Novel Fractionation Schemes and High Linear Energy Transfer1

Douglas, Brianna; Castro, Jorge Ricardo Moreira

doi:10.1159/000408243

Cited by 19 publications

(9 citation statements)

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“…1 The use of fewer fractions of more than 2·0 Gy (hypofractionation) in primary breast cancer is based on data suggesting that breast adenocarcinoma is more sensitive to fraction size than squamous carcinomas, and therefore could have similar fractionation sensitivity to the dose-limiting healthy tissues, including skin, subcutaneous tissues, muscle, and ribs. [2][3][4][5] In classic radiobiological terms, sensitivity to fraction size is quantifi ed by the α/β value, a variable derived from a commonly used empirical model of fractionation. The response to fraction size is typically non-linear and well fi tted by a linear-quadratic function in which clinical response is proportional to αD+βD 2 , where α and β are coeffi cients characteristic of the tissue under consideration and D is the fraction size.…”

Section: Introductionmentioning

confidence: 99%

Effect of radiotherapy fraction size on tumour control in patients with early-stage breast cancer after local tumour excision: long-term results of a randomised trial

Owen¹,

Ashton²,

Bliss

et al. 2006

The Lancet Oncology

536

341

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Section: Introductionmentioning

confidence: 99%

Effect of radiotherapy fraction size on tumour control in patients with early-stage breast cancer after local tumour excision: long-term results of a randomised trial

Owen¹,

Ashton²,

Bliss

et al. 2006

The Lancet Oncology

536

341

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“…Interest in hypofractionation for adjuvant breast radiotherapy re-emerged in the mid-1980s after a re-analysis of historical data, using the linear-quadratic model, suggested that breast cancer is as sensitive to fraction size as the dose-limiting late responding normal tissues [1,2]. Two prospective randomised trials subsequently reported results consistent with this suggestion, including the Royal Marsden NHS Foundation Trust/Gloucestershire Oncology Centre (RMH/GOC) trial, which tested two dose levels of a 13-fraction regimen over 5 weeks against 50 Gy in 25 fractions, and the Ontario trial, which tested a 16-fraction regimen over 3.2 weeks against 50 Gy in 25 fractions [3e5].…”

Section: Introductionmentioning

confidence: 99%

Acute Toxicity and 2-year Adverse Effects of 30 Gy in Five Fractions over 15 Days to Whole Breast after Local Excision of Early Breast Cancer

et al. 2008

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ABSTRACT:Aims: A pilot study was undertaken with the aim of documenting acute skin reactions and 2-year late adverse effects of a five-fraction course of adjuvant whole breast radiotherapy delivered over 15 days after local tumour excision of early breast cancer. Materials and methods: Thirty women with early invasive breast cancer aged R 50 years with a pathological tumour size !3 cm, complete microscopic resection, negative axillary node status and no requirement for cytotoxic therapy were prescribed 30 Gy in five fractions over 15 days to the whole breast using tangential 6e10 MV X-ray beams and three-dimensional dose compensation with written informed consent. Post-surgical baseline photographs of the breasts were taken, and acute skin erythema and moist desquamation were each scored weekly for 7 weeks using four-point graded scales (grade 0 [ none, 1 [ mild, 2 [ moderate, 3 [ severe). This was followed by an annual clinical assessment, including repeat photographs at 2 years. Results: Nine patients (30%, 95% confidence interval 14.7e49.4%) developed grade 2 erythema, with the remaining 21 patients developing milder degrees of reaction. Four (13.3%, 95% confidence interval 3.7e30.7) patients developed moist desquamation, grade 1 in three women and grade 2 in the fourth. At 2 years after treatment, 23/30 (77%) patients scored no change in photographic breast appearance compared with the pre-treatment baseline; seven (23%, 95% confidence interval 9.9e42.3) scored a mild change in breast appearance, and none developed a marked change. After a mean follow-up of 3.1 years (standard deviation 0.37, range 2.1e3.9 years) there have been no ipsilateral local tumour relapses. Conclusions: Further evaluation of a five-fraction regimen of adjuvant whole breast radiotherapy in a phase III randomised trial is justified, including a regimen delivered in a total of 5 days. Martin, S. et al.

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“…However, experimental data suggest that other human tumour types are significantly more sensitive to fraction size than squamous carcinomas [16,17]. Specifically, a/b values of 4-5 Gy have been derived for the radiation response of recurrent or inoperable breast cancer [6,8]. Values of 1.8-2.0 Gy have been reported for the local control of soft tissue sarcoma [7,15].…”

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confidence: 99%

Fractionation sensitivity and dose response of late adverse effects in the breast after radiotherapy for early breast cancer: long-term results of a randomised trial

Yarnold

Ashton²,

Bliss

et al. 2005

Radiotherapy and Oncology

457

306

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Background and purpose: Unlike squamous carcinomas, breast adenocarcinoma may be as sensitive to fraction size as late dose-limiting normal tissues. If so, fewer larger fractions would be as safe and effective as regimens based on 2.0 Gy fractions. The first step is to test the effects of radiotherapy fractions O2.0 Gy on late normal tissue responses in the breast after tumour excision and radiotherapy for early breast cancer.Patients and methods: One thousand four-hundred and ten women with T1-3 N0-1 M0 invasive breast cancer were randomised between 1986-98 into one of three radiotherapy regimens after local tumour excision of early stage breast cancer; 50 Gy in 25 fractions (F) vs two dose levels of a test schedule giving 39 or 42.9 Gy in 13 F over 5 weeks. Fraction sizes were 2.0, 3.0 and 3.3 Gy, respectively. The primary endpoint was late change in breast appearance compared to post-surgical appearance scored from annual photographs blinded to treatment allocation. Secondary endpoints included palpable breast induration (fibrosis) and ipsilateral tumour recurrence.Results: After a minimum 5-year follow up, the risk of scoring any change in breast appearance after 50 Gy/25 F, 39 Gy/13 F and 42.9 Gy/13 F was 39.6, 30.3 and 45.7%, from which an a/b value of 3.6 Gy (95% CI 1.8-5.4) is estimated. The a/b value for palpable breast induration was 3.1 Gy (95% CI 1.8-4.4).Conclusions: An a/b value of around 3 Gy for late normal tissue changes in the breast is derived from the estimated equivalence of 41.6 Gy in 13 fractions and 50 Gy in 25 fractions over 5 weeks, in line with trial predictions. q 2005 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 75 (2005) 9-17.

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Novel Fractionation Schemes and High Linear Energy Transfer1

Cited by 19 publications

References 0 publications

Effect of radiotherapy fraction size on tumour control in patients with early-stage breast cancer after local tumour excision: long-term results of a randomised trial

Effect of radiotherapy fraction size on tumour control in patients with early-stage breast cancer after local tumour excision: long-term results of a randomised trial

Acute Toxicity and 2-year Adverse Effects of 30 Gy in Five Fractions over 15 Days to Whole Breast after Local Excision of Early Breast Cancer

Fractionation sensitivity and dose response of late adverse effects in the breast after radiotherapy for early breast cancer: long-term results of a randomised trial

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