurrence survived 1.8 years (range 0.29 - 4.56). Conclusions: Select T1-T2 N0 buccal mucosa cancers do well when managed with primary surgery. By contrast, advanced tumors (Stage III/ IV) requiring combined modality therapy and Stage I/II tumors managed with primary RT did not do well. Author Disclosure: E.D. Scher: None. E. Handorf: None. J.A. Ridge: None. R. Mehra: None. M.N. Lango: None. B. Burtness: None. J.C. Liu: None. T.J. Galloway: None.