- Email: [email protected]
Comparative Dosimetry of an Extensive Scalp Lesion: High-dose-rate Brachytherapy, Electronic Brachytherapy, and Volumetric Modulated Arc Therapy
S516
International Journal of Radiation Oncology Biology Physics
Conclusions: Our analyses suggest that patients with pre- and post-RT OMEc may be at high risk for post-RT SNHL. The dose to the middle ear and chemo-radiation are significant in the incidence of both post-RT OMEc and SNHL. Post-RT OMEc as an indicator of post-RT SNHL needs further investigation. Author Disclosure: N. Bhandare: None. V. Moisseenko: None. W.Y. Song: None. C.G. Morris: None. P. Antonelli: None. W.M. Mendenhall: None.
data comparable to large academic centers with site-specific oncologists. Materials/Methods: From February 2003 to August 2008, 51 patients with nasopharyngeal (nZ8) or oropharyngeal (nZ43) carcinoma were treated with intensity-modulated radiation therapy (IMRT). The majority of patients received treatment for squamous cell carcinoma (nZ50) with one patient undergoing IMRT for treatment of adenoid cystic carcinoma of the oropharynx. One patient treated for nasopharyngeal squamous cell carcinoma was lost to follow-up after 7 months with exclusion from this analysis. Of the 50 patients, 49 were treated with definitive IMRT and 1 received re-treatment for recurrent base of tongue squamous cell carcinoma. Results: The combined median follow-up was 61 months (range, 7-102 months). The overall survival (OS) and local control (LC) were 84% (42/50 patients) and 94% (47/50 patients), respectively. We achieved 100% local control in the treatment of nasopharyngeal carcinoma with a median follow-up of 64.5 months (range, 62 - 95 months). The 5-year overall survival in this group was 100% (7/7 patients). The median time to loco-regional recurrence in the oropharynx population was 11 months (range, 7-18 months) with 93% (40/43 patients) maintaining local control and an overall survival of 83% (40/43 patients)at a median follow-up of 58 months (range, 7-102 months). All patients with local control at 18 months remained free of loco-regional failure in our analysis. Two of the 8 deceased patients (25%) experienced a loss of local control with four (50%) developing metastatic disease prior to the time of death. Only one patient experienced both loco-regional recurrence and distant disease. Conclusions: Institutional reviews from large academic centers provide encouraging results regarding the efficacy and delivery of IMRT in the treatment of head and neck cancer. This retrospective, single-institution analysis demonstrates the ability to effectively implement and utilize IMRT in the treatment of head and neck cancer in an environment with relatively modest patient volume. The excellent overall survival and local control outcomes confirms the possibility for small academic and community centers with low head and neck patient throughput to deliver effective therapy despite the inherent complexity of IMRT. The views expressed are those of the author and do not reflect the official policy of the Department of Defense or U.S. Government. Author Disclosure: J.D. Kehrer: None. R.A. Kiteley: None.
2795 Retrospective Comparison of 2 Feeding Tube Approaches for Headand-Neck Cancer Patients Receiving Concurrent Chemoradiation Therapy I. Karam,1,2 G. Wilson,2 A. Bowman,1 F. Wong,3 and R. Olson1; 1BC Cancer Agency - Vancouver Centre, Vancouver, BC, Canada, 2University of British Columbia, Vancouver, BC, Canada, 3BC Cancer Agency - Fraser Valley Centre, Surrey, BC, Canada Purpose/Objective(s): To compare patient outcomes between a therapeutic versus a prophylactic gastrostomy tube (G-tube) placement approach, in patients treated with concurrent chemo-radiation therapy for head and neck cancer. Materials/Methods: Outcomes were compared between all head and neck patients treated with concurrent chemo-radiation therapy from January 2001 to June 2009 from a centre that places tubes for immediate therapeutic use (centre A) versus a centre that generally places them prophylactically (centre B). A retrospective chart review comparing patient, tumor and treatment characteristics between the two centers was performed. The difference in outcomes between centers was calculated with chi-square tests. Multivariable survival analysis was performed using Cox regression modeling. Results: A total of 434 patients with head and neck cancer were identified, with 62% from centre A. G-tubes were placed in 31% and 88% of patients from centers A and B, respectively. Centre B had significantly higher number of G-tube complications (p<0.001), including infection (16% vs. 5%), leakage (10% vs. 2%), and blockage (3% vs. 1%). Conversely, centre A had more admissions for G-tube related issues (25% vs. 13%, p Z 0.001). Centre B had higher G-tube presence rates at 90 days post-radiation therapy (34% versus 12%; p<0.001). Centre B had non-significantly greater mean weight loss at 1 year (9.1 vs. 7.0 kg, p Z 0.08). There was no significant difference in overall survival on multivariable analysis (A vs. B: HR Z 0.99; p Z 0.96). Conclusions: A prophylactic G-tube approach results in exposing higher number of patients to G-tube complications for longer period of time. The higher rate of hospitalizations using a therapeutic approach suggests that patients are sicker when G-tubes are required. Given the similar weight loss and survival, a therapeutic approach at an earlier stage of need may be a preferable approach. Author Disclosure: I. Karam: None. G. Wilson: None. A. Bowman: None. F. Wong: None. R. Olson: None.
2796 Implementation of Intensity Modulated Radiation Therapy in the Treatment of Carcinoma of the Nasopharynx and Oropharynx: A Retrospective Single Institution Analysis J.D. Kehrer and R.A. Kiteley; Department of Radiation Oncology, Walter Reed National Military Medical Center, Bethesda, MD Purpose/Objective(s): To review the implementation and utilization of intensity-modulated radiation therapy (IMRT) in the treatment of nasopharynx and oropharynx carcinoma at National Naval Medical Center and demonstrate the ability for general radiation oncologists in a low-volume setting to generate local control and overall survival
2797 Comparative Dosimetry of an Extensive Scalp Lesion: High-doserate Brachytherapy, Electronic Brachytherapy, and Volumetric Modulated Arc Therapy S. Park, M. Kamrava, O. Kayode, S.P. Lee, M.L. Steinberg, and D.J. Demanes; University of California Los Angeles, Los Angeles, CA Purpose/Objective(s): It is difficult to deliver conformal homogeneous radiation doses to superficial targets with complex geometry. We studied a patient with an extensive scalp lesion to compare the target and normal tissue dosimetry of high-dose-rate brachytherapy (HDR), electronic brachytherapy (EBT), and volumetric modulated arc therapy (VMAT). Materials/Methods: The patient had a large atypical fibroxanthoma resected from the skin of the calvarium. A customized HDR skin
Poster Viewing Abstract 2797; Table prescription
Brain Brainstem Lens Eyes Optic nerves
Mean dose to the OARs as % of
Ir-192 HDR
50kVp EBT
6MV VMAT
18.3 7.4 2.7 2.9 4.6
8.6 1.4 0.4 0.4 0.7
11.7 0.6 0.5 0.5 0.6
Volume 84 Number 3S Supplement 2012 applicator was constructed by attaching brachytherapy catheters at 1 cm intervals to a 5 mm thick bolus. Two treatment plans were generated for brachytherapy: one for Iridum-192 HDR and the other which assumed treatment with 50 kVp EBT using the same applicator. A third plan was generated for a 2 full arc 6 MV photon VMAT (also with a 5 mm thick bolus). The target and organs at risk (OARs) were contoured on a simulation CT scan. The prescription was 36 Gy in 8 fractions for a 9 cm 12 cm 1 cm target. The plans were optimized to a standard target coverage (V100% > 98%) and to minimize dose to OARs using Nucletron Oncentra MasterPlan (HDR), Varian BrachyVision (EBT) and Eclipse (VMAT). We compared mean target dose, dose heterogeneity, and doses to OARs. Results: The target V100% and D90% were 98% and 104% (HDR), 100% and 119% (EBT), and 98% and 102% (VMAT). The mean (and range from minimum to 1cc maximum) target doses were HDR 119% (86-157%), EBT 164% (86-271%), and VMAT 104% (96-108%). The Table summarizes mean dose to OARs. Conclusions: EBT provided the least dose to closest OAR (brain) due to rapid dose fall-off of low-energy X-rays, but it resulted in higher mean target doses and more heterogeneity than HDR and VMAT. HDR and VMAT provided similar V100% and D90% target doses. As expected, VMAT provided most dose uniformity. All methods resulted in acceptable normal tissue doses, but they were lower for EBT and VMAT than HDR specifically for this lesion located on the top of the skull. Comparative dosimetry facilitates treatment modality selection for extensive superficial lesions with complex surfaces, irregular contours, and close proximity to OARs. Author Disclosure: S. Park: None. M. Kamrava: None. O. Kayode: None. S.P. Lee: None. M.L. Steinberg: None. D.J. Demanes: None.
2798 Fentanyl Pectin Nasal Citrate (FPNC) to Control Breakthrough Pain (BP) and Improve Dysphagia in Head-and-Neck Cancer Patients Receiving Radiation Therapy (RT) I. Prieto,1 J. Pardo,2 A. Perez-Casas,1 J. Olivera,1 J. Luna,1 and J. Vara1; 1 Fundacion Jimenez Diaz, Madrid, Spain, 2Hospital General de Catalun˜a, Barcelona, Spain Purpose/Objective(s): To evaluate the breakthrough pain control and the improvement of the dysphagia in head and neck cancer patients (HNCP) who develop mucositis and moderate-severe dysphagia radiation therapyinduced. Materials/Methods: Eleven patients with breakthrough pain due to radiation therapy-induced mucositis were selected to start treatment with FPNC in order to relief the pain associated with swallowing. Patients were already receiving an opioid treatment at total dose equivalent to 40-80 mg morphine. Incidental pain was treated before eating 4-5 times /day with a dose of 100-400 mg of FPNC. Data related to tolerance, pain relief and efficient dose for swallowing maintenance were collected. Results: Patients who adhered to the FPNC treatment reached satisfactory pain control. Three patients chose do not receive the basal opioid treatment, and then achieved BP relieve only with FPNC. The efficient dose of FPNC was 200 mg in most of patients. Only 1 needed 400 mg. The mean onset time of the pain relief was 7 minutes (range 5-10) in 6 patients, and the mean response duration was 60 min (range 45-75 min). This relief effect allowed oral feeding, nutritional parameters maintenance, and, therefore, improvement in the patient’s quality of life. Also permitted deliver RT treatment without interruptions. Conclusions: BP management is difficult to manage and so are most agents used to treat it. HNCP treated with radiation therapy develop oral mucositis with severe breakthrough incidental pain associated with swallowing, so a simple, rapid and strong analgesic is needed. The oral rescue dose is likely to be inadequate for a significant percentage of these patients with xerostomia and severe oral pain. The intranasal way eliminate this
Poster Viewing Abstracts S517 problem and offers a rapid an efficient absorption. FPNC seems to be particularly beneficial and well accepted in patients with BP due to radiation therapy-induced mucositis. Author Disclosure: I. Prieto: None. J. Pardo: None. A. Perez-Casas: None. J. Olivera: None. J. Luna: None. J. Vara: None.
2799 WITHDRAWN
2800 Prognostic Utility of Pretreatment Metabolic Tumor Volume, Gross Tumor Volume, Maximum Standardized Uptake Value in Head-andNeck Cancer Patients Receiving IMRT P. Romesser,1 B.A. Shah,1 M.M. Qureshi,1 S. Jalisi,1,2 R.M. Subramaniam,1,2 and M. Truong1,2; 1Boston University School of Medicine, Boston, MA, 2Boston Medical Center, Boston, MA Purpose/Objective(s): This retrospective study compared the prognostic utility of pretreatment metabolic tumor volume (MTV), gross tumor volume (GTV) and raw maximum standardized uptake value (SUVmax), with respect to tumor control and survival in patients with head and neck squamous cell carcinoma (HNSCC) undergoing intensity modulated radiation therapy (IMRT) with or without concomitant chemotherapy. Materials/Methods: Between 2004 and 2009, 41 HNSCC patients who underwent a pretreatment PET/CT and definitive IMRT were identified. All PET/CT studies were retrieved from the electronic archival system and reviewed on a MIMvista workstation (software version 4.1). Fused PET/CT images were reviewed in axial, coronal, and sagittal planes. SUVmax and MTV were obtained from the PET/CT scans. GTVs manually contoured by the radiation oncologist were obtained from the Dose Volume Histograms (DVH). The SUVmax was defined as the maximum standardized uptake value within the tumor normalized to lean body mass, MTV was defined as the tumor volume with FDG uptake using a gradient-based (PET Edge) auto-segmentation method. Local (LC), nodal (NC), distant (DC), overall (OC) control and overall (OS) and disease free (DFS) survival were calculated using the Kaplan Meier product-limit method. Receiver operator characteristic (ROC) curves were constructed by plotting sensitivity versus (1-specificity) and optimum cutoff values for above parameters were derived for endpoint LC. Percent area under the ROC curves (AUC) and their 95% confidence intervals were found. A probability value of less than 0.05 was considered statistically significant. Results: Median follow up was 24.2 months (range, 2.7- 56.3 months). The GTV and MTV were 22.2 cc, and 7.2 cc respectively. The median SUVmax was 15.8. Patients with smaller GTVs (<22.2 cc) demonstrated two-year actuarial LC rates of 100% versus 56.4% (pZ0.001) and OS rates of 94.4% versus 65.9% (pZ0.045). Similarly, a smaller MTV (<7.2 cc) correlated with improved LC and OS with two-year actuarial LC rates of 100% versus 54.2% (pZ0.0003) and OS rates of 94.7% versus 64.2% (pZ0.040). Smaller GTV and MTV correlated with improved NC, DC, OC and DFS. SUVmax did not correlate with LC and OS when analyzed by median threshold. An exploratory analysis using ROC curves constructed for the LC endpoint identified a cutoff value of SUVmax of 19.3 (AUCZ73%, 95% CI 56% - 85%), GTV of 29.6 cc (AUCZ89%, 95% CI 75% - 97%), and MTV of 7.7 cc (AUCZ81%, 95% CI 66% - 92%). Both GTV and MTV retained significance using ROC optimized cutoff values. In all cases the MTV was smaller than the GTV. Conclusions: In HNSCC patients undergoing IMRT, MTV and GTV demonstrate superior prognostic utility compared to SUVmax. Author Disclosure: P. Romesser: None. B.A. Shah: None. M.M. Qureshi: None. S. Jalisi: None. R.M. Subramaniam: None. M. Truong: None.
International Journal of Radiation Oncology Biology Physics
Conclusions: Our analyses suggest that patients with pre- and post-RT OMEc may be at high risk for post-RT SNHL. The dose to the middle ear and chemo-radiation are significant in the incidence of both post-RT OMEc and SNHL. Post-RT OMEc as an indicator of post-RT SNHL needs further investigation. Author Disclosure: N. Bhandare: None. V. Moisseenko: None. W.Y. Song: None. C.G. Morris: None. P. Antonelli: None. W.M. Mendenhall: None.
data comparable to large academic centers with site-specific oncologists. Materials/Methods: From February 2003 to August 2008, 51 patients with nasopharyngeal (nZ8) or oropharyngeal (nZ43) carcinoma were treated with intensity-modulated radiation therapy (IMRT). The majority of patients received treatment for squamous cell carcinoma (nZ50) with one patient undergoing IMRT for treatment of adenoid cystic carcinoma of the oropharynx. One patient treated for nasopharyngeal squamous cell carcinoma was lost to follow-up after 7 months with exclusion from this analysis. Of the 50 patients, 49 were treated with definitive IMRT and 1 received re-treatment for recurrent base of tongue squamous cell carcinoma. Results: The combined median follow-up was 61 months (range, 7-102 months). The overall survival (OS) and local control (LC) were 84% (42/50 patients) and 94% (47/50 patients), respectively. We achieved 100% local control in the treatment of nasopharyngeal carcinoma with a median follow-up of 64.5 months (range, 62 - 95 months). The 5-year overall survival in this group was 100% (7/7 patients). The median time to loco-regional recurrence in the oropharynx population was 11 months (range, 7-18 months) with 93% (40/43 patients) maintaining local control and an overall survival of 83% (40/43 patients)at a median follow-up of 58 months (range, 7-102 months). All patients with local control at 18 months remained free of loco-regional failure in our analysis. Two of the 8 deceased patients (25%) experienced a loss of local control with four (50%) developing metastatic disease prior to the time of death. Only one patient experienced both loco-regional recurrence and distant disease. Conclusions: Institutional reviews from large academic centers provide encouraging results regarding the efficacy and delivery of IMRT in the treatment of head and neck cancer. This retrospective, single-institution analysis demonstrates the ability to effectively implement and utilize IMRT in the treatment of head and neck cancer in an environment with relatively modest patient volume. The excellent overall survival and local control outcomes confirms the possibility for small academic and community centers with low head and neck patient throughput to deliver effective therapy despite the inherent complexity of IMRT. The views expressed are those of the author and do not reflect the official policy of the Department of Defense or U.S. Government. Author Disclosure: J.D. Kehrer: None. R.A. Kiteley: None.
2795 Retrospective Comparison of 2 Feeding Tube Approaches for Headand-Neck Cancer Patients Receiving Concurrent Chemoradiation Therapy I. Karam,1,2 G. Wilson,2 A. Bowman,1 F. Wong,3 and R. Olson1; 1BC Cancer Agency - Vancouver Centre, Vancouver, BC, Canada, 2University of British Columbia, Vancouver, BC, Canada, 3BC Cancer Agency - Fraser Valley Centre, Surrey, BC, Canada Purpose/Objective(s): To compare patient outcomes between a therapeutic versus a prophylactic gastrostomy tube (G-tube) placement approach, in patients treated with concurrent chemo-radiation therapy for head and neck cancer. Materials/Methods: Outcomes were compared between all head and neck patients treated with concurrent chemo-radiation therapy from January 2001 to June 2009 from a centre that places tubes for immediate therapeutic use (centre A) versus a centre that generally places them prophylactically (centre B). A retrospective chart review comparing patient, tumor and treatment characteristics between the two centers was performed. The difference in outcomes between centers was calculated with chi-square tests. Multivariable survival analysis was performed using Cox regression modeling. Results: A total of 434 patients with head and neck cancer were identified, with 62% from centre A. G-tubes were placed in 31% and 88% of patients from centers A and B, respectively. Centre B had significantly higher number of G-tube complications (p<0.001), including infection (16% vs. 5%), leakage (10% vs. 2%), and blockage (3% vs. 1%). Conversely, centre A had more admissions for G-tube related issues (25% vs. 13%, p Z 0.001). Centre B had higher G-tube presence rates at 90 days post-radiation therapy (34% versus 12%; p<0.001). Centre B had non-significantly greater mean weight loss at 1 year (9.1 vs. 7.0 kg, p Z 0.08). There was no significant difference in overall survival on multivariable analysis (A vs. B: HR Z 0.99; p Z 0.96). Conclusions: A prophylactic G-tube approach results in exposing higher number of patients to G-tube complications for longer period of time. The higher rate of hospitalizations using a therapeutic approach suggests that patients are sicker when G-tubes are required. Given the similar weight loss and survival, a therapeutic approach at an earlier stage of need may be a preferable approach. Author Disclosure: I. Karam: None. G. Wilson: None. A. Bowman: None. F. Wong: None. R. Olson: None.
2796 Implementation of Intensity Modulated Radiation Therapy in the Treatment of Carcinoma of the Nasopharynx and Oropharynx: A Retrospective Single Institution Analysis J.D. Kehrer and R.A. Kiteley; Department of Radiation Oncology, Walter Reed National Military Medical Center, Bethesda, MD Purpose/Objective(s): To review the implementation and utilization of intensity-modulated radiation therapy (IMRT) in the treatment of nasopharynx and oropharynx carcinoma at National Naval Medical Center and demonstrate the ability for general radiation oncologists in a low-volume setting to generate local control and overall survival
2797 Comparative Dosimetry of an Extensive Scalp Lesion: High-doserate Brachytherapy, Electronic Brachytherapy, and Volumetric Modulated Arc Therapy S. Park, M. Kamrava, O. Kayode, S.P. Lee, M.L. Steinberg, and D.J. Demanes; University of California Los Angeles, Los Angeles, CA Purpose/Objective(s): It is difficult to deliver conformal homogeneous radiation doses to superficial targets with complex geometry. We studied a patient with an extensive scalp lesion to compare the target and normal tissue dosimetry of high-dose-rate brachytherapy (HDR), electronic brachytherapy (EBT), and volumetric modulated arc therapy (VMAT). Materials/Methods: The patient had a large atypical fibroxanthoma resected from the skin of the calvarium. A customized HDR skin
Poster Viewing Abstract 2797; Table prescription
Brain Brainstem Lens Eyes Optic nerves
Mean dose to the OARs as % of
Ir-192 HDR
50kVp EBT
6MV VMAT
18.3 7.4 2.7 2.9 4.6
8.6 1.4 0.4 0.4 0.7
11.7 0.6 0.5 0.5 0.6
Volume 84 Number 3S Supplement 2012 applicator was constructed by attaching brachytherapy catheters at 1 cm intervals to a 5 mm thick bolus. Two treatment plans were generated for brachytherapy: one for Iridum-192 HDR and the other which assumed treatment with 50 kVp EBT using the same applicator. A third plan was generated for a 2 full arc 6 MV photon VMAT (also with a 5 mm thick bolus). The target and organs at risk (OARs) were contoured on a simulation CT scan. The prescription was 36 Gy in 8 fractions for a 9 cm 12 cm 1 cm target. The plans were optimized to a standard target coverage (V100% > 98%) and to minimize dose to OARs using Nucletron Oncentra MasterPlan (HDR), Varian BrachyVision (EBT) and Eclipse (VMAT). We compared mean target dose, dose heterogeneity, and doses to OARs. Results: The target V100% and D90% were 98% and 104% (HDR), 100% and 119% (EBT), and 98% and 102% (VMAT). The mean (and range from minimum to 1cc maximum) target doses were HDR 119% (86-157%), EBT 164% (86-271%), and VMAT 104% (96-108%). The Table summarizes mean dose to OARs. Conclusions: EBT provided the least dose to closest OAR (brain) due to rapid dose fall-off of low-energy X-rays, but it resulted in higher mean target doses and more heterogeneity than HDR and VMAT. HDR and VMAT provided similar V100% and D90% target doses. As expected, VMAT provided most dose uniformity. All methods resulted in acceptable normal tissue doses, but they were lower for EBT and VMAT than HDR specifically for this lesion located on the top of the skull. Comparative dosimetry facilitates treatment modality selection for extensive superficial lesions with complex surfaces, irregular contours, and close proximity to OARs. Author Disclosure: S. Park: None. M. Kamrava: None. O. Kayode: None. S.P. Lee: None. M.L. Steinberg: None. D.J. Demanes: None.
2798 Fentanyl Pectin Nasal Citrate (FPNC) to Control Breakthrough Pain (BP) and Improve Dysphagia in Head-and-Neck Cancer Patients Receiving Radiation Therapy (RT) I. Prieto,1 J. Pardo,2 A. Perez-Casas,1 J. Olivera,1 J. Luna,1 and J. Vara1; 1 Fundacion Jimenez Diaz, Madrid, Spain, 2Hospital General de Catalun˜a, Barcelona, Spain Purpose/Objective(s): To evaluate the breakthrough pain control and the improvement of the dysphagia in head and neck cancer patients (HNCP) who develop mucositis and moderate-severe dysphagia radiation therapyinduced. Materials/Methods: Eleven patients with breakthrough pain due to radiation therapy-induced mucositis were selected to start treatment with FPNC in order to relief the pain associated with swallowing. Patients were already receiving an opioid treatment at total dose equivalent to 40-80 mg morphine. Incidental pain was treated before eating 4-5 times /day with a dose of 100-400 mg of FPNC. Data related to tolerance, pain relief and efficient dose for swallowing maintenance were collected. Results: Patients who adhered to the FPNC treatment reached satisfactory pain control. Three patients chose do not receive the basal opioid treatment, and then achieved BP relieve only with FPNC. The efficient dose of FPNC was 200 mg in most of patients. Only 1 needed 400 mg. The mean onset time of the pain relief was 7 minutes (range 5-10) in 6 patients, and the mean response duration was 60 min (range 45-75 min). This relief effect allowed oral feeding, nutritional parameters maintenance, and, therefore, improvement in the patient’s quality of life. Also permitted deliver RT treatment without interruptions. Conclusions: BP management is difficult to manage and so are most agents used to treat it. HNCP treated with radiation therapy develop oral mucositis with severe breakthrough incidental pain associated with swallowing, so a simple, rapid and strong analgesic is needed. The oral rescue dose is likely to be inadequate for a significant percentage of these patients with xerostomia and severe oral pain. The intranasal way eliminate this
Poster Viewing Abstracts S517 problem and offers a rapid an efficient absorption. FPNC seems to be particularly beneficial and well accepted in patients with BP due to radiation therapy-induced mucositis. Author Disclosure: I. Prieto: None. J. Pardo: None. A. Perez-Casas: None. J. Olivera: None. J. Luna: None. J. Vara: None.
2799 WITHDRAWN
2800 Prognostic Utility of Pretreatment Metabolic Tumor Volume, Gross Tumor Volume, Maximum Standardized Uptake Value in Head-andNeck Cancer Patients Receiving IMRT P. Romesser,1 B.A. Shah,1 M.M. Qureshi,1 S. Jalisi,1,2 R.M. Subramaniam,1,2 and M. Truong1,2; 1Boston University School of Medicine, Boston, MA, 2Boston Medical Center, Boston, MA Purpose/Objective(s): This retrospective study compared the prognostic utility of pretreatment metabolic tumor volume (MTV), gross tumor volume (GTV) and raw maximum standardized uptake value (SUVmax), with respect to tumor control and survival in patients with head and neck squamous cell carcinoma (HNSCC) undergoing intensity modulated radiation therapy (IMRT) with or without concomitant chemotherapy. Materials/Methods: Between 2004 and 2009, 41 HNSCC patients who underwent a pretreatment PET/CT and definitive IMRT were identified. All PET/CT studies were retrieved from the electronic archival system and reviewed on a MIMvista workstation (software version 4.1). Fused PET/CT images were reviewed in axial, coronal, and sagittal planes. SUVmax and MTV were obtained from the PET/CT scans. GTVs manually contoured by the radiation oncologist were obtained from the Dose Volume Histograms (DVH). The SUVmax was defined as the maximum standardized uptake value within the tumor normalized to lean body mass, MTV was defined as the tumor volume with FDG uptake using a gradient-based (PET Edge) auto-segmentation method. Local (LC), nodal (NC), distant (DC), overall (OC) control and overall (OS) and disease free (DFS) survival were calculated using the Kaplan Meier product-limit method. Receiver operator characteristic (ROC) curves were constructed by plotting sensitivity versus (1-specificity) and optimum cutoff values for above parameters were derived for endpoint LC. Percent area under the ROC curves (AUC) and their 95% confidence intervals were found. A probability value of less than 0.05 was considered statistically significant. Results: Median follow up was 24.2 months (range, 2.7- 56.3 months). The GTV and MTV were 22.2 cc, and 7.2 cc respectively. The median SUVmax was 15.8. Patients with smaller GTVs (<22.2 cc) demonstrated two-year actuarial LC rates of 100% versus 56.4% (pZ0.001) and OS rates of 94.4% versus 65.9% (pZ0.045). Similarly, a smaller MTV (<7.2 cc) correlated with improved LC and OS with two-year actuarial LC rates of 100% versus 54.2% (pZ0.0003) and OS rates of 94.7% versus 64.2% (pZ0.040). Smaller GTV and MTV correlated with improved NC, DC, OC and DFS. SUVmax did not correlate with LC and OS when analyzed by median threshold. An exploratory analysis using ROC curves constructed for the LC endpoint identified a cutoff value of SUVmax of 19.3 (AUCZ73%, 95% CI 56% - 85%), GTV of 29.6 cc (AUCZ89%, 95% CI 75% - 97%), and MTV of 7.7 cc (AUCZ81%, 95% CI 66% - 92%). Both GTV and MTV retained significance using ROC optimized cutoff values. In all cases the MTV was smaller than the GTV. Conclusions: In HNSCC patients undergoing IMRT, MTV and GTV demonstrate superior prognostic utility compared to SUVmax. Author Disclosure: P. Romesser: None. B.A. Shah: None. M.M. Qureshi: None. S. Jalisi: None. R.M. Subramaniam: None. M. Truong: None.