Radioactive seed migration after prostate brachytherapy with iodine-125 using loose seeds versus stranded seeds.

OBJECTIVES: To assess the incidence and clinical parameters that could influence migration of seeds in localized prostate cancer patients treated by stranded versus loose sources by Iodine-125 brachytherapy. MATERIALS AND METHODS: 100 patients were treated from January/1998 until December/2006. Age, PSA, clinical stage, Gleason, prostate volume, number of seeds, activity of radioactive seeds, and dosimetric parameters, such as V100, V150 and D90 were evaluated. RESULTS: Mean follow-up was 79 months (18 - 120. CI 95%: 72 - 85). Overall, 6 of 100 patients experienced seed migration. Seed migration was found in 4/50 (8%) patients using loose seeds and in 2/50 (4%) treated by stranded seeds. Mean value dosimetric parameters for stranded seeds were greater than those for loose seeds (V100(%): 88.7/82, D90(Gy): 149.2/140.3, D90(%): 104.2/93.8, V150 (%): 53.8/47, respectively). No significant difference in migration of seeds was detected between loose and stranded seeds considering age (p = 0.33), PSA (p = 0.391), prostate volume (p = 0.397), activity of radioactive seeds (p = 0.109), number of seeds (p = 0.338), V100 (p = 0.332), although significant differences were measured in the values of D90(% and Gy) (p = 0.022 and 0.011) and V150 (p = 0.023). CONCLUSIONS: Seed migration after brachytherapy might occur and it does affect post-implant dosimetry.

The seven-year preliminary results of brachytherapy with Iodine-125 seeds for localized prostate cancer treated at a Brazilian single-center.

OBJECTIVE: To report the seven-year preliminary results of a single-center on brachytherapy with Iodine-125 seeds, used in combination with external beam radiotherapy in selected patients with localized prostate cancer (T1-T2). MATERIALS AND METHODS: All 105 patients treated by brachytherapy with Iodine-125 seeds, from January/1998 to December/2004, were retrospectively analyzed. The prescribed dose was 144 Gy at the periphery of the prostate for isolated brachytherapy, and 110 Gy for the combination with external beam radiotherapy. The external beam radiotherapy dose was 45 Gy, at the prostatic bed. Neoadjuvant hormone therapy was indicated for selected patients, who received luteinizing hormone-releasing hormone (LH-RH) and/or antiandrogens. For definition of biochemical relapse, it was adopted the American Society for Therapeutic Radiology and Oncology consensus. RESULTS: Of the 105 patients treated, 90 were followed for a mean period of 70 months. Biochemical disease control was achieved in 62 (69%) and biochemical recurrence was manifested in 28 (31%). The analysis of each risk group showed biochemical disease control rates of 79%, 71% and 52% in the low, intermediate and high risk groups, respectively. The mean time for biochemical recurrence was 22 months. Genitourinary acute toxicity was classified as grade 0-2 (RTOG) in 88.5% and in 94.2% for the late toxicity (RTOG/EORTC). Gastrointestinal acute toxicity was graded as 0-2 (RTOG) in 100% and in 97.7% for the late morbidity. No grade 5 was detected. CONCLUSIONS: Brachytherapy with Iodine-125 seeds is an effective alternative treatment for early stage prostatic cancer, with good biochemical disease control rates and low to moderate toxicity. The best results were obtained in low and intermediate risk patients.

Sea-land limits: a case study

The limits between sea and land were estimated at "Pulso" beach located in the Southeastern Brazilian shelf (φ = 23°33/17.4886"S; Λ = 045° 13'13.0504"W - WGS84), between the island of São Sebastião and the city of Ubatuba, SP, Brazil. The relative sea level of the year 1831 at "Pulso" beach, as per Brazilian law Number 9760 dated from 1946, was estimated and materialized. The retro-estimation allowed the demarcation of the Legal Sea-Land Limits at "Pulso" beach as per the terms of the law. The accuracy of the procedure for the transference of the long-term sea level from the research station of Ubatuba to "Pulso" beach was assessed by parallel work of geometrical leveling referred to the IBGE (Brazilian Institute of Geography and Statistics) geodetic network. The motivation, the hypotheses (Brest, Cananeia and IPCC) and the methods here used are described, together with a short history of the Legal Sea-Land Limits. The results indicated that the legal Sea-Land Limits at "Pulso" beach are well within the beach area. They were determined as per law 9760, and there is the need to reactivate the national network of sea level gauge.

Os limites entre mar e terra foram estimados na praia chamada Pulso, localizada na costa sudeste do Brasil (φ = 23°33'17, 4886"S; Λ = 045°13'13, 0504"W) entre a Ilha de São Sebastião e a cidade de Ubatuba, no Estado de São Paulo, SP, Brasil. O nível relativo do mar do ano de 1831 na praia do Pulso, ou "Praia do Pulso" (PP), foi estimado e materializado, de acordo com a Lei brasileira Número 9760 de 1946. A acurácia do procedimento foi acompanhada por trabalho paralelo de nivelamento geométrico referido ao sistema nacional de geodésia do IBGE (Instituto Brasileiro de Geografia e Estatística). A motivação, as hipóteses (Brest, Cananeia e IPCC) e os métodos utilizados são descritos, acompanhados por um breve histórico dos "Terrenos de Marinha". Os resultados indicaram que os limites em (PP) estão bem dentro da área da praia. Eles fora deterinados de acordo co a Lei No. 9760 e há a necessidade de reativar a rede nacional de medidores do nível do mar.

Radioactive seed migration after prostate brachytherapy with Iodine-125 using loose seeds versus stranded seeds

Objectives: To assess the incidence and clinical parameters that could influence migration of seeds in localized prostate cancer patients treated by stranded versus loose sources by Iodine-125 brachytherapy. Material and Methods: 100 patients were treated from January/1998 until December/2006. Age, PSA, clinical stage, Gleason, prostate volume, number of seeds, activity of radioactive seeds, and dosimetric parameters, such as V100, V150 and D90 were evaluated. Results: Mean follow-up was 79 months (18 - 120. CI 95 percent: 72 - 85). Overall, 6 of 100 patients experienced seed migration. Seed migration was found in 4/50 (8 percent) patients using loose seeds and in 2/50 (4 percent) treated by stranded seeds. Mean value dosimetric parameters for stranded seeds were greater than those for loose seeds (V100( percent): 88.7/82, D90(Gy): 149.2/140.3, D90( percent): 104.2/93.8, V150 ( percent): 53.8/47, respectively). No significant difference in migration of seeds was detected between loose and stranded seeds considering age (p = 0.33), PSA (p = 0.391), prostate volume (p = 0.397), activity of radioactive seeds (p = 0.109), number of seeds (p = 0.338), V100 (p = 0.332), although significant differences were measured in the values of D90( percent and Gy) (p = 0.022 and 0.011) and V150 (p = 0.023). Conclusions: Seed migration after brachytherapy might occur and it does affect post-implant dosimetry.

The seven-year preliminary results of brachytherapy with Iodine-125 seeds for localized prostate cancer treated at a Brazilian single-center

OBJECTIVE: To report the seven-year preliminary results of a single-center on brachytherapy with Iodine-125 seeds, used in combination with external beam radiotherapy in selected patients with localized prostate cancer (T1-T2). MATERIALS AND METHODS: All 105 patients treated by brachytherapy with Iodine-125 seeds, from January/1998 to December/2004, were retrospectively analyzed. The prescribed dose was 144 Gy at the periphery of the prostate for isolated brachytherapy, and 110 Gy for the combination with external beam radiotherapy. The external beam radiotherapy dose was 45 Gy, at the prostatic bed. Neoadjuvant hormone therapy was indicated for selected patients, who received luteinizing hormone-releasing hormone (LH-RH) and/or antiandrogens. For definition of biochemical relapse, it was adopted the American Society for Therapeutic Radiology and Oncology consensus. RESULTS: Of the 105 patients treated, 90 were followed for a mean period of 70 months. Biochemical disease control was achieved in 62 (69 percent) and biochemical recurrence was manifested in 28 (31 percent). The analysis of each risk group showed biochemical disease control rates of 79 percent, 71 percent and 52 percent in the low, intermediate and high risk groups, respectively. The mean time for biochemical recurrence was 22 months. Genitourinary acute toxicity was classified as grade 0-2 (RTOG) in 88.5 percent and in 94.2 percent for the late toxicity (RTOG/EORTC). Gastrointestinal acute toxicity was graded as 0-2 (RTOG) in 100 percent and in 97.7 percent for the late morbidity. No grade 5 was detected. CONCLUSIONS: Brachytherapy with Iodine-125 seeds is an effective alternative treatment for early stage prostatic cancer, with good biochemical disease control rates and low to moderate toxicity. The best results were obtained in low and intermediate risk patients.