{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T11:01:38Z","timestamp":1791198098147,"version":"4.1.0"},"reference-count":40,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T00:00:00Z","timestamp":1790985600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Purpose: Tile-based radiation therapy (TBRT) delivers adjuvant radiation to brain tumor beds using evenly spaced cesium-131 (Cs-131) sources in collagen tiles. This study evaluated TBRT as spatially fractionated radiation therapy (SFRT) across tumor sizes and source counts. Methods and Materials: Dose distributions were generated from postoperative CT scans for 18 patients treated with TBRT, using 10\u201332 implanted Cs-131 sources per case (median, 20). The resection cavity (RC) was contoured on CT with registered postoperative T1-weighted MRI guidance. CTV_5mm was defined as the RC plus a 5 mm expansion excluding skull and surgical tract, and CTV_5mm_Eval as CTV_5mm minus the RC. Both volumes were analyzed using SFRT dose metrics from the Radiosurgery Society SFRT\/Flash working group white paper, and planar high-dose core number density (HCND_A) was used to characterize TBRT spatial fractionation. Results: The mean dose indices of D5 (dose covering 5% of the target volume), D10, D50, D90, D95 and D100 were 175.8 \u00b1 43.3, 148.8 \u00b1 35.1, 86.7 \u00b1 18.5, 56.1 \u00b1 10.5, 50.2 \u00b1 9.0 and 33.4 \u00b1 7.2 Gy for the CTV_5mm_Eval, respectively. The heterogeneity indices, represented by the ratio of D5\/D95 and D10\/D90, were 3.5 \u00b1 0.6 and 2.7 \u00b1 0.4, respectively, which were in the range of the linac-based Lattice therapy. HCND_A was a constant, TBRT delivered one high dose core for every 1 cm2 of tumor bed. All dose metrics in both the CTV_5mm and CTV_5mm_Eval were largely consistent across all plans. Conclusions: TBRT produced heterogeneous dose distributions comparable to conventional SFRT. A 60 Gy TBRT nominal prescription dose approximated the SFRT D90, or valley dose of the 5 mm expansion target volume, suggesting TBRT may provide an SFRT platform for tile-accessible cancers.<\/jats:p>","DOI":"10.3390\/cancers18193201","type":"journal-article","created":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T10:02:27Z","timestamp":1791194547000},"page":"3201","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["GammaTile\u00ae Brachytherapy as Spatially Fractionated Radiation Therapy for Postoperative Brain Cancer: A Paradigm for Precision Intracranial Radiotherapy"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3972-0107","authenticated-orcid":false,"given":"Hualin","family":"Zhang","sequence":"first","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, 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C.","family":"Ye","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5451-1733","authenticated-orcid":false,"given":"Adam","family":"Garsa","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7586-9833","authenticated-orcid":false,"given":"Aram S.","family":"Modrek","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhilei Liu","family":"Shen","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Salim","family":"Balik","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2893-8039","authenticated-orcid":false,"given":"Zhengzheng","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6189-0313","authenticated-orcid":false,"given":"Kaley","family":"Woods","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Adam C.","family":"Turner","sequence":"additional","affiliation":[{"name":"Department of Medical Affairs, GT Medical Technologies, Inc., Tempe, AZ 85281, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"David G.","family":"Brachman","sequence":"additional","affiliation":[{"name":"Department of Medical Affairs, GT Medical Technologies, Inc., Tempe, AZ 85281, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2183-4667","authenticated-orcid":false,"given":"Thomas","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, University of Southern California, Los Angeles, CA 90033, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriel","family":"Zada","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, University of Southern California, Los Angeles, CA 90033, 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trial","volume":"10","author":"Stupp","year":"2009","journal-title":"Lancet Oncol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2535","DOI":"10.1001\/jama.2015.16669","article-title":"Maintenance Therapy with Tumor-Treating Fields Plus Temozolomide vs Temozolomide Alone for Glioblastoma: A Randomized Clinical Trial","volume":"314","author":"Stupp","year":"2015","journal-title":"JAMA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"i67","DOI":"10.1093\/noajnl\/vdac088","article-title":"Radiotherapy and radiosurgery for meningiomas","volume":"5","author":"Chen","year":"2023","journal-title":"Neuro-Oncol. Adv."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1695","DOI":"10.3171\/2020.10.JNS201934","article-title":"Time to administration of stereotactic radiosurgery to the cavity after surgery for brain metastases: A real-world analysis","volume":"135","author":"Kaye","year":"2021","journal-title":"J. Neurosurg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e267","DOI":"10.1016\/j.prro.2021.01.011","article-title":"Timing of Adjuvant Fractionated Stereotactic Radiosurgery Affects Local Control of Resected Brain Metastases","volume":"11","author":"Poppas","year":"2021","journal-title":"Pract. Radiat. Oncol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3279","DOI":"10.1118\/1.2098127","article-title":"Dose rate constant of a cesium-131 interstitial brachytherapy seed measured by thermoluminescent dosimetry and gamma-ray spectrometry","volume":"32","author":"Chen","year":"2005","journal-title":"Med. Phys."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1571","DOI":"10.1118\/1.2868754","article-title":"Dosimetric characterization of model Cs-1 Rev2 cesium-131 brachytherapy source in water phantoms and human tissues with MCNP5 Monte Carlo simulation","volume":"35","author":"Wang","year":"2008","journal-title":"Med. Phys."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1007\/s11060-023-04523-z","article-title":"The role of GammaTile in the treatment of brain tumors: A technical and clinical overview","volume":"166","author":"Garcia","year":"2024","journal-title":"J. Neuro-Oncol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1007\/s11060-025-05113-x","article-title":"Cesium-131 collagen tile brachytherapy for salvage of recurrent intracranial metastases","volume":"175","author":"Beckham","year":"2025","journal-title":"J. Neuro-Oncol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/s11060-026-05455-0","article-title":"Local control and leptomeningeal disease after resection and GammaTile brachytherapy for newly diagnosed brain metastases: Results from a prospective registry","volume":"176","author":"Kite","year":"2026","journal-title":"J. Neuro-Oncol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1819","DOI":"10.3171\/2018.7.JNS18656","article-title":"Resection and permanent intracranial brachytherapy using modular, biocompatible cesium-131 implants: Results in 20 recurrent, previously irradiated meningiomas","volume":"131","author":"Brachman","year":"2019","journal-title":"J. Neurosurg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"Vdab185","DOI":"10.1093\/noajnl\/vdab185","article-title":"GammaTile(R) brachytherapy in the treatment of recurrent glioblastomas","volume":"4","author":"Gessler","year":"2022","journal-title":"Neuro-Oncol. Adv."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1007\/s11060-022-04101-9","article-title":"Salvage resection plus cesium-131 brachytherapy durably controls post-SRS recurrent brain metastases","volume":"159","author":"Imber","year":"2022","journal-title":"J. Neuro-Oncol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1016\/j.brachy.2023.08.002","article-title":"Surgically targeted radiation therapy (STaRT) for recurrent brain metastases: Initial clinical experience","volume":"22","author":"Kutuk","year":"2023","journal-title":"Brachytherapy"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Youssef, A., Sahgal, A., and Das, S. (2024). Radioresistance and brain metastases: A review of the literature and applied perspective. Front. Oncol., 14.","DOI":"10.3389\/fonc.2024.1477448"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"300","DOI":"10.1016\/j.prro.2024.09.015","article-title":"The Radiosurgery Society Working Groups on GRID, LATTICE, Microbeam, and FLASH Radiotherapies: Advancements Symposium and Subsequent Progress Made","volume":"15","author":"Snider","year":"2025","journal-title":"Pract. Radiat. Oncol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"819","DOI":"10.1016\/j.jtcvs.2021.04.090","article-title":"The emerging role of local therapy in oligometastatic non-small cell lung cancer","volume":"163","author":"Isbell","year":"2022","journal-title":"J. Thorac. Cardiovasc. Surg."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1998","DOI":"10.1111\/1759-7714.14479","article-title":"Successful treatment of induced oligometastasis and repeated oligoprogression of advanced lung adenocarcinoma with immunotherapy and radiotherapy","volume":"13","author":"Lee","year":"2022","journal-title":"Thorac. Cancer"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1683","DOI":"10.3390\/curroncol29030140","article-title":"Repeated Multimodality Ablative Therapies for Oligorecurrent Pulmonary Metastatic Disease","volume":"29","author":"Macagno","year":"2022","journal-title":"Curr. Oncol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"100866","DOI":"10.1016\/j.adro.2021.100866","article-title":"An International Consensus on the Design of Prospective Clinical-Translational Trials in Spatially Fractionated Radiation Therapy","volume":"7","author":"Mayr","year":"2022","journal-title":"Adv. Radiat. Oncol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3165","DOI":"10.1118\/1.2241998","article-title":"Dosimetric characteristics of a newly designed grid block for megavoltage photon radiation and its therapeutic advantage using a linear quadratic model","volume":"33","author":"Meigooni","year":"2006","journal-title":"Med. Phys."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"101308","DOI":"10.1016\/j.adro.2023.101308","article-title":"Practice Patterns of Spatially Fractionated Radiation Therapy: A Clinical Practice Survey","volume":"9","author":"Mayr","year":"2024","journal-title":"Adv. Radiat. Oncol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1016\/j.semradonc.2024.05.002","article-title":"Optimizing GRID and Lattice Spatially Fractionated Radiation Therapy: Innovative Strategies for Radioresistant and Bulky Tumor Management","volume":"34","author":"Ahmed","year":"2024","journal-title":"Semin. Radiat. Oncol."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Zhang, H., and Mayr, N.A. (2023). The immunologic effects of nonuniform dose irradiation. Spatially Fractionated, Microbeam and FLASH Radiation Therapy, A Physics and Multidisciplinary Approach, IOP.","DOI":"10.1088\/978-0-7503-4046-5"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"673","DOI":"10.1016\/j.brachy.2020.12.005","article-title":"First clinical implementation of GammaTile permanent brain implants after FDA clearance","volume":"20","author":"Ferreira","year":"2021","journal-title":"Brachytherapy"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1120\/jacmp.v16i5.5057","article-title":"Evaluation of the MIM Symphony treatment planning system for low-dose-rate- prostate brachytherapy","volume":"16","author":"Dhanesar","year":"2015","journal-title":"J. Appl. Clin. Med. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1118\/1.1646040","article-title":"Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations","volume":"31","author":"Rivard","year":"2004","journal-title":"Med. Phys."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1667\/RADE-20-00047.1","article-title":"Photon GRID Radiation Therapy: A Physics and Dosimetry White Paper from the Radiosurgery Society (RSS) GRID\/LATTICE, Microbeam and FLASH Radiotherapy Working Group","volume":"194","author":"Zhang","year":"2020","journal-title":"Radiat. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1016\/j.ijrobp.2023.08.061","article-title":"Dosimetric Validation for Prospective Clinical Trial of GRID Collimator-Based Spatially Fractionated Radiation Therapy: Dose Metrics Consistency and Heterogeneous Pattern Reproducibility","volume":"118","author":"Zhang","year":"2024","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Zhang, H., Wong, K., Olch, A., Han, H.R., Chau, B., Lukas, L., and Chang, E.L. (2025). Initial experience of spatially fractionated lattice radiation therapy for palliative treatment of pediatric bulky tumors. Front. Oncol., 15.","DOI":"10.3389\/fonc.2025.1648847"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Rivera, J.N., Kierski, T.M., Kasoji, S.K., Abrantes, A.S., Dayton, P.A., and Chang, S.X. (2020). Conventional dose rate spatially-fractionated radiation therapy (SFRT) treatment response and its association with dosimetric parameters-A preclinical study in a Fischer 344 rat model. PLoS ONE, 15.","DOI":"10.1101\/2020.01.30.926576"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Zhang, H., and Mayr, N.A. (2023). GRID-collimator-based and static-field SFRT. Spatially Fractionated, Microbeam and FLASH Radiation Therapy, A Physics and Multidisciplinary Approach, IOP.","DOI":"10.1088\/978-0-7503-4046-5"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Zhang, H., Grams, M.P., Foy, J.J., and Mayr, N.A. (2022). A Dosimetric Parameter Reference Look-Up Table for GRID Collimator-Based Spatially Fractionated Radiation Therapy. Cancers, 14.","DOI":"10.3390\/cancers14041037"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1016\/j.semradonc.2024.04.006","article-title":"Which Modality of SFRT Should be Considered First for Bulky Tumor Radiation Therapy, GRID or LATTICE?","volume":"34","author":"Zhang","year":"2024","journal-title":"Semin. Radiat. Oncol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"721","DOI":"10.1016\/S0360-3016(99)00170-4","article-title":"High-dose spatially-fractionated radiation (GRID): A new paradigm in the management of advanced cancers","volume":"45","author":"Mohiuddin","year":"1999","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e499","DOI":"10.1016\/j.prro.2023.05.010","article-title":"Postoperative Management of Recurrence After Radiosurgery and Surgical Resection for Brain Metastases and Predicting Benefit from Adjuvant Radiation","volume":"13","author":"Buszek","year":"2023","journal-title":"Pract. Radiat. Oncol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1007\/s11060-021-03872-x","article-title":"Salvage resection of recurrent previously irradiated brain metastases: Tumor control and radiation necrosis dependency on adjuvant re-irradiation","volume":"155","author":"Wilcox","year":"2021","journal-title":"J. Neuro-Oncol."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Holt, D.E., Gill, B.S., Clump, D.A., Leeman, J.E., Burton, S.A., Amankulor, N.M., Engh, J.A., and Heron, D.E. (2015). Tumor bed radiosurgery following resection and prior stereotactic radiosurgery for locally persistent brain metastasis. Front. Oncol., 5.","DOI":"10.3389\/fonc.2015.00084"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Weinberg, J.S., Imber, B.S., DiNapoli, V., Moss, N.S., Hoang, K.B., Wang, F., Mohiuddin, I., Mistry, A.M., Garcia, M.A., and Tawbi, H. (2026). Surgery and tile-based radiation therapy versus surgery and stereotactic radiation for newly diagnosed brain metastases (ROADS): A randomized, open-label, phase 3 trial. J. Clin. Oncol., 101200JCO2601894.","DOI":"10.1200\/JCO-26-01894"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Zhang, H., and Mayr, N.A. (2023). Introduction to the principles of spatially fractionated radiotherapy. Spatially Fractionated, Microbeam and FLASH Radiation Therapy, A Physics and Multidisciplinary Approach, IOP.","DOI":"10.1088\/978-0-7503-4046-5"}],"container-title":["Cancers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6694\/18\/19\/3201\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T10:14:09Z","timestamp":1791195249000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6694\/18\/19\/3201"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,3]]},"references-count":40,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["cancers18193201"],"URL":"https:\/\/doi.org\/10.3390\/cancers18193201","relation":{},"ISSN":["2072-6694"],"issn-type":[{"value":"2072-6694","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,3]]}}}