Local control of carcinoma of the tonsil by radiation therapy: An analysis of patterns of fractionation in nine institutions

Withers, H. Rodney; Peters, Lester J.; Taylor, Jeremy M. G.; Owen, Jean B.; Morrison, William H.; Schultheiss, Timothy E.; Keane, Thomas J.; O’Sullivan, Brian; Dyk, Jacob Van; Gupta, Nirmal Kumar; Wang, C.C.; Jones, Christopher U.; Doppke, Karen P.; Myint, S.; Thompson, Myra; Parsons, James T.; Mendenhall, William M.; Dische, Stanley; Aird, Edwin; Henk, J.M.; Bidmead, M.; Svoboda, V.; Chon, Yun; Hanlon, Alexandra L.; Peters, Theresa L.; Hanks, Gerald E.

doi:10.1016/0360-3016(95)00228-q

Cited by 147 publications

(64 citation statements)

References 46 publications

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“…26 T k (kick-off) is the elapsed time between the start of fractionated radiotherapy and the onset of accelerated repopulation in tumors (or rapid renewing tissues). T k has been estimated for some tumors: 3-4 weeks for head and neck tumors, 26,27 19 days for cervical cancer 28 and between 30 and 69 days, depending on the stage, for prostate cancer. 29 Although nobody really knows the onset time of accelerated repopulation of tumors treated with SBRT, data derived from conventionally fractionated radiotherapy suggest that this phenomenon is probably not very important for SBRT given the relatively short overall treatment time (and irrelevant in single dose SBRT).…”

Section: Repopulation Of Tumor Cellsmentioning

confidence: 99%

Radiobiology of stereotactic body radiation therapy (SBRT)

Garau

2017

Reports of Practical Oncology & Radiotherapy

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a b s t r a c tRecent advances in the technology of radiotherapy have enabled the development of new therapeutic modalities that deliver radiation with very high accuracy, reduced margins and high dose conformation, allowing the reduction of healthy tissue irradiated and therefore minimizing the risk of toxicity. The next step was to increase the total tumor dose using conventional fractionation (which remains the best way to relatively radioprotect healthy tissues when large volumes are treated) or to use new fractionation schemes with greater biological effectiveness. Based on the experience gained in radiosurgery, the latter way was chosen for small and well-defined tumors in the body. Stereotactic body radiotherapy delivers high doses of radiation to small and well-defined targets in an extreme hypofractionated (and accelerated) scheme with a very high biological effectiveness obtaining very good initial clinical results in terms of local tumor control and acceptable rate of late complications.In fact, we realize a posteriori that it was not feasible to administer such biologically equivalent dose in a conventional fractionation because the treatment could last several months.So far, these new therapeutic modalities have been developed due to technologic advances in image guidance and treatment delivery but without a solid biological basis. It is the role of traditional radiobiology (and molecular radiobiology) to explain the effects of high doses of ionizing radiation on tumor and normal tissues. Only through a better understanding of how high doses of ionizing radiation act, clinicians will know exactly what we do, allowing us in the future to refine our treatments. This article attempts to describe through simple and understandable concepts the known aspects of the biological action of high doses of radiation on tumor and normal tissues, but it is clear that we need much more basic research to better understand the biology of high doses of radiation.

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Section: Repopulation Of Tumor Cellsmentioning

confidence: 99%

Radiobiology of stereotactic body radiation therapy (SBRT)

Garau

2017

Reports of Practical Oncology & Radiotherapy

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“…Withers et al 1,2 were among the first to raise concern over rapid tumor regrowth when overall treatment time extends beyond 4 weeks. Subsequently a large number of trials have tested the impact of treatment time on outcomes in H&N cancers.…”

Section: Introductionmentioning

confidence: 99%

Impact of Overall Treatment Time on Survival and Local Control in Patients With Anal Cancer: A Pooled Data Analysis of Radiation Therapy Oncology Group Trials 87-04 and 98-11

Ben‐Josef

Moughan²,

Ajani³

et al. 2010

JCO

159

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A B S T R A C T PurposeTo determine whether increased duration of radiation therapy (RT) and overall treatment (RX) time has a detrimental effect in anal cancer. Patients and MethodsData from Radiation Therapy Oncology Group (RTOG) 87-04 and RTOG 98-11 trials were combined to form three treatment groups: RT/fluorouracil (FU)/mitomycin (n ϭ 472), RT/FU/ cisplatin (n ϭ 320), and RT/FU (n ϭ 145). Cox proportional hazards models were used with the following variables: RT duration, RT intensity, RX duration, treatment group, age, sex, Karnofsky performance score (KPS), T stage, N stage, and RT dose. ResultsIn the univariate analysis, there was a significant association between RX duration and colostomy failure (CF; hazard ratio [HR] ϭ 1.51; 95% CI, 1.07 to 2.14; P ϭ .02), local failure (HR ϭ 1.52; 95% CI, 1.14 to 2.03; P ϭ .005), locoregional failure (HR ϭ 1.51; 95% CI, 1.15 to 1.98; P ϭ .003), and time to failure (HR ϭ 1.40; 95% CI, 1.10 to 1.79; P ϭ .007). The significance of RX duration was maintained after adjusting for treatment group. In multivariate modeling there was a trend toward an association between RX duration and CF (HR ϭ 1.57; 95% CI, 0.98 to 2.50; P ϭ .06) and a statistically significant association with local failure (HR ϭ 1.96; 95% CI, 1.34 to 2.87; P ϭ .0006). Age, sex, KPS, T stage, N stage, and RT dose, but not RT duration, RT intensity, or RX duration, were found to be statistically significant predictors of OS and colostomyfree survival. ConclusionTotal treatment time, but not duration of radiation therapy, seems to have a detrimental effect on local failure and colostomy rate in anal cancer. Induction chemotherapy may contribute to local failure by increasing total treatment time.

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“…Protraction of radiotherapy (RT) has been shown to be detrimental in several treatment sites (1)(2)(3)(4). This has been particularly true in head-and-neck subsites, such as oropharynx and oral cavity cancers (1,4).…”

Section: Introductionmentioning

confidence: 99%

Does Treatment Duration Affect Outcome After Radiotherapy for Prostate Cancer?

D’Ambrosio

Horwitz

et al. 2008

International Journal of Radiation Oncology*Biology*Physics

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Purpose-The protraction of external beam radiotherapy (RT) time is detrimental in several disease sites. In prostate cancer, the overall treatment time can be considerable, as can the potential for treatment breaks. We evaluated the effect of elapsed treatment time on outcome after RT for prostate cancer.Methods and Materials-Between April 1989 and November 2004, 1,796 men with prostate cancer were treated with RT alone. The nontreatment day ratio (NTDR) was defined as the number of nontreatment days divided by the total elapsed days of RT. This ratio was used to account for the relationship between treatment duration and total RT dose. Men were stratified into low risk (n = 789), intermediate risk (n = 798), and high risk (n = 209) using a single-factor model. Results-The 10-year freedom from biochemical failure (FFBF) rate was 68% for a NTDR <33% vs. 58% for NTDR ≥33% (p = 0.02; BF was defined as a prostate-specific antigen nadir + 2 ng/mL). In the low-risk group, the 10-year FFBF rate was 82% for NTDR <33% vs. 57% for NTDR ≥33% (p = 0.0019). The NTDR was independently predictive for FFBF (p = 0.03), in addition to T stage (p = 0.005) and initial prostate-specific antigen level (p < 0.0001) on multivariate analysis, including Gleason score and radiation dose. The NTDR was not a significant predictor of FFBF when examined in the intermediate-risk group, high-risk group, or all risk groups combined.Conclusions-A proportionally longer treatment duration was identified as an adverse factor in low-risk patients. Treatment breaks resulting in a NTDR of ≥33% (e.g., four or more breaks during a 40-fraction treatment, 5 d/wk) should be avoided.

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Local control of carcinoma of the tonsil by radiation therapy: An analysis of patterns of fractionation in nine institutions

Cited by 147 publications

References 46 publications

Radiobiology of stereotactic body radiation therapy (SBRT)

Radiobiology of stereotactic body radiation therapy (SBRT)

Impact of Overall Treatment Time on Survival and Local Control in Patients With Anal Cancer: A Pooled Data Analysis of Radiation Therapy Oncology Group Trials 87-04 and 98-11

Does Treatment Duration Affect Outcome After Radiotherapy for Prostate Cancer?

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