- Email: [email protected]
51 Accelerated whole brain irradiation (WBI) improves local control but not survival in good performance status (PS) patients with unresected brain metastases: Results of a phase III study
S16 September 9-12
of localized NSCLC patients unfit for surgery. From this preliminary experience this hypofractionated scheme is practical and seems to be safe when given using 3DCRT to a limited treatment volume. Further follow up is necessary to assess survival and late effects.
CARO 2004
was 9.0 min (range 5.1-20.7 min), delivery 13.4 min (range 9.720.0 rain) and EPI verification 26.6 min (range 5.0 - 70.0 min). Conclusions: Resource allocation is not significantly impacted by the implementation of an IMRT program. After an initial learning curve, IMRT offers a feasible alternative to standard treatments within a mid-sized RT clinic.
51 Accelerated Whole Brain Irradiation (WBI) Improves Local Control but not Survival in Good Performance Status (PS) Patients with Unresected Brain Metastases: Results of a Phase III Study.
53 A Simulated Dosimetry Study of [1311] and [1251]-MetaIodobenzyl Guanidine (MiBG) Modelling After Neuroblastoma Metastasis.
P. Davey ~, D. Hoegler2, G. DeBoer ~, J. Smith ~. ~Toronto Sunnybrook Regional Cancer Centre, University of Toronto, Toronto, Ontario; 2Cancer Centre of the Southern Interior, University of British Columbia, Kelowna, British Columbia
W. Roa 1, B. Yaremko ~, J. Cho ~, S. Mc Quarrie ~, T. Riauka 1, R. Sloboda ~, L. Wiebe~, C. Janickf. ~Cross Cancer Institute, University of Alberta, Edmonton, Alberta; 2McGi// University, Montrea/, Quebec
Objectives: To validate an accelerated prescription of WBI (40 Gy in 20 fractions [2 Gy b.i.d.]) reported to give a median survival of 26 weeks in good PS patients with unresected brain metastases and compare outcomes with conventional WBI (20 Gy in 5 fractions [4 Gy o.d.]. Methods: Ninety patients limited to ECOG 0-2 from two Canadian centres were randomized between accelerated and conventional WBI. Treatment arms were matched for RPA class. Treatment compliance was 96%. One patient was lost to follow-up. Results: Local control as measured by median time from randomization to salvage treatment for intracranial relapse was 32 weeks in accelerated WBI patients and 14 weeks in conventional WBI patients (log-rank). Conclusions: Accelerated WBI in good PS patients improves local control but not overall survival. A cause specific median survival of - 6 months is achievable but may require retreatment for intracranial relapse in ~ 1/4 of patients. Brain metastases from a colorectal primary carry a poor prognosis.
Purpose: The physical properties of 1311 are suboptimal for the delivery of therapeutic radiation to bone marrow metastases, which are common in the natural history of neuroblastoma. Previous in vitro and preliminary clinical studies have shown promise with emissions of 1251 in this setting, although major areas of uncertainty remain for its intratumoral radiation dosimetry. This study investigated the dosimetry using human neuroblastoma multicellular spheroids as a model of metastasis. Methods and Materials: Voxel-based MIRD and dose-pointkernel techniques were used to calculate 3-D dose distributions for 1311 and 1251 labeled mlBG in spheroids (metastases) of various sizes starting from 100pm diameter. The relative doses delivered to the tumor were compared for the same limiting dose to the bone marrow. The absolute dose was also calculated for the two isotopes over a range of diameters, residence times and radiobiological a-values to estimate the relative variation of tumor-control probability (TCP). Results: 1251 mlBG can deliver a higher and more uniform dose to tumors compared to 1311 mlBG without increasing the dose to the bone marrow. Depending on the biological half-life of the radionuclide, the relative dose to tumors of less than 1 mm diameter can increase several fold. The utility of 1251-MIBG in the case of small-diameter metastases is further supported by TCP modeling. Conclusions: This study suggests that 1251 is can selectively improve the dosimetry in mlBG therapy for bone marrow metastases. For patients with metastatic neuroblastoma and limited marrow reserve, it is logical to consider adding the complimentary 1251 to 1311 in multi-modality therapy.
52 Resource Issues of Implementing Intensity Modulated Radiotherapy within a Mid-Sized Radiotherapy Department.
L. Sa/ter ~, C. Go//ing~, M. Crane2. ~Vancouver Island Cancer Centre, Victoria, British Co/umbia; 2Fraser Valley Cancer Centre, Vancouver, British Co/umbia Objectives: To measure the resource impact of implementing intensity modulated radiotherapy (IMRT) within a mid-size (1400 patients/annum) radiotherapy (RT) department. Methods: Twenty patients with Iocoregionally advanced head and neck squamous cancer (T1-2 N+, or T3-4 N0-3) were entered into a study between September 2003 and March 2004. Planning was performed using Helios inverse planning software. Patients were treated with seven fields on a 21Ex Varian Linac using dynamic leaf sequences generated by a 120 Millennium MLC. Time data was collected on each aspect of treatment planning and delivery. For comparison, conventional treatment plans were retrospectively generated using standard parallel opposed photons and a matched anterior supraclavicular neck field with posterior electrons added mid course, for a total gross disease dose of 6600 cGy in 33 fractions. Time data on planning and conventional treatment delivery was collected. Results: Mean total IMRT planning time was 6.5 hrs (range 3.15-11.0 hrs) compared to mean total conventional planning time of 4.5 hrs (range 2.8-6.2 hrs). A reduction in IMRT planning time was observed for the final 5 patients compared to the initial 3 - means were 5.3 hrs and 8.25 hrs respectively. Contouring and the inverse planning dose constraint iterations were the most time consuming aspects of the IMRT planning mean 125 min (range 100 -145 min) and mean 116 rain (range 83-130 rain) respectively. Mean IMRT treatment set-up time
54 Playful Learning: Strategies for Developing a User-Centred Multimedia Education Program for Pediatric Radiation.
D. Wilier, N. Laperriere, S. Awrey, A. Jusko-Friedman, A. Griffith, H. Guscott, S. McKinnon, J. Nyhof-Young, C. Surka, P. Catton. Princess Margaret Hospital, University Health Network, Toronto, Ontario Objectives: This presentation explores strategies for the development of a multimedia educational intervention for pediatric radiation patients and their parents. The delivery of pediatric radiation is complex, involving a number of different sites and team members; patients are often overwhelmed, anxious and disoriented. Playful learning encourages learning and participation through a playful and dynamic environment that is modeled on the actual treatment process. Children create their own character, meet their treatment team and explore treatment areas through realistic, age-appropriate isometric representations, interactive activities and informative animations.
of localized NSCLC patients unfit for surgery. From this preliminary experience this hypofractionated scheme is practical and seems to be safe when given using 3DCRT to a limited treatment volume. Further follow up is necessary to assess survival and late effects.
CARO 2004
was 9.0 min (range 5.1-20.7 min), delivery 13.4 min (range 9.720.0 rain) and EPI verification 26.6 min (range 5.0 - 70.0 min). Conclusions: Resource allocation is not significantly impacted by the implementation of an IMRT program. After an initial learning curve, IMRT offers a feasible alternative to standard treatments within a mid-sized RT clinic.
51 Accelerated Whole Brain Irradiation (WBI) Improves Local Control but not Survival in Good Performance Status (PS) Patients with Unresected Brain Metastases: Results of a Phase III Study.
53 A Simulated Dosimetry Study of [1311] and [1251]-MetaIodobenzyl Guanidine (MiBG) Modelling After Neuroblastoma Metastasis.
P. Davey ~, D. Hoegler2, G. DeBoer ~, J. Smith ~. ~Toronto Sunnybrook Regional Cancer Centre, University of Toronto, Toronto, Ontario; 2Cancer Centre of the Southern Interior, University of British Columbia, Kelowna, British Columbia
W. Roa 1, B. Yaremko ~, J. Cho ~, S. Mc Quarrie ~, T. Riauka 1, R. Sloboda ~, L. Wiebe~, C. Janickf. ~Cross Cancer Institute, University of Alberta, Edmonton, Alberta; 2McGi// University, Montrea/, Quebec
Objectives: To validate an accelerated prescription of WBI (40 Gy in 20 fractions [2 Gy b.i.d.]) reported to give a median survival of 26 weeks in good PS patients with unresected brain metastases and compare outcomes with conventional WBI (20 Gy in 5 fractions [4 Gy o.d.]. Methods: Ninety patients limited to ECOG 0-2 from two Canadian centres were randomized between accelerated and conventional WBI. Treatment arms were matched for RPA class. Treatment compliance was 96%. One patient was lost to follow-up. Results: Local control as measured by median time from randomization to salvage treatment for intracranial relapse was 32 weeks in accelerated WBI patients and 14 weeks in conventional WBI patients (log-rank). Conclusions: Accelerated WBI in good PS patients improves local control but not overall survival. A cause specific median survival of - 6 months is achievable but may require retreatment for intracranial relapse in ~ 1/4 of patients. Brain metastases from a colorectal primary carry a poor prognosis.
Purpose: The physical properties of 1311 are suboptimal for the delivery of therapeutic radiation to bone marrow metastases, which are common in the natural history of neuroblastoma. Previous in vitro and preliminary clinical studies have shown promise with emissions of 1251 in this setting, although major areas of uncertainty remain for its intratumoral radiation dosimetry. This study investigated the dosimetry using human neuroblastoma multicellular spheroids as a model of metastasis. Methods and Materials: Voxel-based MIRD and dose-pointkernel techniques were used to calculate 3-D dose distributions for 1311 and 1251 labeled mlBG in spheroids (metastases) of various sizes starting from 100pm diameter. The relative doses delivered to the tumor were compared for the same limiting dose to the bone marrow. The absolute dose was also calculated for the two isotopes over a range of diameters, residence times and radiobiological a-values to estimate the relative variation of tumor-control probability (TCP). Results: 1251 mlBG can deliver a higher and more uniform dose to tumors compared to 1311 mlBG without increasing the dose to the bone marrow. Depending on the biological half-life of the radionuclide, the relative dose to tumors of less than 1 mm diameter can increase several fold. The utility of 1251-MIBG in the case of small-diameter metastases is further supported by TCP modeling. Conclusions: This study suggests that 1251 is can selectively improve the dosimetry in mlBG therapy for bone marrow metastases. For patients with metastatic neuroblastoma and limited marrow reserve, it is logical to consider adding the complimentary 1251 to 1311 in multi-modality therapy.
52 Resource Issues of Implementing Intensity Modulated Radiotherapy within a Mid-Sized Radiotherapy Department.
L. Sa/ter ~, C. Go//ing~, M. Crane2. ~Vancouver Island Cancer Centre, Victoria, British Co/umbia; 2Fraser Valley Cancer Centre, Vancouver, British Co/umbia Objectives: To measure the resource impact of implementing intensity modulated radiotherapy (IMRT) within a mid-size (1400 patients/annum) radiotherapy (RT) department. Methods: Twenty patients with Iocoregionally advanced head and neck squamous cancer (T1-2 N+, or T3-4 N0-3) were entered into a study between September 2003 and March 2004. Planning was performed using Helios inverse planning software. Patients were treated with seven fields on a 21Ex Varian Linac using dynamic leaf sequences generated by a 120 Millennium MLC. Time data was collected on each aspect of treatment planning and delivery. For comparison, conventional treatment plans were retrospectively generated using standard parallel opposed photons and a matched anterior supraclavicular neck field with posterior electrons added mid course, for a total gross disease dose of 6600 cGy in 33 fractions. Time data on planning and conventional treatment delivery was collected. Results: Mean total IMRT planning time was 6.5 hrs (range 3.15-11.0 hrs) compared to mean total conventional planning time of 4.5 hrs (range 2.8-6.2 hrs). A reduction in IMRT planning time was observed for the final 5 patients compared to the initial 3 - means were 5.3 hrs and 8.25 hrs respectively. Contouring and the inverse planning dose constraint iterations were the most time consuming aspects of the IMRT planning mean 125 min (range 100 -145 min) and mean 116 rain (range 83-130 rain) respectively. Mean IMRT treatment set-up time
54 Playful Learning: Strategies for Developing a User-Centred Multimedia Education Program for Pediatric Radiation.
D. Wilier, N. Laperriere, S. Awrey, A. Jusko-Friedman, A. Griffith, H. Guscott, S. McKinnon, J. Nyhof-Young, C. Surka, P. Catton. Princess Margaret Hospital, University Health Network, Toronto, Ontario Objectives: This presentation explores strategies for the development of a multimedia educational intervention for pediatric radiation patients and their parents. The delivery of pediatric radiation is complex, involving a number of different sites and team members; patients are often overwhelmed, anxious and disoriented. Playful learning encourages learning and participation through a playful and dynamic environment that is modeled on the actual treatment process. Children create their own character, meet their treatment team and explore treatment areas through realistic, age-appropriate isometric representations, interactive activities and informative animations.