- Email: [email protected]
Radiosurgery versus microsurgery in the treatment of brain metastases
Proceedings of the 46th Annual ASTRO Meeting
2118
Comparison of Repeat GK-SRS for Refractory or Recurrent Trigeminal Neuralgia: Does Dose Matter
P. R. Dutta,1 Y. Kwok,1 J. M. Herman,1 L. S. Chin,3 C. Colliver,2 W. H. St. Clair,4 J. H. Petit,1 B. Young,2 W. F. Regine1 Radiation Oncology, University of Maryland, Baltimore, MD, 2Neurosurgery, University of Kentucky, Louisville, KY, 3 Neurosurgery, University of Maryland, Baltimore, MD, 4Radiation Oncology, University of Kentucky, Louisville, KY 1
Purpose/Objective: Gamma Knife stereotactic radiosurgery (GK-SRS) is an important and minimally invasive treatment modality for patients with trigeminal neuralgia (TN). It is unclear, however, how best to manage patients whose pain is refractory or recurrent after the initial GK-SRS treatment. Here we report and compare the treatment outcomes for patients treated with repeat radiosurgery for refractory or recurrent TN with a low dose (70 –75 Gy) at the University of Maryland Medical System (UM) and high dose (90 Gy) at the University of Kentucky Medical Center (UK). Materials/Methods: From 1996 to 2004, a total of 69 patients received repeat GK-SRS for refractory or recurrent TN at UM and UK. Complete follow-up data were available in 63 patients (64 procedures). Patients at UM (n ⫽ 28) underwent the repeat GK-SRS within a median of 13 months (range, 2–56 months) after the initial treatment. Median prescribed Dmax doses for the first and second treatments were 75 Gy (range, 70 – 80 Gy) and 70 Gy (range, 45–75 Gy), respectively. In addition, patients at UK (n ⫽ 35; GK-SRS ⫽ 36) underwent a second GK-SRS within a median of 12.5 months (range, 6 – 60 months) after the initial treatment. One patient required repeat treatment of both nerves. Median prescribed Dmax doses were 90 Gy for both first (range, 80 –90 Gy) and second procedures (range, 70 –90 Gy). Efficacy was measured through follow-up visits and standardized questionnaires. Pain relief was defined as: excellent (pain-free requiring no medications), good (pain-free but continuing medications), fair (ⱖ50% pain reduction), and poor (⬍50% pain reduction). The median follow-up for UM and UK patients were 14 months (range: 1– 65 months) and 19 months (range: 1– 63 months), respectively. Results: Following initial GK-SRS at UM, 24 of 28 patients (85.7%) had excellent (42.9%) or good responses (42.9%) responses. After the second GK-SRS procedure, pain outcomes were excellent in 11 (39.3%), good in 12 (42.9%), and poor in 5 (17.9%) patients, for a total complete pain relief rate of 82.4%. All 3 patients with poor response after the initial GK-SRS did not respond to second GK-SRS. Although 12 patients (42.9%) reported numbness after the second GK-SRS treatment, only 7 (25%) of these were new or increased. Four patients (14.2%) described this as somewhat bothersome; however, all 4 patients had complete pain relief. Similarly, following initial GK-SRS at UK, 20 out of 36 procedures (55.6%) achieved excellent (33.3%) or good (22.2%) responses. After the second GK-SRS procedure, pain outcomes were excellent in 23 (63.9%), good in 7 (19.4%), fair in 3 (8.3%), and poor in 3 (8.3%) patients, for a total complete pain relief rate of 83.3%. Of the 8 patients who were never pain free after the first treatment, 4 (50%) reported obtaining excellent results after the second procedure. Twelve patients (33%) reported numbness or dysesthesia after the second procedure, but only 9 (25%) were increased or new onset; only one (2.8%) patient reported this to be bothersome. Although the chance of achieving complete pain relief was similar in UM (median cumulative dose 150 Gy) and UK (median cumulative dose 180 Gy) patients after repeat GK-SRS, UK patients had a significantly higher chance of discontinuing all medications (p ⬍ 0.05). The toxicity was similar in both groups. Conclusions: Despite different cumulative doses, repeat GK-SRS provided similar rates of pain control in both the UK (83.3%) and UM (82.4%) groups. It appears that cumulative doses of 180 Gy increases the probability of discontinuing all medications compared to a cumulative dose of 150 Gy in patients with recurrent or refractory TN. Our study suggests that doses as high as 90 Gy are effective for treating refractory or recurrent trigeminal neuralgia pain, and cumulative doses up to 180 Gy to the Dmax appear safe with minimal residual bothersome side effects. Long-term follow-up is required to see if these results are durable. To date this is the largest reported series of repeat GK-SRS for TN.
2119
Radiosurgery Versus Microsurgery in the Treatment of Brain Metastases
S. Pigorsch,1 A. Grosu,1 S. Staerk,1 M. Leonardi,2 C. Lumenta,2 M. Molls1 Radiotherapy, Technical University of Munich, Munich, Germany, 2Neurosurgery, Munich-Bogenhausen Hospital, Munich, Germany 1
Purpose/Objective: The aim of the study is to analyse the tumor control rate, the side effects of therapy and the survival in a group of patients with two or three brain metastases. In all these cases one (or two) brain lesion was removed by microsurgery (MS) and the other one (or two) was treated by radiosurgery (RS). We also sought to compare these two approaches (RS and MS) in the same group of patients. Materials/Methods: Between 5/1997 and 12/2002, 35 patients with a total of 103 brain metastases (2 or 3 lesions per patient) were treated for brain metastases at one (or two) lesion by RS and the other one (or two) by MS. The median age of the patients was 61 years (range: 42 to 81 years). Fifty seven metastases were irradiated and 46 lesions were treated by surgery. The origin of the brain metastases were from the following primary tumors: 11 bronchial carcinomas, 5 breast carcinomas, 8 renal carcinomas, 1 urothel carcinoma, 1 stomach cancer, 4 colorectal carcinomas, 3 melanomas, 1 sarcoma of the uterus, 1 cervical cancer. The indication of MS was decompression and/ or biopsy for histological diagnosis. The median follow-up time was 9 months (7/1997 to 10/2003). The diameter of the removed lesions was at a median of 30 mm (range: 20 to 50 mm) and the diameter of the irradiated lesions was at a median of 15 mm (range: 2 to 37 mm). RS was performed with an adapted LINAC (Mevatron MXE2, Siemens, Germany and BrainLab-System). The applied dose given to the 100% isodose at the tumor edge was 20 Gy. The therapy effect was proven 6 weeks and every 3 months after RS until death, by imaging (MRI, CT) and a complete neurological examination. Results: Six weeks after RS, 49 of 57 irradiated lesions were evaluable by radiological imaging. Forty four of 49 evaluable lesions (90% tumor response rate) revealed good response 6 weeks after RS (10 x complete remission, 15 x partial remission and 19 x no change). Six weeks after RS in 5/49 (10%) lesions progressive disease was seen. After MS all lesions were completely resected (24 h MRI, no residual tumor). The average of tumor control time after RS was 8.45⫹ 6.7 months. For MS the mean local tumor control time was 6.4⫹3.5 months, the difference was not significant (t-test, p ⫽ 0.25). Over the follow-up, local tumour control rate of the RS lesions versus the MS lesions was 82.5% (10/57 lesions) respectively 76% (11/46 metastases). Thirteen of 35 (37%) patients developed multiple brain metastases and were treated by whole brain irradiation. Eleven of 46 (24%) lesions removed by MS relapsed and were treated by RS. One lesion came into complete remission, 4 lesions revealed partial remission, 3 lesions showed no change, in 2 lesions the outcome is unknown and one patient developed progressive brain metastases with a tumor control rate of 90% in this group. In 3 cases, edema and 1 radionecrosis were seen
S405
S406
I. J. Radiation Oncology
● Biology ● Physics
Volume 60, Number 1, Supplement, 2004
as late side effects of RS. There were no severe side effects of MS. The survival starting at RS was 10.9⫹ 9.2 (mean) months with a median survival of 9 months (1.2– 44 months). Twenty seven of 35 patients (37%) died: 8 patients (22.8%) died of progressive brain metastases, 1 died of meningeal carcinomatosis (2.9%), 15 patients (42.6%) died of extra-cerebral progressive disease and in 3 cases (8.6%) the cause of death is unknown. Conclusions: This is the first study demonstrating the equivalence of RS and MS in the same group of patients. Tumor control and treatment tolerance after RS was comparable with tumor control and treatment tolerance after MS.
2120
Preference Elicitation Using the Time Trade-Off Method in Patients with 1 to 3 Newly Diagnosed Brain Metastases in a Prospective Randomized Clinical Trial Comparing Radiosurgery With and Without Whole Brain Radiation
A. T. Adamus,1 E. L. Chang,2 M. A. Leni,2 L. Franzini,3 J. M. Swint3 Pharmaceutical Policy and Outcomes Research, University of Texas M.D. Anderson Cancer Center, Houston, TX, 2 Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX, 3Management and Policy Sciences, University of Texas Health Science Center School of Public Health, Houston, TX 1
Purpose/Objective: Preference elicitation is used to address the value of healthcare outcomes. Patient preferences for health states were compared in brain metastasis patients randomized to be treated with radiosurgery (SRS) with or without whole brain radiation (WBRT). The objectives of the preference elicitation study were to 1) evaluate differences in utilities between treatment groups and 2) to evaluate changes in utilities over time. Materials/Methods: A time trade-off instrument was developed to directly elicit preferences from patients on the trial. The elicitation instrument included a written script, data collection form, and visual aid to facilitate the understanding of trading time. The instrument was administered face-to-face during patient clinic visits at baseline, 1, 2, 4, 6 months, and every 3 months thereafter. Patients traded time based on their preference for a fixed amount of time in their current state of health (reference period) versus a reduced amount of time in optimal health. The elicitation procedure was framed using three different reference periods - 10-year, 5-year, and 1-year. Mean utilities were evaluated between treatment groups (SRS vs. SRS ⫹ WBRT), demographic variables, and within subjects over time. Results: The mean age of patients in the trial was 61 years (range ⫽ 32– 80). Twenty-four patients received SRS and 17 received SRS and WBRT. The majority of patients had lung cancer as their primary tumor (61%) and most had only one metastatic lesion to the brain (68.3%). Of the 43 patients enrolled in the trial, 41 participated in the elicitation exercise. The mean baseline utility over all reference periods was 0.87 and the mean 6-month follow-up utility over all reference periods was 0.82. There were no significant differences in mean utilities from baseline to six-month follow-up between treatment groups or demographic variables. There were significant differences in mean utilities for all patients across different reference periods. Utilities were significantly higher when using the1yr reference period (1yr reference period mean ⫽ 0.91, 5yr reference period mean ⫽ 0.88, 10yr reference period mean ⫽ 0.84; adj. F ⫽ 4.2, p ⫽ 0.049). The same effect was observed for one-month follow-up utilities (1yr reference period mean ⫽ 0.97, 5yr reference period mean ⫽ 0.87, 10yr reference period mean ⫽ 0.85; adj. F ⫽ 5.3, p ⫽ 0.03). At the one-month follow-up, mean utilities were significantly higher for those receiving SRS without WBRT using the 1yr reference period (SRS group mean ⫽ 1.0; SRS⫹WBRT group mean ⫽ 0.93; F ⫽ 4.7, p ⫽ 0.042). At the two-month follow-up, mean utilities were significantly higher for patients having their primary tumor site in the lung versus all other primary tumor sites (lung primary mean utilities ⫽ 0.93, other primary mean utilities ⫽ 0.71; F ⫽ 5.0, p ⫽ 0.037). Conclusions: Utilities for patients in this trial were relatively stable and remained high suggesting reasonable preference for their current health state at the time of elicitation. Most patients did not trade time in their current health state for less time in a more optimal health state when the trade-off was presented with a short 1-year reference period. This utility analysis will provide data needed to perform cost-utility analysis of SRS vs. SRS and WBRT in the future.
2121
Choroidal Melanoma Treated With Iodine-125 Episcleral Plaque: Analysis of Dose on Disease Control and Visual Outcome
D. Rivera,1 A. Alkaissi,1 J. Johnson,2 E. Halperin,1 L. Marks1 Radiation Oncology, Duke University Medical Center, Durham, NC, 2Biostatistics, Duke University, Durham, NC
1
Purpose/Objective: The Collaborative Ocular Melanoma Study (COMS) group randomized trial has established the use of episcleral I125 plaques as an alternative treatment to enucleation for medium sized choroidal malignant melanoma (CMM). The COMS protocol utilizes a dose of 85 Gy to the tumor apex or a minimum 5 mm height, which ever is greater. The optimal prescribed dose to ensure acceptable disease free survival, yet minimize radiation related ocular complications, is uncertain. We have often used doses that are lower than the COMS group trial and have prescribed dose to the tumor apex even when tumors were ⬍ 5 mm in height. We herein report our experience, specifically assessing the impact of dose on outcome. Materials/Methods: All patients treated at our institution for CMM between 1988 through 2001 with I125 plaques were retrospectively reviewed. Preoperative and postoperative tumor characteristics, treatment related side effects, and best-corrected visual acuity were assessed by regular follow-up. Poor visual outcome was defined as a visual acuity decrease of ⱕ4 lines on
2118
Comparison of Repeat GK-SRS for Refractory or Recurrent Trigeminal Neuralgia: Does Dose Matter
P. R. Dutta,1 Y. Kwok,1 J. M. Herman,1 L. S. Chin,3 C. Colliver,2 W. H. St. Clair,4 J. H. Petit,1 B. Young,2 W. F. Regine1 Radiation Oncology, University of Maryland, Baltimore, MD, 2Neurosurgery, University of Kentucky, Louisville, KY, 3 Neurosurgery, University of Maryland, Baltimore, MD, 4Radiation Oncology, University of Kentucky, Louisville, KY 1
Purpose/Objective: Gamma Knife stereotactic radiosurgery (GK-SRS) is an important and minimally invasive treatment modality for patients with trigeminal neuralgia (TN). It is unclear, however, how best to manage patients whose pain is refractory or recurrent after the initial GK-SRS treatment. Here we report and compare the treatment outcomes for patients treated with repeat radiosurgery for refractory or recurrent TN with a low dose (70 –75 Gy) at the University of Maryland Medical System (UM) and high dose (90 Gy) at the University of Kentucky Medical Center (UK). Materials/Methods: From 1996 to 2004, a total of 69 patients received repeat GK-SRS for refractory or recurrent TN at UM and UK. Complete follow-up data were available in 63 patients (64 procedures). Patients at UM (n ⫽ 28) underwent the repeat GK-SRS within a median of 13 months (range, 2–56 months) after the initial treatment. Median prescribed Dmax doses for the first and second treatments were 75 Gy (range, 70 – 80 Gy) and 70 Gy (range, 45–75 Gy), respectively. In addition, patients at UK (n ⫽ 35; GK-SRS ⫽ 36) underwent a second GK-SRS within a median of 12.5 months (range, 6 – 60 months) after the initial treatment. One patient required repeat treatment of both nerves. Median prescribed Dmax doses were 90 Gy for both first (range, 80 –90 Gy) and second procedures (range, 70 –90 Gy). Efficacy was measured through follow-up visits and standardized questionnaires. Pain relief was defined as: excellent (pain-free requiring no medications), good (pain-free but continuing medications), fair (ⱖ50% pain reduction), and poor (⬍50% pain reduction). The median follow-up for UM and UK patients were 14 months (range: 1– 65 months) and 19 months (range: 1– 63 months), respectively. Results: Following initial GK-SRS at UM, 24 of 28 patients (85.7%) had excellent (42.9%) or good responses (42.9%) responses. After the second GK-SRS procedure, pain outcomes were excellent in 11 (39.3%), good in 12 (42.9%), and poor in 5 (17.9%) patients, for a total complete pain relief rate of 82.4%. All 3 patients with poor response after the initial GK-SRS did not respond to second GK-SRS. Although 12 patients (42.9%) reported numbness after the second GK-SRS treatment, only 7 (25%) of these were new or increased. Four patients (14.2%) described this as somewhat bothersome; however, all 4 patients had complete pain relief. Similarly, following initial GK-SRS at UK, 20 out of 36 procedures (55.6%) achieved excellent (33.3%) or good (22.2%) responses. After the second GK-SRS procedure, pain outcomes were excellent in 23 (63.9%), good in 7 (19.4%), fair in 3 (8.3%), and poor in 3 (8.3%) patients, for a total complete pain relief rate of 83.3%. Of the 8 patients who were never pain free after the first treatment, 4 (50%) reported obtaining excellent results after the second procedure. Twelve patients (33%) reported numbness or dysesthesia after the second procedure, but only 9 (25%) were increased or new onset; only one (2.8%) patient reported this to be bothersome. Although the chance of achieving complete pain relief was similar in UM (median cumulative dose 150 Gy) and UK (median cumulative dose 180 Gy) patients after repeat GK-SRS, UK patients had a significantly higher chance of discontinuing all medications (p ⬍ 0.05). The toxicity was similar in both groups. Conclusions: Despite different cumulative doses, repeat GK-SRS provided similar rates of pain control in both the UK (83.3%) and UM (82.4%) groups. It appears that cumulative doses of 180 Gy increases the probability of discontinuing all medications compared to a cumulative dose of 150 Gy in patients with recurrent or refractory TN. Our study suggests that doses as high as 90 Gy are effective for treating refractory or recurrent trigeminal neuralgia pain, and cumulative doses up to 180 Gy to the Dmax appear safe with minimal residual bothersome side effects. Long-term follow-up is required to see if these results are durable. To date this is the largest reported series of repeat GK-SRS for TN.
2119
Radiosurgery Versus Microsurgery in the Treatment of Brain Metastases
S. Pigorsch,1 A. Grosu,1 S. Staerk,1 M. Leonardi,2 C. Lumenta,2 M. Molls1 Radiotherapy, Technical University of Munich, Munich, Germany, 2Neurosurgery, Munich-Bogenhausen Hospital, Munich, Germany 1
Purpose/Objective: The aim of the study is to analyse the tumor control rate, the side effects of therapy and the survival in a group of patients with two or three brain metastases. In all these cases one (or two) brain lesion was removed by microsurgery (MS) and the other one (or two) was treated by radiosurgery (RS). We also sought to compare these two approaches (RS and MS) in the same group of patients. Materials/Methods: Between 5/1997 and 12/2002, 35 patients with a total of 103 brain metastases (2 or 3 lesions per patient) were treated for brain metastases at one (or two) lesion by RS and the other one (or two) by MS. The median age of the patients was 61 years (range: 42 to 81 years). Fifty seven metastases were irradiated and 46 lesions were treated by surgery. The origin of the brain metastases were from the following primary tumors: 11 bronchial carcinomas, 5 breast carcinomas, 8 renal carcinomas, 1 urothel carcinoma, 1 stomach cancer, 4 colorectal carcinomas, 3 melanomas, 1 sarcoma of the uterus, 1 cervical cancer. The indication of MS was decompression and/ or biopsy for histological diagnosis. The median follow-up time was 9 months (7/1997 to 10/2003). The diameter of the removed lesions was at a median of 30 mm (range: 20 to 50 mm) and the diameter of the irradiated lesions was at a median of 15 mm (range: 2 to 37 mm). RS was performed with an adapted LINAC (Mevatron MXE2, Siemens, Germany and BrainLab-System). The applied dose given to the 100% isodose at the tumor edge was 20 Gy. The therapy effect was proven 6 weeks and every 3 months after RS until death, by imaging (MRI, CT) and a complete neurological examination. Results: Six weeks after RS, 49 of 57 irradiated lesions were evaluable by radiological imaging. Forty four of 49 evaluable lesions (90% tumor response rate) revealed good response 6 weeks after RS (10 x complete remission, 15 x partial remission and 19 x no change). Six weeks after RS in 5/49 (10%) lesions progressive disease was seen. After MS all lesions were completely resected (24 h MRI, no residual tumor). The average of tumor control time after RS was 8.45⫹ 6.7 months. For MS the mean local tumor control time was 6.4⫹3.5 months, the difference was not significant (t-test, p ⫽ 0.25). Over the follow-up, local tumour control rate of the RS lesions versus the MS lesions was 82.5% (10/57 lesions) respectively 76% (11/46 metastases). Thirteen of 35 (37%) patients developed multiple brain metastases and were treated by whole brain irradiation. Eleven of 46 (24%) lesions removed by MS relapsed and were treated by RS. One lesion came into complete remission, 4 lesions revealed partial remission, 3 lesions showed no change, in 2 lesions the outcome is unknown and one patient developed progressive brain metastases with a tumor control rate of 90% in this group. In 3 cases, edema and 1 radionecrosis were seen
S405
S406
I. J. Radiation Oncology
● Biology ● Physics
Volume 60, Number 1, Supplement, 2004
as late side effects of RS. There were no severe side effects of MS. The survival starting at RS was 10.9⫹ 9.2 (mean) months with a median survival of 9 months (1.2– 44 months). Twenty seven of 35 patients (37%) died: 8 patients (22.8%) died of progressive brain metastases, 1 died of meningeal carcinomatosis (2.9%), 15 patients (42.6%) died of extra-cerebral progressive disease and in 3 cases (8.6%) the cause of death is unknown. Conclusions: This is the first study demonstrating the equivalence of RS and MS in the same group of patients. Tumor control and treatment tolerance after RS was comparable with tumor control and treatment tolerance after MS.
2120
Preference Elicitation Using the Time Trade-Off Method in Patients with 1 to 3 Newly Diagnosed Brain Metastases in a Prospective Randomized Clinical Trial Comparing Radiosurgery With and Without Whole Brain Radiation
A. T. Adamus,1 E. L. Chang,2 M. A. Leni,2 L. Franzini,3 J. M. Swint3 Pharmaceutical Policy and Outcomes Research, University of Texas M.D. Anderson Cancer Center, Houston, TX, 2 Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX, 3Management and Policy Sciences, University of Texas Health Science Center School of Public Health, Houston, TX 1
Purpose/Objective: Preference elicitation is used to address the value of healthcare outcomes. Patient preferences for health states were compared in brain metastasis patients randomized to be treated with radiosurgery (SRS) with or without whole brain radiation (WBRT). The objectives of the preference elicitation study were to 1) evaluate differences in utilities between treatment groups and 2) to evaluate changes in utilities over time. Materials/Methods: A time trade-off instrument was developed to directly elicit preferences from patients on the trial. The elicitation instrument included a written script, data collection form, and visual aid to facilitate the understanding of trading time. The instrument was administered face-to-face during patient clinic visits at baseline, 1, 2, 4, 6 months, and every 3 months thereafter. Patients traded time based on their preference for a fixed amount of time in their current state of health (reference period) versus a reduced amount of time in optimal health. The elicitation procedure was framed using three different reference periods - 10-year, 5-year, and 1-year. Mean utilities were evaluated between treatment groups (SRS vs. SRS ⫹ WBRT), demographic variables, and within subjects over time. Results: The mean age of patients in the trial was 61 years (range ⫽ 32– 80). Twenty-four patients received SRS and 17 received SRS and WBRT. The majority of patients had lung cancer as their primary tumor (61%) and most had only one metastatic lesion to the brain (68.3%). Of the 43 patients enrolled in the trial, 41 participated in the elicitation exercise. The mean baseline utility over all reference periods was 0.87 and the mean 6-month follow-up utility over all reference periods was 0.82. There were no significant differences in mean utilities from baseline to six-month follow-up between treatment groups or demographic variables. There were significant differences in mean utilities for all patients across different reference periods. Utilities were significantly higher when using the1yr reference period (1yr reference period mean ⫽ 0.91, 5yr reference period mean ⫽ 0.88, 10yr reference period mean ⫽ 0.84; adj. F ⫽ 4.2, p ⫽ 0.049). The same effect was observed for one-month follow-up utilities (1yr reference period mean ⫽ 0.97, 5yr reference period mean ⫽ 0.87, 10yr reference period mean ⫽ 0.85; adj. F ⫽ 5.3, p ⫽ 0.03). At the one-month follow-up, mean utilities were significantly higher for those receiving SRS without WBRT using the 1yr reference period (SRS group mean ⫽ 1.0; SRS⫹WBRT group mean ⫽ 0.93; F ⫽ 4.7, p ⫽ 0.042). At the two-month follow-up, mean utilities were significantly higher for patients having their primary tumor site in the lung versus all other primary tumor sites (lung primary mean utilities ⫽ 0.93, other primary mean utilities ⫽ 0.71; F ⫽ 5.0, p ⫽ 0.037). Conclusions: Utilities for patients in this trial were relatively stable and remained high suggesting reasonable preference for their current health state at the time of elicitation. Most patients did not trade time in their current health state for less time in a more optimal health state when the trade-off was presented with a short 1-year reference period. This utility analysis will provide data needed to perform cost-utility analysis of SRS vs. SRS and WBRT in the future.
2121
Choroidal Melanoma Treated With Iodine-125 Episcleral Plaque: Analysis of Dose on Disease Control and Visual Outcome
D. Rivera,1 A. Alkaissi,1 J. Johnson,2 E. Halperin,1 L. Marks1 Radiation Oncology, Duke University Medical Center, Durham, NC, 2Biostatistics, Duke University, Durham, NC
1
Purpose/Objective: The Collaborative Ocular Melanoma Study (COMS) group randomized trial has established the use of episcleral I125 plaques as an alternative treatment to enucleation for medium sized choroidal malignant melanoma (CMM). The COMS protocol utilizes a dose of 85 Gy to the tumor apex or a minimum 5 mm height, which ever is greater. The optimal prescribed dose to ensure acceptable disease free survival, yet minimize radiation related ocular complications, is uncertain. We have often used doses that are lower than the COMS group trial and have prescribed dose to the tumor apex even when tumors were ⬍ 5 mm in height. We herein report our experience, specifically assessing the impact of dose on outcome. Materials/Methods: All patients treated at our institution for CMM between 1988 through 2001 with I125 plaques were retrospectively reviewed. Preoperative and postoperative tumor characteristics, treatment related side effects, and best-corrected visual acuity were assessed by regular follow-up. Poor visual outcome was defined as a visual acuity decrease of ⱕ4 lines on