Bremsstrahlung imaging after 32P treatment for residual suprasellar cyst

Balachandran, Suppiah; McGuire, Lynn; Flanigan, Stevenson; Shah, Hemendra R.; Boyd, Christina L.

doi:10.1016/0047-0740(85)90028-2

Cited by 12 publications

(5 citation statements)

References 3 publications

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“…32 P bremsstrahlung SPECT imaging facilitates the positioning, effective for half-life evaluation under physical conditions [ 21 ]. Any immigration or abnormal uptake can easily be detected, and SPECT-CT fusion techniques with a certain postprocessing attenuation correction algorithm may contribute to precise localization, dosiology studies, and future establishment of brachytherapy in clinical settings [ 6 ].…”

Section: Discussionmentioning

confidence: 99%

Investigation of Newly Prepared Biodegradable ³²P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

Shao

Wang

Liu

et al. 2018

Contrast Media & Molecular Imaging

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32P high-dose rate brachytherapy allows high-dose radiation delivery to target lesions with less damage to adjacent tissues. The early evaluation of its therapeutic effect on tumours is vital for the optimization of treatment regimes. The most commonly used 32P-CP colloid tends to leak with blind therapeutic area after intratumour injection. We prepared 32P-chromic phosphate-polylactide-co-glycolide (32P-CP-PLGA) seeds with biodegradable PLGA as a framework and investigated their characteristics in vitro and in vivo. We also evaluated the therapeutic effect of 32P-CP-PLGA brachytherapy for glioma with the integrin αvβ3-targeted radiotracer 68Ga-3PRGD2. 32P-CP-PLGA seeds (seed group, SG, 185 MBq) and 32P-CP colloid (colloid group, CG, 18.5 MBq) were implanted or injected into human glioma xenografts in nude mice. Scanning electron microscopy (SEM) of the seeds, micro-SPECT imaging, and biodistribution studies were performed at different time points. The tumour volume was measured using a caliper, and 68Ga-3PRGD2 micro-PET-CT imaging was performed to evaluate the therapeutic effect after 32P intratumour administration. The delayed release of 32P-CP was observed with biodegradation of vehicle PLGA. Intratumoural effective half-life of 32P-CP in the SG (13.3 ± 0.3) d was longer than that in the CG (10.4 ± 0.3) d (P < 0.05), with liver appearance in the CG on SPECT. A radioactivity gradient developed inside the tumour in the SG, as confirmed by micro-SPECT and SEM. Tumour uptake of 68Ga-3PRGD2 displayed a significant increase on day 0.5 in the SG and decreased earlier (on day 2) than the volume reduction (on day 8). Thus, 32P-CP-PLGA seeds, controlling the release of entrapped 32P-CP particles, are promising for glioma brachytherapy, and 68Ga-3PRGD2 imaging shows potential for early response evaluation of 32P-CP-PLGA seeds brachytherapy.

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Section: Discussionmentioning

confidence: 99%

Investigation of Newly Prepared Biodegradable ³²P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

Shao

Wang

Liu

et al. 2018

Contrast Media & Molecular Imaging

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“…[16] Our dosimetry was also based on the Loevinger formula, [29] as done by other authors as well. [2,5,21,26,33,35,40,48,52] Implantation of 90 Y into the cyst was performed through a frontal burr hole or by transsphenoidal puncture. In the initial cases we used a free-handed technique; however, since 1989 we have applied stereotactic techniques using Leksell and Riechert-Mundinger frames.…”

Section: Clinical Materials and Methodsmentioning

confidence: 99%

“…To detect possible leakage of the isotope we performed gamma camera examinations in all cases following implantation, detecting the "Bremsstrahlung." [5] Cyst shrinkage was monitored by repeated CT examinations (by cystography or autopsy during earlier years). The time course of postirradiation relative volume reduction (VR) was analyzed by 88 measurements obtained from CT scanning of cyst volume in 33 patients (Fig.…”

Section: Clinical Materials and Methodsmentioning

confidence: 99%

Treatment of cystic craniopharyngiomas with yttrium-90 colloid solution.

Degnan

1997

FOC

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The authors analyzed long-term follow-up data to assess the value of intracavitary irradiation with stereotactically implanted beta-emitting radioisotope 90Y-silicate colloid for the treatment of craniopharyngiomas. Fifty-seven craniopharyngiomas in 42 patients were selected for retrospective analysis. The yttrium-90 was implanted intracavitally, using computerized tomography-guided and three-dimensional stereotactic treatment planning. The cumulative dose aimed at the inner surface of the cyst wall was 300 Gy. An average of 75% shrinkage of the initial cyst volume was observed. In 18 cases the reduction was more than 91%, and the cyst disappeared totally in 11 cases. A 50% decrease in cyst volume was usually apparent between the 2nd and 4th months. A 70% decrease in cyst volume was seen by the 5th and 6th months and an 80% reduction by the 7th and 8th months. Cysts that were unchanged remained so throughout the observation period. The time course of volume reduction could be expressed mathematically by the formula of 0.73 X e-0.62 X T + 0.27, where “e” is the basic number of natural logarithm and “T” is the time expressed in months. Mean survival duration after intracavitary irradiation was 9.4 years. The shrinkage of the cyst was a consequence of fibrosis of the wall, as seen on histopathological examination. The neuroophthalmological prognosis was favorable only when the optic disc was normal or nearly normal at the time of the treatment. In the presence of preexisting optic atrophy, visual deterioration proved to be irreversible. The long-term results support the view that intracavitary90Y-irradiation is a noninvasive and very effective method of treatment for craniopharyngioma cysts. Because of the 1.1 mm half-life decay of beta irradiation, it cannot influence the solid part of the tumor; therefore, the best result can be expected in solitary cysts.

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“…There is some evidence that the radiocolloid does not always remain uniformly distributed throughout the cyst volume, but partly accumulates on the cyst wall during the course of therapy (e.g. Young et al 1976, Balachandran et al 1985, Harbert 1987, Hechtman et al 2005. As a consequence, such accumulation leads to an increased dose reaching surrounding structures at risk, with a magnitude depending on the size of the cyst (Harbert 1987, Hechtman et al 2005.…”

Section: Introductionmentioning

confidence: 99%

“…As a consequence, such accumulation leads to an increased dose reaching surrounding structures at risk, with a magnitude depending on the size of the cyst (Harbert 1987, Hechtman et al 2005. Attempts have been made to measure the spatial and temporal activity distribution using bremsstrahlung imaging but the accuracy is limited mainly due to poor spatial resolution (Balachandran et al 1985, Denis-Bacelar et al 2013. The dose to structures outside the cyst can be estimated point-wise on the basis of Monte Carlo calculations for standard geometries (Rojas et al 2003, Hechtman et al 2005, Sadeghi et al 2009.…”

Section: Introductionmentioning

confidence: 99%

Voxel-based dose calculation in radiocolloid therapy of cystic craniopharyngiomas

Treuer

Hoevels²,

Luyken³

et al. 2015

Phys. Med. Biol.

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Very high doses are administered in radiocolloid therapy of cystic craniopharyngiomas. However individual dose planning is not common yet mainly due to insufficient image resolution. Our aim was to investigate whether currently available high-resolution image data can be used for voxel-based dose calculation for short-ranged β-emitters ((32)P,(90)Y,(186)Re) and to assess the achievable accuracy. We developed a convolution algorithm based on voxelized dose activity distributions and dose-spread kernels. Results for targets with 5-40 mm diameter were compared with high-resolution Monte Carlo calculations in spherical phantoms. Voxel size was 0.35 mm. Homogeneous volume and surface activity distributions were used. Dose-volume histograms of targets and shell structures were compared and γ index (dose tolerance 5%, distance to agreement 0.35 mm) was calculated for dose profiles along the principal axes. For volumetric activity distributions 89.3% ± 11.9% of all points passed the γ test (mean γ 0.53 ± 0.16). For surface distributions 33.6% ± 14.8% of all points passed the γ test (mean γ 2.01 ± 0.60). The shift of curves in dose-volume histograms was -1.7 Gy ± 7.6 Gy (-4.4 Gy ± 24.1 Gy for (186)Re) in volumetric distributions and 46.3% ± 32.8% in surface distributions. The results show that individual dose planning for radiocolloid therapy of cystic craniopharyngiomas based on high-resolution voxelized image data is feasible and yields highly accurate results for volumetric activity distributions and reasonable dose estimates for surface distributions.

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Bremsstrahlung imaging after 32P treatment for residual suprasellar cyst

Cited by 12 publications

References 3 publications

Investigation of Newly Prepared Biodegradable ³²P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

Investigation of Newly Prepared Biodegradable ³²P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

Treatment of cystic craniopharyngiomas with yttrium-90 colloid solution.

Voxel-based dose calculation in radiocolloid therapy of cystic craniopharyngiomas

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Bremsstrahlung imaging after 32P treatment for residual suprasellar cyst

Cited by 12 publications

References 3 publications

Investigation of Newly Prepared Biodegradable 32P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

Investigation of Newly Prepared Biodegradable 32P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

Treatment of cystic craniopharyngiomas with yttrium-90 colloid solution.

Voxel-based dose calculation in radiocolloid therapy of cystic craniopharyngiomas

Contact Info

Product

Resources

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Investigation of Newly Prepared Biodegradable ³²P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

Investigation of Newly Prepared Biodegradable ³²P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy