Effect of Radiation Fraction Size on Local Control Rates for Early Glottic Carcinoma: A Model Analysis for In Vivo Tumor Growth and Radioresponse Parameters

Ricciardelli, Edward J.; Weymuller, Ernest A.; Koh, Wui-Jin; Austin-Seymour, M.; Desautel, M. C.; Laramore, George E.

doi:10.1001/archotol.1994.01880310041008

Cited by 20 publications

(3 citation statements)

References 15 publications

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“…21 In another study covering 171 patients control rate was significantly improved using 2 Gy than 1.8 Gy per fraction. 23 Patients treated with higher fraction size > 3 Gy have a higher risk of developing late complications and this is in contrast to the findings of the BIR trial. 10,25 The optimum beam energy advocated for the management of early glottic carcinoma is cobalt-60 or 4-MV photons.…”

Section: Discussionmentioning

confidence: 77%

Hypofractionated Radiotherapy in the Treatment of Early Glottic Carcinoma

Hussain¹,

Jamshed²,

Majeed³

et al. 2011

International Journal of Head and Neck Surgery

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Introduction: Given the high probability of cure, the aims of treatment are cure, laryngeal preservation and good voice quality while making effective use of available resources. In this study we analyze locoregional control (LRC) and survival following hypofractionated radiotherapy in early stage glottic squamous cell carcinoma treated at patients with early glottic squamous cell carcinoma were treated with hypofractionated radiotherapy. All patients were included in the study (M: 94%; F:6%). Median age was 60 years (range: 21-81 years). Sixty-six percent of patients were smokers. AJCC stage was T1 in 95% and T2 in 5% of the patients. Radiotherapy dose was 55 Gy in 20 fractions over 4 weeks. All patients were treated on cobalt-60. Median radiotherapy treatment time was 28 days (range: 23-35 days). Results:The LRC rate after primary radiotherapy at 5 years was 91% (95% CI: 88-94%). The 5 years overall and disease-specific survival was 86% (95% CI: 81 and 91%) and 97% (CI 95%: 95 and 99%) respectively. Patients with T1a and T1b disease had LRC rates of 95 and 88% (p = 0.32). The LRC rates for patients with and without anterior commissure involvement at 5 years were 80 and 96% (p = 0.02) respectively.Conclusion: Hypofractionated radiotherapy 55 Gy in 20 fractions is comparable to conventional fractionation schedules in terms of locoregional control and survival while offering potential for optimizing resources usage.

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Section: Discussionmentioning

confidence: 77%

Hypofractionated Radiotherapy in the Treatment of Early Glottic Carcinoma

Hussain¹,

Jamshed²,

Majeed³

et al. 2011

International Journal of Head and Neck Surgery

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“…Many studies have demonstrated better local control rates if fraction size is ≥2 Gy. [26][27][28][29][30] Short et al reported 95% LRC with accelerated hypofractionated regimen 52.5-55 Gy over the period of 4 weeks compared with 75% when treating with 60-66 Gy over the period of 6-6.5 weeks (P = 0.002). [26] In another study covering 171 patients, control rate was significantly improved using 2 Gy than 1.8 Gy/fraction.…”

Section: Discussionmentioning

confidence: 99%

“…[32] Conversely, data from other retrospective studies suggest that the estimated 5-year local control rates with 6, 8 and 10 MV photons may be similar to those achieved with cobalt-60. [28] Various studies have indicated that endoscopic laser excision produces oncologic outcome and voice quality comparable to RT treatment. [33] While radiation is often favoured as it appears to be associated with reduced impairment of voice quality, but qualitative studies about vocal function in post-irradiated patients have been inconclusive and not uniform.…”

Section: Discussionmentioning

confidence: 99%

Survival Outcomes in Early Glottic Carcinoma; A Single Institution Experience

Munawar

Saeed

Sadaf

et al. 2016

J Cancer Allied Spec

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Purpose: Laryngeal cancers are amongst the most common cancers affecting head and neck region. In this study, we analyse the overall survival (OS) following hypofractionated radiotherapy (RT) in early stage glottic carcinoma treated at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore. Methods: Between October 2003 and June 2009, 87 patients with early stage glottic carcinoma were treated with hypofractionated RT. All patients were included in the study. The ratio of male: female is 94%:6%. Mean age was 62 years (range 31–83 years). 66% of the patients were smokers. AJCC stage was T1a in 76%, T1b 20% and T2 in 4% of the patients. Histological distribution was; squamous cell carcinoma 97%, verrucous carcinoma 2% and squamous cell spindle variant 1%. Median follow-up time was 59 months (range 4–122 months). RT dose was 55 Gy in 20 fractions over a period of 4 weeks. Median RT treatment time was 28 days (range 23–35 days). Patients that lost to follow-up were contacted through telephone. Results: The 10-year OS was 83%. Patterns of failure was 7 local and 1 distant while 1 patient had persistent disease. 15 patients were dead at the time of study. Cause of death; 13 patients died due to Ischemic heart disease and 2 due to primary disease. Conclusion: Hypofractionated RT 55 Gy in 20 fractions seems to achieve good OS while offering potential for optimizing resources usage. Key words: Glottic carcinoma, hypofractionated, overall survival, radiotherapy

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Foote

Olsen

Bonner

et al. 1996

Cancer

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e have read Foote et al.' with interest. Certainly a W modern series showing the efficacy of 6 megavolt (MY) photon therapy in the treatment of early glottic cancer is reassuring but it is important to note the effect of fraction size. Updated data regarding treatment with 6 MV linear accelerators2 reveals that 22 T1 glottic cancer patients have now been treated with 2.25 gray (Gy) fractions to 63 Gy with 95% 2-year local control (Foote RL, personal communication, 1996). Isn't it possible that the prescription dose per fraction of 2.25 Gy compensated for the decreased dose at the tumor surface as a consequence of the higher energy linear accelerator? If so, Foote et al. have confirmed Schwaibold et al.'s analysis of T1 glottic cancer,' which found that age, sex, hemoglobin, tumor bulk, differentiation, field size, total dose, and total treatment time were not significant predictors of local control, whereas fraction size of 2 Gy or greater was critical to local control. Of course the 4 MV linear accelerator used by Schwaibold et al. would have a dose distribution similar to the bi-energetic Co-60.The "magic" dose per fraction figure may be the dose at the free edge or anterior commissure. Perhaps we can use any of a number of methods of delivering the dose as long as we "overprescribe" to ensure the free edge and anterior commissure are treated to the critical daily tumoricidal dose.Why should daily fraction size matter if the overall treatment time does not? It has been pointed out3 that the lack of an effect of overall treatment time on outcome may be due to the shape of the sigmoid dose response curve, and prolongation of the treatment time will be most important when the tumor control probability is steeply rising.The dependence of local control on fraction size is the best evidence proliferation is alive and important for early glottic cancer. Since demonstrable improvement over current results for T1 glottic cancer is difficult, there is little incentive to further increase the fraction size. Conversely, if the critical dosimetry is within mm of the tumor surface underdosage at the mucosal surface of exophytic tonsillar or nasopharyngeal tumors might also be detrimental if treated with 2 6 MV linear accelerators. Rouby E, et al. The effect of fraction size on control of early glottic cancer.

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Effect of Radiation Fraction Size on Local Control Rates for Early Glottic Carcinoma: A Model Analysis for In Vivo Tumor Growth and Radioresponse Parameters

Cited by 20 publications

References 15 publications

Hypofractionated Radiotherapy in the Treatment of Early Glottic Carcinoma

Hypofractionated Radiotherapy in the Treatment of Early Glottic Carcinoma

Survival Outcomes in Early Glottic Carcinoma; A Single Institution Experience

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