{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T13:19:43Z","timestamp":1787750383190,"version":"build-2784847793"},"reference-count":15,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"2","license":[{"start":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T00:00:00Z","timestamp":1775001600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2026,4]]},"abstract":"\n Aim:<\/jats:title>\n To assess and compare the radiation-induced effects on the spinal cord of rats following fractionated irradiation with doses of 1.36 Gy and 2.0 Gy per fraction.<\/jats:p>\n <\/jats:sec>\n \n Materials and Methods:<\/jats:title>\n \n The risk of radiation-induced myelopathy and spinal cord tolerance represent the major dose-limiting factors during re-irradiation of head-and-neck cancers since spinal cord is exposed to maximum tolerance dose of 45 Gy in 1.8\u20132 Gy per fraction during first radiation treatment. However, modern radiotherapy techniques such as Volumetric-modulated Arc Therapy (VMAT) with simultaneous integrated boost (SIB) usually irradiate spinal cord with much less dose per fraction than 2 Gy per fraction of prescription dose. In this experimental study, the cervical spinal cord of male Wistar rats was irradiated to a total biologically effective dose of 120 Gy\n 2<\/jats:sub>\n using different dose-per-fraction, control group was irradiated with 2 Gy per fraction for a total dose of 60 Gy\/30F in 6 weeks while experimental group was given 1.36 Gy per fraction for a total dose of 70.72 Gy\/52F in 10.5 weeks. The motor function including motor co-ordination and balance, locomotor activity was observed at 1, 3, and 5 months after the completion of radiation and was compared with baseline values.\n <\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n \n Motor co-ordination and balance were preserved until the 3\n rd<\/jats:sup>\n month in both control and experimental groups, with no significant difference from baseline (0 \u00b1 0). Gradual functional deterioration became evident after 3 months and a significant decline was observed at 5 months in both groups, with a greater reduction in the control group (72 \u00b1 2.4) compared to the experimental group (105 \u00b1 2.8) (\n F<\/jats:italic>\n = 367.9,\n P<\/jats:italic>\n < 0.001). The decline was more pronounced in rats treated with 2 Gy per fraction than in those receiving 1.36 Gy per fraction. Locomotor activity declined progressively after irradiation in both groups. Baseline activity was 388.8 (control group) and 369.7 (experimental group). At 1 month, the control group showed a significantly greater reduction (180.2 \u00b1 8.2) than the experimental group (272.5 \u00b1 12.1), with a significant group and time interaction (\n F<\/jats:italic>\n = 110.4,\n P<\/jats:italic>\n < 0.001). This difference persisted at 3 months (control group: 130.2 \u00b1 3.6; experimental group: 185.4 \u00b1 4.8;\n F<\/jats:italic>\n = 208.7,\n P<\/jats:italic>\n < 0.001) and was most pronounced at 5 months (control group: 99.5 \u00b1 1.7; experimental group: 147.4 \u00b1 4.0;\n F<\/jats:italic>\n = 610.9,\n P<\/jats:italic>\n < 0.001).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions:<\/jats:title>\n This study demonstrates that fractionated irradiation of the spinal cord at 1.36 Gy per fraction, as commonly delivered during VMAT SIB, is less damaging in rats compared to the conventional 2 Gy per fraction used in three-dimensional conformal radiotherapy. Motor co-ordination and locomotor activity deterioration were more pronounced in the control group than in the experimental group. These findings suggest that smaller dose-per-fraction schedules may be well within the spinal cord tolerance, thereby potentially enabling safer re-irradiation scenarios.<\/jats:p>\n <\/jats:sec>","DOI":"10.4103\/jmp.jmp_296_25","type":"journal-article","created":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T20:01:47Z","timestamp":1782244907000},"page":"387-393","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":0,"title":["Comparative Study of Spinal Cord Toxicity from Dose Per Fraction Delivered to Cervical Spinal Cord in Head-and-neck Cancers by Volumetric-modulated Arc Therapy with Simultaneous Integrated Boost versus Three-dimensional Conformal Radiotherapy in a Murine Model"],"prefix":"10.4103","volume":"51","author":[{"given":"Swati","family":"Verma","sequence":"first","affiliation":[{"name":"Department of Radiation Oncology, AIIMS, Rishikesh, Uttarakhand, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manoj Kumar","family":"Gupta","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, AIIMS, Rishikesh, Uttarakhand, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shailendra","family":"Handu","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, AIIMS, Rishikesh, Uttarakhand, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shalinee","family":"Rao","sequence":"additional","affiliation":[{"name":"Department of Pathology, AIIMS, Rishikesh, Uttarakhand, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2026,6,23]]},"reference":[{"key":"R1-20260623","doi-asserted-by":"crossref","first-page":"E97","DOI":"10.1002\/lary.24257","article-title":"Simultaneous integrated boost-intensity-modulated radiotherapy in head and neck cancer","volume":"123","author":"Franceschini","year":"2013","journal-title":"Laryngoscope"},{"key":"R2-20260623","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1186\/1748-717X-1-7","article-title":"IMRT using simultaneously integrated boost (SIB) in head and neck cancer patients","volume":"1","author":"Studer","year":"2006","journal-title":"Radiat Oncol"},{"key":"R3-20260623","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/0360-3016(82)90517-X","article-title":"Changes in early and late radiation responses with altered dose fractionation: Implications for dose-survival relationships","volume":"8","author":"Thames","year":"1982","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"R4-20260623","first-page":"244","article-title":"Oral field cancerization: An update on current concepts","volume":"8","author":"Mohan","year":"2014","journal-title":"Oncol Rev"},{"key":"R5-20260623","doi-asserted-by":"crossref","first-page":"4957","DOI":"10.7314\/APJCP.2014.15.12.4957","article-title":"Stage-wise presentation of non-metastatic head and neck cancer: An analysis of patients from the Kumaon hills of India","volume":"15","author":"Pandey","year":"2014","journal-title":"Asian Pac J Cancer Prev"},{"key":"R6-20260623","doi-asserted-by":"crossref","first-page":"01TR01","DOI":"10.1088\/1361-6560\/aaf26a","article-title":"The linear quadratic model: Usage, interpretation and challenges","volume":"64","author":"McMahon","year":"2018","journal-title":"Phys Med Biol"},{"key":"R7-20260623","first-page":"100159","article-title":"Demystifying the radiobiology of hypofractionation: Simple equations to determine tumour alpha beta ratio","volume":"3","author":"Joseph","year":"2025","journal-title":"Royal Coll Radiol Open"},{"key":"R8-20260623","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/0360-3016(91)90171-Y","article-title":"Tolerance of normal tissue to therapeutic irradiation","volume":"21","author":"Emami","year":"1991","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"R9-20260623","first-page":"1189","article-title":"Radiation tolerance dose of the spinal cord following conventionally fractionated irradiation","volume":"33","author":"Yamada","year":"1987","journal-title":"Gan No Rinsho"},{"key":"R10-20260623","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1016\/0360-3016(93)90282-Z","article-title":"Late effects of radiation on the lumbar spinal cord of guinea pigs: Re-treatment tolerance","volume":"26","author":"Mason","year":"1993","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"R11-20260623","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1016\/0360-3016(92)90947-G","article-title":"The extent, time course, and fraction size dependence of mouse spinal cord recovery from radiation injury","volume":"30","author":"Lavey","year":"1994","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"R12-20260623","doi-asserted-by":"crossref","first-page":"1487","DOI":"10.1016\/0360-3016(83)90323-1","article-title":"The effect of small radiation doses on the rat spinal cord: The concept of partial tolerance","volume":"9","author":"Ang","year":"1983","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"R13-20260623","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1016\/0360-3016(93)90242-N","article-title":"The effect of fractionated doses of radiation on mouse spinal cord","volume":"27","author":"Lo","year":"1993","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"R14-20260623","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1016\/0360-3016(94)00594-B","article-title":"Blood-spinal cord barrier function and morphometry after single doses of x-rays in rat spinal cord","volume":"32","author":"Stewart","year":"1995","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"R15-20260623","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1007\/s13566-015-0212-9","article-title":"Radiation dose-fractionation effects in spinal cord: Comparison of animal and human data","volume":"4","author":"Jin","year":"2015","journal-title":"J Radiat Oncol"}],"container-title":["Journal of Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ovid.com\/10.4103\/jmp.jmp_296_25","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T12:27:40Z","timestamp":1787747260000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ovid.com\/10.4103\/jmp.jmp_296_25"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4]]},"references-count":15,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2026]]}},"URL":"https:\/\/doi.org\/10.4103\/jmp.jmp_296_25","relation":{},"ISSN":["0971-6203","1998-3913"],"issn-type":[{"value":"0971-6203","type":"print"},{"value":"1998-3913","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4]]},"assertion":[{"value":"2025-11-05","name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-05-21","name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}}]}}