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PO-379 ENDOLUMINAL HIGH DOSE RATE BRACHYTHERAPY FOR EARLY STAGE AND RECURRENT ESOPHAGEAL CANCER
World Congress of Brachytherapy 2012
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were negative in all cases (half minimum distance 0.1 cm).One patient had G3 dermatitis and required surgery with placement of a dermal graft. All patients were alive at the time of this report, with no evidence of local recurrence. One patient had lung metastases that were resected and is currently free of disease. There was no correlation between surgical margins and / or histological type and local or distant recurrence. Conclusions: In soft tissue sarcomas of the extremities HDR brachytherapy can be used as a single modality or combined with external radiation therapy effectively and safely. In our opinion using HDR brachytherapy translates into better oncology team work. PO-378 RADIOBIOLOGICAL ASSESSMENT OF TREATMENT DURATION RADIONUCLIDE CHOICE FOR COMS EYE PLAQUE BRACHYTHERAPY N.L. Gagne1, M.J. Rivard1 1 Tufts Medical Center, Radiation Oncology, Boston MA, USA
AND
Purpose/Objective: Clinical optimization of Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy is currently limited to tumor coverage, consensus prescription dosage, and dose calculations to ocular structures. The biologically effective dose (BED) of temporary brachytherapy treatments is a function of both implant duration T and chosen radionuclide R. Enhanced clinical optimization should evaluate BED delivered to the tumor volume and surrounding normal ocular structures as a function of plaque position P, R, T, and prescription dose. Materials and Methods: MCNP5 was used to generate plaqueheterogeneity-corrected dose distributions for 10, 16, and 22 mm COMS plaques using 103Pd, 125I, and 131Cs brachytherapy seeds. These physical dose (D) distributions were imported into the Pinnacle3 TPS using the TG-43 hybrid technique. DVHs for a T=7 day implant were made within a reference eye geometry including the ciliary body, cornea, eyelid, foveola, lacrimal gland, lens, optic disc, optic nerve, retina, and tumor for 8 standard treatment positions. Equation 1, based on Dale and Jones for temporary brachytherapy implants,
(1) was employed to create biologically effective dose volume histograms (BEDVHs), allowing for a volumetric analysis of the BED for structures receiving dose. Equation 1 was also used to calculate the isobiologically-effective physical prescription doses for 5>T>0.01 day. BEDVHs were generated for all ROIs using these T values and correspondingly reduced prescription doses. Objective functions were created to evaluate the BEDVHs as a function of both implant duration vs. T=7 and radionuclide selection vs. R=125I. Results: Reducing T from 7 to 0.01 day for a 10 mm plaque produced a BED benefit of 26%, 20%, and 17% for 103Pd, 125I, and 131Cs, respectively, across all treatment positions considered. Results were somewhat position-dependent for the larger plaques. For all positions, T, and plaque sizes, we calculated a 16%-35% BED benefit for 103Pd vs. 125 I and a 3%-7% BED detriment for 131Cs vs. 125I. Additionally, the corresponding OAR physical doses were lowest for 103Pd under all circumstances. Conclusions: Shorter implant durations may correlate with more favorable outcomes compared to 7 day implants when treating small or medium intraocular lesions. Results also indicate that implant duration may be safely reduced if the prescription physical dose is appropriately diminished, and that 103Pd offers a substantial radiobiological benefit over 125I and 131Cs irrespective of plaque position, implant duration, and tumor size. PO-379 ENDOLUMINAL HIGH DOSE RATE BRACHYTHERAPY FOR EARLY STAGE AND RECURRENT ESOPHAGEAL CANCER M.R. Folkert1, G.N. Cohen2, A.J. Wu1, H. Gerdes3, M.A. Schattner3, E. Ludwig3, D.H. Ilson4, K.A. Goodman1 1 Memorial Sloan-Kettering Cancer Center, Radiation Oncology, New York NY, USA 2 Memorial Sloan-Kettering Cancer Center, Medical Physics, New York NY, USA 3 Memorial Sloan-Kettering Cancer Center, Gastroenterology, New
York NY, USA Memorial Sloan-Kettering Cancer Center, Medical Oncology, New York NY, USA
4
Purpose/Objective: The management of locally recurrent esophageal cancer (EC) after definitive chemoradiotherapy or early stage EC in patients who are poor surgical candidates is complex. Endoluminal high-dose-rate (HDR) brachytherapy utilizing a wide range of techniques and dosing regimens has been used with mixed results in terms of toxicity and local control. In this study we examine the outcomes and toxicities in early stage and locally recurrent EC patients treated with a consistent HDR technique. Materials and Methods: Between 8/2008 and 7/2011, 14 patients with EC were treated with HDR intraluminal brachytherapy, 10 (71.4%) with recurrent disease after chemoradiotherapy and 4 (28.6%) with previously unirradiated lesions. 12 (85.7%) patients had adenocarcinoma and 2 (14.3%) had squamous cell carcinoma. Of the previously treated patients, median dose of prior radiotherapy was 5040 cGy (range 4500-5600 cGy). HDR treatments were performed under general anesthesia in conjunction with a gastroenterologist. At the time of the procedure, tumor extent was defined endoscopically and radioopaque markers were placed on the skin surface to demarcate the proximal and distal tumor and facilitate catheter positioning. Treatments were delivered in 3 fractions over 3 weeks to a median dose of 1200 cGy (range 1000-1500 cGy); dose was prescribed to a median depth of 7mm (range 4-10mm) with mucosal surface dose limited to 800-1000 cGy. 6 (42.9%) patients also received concurrent chemotherapy (capecitabine, 1000 mg BID) during the 3 week course of brachytherapy. Patients were followed with serial imaging and esophagoscopy every 2-3 months. Results: Overall median followup was 9.7 months; 1 year local progression-free (PFS) and overall survival (OS) were 48.8% (95% CI: 22.3-75.9%) and 88.9% (95% CI: 58.2-98.8%) respectively. For patients with recurrent disease, median followup was 6.7 months; 1 year PFS and OS were 32.4% (95% CI: 8.6-68.3%) and 80% (95% CI: 42.2-96.9%) respectively. For patients with previously unirradiated disease, median followup was 21.9 months; 1 year PFS and OS were 75.0% (95% CI: 21.9-98.7%) and 100.0% (95% CI: 39.6-100.0%) respectively. 1 patient (7.1%) with recurrent squamous cell carcinoma developed distant metastases 8.5 months after treatment. 8 of 14 (57.1%) patients had Grade 1 acute adverse effects; 6 of 14 (42.9%) patients had chronic Grade 1 adverse effects; 2 of 14 (14.3%) patients developed Grade 1 strictures noted on endoscopy (both with recurrent disease). There were no Grade 2 or higher complications. Conclusions: HDR brachytherapy with or without concurrent chemotherapy is a safe and well-tolerated treatment for both early stage, previously untreated and recurrent EC. Given the high rate of local recurrence and minimal toxicity in these patients, we are planning a prospective dose escalation trial for recurrent EC to determine the optimal brachytherapy regimen. PO-380 THE “CLAWS” : A GOLD APPLICATOR LOADED WITH I-125 SEEDS FOR LOCALIZED WHOLE EYE RADIOTHERAPY C.J. Trauernicht1, G.J. Maree1, E.R. Hering1, F.C.P. Du Plessis2, C. Stannard3, K. Lecuona4, R. Munro1, S. Tovey1 1 Groote Schuur Hospital, Medical Physics, Cape Town, South Africa 2 University of the Free State, Medical Physics, Bloemfontein, South Africa 3 Groote Schuur Hospital, Radiation Oncology, Cape Town, South Africa 4 Groote Schuur Hospital, Ophthalmology, Cape Town, South Africa Purpose/Objective: This applicator (Fig. 1) is a specially designed gold applicator which is loaded with I-125 seeds. The applicator is used to mainly treat children with retinoblastoma, who require whole eye radiotherapy. Materials and Methods: Under general anaesthesia, a pericorneal ring is attached to the 4 extraocular muscles, and 4 appendages, each loaded with I-125 seeds, are inserted beneath the conjunctiva inbetween each pair of muscles and attached anteriorly to the ring. The applicator has an inside diameter of 22 mm.
S 151
were negative in all cases (half minimum distance 0.1 cm).One patient had G3 dermatitis and required surgery with placement of a dermal graft. All patients were alive at the time of this report, with no evidence of local recurrence. One patient had lung metastases that were resected and is currently free of disease. There was no correlation between surgical margins and / or histological type and local or distant recurrence. Conclusions: In soft tissue sarcomas of the extremities HDR brachytherapy can be used as a single modality or combined with external radiation therapy effectively and safely. In our opinion using HDR brachytherapy translates into better oncology team work. PO-378 RADIOBIOLOGICAL ASSESSMENT OF TREATMENT DURATION RADIONUCLIDE CHOICE FOR COMS EYE PLAQUE BRACHYTHERAPY N.L. Gagne1, M.J. Rivard1 1 Tufts Medical Center, Radiation Oncology, Boston MA, USA
AND
Purpose/Objective: Clinical optimization of Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy is currently limited to tumor coverage, consensus prescription dosage, and dose calculations to ocular structures. The biologically effective dose (BED) of temporary brachytherapy treatments is a function of both implant duration T and chosen radionuclide R. Enhanced clinical optimization should evaluate BED delivered to the tumor volume and surrounding normal ocular structures as a function of plaque position P, R, T, and prescription dose. Materials and Methods: MCNP5 was used to generate plaqueheterogeneity-corrected dose distributions for 10, 16, and 22 mm COMS plaques using 103Pd, 125I, and 131Cs brachytherapy seeds. These physical dose (D) distributions were imported into the Pinnacle3 TPS using the TG-43 hybrid technique. DVHs for a T=7 day implant were made within a reference eye geometry including the ciliary body, cornea, eyelid, foveola, lacrimal gland, lens, optic disc, optic nerve, retina, and tumor for 8 standard treatment positions. Equation 1, based on Dale and Jones for temporary brachytherapy implants,
(1) was employed to create biologically effective dose volume histograms (BEDVHs), allowing for a volumetric analysis of the BED for structures receiving dose. Equation 1 was also used to calculate the isobiologically-effective physical prescription doses for 5>T>0.01 day. BEDVHs were generated for all ROIs using these T values and correspondingly reduced prescription doses. Objective functions were created to evaluate the BEDVHs as a function of both implant duration vs. T=7 and radionuclide selection vs. R=125I. Results: Reducing T from 7 to 0.01 day for a 10 mm plaque produced a BED benefit of 26%, 20%, and 17% for 103Pd, 125I, and 131Cs, respectively, across all treatment positions considered. Results were somewhat position-dependent for the larger plaques. For all positions, T, and plaque sizes, we calculated a 16%-35% BED benefit for 103Pd vs. 125 I and a 3%-7% BED detriment for 131Cs vs. 125I. Additionally, the corresponding OAR physical doses were lowest for 103Pd under all circumstances. Conclusions: Shorter implant durations may correlate with more favorable outcomes compared to 7 day implants when treating small or medium intraocular lesions. Results also indicate that implant duration may be safely reduced if the prescription physical dose is appropriately diminished, and that 103Pd offers a substantial radiobiological benefit over 125I and 131Cs irrespective of plaque position, implant duration, and tumor size. PO-379 ENDOLUMINAL HIGH DOSE RATE BRACHYTHERAPY FOR EARLY STAGE AND RECURRENT ESOPHAGEAL CANCER M.R. Folkert1, G.N. Cohen2, A.J. Wu1, H. Gerdes3, M.A. Schattner3, E. Ludwig3, D.H. Ilson4, K.A. Goodman1 1 Memorial Sloan-Kettering Cancer Center, Radiation Oncology, New York NY, USA 2 Memorial Sloan-Kettering Cancer Center, Medical Physics, New York NY, USA 3 Memorial Sloan-Kettering Cancer Center, Gastroenterology, New
York NY, USA Memorial Sloan-Kettering Cancer Center, Medical Oncology, New York NY, USA
4
Purpose/Objective: The management of locally recurrent esophageal cancer (EC) after definitive chemoradiotherapy or early stage EC in patients who are poor surgical candidates is complex. Endoluminal high-dose-rate (HDR) brachytherapy utilizing a wide range of techniques and dosing regimens has been used with mixed results in terms of toxicity and local control. In this study we examine the outcomes and toxicities in early stage and locally recurrent EC patients treated with a consistent HDR technique. Materials and Methods: Between 8/2008 and 7/2011, 14 patients with EC were treated with HDR intraluminal brachytherapy, 10 (71.4%) with recurrent disease after chemoradiotherapy and 4 (28.6%) with previously unirradiated lesions. 12 (85.7%) patients had adenocarcinoma and 2 (14.3%) had squamous cell carcinoma. Of the previously treated patients, median dose of prior radiotherapy was 5040 cGy (range 4500-5600 cGy). HDR treatments were performed under general anesthesia in conjunction with a gastroenterologist. At the time of the procedure, tumor extent was defined endoscopically and radioopaque markers were placed on the skin surface to demarcate the proximal and distal tumor and facilitate catheter positioning. Treatments were delivered in 3 fractions over 3 weeks to a median dose of 1200 cGy (range 1000-1500 cGy); dose was prescribed to a median depth of 7mm (range 4-10mm) with mucosal surface dose limited to 800-1000 cGy. 6 (42.9%) patients also received concurrent chemotherapy (capecitabine, 1000 mg BID) during the 3 week course of brachytherapy. Patients were followed with serial imaging and esophagoscopy every 2-3 months. Results: Overall median followup was 9.7 months; 1 year local progression-free (PFS) and overall survival (OS) were 48.8% (95% CI: 22.3-75.9%) and 88.9% (95% CI: 58.2-98.8%) respectively. For patients with recurrent disease, median followup was 6.7 months; 1 year PFS and OS were 32.4% (95% CI: 8.6-68.3%) and 80% (95% CI: 42.2-96.9%) respectively. For patients with previously unirradiated disease, median followup was 21.9 months; 1 year PFS and OS were 75.0% (95% CI: 21.9-98.7%) and 100.0% (95% CI: 39.6-100.0%) respectively. 1 patient (7.1%) with recurrent squamous cell carcinoma developed distant metastases 8.5 months after treatment. 8 of 14 (57.1%) patients had Grade 1 acute adverse effects; 6 of 14 (42.9%) patients had chronic Grade 1 adverse effects; 2 of 14 (14.3%) patients developed Grade 1 strictures noted on endoscopy (both with recurrent disease). There were no Grade 2 or higher complications. Conclusions: HDR brachytherapy with or without concurrent chemotherapy is a safe and well-tolerated treatment for both early stage, previously untreated and recurrent EC. Given the high rate of local recurrence and minimal toxicity in these patients, we are planning a prospective dose escalation trial for recurrent EC to determine the optimal brachytherapy regimen. PO-380 THE “CLAWS” : A GOLD APPLICATOR LOADED WITH I-125 SEEDS FOR LOCALIZED WHOLE EYE RADIOTHERAPY C.J. Trauernicht1, G.J. Maree1, E.R. Hering1, F.C.P. Du Plessis2, C. Stannard3, K. Lecuona4, R. Munro1, S. Tovey1 1 Groote Schuur Hospital, Medical Physics, Cape Town, South Africa 2 University of the Free State, Medical Physics, Bloemfontein, South Africa 3 Groote Schuur Hospital, Radiation Oncology, Cape Town, South Africa 4 Groote Schuur Hospital, Ophthalmology, Cape Town, South Africa Purpose/Objective: This applicator (Fig. 1) is a specially designed gold applicator which is loaded with I-125 seeds. The applicator is used to mainly treat children with retinoblastoma, who require whole eye radiotherapy. Materials and Methods: Under general anaesthesia, a pericorneal ring is attached to the 4 extraocular muscles, and 4 appendages, each loaded with I-125 seeds, are inserted beneath the conjunctiva inbetween each pair of muscles and attached anteriorly to the ring. The applicator has an inside diameter of 22 mm.