Abstract: Purpose: Palliative whole-brain radiotherapy (WBRT) is a useful treatment modality for patients diagnosed with brain metastasis. Our study aimed to document parotid doses using a short course of 20 Gy in five fractions (SC-WBRT) and compare them with the known xerostomia parameters.
Methods and Materials: We retrieved dosimetric parameters for 59 patients who received SC-WBRT. The contouring of parotids was done retrospectively. The data was stratified depending on the lower edge of the planning target volume (PTV) border, up to either the first cervical vertebra (C1) or the second cervical vertebra (C2). The biologically effective dose (BED) of the parotid dose constraints from the literature was calculated and corrected to obtain the dose for a five-fraction treatment. These were used as a reference for assessing the parotid doses of our cohort.
Results: With SC-WBRT, the mean doses of either gland (11.46 Gy) and of total parotids (11.48 Gy) were statistically significantly less than the BED corrected constraints of 12.82 Gy (p < 0.01) and 15.31 Gy (p < 0.01). Patients with PTV to C1, compared to those with a PTV to C2, had significantly lower mean doses of either gland (9.44 Gy vs 12.76 Gy, p < 0.01) and total parotid dose (9.44 Gy vs 12.78 Gy, p < 0.01). Patients with PTV to C1 had doses significantly lower than all the reference dose parameters.
Conclusion: Routine delineation and documentation of parotid dosimetry would enable parotid sparing, irrespective of the dose regimen used. SC-WBRT provides better parotid sparing dosimetrically which may reduce the related toxicities even in palliative settings. Limiting the lower border of the PTV to C1 will further decrease the parotid doses.
Competing Interests: Declarations. Ethics approval: This is a retrospective study. The National Cancer Institute, Nagpur Ethics Committee, has reviewed and approved it on December 18, 2021—Ref No.: NCI/EC/2018/022/12/2021—ensuring that this was in adherence to the principles outlined in the Declaration of Helsinki and in accordance with the highest ethical standards and national and international regulations. Consent for publication: The authors affirm that human research participants provided informed consent for publication. Competing interests: The authors declare no competing interests.
(© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
References: Fox BD, Cheung VJ, Patel AJ et al (2011) Epidemiology of metastatic brain tumors. Neurosurg Clin N Am 22(1–6):v. https://doi.org/10.1016/j.nec.2010.08.007. (PMID: 10.1016/j.nec.2010.08.00721109143)
Davis FG, Dolecek TA, McCarthy BJ, Villano JL (2012) Toward determining the lifetime occurrence of metastatic brain tumors estimated from 2007 United States cancer incidence data. Neuro Oncol 14:1171–1177. https://doi.org/10.1093/neuonc/nos152. (PMID: 10.1093/neuonc/nos152228983723424213)
Tsao MN, Xu W, Wong RK, et al (2018) Whole brain radiotherapy for the treatment of newly diagnosed multiple brain metastases. Cochrane Database Syst Rev 1:CD003869. https://doi.org/10.1002/14651858.CD003869.pub4.
Tsao MN, Rades D, Wirth A et al (2012) Radiotherapeutic and surgical management for newly diagnosed brain metastasis(es): an American Society for Radiation Oncology evidence-based guideline. Pract Radiat Oncol 2:210–225. https://doi.org/10.1016/j.prro.2011.12.004. (PMID: 10.1016/j.prro.2011.12.004259256263808749)
Scoccianti S, Ricardi U (2012) Treatment of brain metastases: review of phase III randomized controlled trials. Radiother Oncol 102:168–179. https://doi.org/10.1016/j.radonc.2011.08.041. (PMID: 10.1016/j.radonc.2011.08.04121996522)
Haie-Meder C, Pellae-Cosset B, Laplanche A et al (1993) Results of a randomized clinical trial comparing two radiation schedules in the palliative treatment of brain metastases. Radiother Oncol 26:111–116. https://doi.org/10.1016/0167-8140(93)90091-l. (PMID: 10.1016/0167-8140(93)90091-l7681997)
Davey P, Hoegler D, Ennis M, Smith J (2008) A phase III study of accelerated versus conventional hypofractionated whole brain irradiation in patients of good performance status with brain metastases not suitable for surgical excision. Radiother Oncol 88:173–176. https://doi.org/10.1016/j.radonc.2008.05.020. (PMID: 10.1016/j.radonc.2008.05.02018555546)
Agarwal JP, Wadasadawala T, Munshi A et al (2010) Validation of recursive partitioning analysis classification in patients with brain metastases from non-small cell lung cancer treated with short-course accelerated radiotherapy. Clin Oncol (R Coll Radiol) 22:837–843. https://doi.org/10.1016/j.clon.2010.05.022. (PMID: 10.1016/j.clon.2010.05.02220591632)
Eisbruch A, Ten Haken RK, Kim HM et al (1999) Dose, volume, and function relationships in parotid salivary glands following conformal and intensity-modulated irradiation of head and neck cancer. Int J Radiat Oncol Biol Phys 45:577–587. https://doi.org/10.1016/s0360-3016(99)00247-3. (PMID: 10.1016/s0360-3016(99)00247-310524409)
Trignani M, Genovesi D, Vinciguerra A et al (2015) Parotid glands in whole-brain radiotherapy: 2D versus 3D technique for no sparing or sparing. Radiol Med 120:324–328. https://doi.org/10.1007/s11547-014-0436-6. (PMID: 10.1007/s11547-014-0436-625033946)
Noh OK, Chun M, Nam SS et al (2011) Parotid gland as a risk organ in whole brain radiotherapy. Radiother Oncol 98:223–226. https://doi.org/10.1016/j.radonc.2010.12.013. (PMID: 10.1016/j.radonc.2010.12.01321300416)
Wang K, Pearlstein KA, Moon DH et al (2019) Assessment of risk of xerostomia after whole-brain radiation therapy and association with parotid dose. JAMA Oncol 5:221–228. https://doi.org/10.1001/jamaoncol.2018.4951. (PMID: 10.1001/jamaoncol.2018.495130489607)
Orton A, Gordon J, Vigh T et al (2017) Differences in parotid dosimetry and expected normal tissue complication probabilities in whole brain radiation plans covering C1 versus C2. Cureus 9:e1217. https://doi.org/10.7759/cureus.1217. (PMID: 10.7759/cureus.1217285890665453748)
Ortholan C, Chamorey E, Benezery K et al (2009) Modeling of salivary production recovery after radiotherapy using mixed models: determination of optimal dose constraint for IMRT planning and construction of convenient tools to predict salivary function. Int J Radiat Oncol Biol Phys 73:178–86. https://doi.org/10.1016/j.ijrobp.2008.03.068. (PMID: 10.1016/j.ijrobp.2008.03.06818565687)
Bentzen SM, Constine LS, Deasy JO et al (2010) Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC): an introduction to the scientific issues. Int J Radiat Oncol Biol Phys 76:S3-9. https://doi.org/10.1016/j.ijrobp.2009.09.040. (PMID: 10.1016/j.ijrobp.2009.09.040201715153431964)
Deasy JO, Moiseenko V, Marks L et al (2010) Radiotherapy dose-volume effects on salivary gland function. Int J Radiat Oncol Biol Phys 76:S58-63. https://doi.org/10.1016/j.ijrobp.2009.06.090. (PMID: 10.1016/j.ijrobp.2009.06.090201715194041494)
Gillison ML, Trotti AM, Harris J et al (2019) Radiotherapy plus cetuximab or cisplatin for human papillomavirus (HPV)-positive oropharyngeal cancer: a randomized, multicentre, non-inferiority clinical trial. Lancet 393:40–50. https://doi.org/10.1016/S0140-6736(18)32779-X. (PMID: 10.1016/S0140-6736(18)32779-X30449625)
Lee NY, Zhang Q, Pfister DG et al (2012) Addition of bevacizumab to standard chemoradiation for locoregionally advanced nasopharyngeal carcinoma (RTOG 0615): a phase 2 multi-institutional trial. Lancet Oncol 13:172–80. https://doi.org/10.1016/S1470-2045(11)70303-5. (PMID: 10.1016/S1470-2045(11)70303-522178121)
Burlage FR, Coppes RP, Meertens H et al (2001) Parotid and submandibular/sublingual salivary flow during high dose radiotherapy. Radiother Oncol 61:271–274. https://doi.org/10.1016/s0167-8140(01)00427-3. (PMID: 10.1016/s0167-8140(01)00427-311730996)
Mavroidis P, Pearlstein KA, Moon DH et al (2021) NTCP modeling and dose-volume correlations for acute xerostomia and dry eye after whole brain radiation. Radiat Oncol 16:56. https://doi.org/10.1186/s13014-021-01786-6. (PMID: 10.1186/s13014-021-01786-6337437737981795)
Le Péchoux C, Dunant A, Senan S et al (2009) Standard-dose versus higher-dose prophylactic cranial irradiation (PCI) in patients with limited-stage small-cell lung cancer in complete remission after chemotherapy and thoracic radiotherapy (PCI 99–01, EORTC 22003–08004, RTOG 0212, and IFCT 99–01): a randomised clinical trial. Lancet Oncol 10:467–74. https://doi.org/10.1016/S1470-2045(09)70101-9. (PMID: 10.1016/S1470-2045(09)70101-919386548)
Wu C-C, Wuu Y-R, Jani A et al (2017) Whole-brain irradiation field design: a comparison of parotid dose. Med Dosim 42:145–149. https://doi.org/10.1016/j.meddos.2017.02.006. (PMID: 10.1016/j.meddos.2017.02.00628479012)
Park J, Park JW, Yea JW (2019) Non-coplanar whole brain radiotherapy is an effective modality for parotid sparing. Yeungnam Univ J Med 36:36–42. https://doi.org/10.12701/yujm.2019.00087. (PMID: 10.12701/yujm.2019.00087316206106784623)
Processing Request
No Comments.