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Radiation Retinopathy and Neuropathy following Plaque Therapy of Small Choroidal Melanoma
Proceedings of the 52nd Annual ASTRO Meeting Conclusions: Patients treated with definitive radiotherapy for MCC have excellent local control and overall survival rates, comparable to historical outcomes of patients treated with surgery and adjuvant radiation therapy. Given the potential to spare patients the morbidity of an additional treatment modality, radiation monotherapy can be carefully considered in select patients. Author Disclosure: C. Loiselle, None; L. Fang, None; S. Koba, None; U. Parvathaneni, None; P. Nghiem, None.
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Radiation Retinopathy and Neuropathy following Plaque Therapy of Small Choroidal Melanoma
D. Wilkinson, V. Torres, M. Kolar, P. Fleming, A. Singh Cleveland Clinic Foundation, Cleveland, OH Purpose/Objective(s): Despite yielding excellent local tumor control, the long term visual outcome following plaque radiotherapy is poor. The purpose of this study is to examine the incidence of radiation retinopathy (RR) and radiation optic neuropathy (RON) following I-125 and Ru-106 plaque therapy for the treatment of small choroidal melanomas as a function of radiation dose to the macula and optic disc. Materials/Methods: A retrospective outcomes and dose analysis was performed for patients treated with either I-125 or Ru-106 plaque therapy between January/2006 and July/2008. The inclusion criteria were tumor measuring up to 4 mm in thickness and minimum follow-up of 18 months. The radiation retinopathy was classified in four groups (Finger Classification), based on the ophthalmoscopic/angiographic signs. Plaques were either COMS (Collaborative Ocular Melanoma Study) with silastic carrier for I-125 or Bebig Ru-106 (Eckert & Ziegler Bebig GmbH, Berlin, Germany). The prescription was 85 Gy to the tumor apex delivered in 72 to 96 hr. Dose estimates to the macula (for RR) and to the optic disc (for RON) were made using the software Plaquesimulator (Bebig) which was also used for treatment planning. Results: A total of 52 eyes/52 patients were analyzed (34 female, 18 male), with 38 (73%) treated using I-125 and 14 (27%) using Ru-106. Local tumor control was achieved in 100% of the patients treated with I-125 plaques and 85.7% with Ru-106. In the I-125 treated group, 12/38 (31.6%) developed signs of RR and RON over a mean follow-up of 28.4 months (range, 22 -36 mo). The RR was classified as group 1: 9%, group 2: 30% and groups 3 and 4: 55.5%. In the Ru-106 treated group, 3/14 (21.4%) presented RR over a mean follow-up of 17.6 months (range, 12-24 mo): Group 1: 33% and Group 3: 66%. The mean dose delivered to the macula in the I-125 treated patients was 60.86 Gy for the subgroup that did not develop RR and 54.8 Gy in the RR subgroup. In the Ru-106 treated group, the macular doses were 23.8 Gy and 80.76 Gy respectively. Patients who developed signs of RR and/or RON had mean macular doses of 29.4 Gy (Group 1), 56.3 Gy (Group 2), and 76.1 Gy (Groups 3 and 4). The mean dose to the optic disc in RON patients was 39.2 Gy; it was 23.1 Gy for patients with no complications. Conclusions: A dose of 85 Gy to the apex of these small melanomas, rather than to the 5mm COMS point, provided adequate local control. The incidence of RR for patients treated with I-125 was slightly higher than with Ru-106, with a longer time interval between the treatment and onset of RR. There was no apparent dependence of the development of RR in I-125 treated patients on the macula point dose. However, there are hints of a dose response for the Ru-106 treated patients, for the development of RON, and for the severity of complications in the RR group of I-125 treated patients. Author Disclosure: D. Wilkinson, None; V. Torres, None; M. Kolar, None; P. Fleming, None; A. Singh, None.
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Sphincter-sparing Local Excision and Hypofractionated Radiation Therapy for Anal-rectal Melanoma: A 20 Year Experience
P. Kelly, A. Guadagnolo, J. N. Cormier, M. I. Ross, G. K. Zagars M.D. Anderson Cancer Center, Houston, TX Purpose/Objective(s): Anal-rectal melanoma is a rare disease with a poor prognosis. As outcome is dictated by distant failure, the use of radical, non-sphincter sparing surgery has been questioned. However, concerns remain about the effectiveness of sphincter sparing approaches in controlling the disease locally. Here we report our institution’s 20 year experience with sphincter sparing local excision and hypofractionated radiation therapy in the treatment of anal-rectal melanoma. Materials/Methods: We retrospectively reviewed the records of 55 patients with localized anal-rectal melanoma treated at MD Anderson Cancer Center between 1989 and 2008. All patients received definitive local excision with or without nodal biopsy or dissection. Hypofractionated radiation was delivered preoperatively in 2 patients (25 Gy, 5 daily fractions) and post-operatively in 53 patients (30-36 Gy, 5-6 twice weekly fractions). Extended fields (EF) that targeted the primary site and draining pelvic/inguinal lymphatics were used in 38 patients and limited fields (LF) targeting only the primary site in 17 patients. Univariate and multivariate analyses were performed to assess prognostic influence of clinical, pathologic, and treatment related factors. The endpoints analyzed were local control (LC), nodal control (NC), sphincter preservation (SP), disease free survival (DFS), overall survival (OS), and treatment related toxicity. Actuarial curves were calculated using the Kaplan-Meier method and the log-rank statistic was used to assess for significance of difference between curves. Results: With a median follow-up time of 42 months, the actuarial 5-year rates of LC, NC and SP were 82%, 81% and 98%, respectively. However, due to the high rate of distant metastasis (73% at 5 years), the actuarial 5-year DFS rate was only 27%, and OS at 5 years was 30%. Nodal involvement at presentation was the only factor predictive of inferior DFS or OS. No factor was prognostic for LC. Of note, there was no significant difference in the 5 year rates of LC (EF 81% vs. LF 86%; p = 0.84) or NC (EF 78% vs. LF 88%; p = 0.80) based on field size. Treatment related toxicity occurred in 25 patients (45%), with only 1 severe complication. The most common side effects were radiation proctitis (n = 18) and scrotal edema (n = 9). Whereas the rates of radiation proctitis were not significantly different between the patients treated with EF and LF (34% vs. 28%; p = 0.73), scrotal edema was only seen in the EF group.
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Radiation Retinopathy and Neuropathy following Plaque Therapy of Small Choroidal Melanoma
D. Wilkinson, V. Torres, M. Kolar, P. Fleming, A. Singh Cleveland Clinic Foundation, Cleveland, OH Purpose/Objective(s): Despite yielding excellent local tumor control, the long term visual outcome following plaque radiotherapy is poor. The purpose of this study is to examine the incidence of radiation retinopathy (RR) and radiation optic neuropathy (RON) following I-125 and Ru-106 plaque therapy for the treatment of small choroidal melanomas as a function of radiation dose to the macula and optic disc. Materials/Methods: A retrospective outcomes and dose analysis was performed for patients treated with either I-125 or Ru-106 plaque therapy between January/2006 and July/2008. The inclusion criteria were tumor measuring up to 4 mm in thickness and minimum follow-up of 18 months. The radiation retinopathy was classified in four groups (Finger Classification), based on the ophthalmoscopic/angiographic signs. Plaques were either COMS (Collaborative Ocular Melanoma Study) with silastic carrier for I-125 or Bebig Ru-106 (Eckert & Ziegler Bebig GmbH, Berlin, Germany). The prescription was 85 Gy to the tumor apex delivered in 72 to 96 hr. Dose estimates to the macula (for RR) and to the optic disc (for RON) were made using the software Plaquesimulator (Bebig) which was also used for treatment planning. Results: A total of 52 eyes/52 patients were analyzed (34 female, 18 male), with 38 (73%) treated using I-125 and 14 (27%) using Ru-106. Local tumor control was achieved in 100% of the patients treated with I-125 plaques and 85.7% with Ru-106. In the I-125 treated group, 12/38 (31.6%) developed signs of RR and RON over a mean follow-up of 28.4 months (range, 22 -36 mo). The RR was classified as group 1: 9%, group 2: 30% and groups 3 and 4: 55.5%. In the Ru-106 treated group, 3/14 (21.4%) presented RR over a mean follow-up of 17.6 months (range, 12-24 mo): Group 1: 33% and Group 3: 66%. The mean dose delivered to the macula in the I-125 treated patients was 60.86 Gy for the subgroup that did not develop RR and 54.8 Gy in the RR subgroup. In the Ru-106 treated group, the macular doses were 23.8 Gy and 80.76 Gy respectively. Patients who developed signs of RR and/or RON had mean macular doses of 29.4 Gy (Group 1), 56.3 Gy (Group 2), and 76.1 Gy (Groups 3 and 4). The mean dose to the optic disc in RON patients was 39.2 Gy; it was 23.1 Gy for patients with no complications. Conclusions: A dose of 85 Gy to the apex of these small melanomas, rather than to the 5mm COMS point, provided adequate local control. The incidence of RR for patients treated with I-125 was slightly higher than with Ru-106, with a longer time interval between the treatment and onset of RR. There was no apparent dependence of the development of RR in I-125 treated patients on the macula point dose. However, there are hints of a dose response for the Ru-106 treated patients, for the development of RON, and for the severity of complications in the RR group of I-125 treated patients. Author Disclosure: D. Wilkinson, None; V. Torres, None; M. Kolar, None; P. Fleming, None; A. Singh, None.
2911
Sphincter-sparing Local Excision and Hypofractionated Radiation Therapy for Anal-rectal Melanoma: A 20 Year Experience
P. Kelly, A. Guadagnolo, J. N. Cormier, M. I. Ross, G. K. Zagars M.D. Anderson Cancer Center, Houston, TX Purpose/Objective(s): Anal-rectal melanoma is a rare disease with a poor prognosis. As outcome is dictated by distant failure, the use of radical, non-sphincter sparing surgery has been questioned. However, concerns remain about the effectiveness of sphincter sparing approaches in controlling the disease locally. Here we report our institution’s 20 year experience with sphincter sparing local excision and hypofractionated radiation therapy in the treatment of anal-rectal melanoma. Materials/Methods: We retrospectively reviewed the records of 55 patients with localized anal-rectal melanoma treated at MD Anderson Cancer Center between 1989 and 2008. All patients received definitive local excision with or without nodal biopsy or dissection. Hypofractionated radiation was delivered preoperatively in 2 patients (25 Gy, 5 daily fractions) and post-operatively in 53 patients (30-36 Gy, 5-6 twice weekly fractions). Extended fields (EF) that targeted the primary site and draining pelvic/inguinal lymphatics were used in 38 patients and limited fields (LF) targeting only the primary site in 17 patients. Univariate and multivariate analyses were performed to assess prognostic influence of clinical, pathologic, and treatment related factors. The endpoints analyzed were local control (LC), nodal control (NC), sphincter preservation (SP), disease free survival (DFS), overall survival (OS), and treatment related toxicity. Actuarial curves were calculated using the Kaplan-Meier method and the log-rank statistic was used to assess for significance of difference between curves. Results: With a median follow-up time of 42 months, the actuarial 5-year rates of LC, NC and SP were 82%, 81% and 98%, respectively. However, due to the high rate of distant metastasis (73% at 5 years), the actuarial 5-year DFS rate was only 27%, and OS at 5 years was 30%. Nodal involvement at presentation was the only factor predictive of inferior DFS or OS. No factor was prognostic for LC. Of note, there was no significant difference in the 5 year rates of LC (EF 81% vs. LF 86%; p = 0.84) or NC (EF 78% vs. LF 88%; p = 0.80) based on field size. Treatment related toxicity occurred in 25 patients (45%), with only 1 severe complication. The most common side effects were radiation proctitis (n = 18) and scrotal edema (n = 9). Whereas the rates of radiation proctitis were not significantly different between the patients treated with EF and LF (34% vs. 28%; p = 0.73), scrotal edema was only seen in the EF group.
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