Skip to main content

Influence of radiotherapy interruption on esophageal cancer with intensity-modulated radiotherapy: a retrospective study

Abstract

Background

Radiotherapy interruption (RTI) prolongs the overall total treatment time and leads to local control loss in many cancers, but it is unclear in esophageal cancer. We aimed to evaluate the influence of RTI on the overall survival (OS), progression-free survival (PFS), and local-regional recurrence-free survival (LRFS) of patients with esophageal cancer undergoing chemoradiotherapy.

Methods

A total of 299 patients with esophageal squamous cell carcinoma from 2017 to 2019 were retrospectively analyzed to investigate the effect of RTI on OS, PFS, and LRFS. The delayed time of radiotherapy interruption was calculated as the actual radiation treatment time minus the scheduled time. The univariate and multivariate analyses were performed by the COX proportional hazards regression models, and the survival analysis was performed through the Kaplan‒Meier method, and compared with the log-rank test.

Results

The 3-year OS, PFS, and LRFS rates were 53.0%, 42.0%, and 48.0%, respectively. The univariate and multivariate analyses showed that the delayed time > 3 days was an independent adverse prognostic factor for OS (HR = 1.68, 95% CI 1.10–2.55, p = 0.016), and LRFS (HR = 1.74, 95% CI 1.18–2.57, p = 0.006). The patient with a delayed time of > 3 days had poorer survival rates of OS, and LRFS than patients with a delayed time of ≤ 3 days (OS, p = 0.047; LRFS, p = 0.013), and the survival outcomes of patients with shorter delayed time (1–3 days) were slightly different from the patients without interruptions. The impact of delay time on PFS is not statistically significant, but the survival outcomes of the two groups were slightly different.

Conclusion

There was a significant correlation between delayed time and local control of esophageal cancer. The delayed time for more than 3 days might decrease the survival outcome, and increase the local recurrence risk.

Peer Review reports

Background

Esophageal cancer, a prominent gastrointestinal cancer, has a poor prognosis. The 3-year overall survival (OS) was approximately 40% in the ARTDECO study, for patients who had undergone chemoradiotherapy [1]. It has been confirmed that the prognostic factors for esophageal cancer are numerous and complex based on previous studies, such as, body mass index(BMI) [2], smoking [3], gross tumor volume [4], and positive lymph nodes [5].

Radiotherapy (RT), as one of the common treatment options, undergoes unscheduled treatment when radiotherapy interruption (RTI) occurs. RTI is affected by equipment breakdown, public holidays, and toxicity [6], prolongs the overall treatment time, and significantly affects local tumor control. The severity is determined by the delayed time. Some studies have shown that the five-year OS decreased by 15% with more than 5 days of RTI for nasopharyngeal cancer using intensity-modulated radiotherapy [7], and only one day of RTI increased the risk of local relapse by 4.8% and led to a decrease in the local tumor control by 1.4% for laryngeal cancer [8]. The existing data about RTI were published on head and neck cancer, cervical cancer, prostate cancer, etc., but its use is not clear for esophageal cancer. We aim to investigate the influence of RTI on the survival outcome of patients with esophageal cancer.

Methods

Patients

A total of 299 patients with esophageal squamous cell carcinoma (ESCC) were selected between 2017 and 2019. All the patients newly received chemoradiotherapy (including concurrent chemoradiotherapy and induction chemotherapy). A total of 228 patients received intensity-modulated radiation therapy (IMRT), while the others underwent volume-modulated arc radiotherapy (VMAT). The characteristics are summarized in Table 1.

Table 1 Characteristics of 299 patients

Radiotherapy

The planning CT was conducted based on the CT simulation planning system, with an axial slice thickness of 5 mm, ranging from the bottom of the mandible to 5 cm below the costophrenic angle, including the whole neck and lung. The primary gross tumor (GTV) and positive lymph nodes (GTVnd) were delineated on CT-enhanced images, combined with barium meal X-ray and endoscopic ultrasound. The clinical tumor volume (CTV) of the primary gross tumor was outlined by the expansion of the GTV (5 mm cm top-bottom, 5–6 mm left-right, 5–6 mm anterior-posterior) and the clinical tumor volume (CTVnd) of the positive lymph nodes referred to the latest UICC/AJCC guidelines. The planning tumor volume (PTV) was expanded from 5 mm of CTV and CTVnd. The IMRT plan was designed with 5–7 beams from the patient’s anterior and posterior sides to effectively reduce the lung dosage. The VMAT plan was designed with 2 arcs (330º-180º for CW, 180º-330º for CCW). The limits of OARs were as follows: heart V30 ≤ 40%, V40 ≤ 30%; lungs V5 ≤ 65%, V20 ≤ 30%, V30 ≤ 18%; mean lung dose ≤ 17 Gy; and spinal cord maximum dose ≤ 45 Gy. The dose distribution was calculated with Philips Radiation Oncology’s Pinnacle3 collapsed cone convolution superposition (CCCS) with 58.80 Gy to 66 Gy for GTV/GTVnd and 48.60 Gy to 60 Gy for PTV in 27 to 30 fractions scheduled once a day for 5 days per week. The delayed time was calculated as the actual radiation treatment time minus the scheduled time.

Follow-up and endpoint

Follow-up was performed with barium meal X-ray examination, endoscopic ultrasound, or CT scan every 3 months, 6 months, and 1 year for the first year, second year, and thereafter.

Overall survival refers to the event from the beginning of treatment to death (for any reason) or the last follow-up, and the endpoint is death. Progression-free survival (PFS) refers to the time from the beginning of treatment to tumor progression (in any aspect) or death (for any reason); the endpoint is progression or death. Local-regional recurrence-free survival (LRFS) refers to the time from the beginning of treatment to the date of local-regional recurrence or death (for any reason); the endpoint is recurrence or death.

Data Collection and Analysis

The data were collected and transformed into categorical variables by reference [9], including BMI, smoking history, alcohol consumption, TNM stage, GTV, GTVnd, and delayed time. The cutoff value was calculated by the survival package of the R project, The survival curves were drawn using Kaplan‒Meier methods and compared with the log-rank test. The univariate and multivariate analysis was performed by the Cox proportional hazards regression model to calculate the hazard ratio (HR) with 95% confidence intervals (CIs). A p-value of < 0.05 was statistically significant.

Results

RT interruption events

A total of 147 patients suffered RT treatment interruption, and 57 patients had multiple interruptions. There were 70 interruptions of linear accelerator (LINAC) breakdown, 9 interruptions of replans, 16 interruptions of public holidays, and the rest were patient reasons such as toxicity and complications, as shown in Fig. 1.

Fig. 1
figure 1

Details of radiotherapy interruption. (A), the bar chart of the delayed time, the counts were calculated by the number of patients; (B) the pie chart of the interruption’s reason, the counts were calculated based on the interruptions

Cutoff

The cutpoints were calculated by the survival package of the R project. The cutpoints of Age, GTV, and GTVnd were 74 years, 23.27 cc, and 8.50 cc respectively. The cutoff of the delayed time was 3 days, The patients were divided into the delayed time > 3 days group and the delayed time ≤ 3 days group. The patients’ characteristics were compared with different delayed time groups using Fisher’s precision probability test, summarized in Table 2.

Table 2 Comparison of patients’ characteristics between delayed time ≤ 3 days and > 3 days

Survival

The 3-year OS, PFS, and LRFS rates were 53.0%, 42.0%, and 48.0%, respectively, with a follow-up range of 2–62 months. The median OS time was 14 months (range 2–50 months) for 132 death events.

Univariate and multivariate analysis

It was shown that age, gender, smoking, T category, N category, GTV, and GTVnd were significantly different in OS, PFS, and LRFS of patients by the univariate analysis listed in Table 3 (p < 0.05). The delayed time had a significant impact on LRFS. From the multivariate analysis result, age, smoking, delayed time, GTV, and GTVnd were independent prognostic factors of OS and LRFS (p < 0.05, Fig. 2 and Fig. 3). While age, smoking, GTV, and GTVnd were independent prognostic factors of PFS (p < 0.05, Fig. 4). The mortality risk of patients with a delayed time > 3 days was 1.68 (95% CI 1.10–2.55, p = 0.016) times higher than those of patients with a delayed time ≤ 3 days. The local regional recurrence risk of patients with a delayed time > 3 days was 1.74 (95% CI 1.18–2.57, p = 0.006) times higher than those of patients with a delayed time ≤ 3 days. From the Kaplan‒Meier curves, the OS and LRFS outcomes of delayed time > 3 days were poorer than those of patients with delayed time ≤ 3 days (p < 0.05, Fig. 5). Furthermore, the delayed time was divided into non-interruptions (0 days), shorter delayed time (1 to 3 days), and longer delayed time (> 3 days), it was found that the outcomes of patients with shorter delayed were slightly different from the non-interruptions.

Table 3 Univariate analysis for the survival outcome
Fig. 2
figure 2

Multivariable analysis of Cox proportional hazards regression model to estimate the risk of overall survival

Fig. 3
figure 3

Multivariable analysis of Cox proportional hazards regression model to estimate the risk of local-regional recurrence-free survival

Fig. 4
figure 4

Multivariable analysis of Cox proportional hazards regression model to estimate the risk of progression-free survival

Fig. 5
figure 5

Kaplan-Meier representation of survival outcomes. OS overall survival, PFS Progression-free survival, LRFS Local-regional recurrence-free survival. (A, C, and E, the patients with a delayed time ≤ 3 days group included non-interruption), (B, D, and F, the patients with a delayed time ≤ 3 days excluded non-interruption)

Discussion

Esophageal cancer is one of the most common tumors in China [10]. Most patients with locally advanced esophageal carcinoma missed the best time for surgical treatment. Radiation therapy has become important [11, 12]. More interest was aroused in RT sustainability. Evidence was confirmed that RTI had unattractive effects on the prognosis of patients with cancer [13,14,15]. Cheng X et al [6] found that patients with 5 days of delayed time had lower OS and FFS in nasopharyngeal carcinoma. However, there is rarely research reporting the impact of delayed time on the prognosis of esophageal cancer. Our study discovered that delayed time could cause worse survival outcomes for patients with ESCC.

RTI prolonged the overall treatment time and resulted in dismal survival. Our results confirmed that RTI affects the survival of patients suffering from ESCC. The delayed time was an independent prognostic factor of OS and LRFS. The mortality risk of patients with longer delayed time (> 3 days) was significantly increased (HR = 1.68, 95% CI 1.10–2.55, p = 0.016) compared to patients with shorter delayed time (≤ 3 days). Meanwhile, the risk of local recurrence was increased (HR = 1.74, 95% CI 1.18–2.57, p = 0.006) for the patients with longer delayed time (> 3 days). Nishimura Y [16] found that the rate of esophageal cancer local control treated with external RT lost 2.3% per day of delay, and 1.4% per day for combined with intraluminal brachytherapy. Yao JJ et al. [17] proposed similar conclusions, The delayed time ≥ 7 days had significant adverse effects on the prognosis of nasopharyngeal carcinoma, and the groups with the longer RTI had poorer survival rates. For the T3-T4 stage, RTI ≥ 5 days led to worse outcomes [18]. It was noticeable that their results (Yao et al.) were based on the assumption starting on Monday, while we used the actual date. It was indicated that the prolonged overall treatment time significantly influenced the survival outcome of patients with ESCC. The mechanism is mainly that the tumor clonogen cells are activated and accelerated repopulation. More additional dose is needed to kill the new cells and maintain the tumor control probability, which is increased linearly with delayed time (the “dog-leg” shape between total dose and overall time) [19, 20]. Otherwise, the tumor cells will be incompletely eliminated.

Many studies have shown that the influence of RTI was negative on PFS. In the study by Xu GZ et al., the 3-year PFS (72.1% vs. 81.9%, p = 0.01) was significantly difference between patients with delayed time > 4 days and those with delayed time ≤ 4 days [21]. Hallemeier CL et al. [22] analyzed the association between RTI and outcomes in patients with esophageal cancer using randomized clinical trials of National Cancer Institute–sponsored NRG Oncology (RTOG8501, RTOG0436, RTOG9415). Radiotherapy overall treatment time > 45 days (vs. ≤ 45 days) has a higher risk of disease-free survival (HR = 1.34, 95% CI 1.01–1.77, p = 0.04). The delayed time was more applicable to the variable fractionation schedule than the overall treatment time. Unfortunately, Our findings demonstrated that delay time was not an independent prognostic factor for PFS. From the Kaplan‒Meier curves, the delayed time > 3 days (vs. ≤ 3 days) had an insignificant effect on PFS (p = 0.15), but the survival outcomes of patients with delayed time > 3 days were slightly different from the patients with delayed time ≤ 3 days. It was necessary to be vigilant about the impact of treatment interruption on the disease-free survival outcome of esophageal cancer.

In addition, the survival curve displayed that the outcome of patients with shorter delayed time (1 to 3 days) was similar to the non-interruptions (0 days), both were better than the longer delayed time (> 3 days). Skladowski et al. submitted a practical result. They explained the relationship between local tumor control and the position of radiotherapy gaps in laryngeal cancer and reported the survival rate of patients with a gap in the middle period was similar to that of patients who had no gap [23]. This was mainly due to the reoxygenation of hypoxic tumor cells. This finding should be given more attention in clinical practice.

In this treatment course, the incidence of RTI was 49.16% (147/299), because of machinery breakdown, public holidays, replan, and patient reason. 57 patients had multiple interruptions, which implied that more than 3 days of prolongation might be one or more interruptions with different reasons or multiple reasons. The characteristics were compared between patients’ reasons and other reasons that resulted in RT interruptions, as shown in Appendix 1, which excluded the multiple interruptions, and it was found that the N stage and volume of positive lymph nodes were different (p = 0.007 and 0.042). It should be continuously sought how these reasons work on RTI in the following work. It was difficult to accurately assess which reason is more likely to lead to a delayed time of > 3 days since lacking the acute and late toxicities and only 68 people experienced a delay of > 3 days. However, researchers deduced toxicity was one of the most common reasons for RTI, closely following equipment damages and/or maintenance [24]. Sapienza Lucas G et al. [25] found that one in every 10 patients presented RTI and it was strongly associated with grade 3 and 4 toxicities for locally advanced rectal cancer treated with neoadjuvant chemotherapy. During the treatment, it is necessary to keep a close watch on the toxicity and intervene timely to prevent RTI.

The prognosis of the patient with esophageal cancer is not only related to the treatment protocol, TNM stage, and the factors mentioned, but also concerned with the patient’s psychological state, social status, and compliance [26,27,28]. We mainly aimed to evaluate the influence of RTI on the prognosis of patients with ESCC receiving chemoradiotherapy. However, the study had some limitations. First, the chemotherapy regimens and RT fractionation were various, the analyses did not rule out confounding factors. Second, the delayed time was not refined as a continuous or discontinuous interruption, and there was no impact of interruption location on survival outcome. Third, the study failed to predict the reason for a delayed time of > 3 days because of lacking the acute and late toxicities. Finally, this study did not conduct stage subgroup analysis. In the future, the sample size will be expanded for subgroup analysis will be conducted for stage heterogeneity.

Conclusion

There was a significant correlation between RTI and local control of esophageal cancer. The mortality risk and local recurrence risk of patients with longer delayed time (> 3 days) was higher than that of patients with shorter delayed time (≤ 3 days).

Data availability

No datasets were generated or analysed during the current study.

Abbreviations

RT:

Radiotherapy

RTI:

Radiotherapy interruption

BMI:

Body mass index

GTV:

Gross tumor volume

GTVnd:

Gross tumor volume of the positive lymph nodes

OS:

Overall survival

PFS:

Progress-free survival

LRFS:

Local-regional recurrence-free survival

IMRT:

Intensity modulated radiation therapy

VMAT:

Volume modulated arc radiotherapy

CTV:

Clinical tumor volume of the primary tumor

CTVnd:

Clinical tumor volume of the positive lymph nodes

PTV:

Planning tumor volumes

OARs:

Organs at risk

UICC/AJCC:

Union for International Cancer Control/ American Joint Committee on Cancer

RTOG:

Radiation therapy oncology group

CW:

Clockwise

CCW:

Counterclockwise

CCCS:

Collapsed cone convolution superposition

HR:

Hazard ratio

CIs:

Confidence intervals

LINAC:

Linear accelerator

ESCC:

Esophageal squamous cell carcinoma

References

  1. Hulshof MCCM, Geijsen ED, Rozema T et al. Randomized study on dose escalation in definitive chemoradiation for patients with locally Advanced Esophageal Cancer (ARTDECO Study). J Clin Oncol. 2021-09-01;39(25):2816–24.https://0-doi-org.brum.beds.ac.uk/10.1200/JCO.20.03697.

  2. Sugawara K, Yamashita H, Okumura Y, et al. Age-dependent survival impact of body mass index in patients with oesophageal squamous cell carcinoma. EJSO-Eur J Surg Onc. 2020-10-01;46(10 Pt A):1948–55. https://0-doi-org.brum.beds.ac.uk/10.1016/j.ejso.2020.05.012.

  3. Spreafico A, Coate L, Zhai R, et al. Early adulthood body mass index, cumulative smoking, and esophageal adenocarcinoma survival. Cancer Epidemiol. 2017;47:28–34. https://0-doi-org.brum.beds.ac.uk/10.1016/j.canep.2016.11.009.

    Article  PubMed  Google Scholar 

  4. Wang R, Zhou XM, Liu TX et al. Gross tumor volume predicts survival and pathological complete response of locally Advanced Esophageal Cancer after Neoadjuvant Chemoradiotherapy. Front Oncol. 2022-01-01;12:898383. https://0-doi-org.brum.beds.ac.uk/10.3389/fonc.2022.898383.

  5. Huang X, Jiang DX,Jian ZT et al. Identification of optimal parameters for assessing Lymph Node Status of patients with esophageal squamous cell Carcinoma after Neoadjuvant Chemoradiotherapy. Ann Surg Oncol. 2023https://0-doi-org.brum.beds.ac.uk/10.1245/s10434-023-14135-6.

  6. Cheng X, Yang KB, Feng RJ et al. Radiotherapy interruption due to holidays adversely affects the survival of patients with nasopharyngeal carcinoma: a joint analysis based on large-scale retrospective data and clinical trials. Radiat Oncol. 2022-02-19;17(1):36. https://0-doi-org.brum.beds.ac.uk/10.1186/s13014-022-02006-5.

  7. Yeh SA, Hwang TZ, Wang CC, Yang CC, Lien CF, Wang CC, et al. Outcomes of patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy. J Radiat Res. 2021;62:438–47. https://0-doi-org.brum.beds.ac.uk/10.1093/jrr/rrab008.

    Article  PubMed  PubMed Central  Google Scholar 

  8. Barton MB, Keane TJ, Gadalla T et al. The effect of treatment time and treatment interruption on tumour control following radical radiotherapy of laryngeal cancer. Radiother Oncol. 1992-03-01;23(3):137 – 43. https://0-doi-org.brum.beds.ac.uk/10.1016/0167-8140(92)90323-m.

  9. Chen CM, Kong LZ. The guidelines of the Prevention and Control of overweight and obesity in Chinese Adults[M]. Beijing: People’s Medical Publishing House; 2006. p. 3.

    Google Scholar 

  10. Chen W, Zheng R, Baade PD, et al. Cancer statistics in China, 2015. CA Cancer J Clin. 2016;66:115–32.

    Article  PubMed  Google Scholar 

  11. Xin Z, Liu Q, Ai D et al. Radiotherapy for Advanced Esophageal Cancer: from Palliation to Curation. Curr Treat Option On. 2023-11-01;24(11):1568–79.https://0-doi-org.brum.beds.ac.uk/10.1007/s11864-023-01134-8.

  12. Kim K, Oh D, Noh JM, et al. Outcomes following hypofractionated radiation therapy alone for surgically unfit early esophageal squamous cell carcinoma patients; a retrospective single center analysis. Radiother Oncol. 2023. https://0-doi-org.brum.beds.ac.uk/10.1016/j.radonc.2023.109982.

    Article  PubMed  Google Scholar 

  13. Yarn C, Wakefield DV, Spencer S et al. Insurance status and head and neck radiotherapy interruption disparities in the Mid-southern United States. Head Neck-J Sci Spec. 2020-08-01;42(8):2013–20. https://0-doi-org.brum.beds.ac.uk/10.1002/hed.26128.

  14. Zhao FR, Yang DSi, Li XP. Effect of radiotherapy interruption on nasopharyngeal cancer. Front Oncol. 2023. https://0-doi-org.brum.beds.ac.uk/10.3389/fonc.2023.1114652.

    Article  PubMed  PubMed Central  Google Scholar 

  15. Pechačová Z, Lohynská R. Clinical application of time factor principles in radiotherapy in compensation of radiation series interruptions. Klin Onkol. 2021-01-01;34(6):455–62. https://0-doi-org.brum.beds.ac.uk/10.48095/ccko2021455.

  16. Nishimura Y, Ono K, Tsutsui K et al. Esophageal cancer treated with radiotherapy: impact of total treatment time and fractionation. Int J Radiat Oncol. 1994-12-01;30(5):1099 – 105. https://0-doi-org.brum.beds.ac.uk/10.1016/0360-3016(94)90315-8.

  17. Yao JJ, Zhang FG, Tian S, et al. Survival impact of radiotherapy interruption in nasopharyngeal carcinoma in the intensity-modulated radiotherapy era: a big-data intelligence platform-based analysis. Radiother Oncol. 2019-03-01;132:178–87. https://0-doi-org.brum.beds.ac.uk/10.1016/j.radonc.2018.10.018.

  18. Yao JJ, Jin YN, Wang SY et al. The detrimental effects of radiotherapy interruption on local control after concurrent chemoradiotherapy for advanced T-stage nasopharyngeal carcinoma: an observational, prospective analysis. BMC cancer.2018;18 (1):740. https://0-doi-org.brum.beds.ac.uk/10.1186/s12885-018-4495-2.

  19. Withers H R, Taylor J M, Maciejewski B. The hazard of accelerated tumor clonogen repopulation during radiotherapy. Acta Oncol. 1988;27(2):131–46. https://0-doi-org.brum.beds.ac.uk/10.3109/02841868809090333.

  20. Dale RG, Jones B. Radiotherapy treatment interruptions during the Covid-19 pandemic: the UK experience and implications for radiobiology training. Radiat Phys Chem. 2022-11-01;https://0-doi-org.brum.beds.ac.uk/10.1016/j.radphyschem.2022.110214.

  21. Xu GZ, Li L, Zhu XD. Effect of interrupted time during intensity modulated radiation therapy on survival outcomes in patients with nasopharyngeal cancer.Oncotarget.2017;8 (23): 37817–25.https://doi.org/10.18632/oncotarget.13713.

  22. Hallemeier CL, Moughan J, Haddock MG, et al. Association of Radiotherapy Duration with Clinical outcomes in patients with esophageal Cancer treated in NRG oncology trials: a secondary analysis of NRG Oncology Randomized clinical trials. JAMA Netw Open. 2023;6(4):e238504. https://0-doi-org.brum.beds.ac.uk/10.1001/jamanetworkopen.2023.8504.

    Article  PubMed  PubMed Central  Google Scholar 

  23. Skladowski K, Law MG, Maciejewski B, et al. Planned and unplanned gaps in radiotherapy: the importance of gap position and gap duration. Radiother Oncol. 1994;2109–20. https://0-doi-org.brum.beds.ac.uk/10.1016/0167-8140(94)90039-6. -02-01;30.

  24. Razmjoo S, Haghi N, Birgani MJT, et al. Radiotherapy Interruption in Cancer patients: Rates and causes at Ahvaz Golestan Hospital.Asian Pacific. J Cancer Care. 2020;110.31557/APJCC.2020.5.1.33-36.

  25. Sapienza Lucas G, Raychaudhuri S, Nahlawi Suraya K et al. Predictors of definitive treatment interruptions of Long-Course Neoadjuvant Chemoradiotherapy in locally advanced rectal Cancer. Cureus. 2022-10-01;14(10):e30159. https://0-doi-org.brum.beds.ac.uk/10.7759/cureus.30159.

  26. Zhou SX, Yang Y, Zhang Q et al. Analysis of the prognostic factors of simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) in 220 cases of locally advanced squamous esophageal cancer: a retrospective cohort study. Ann Transl Med. 2023-01-31;11(2):103. https://0-doi-org.brum.beds.ac.uk/10.21037/atm-22-6462.

  27. Yuan S, Wei C,Wang M, et al. Prognostic impact of examined lymph-node count for patients with esophageal cancer: development and validation prediction model. Sci Rep. 2023;13(1):476. https://0-doi-org.brum.beds.ac.uk/10.1038/s41598-022-27150-6.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Chen J, Lin Y, Cai W et al. A new clinical staging system for esophageal cancer to predict survival after definitive chemoradiation or radiotherapy. Dis Esophagus. 2018-11-01;31(11). https://0-doi-org.brum.beds.ac.uk/10.1093/dote/doy043.

Download references

Funding

Not applicable.

Author information

Authors and Affiliations

Authors

Contributions

YHM and PL contributed to design, writing, and data collection; QL contributed to illustration and manuscript review; XH, XC, JZ, and LZL contributed to data collection and analysis. All authors were involved in drafting and revising the manuscript. All authors have read and approved the final manuscript.

Corresponding author

Correspondence to Qiang Liu.

Ethics declarations

Ethics approval and consent to participate

Ethics approval was obtained from the Ethics Committee of the Chongqing University Three Gorges Hospital, and the informed consent requirement was exempt.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary Material 1

Supplementary Material 2

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mou, Y., Liang, P., Cheng, X. et al. Influence of radiotherapy interruption on esophageal cancer with intensity-modulated radiotherapy: a retrospective study. BMC Cancer 24, 646 (2024). https://0-doi-org.brum.beds.ac.uk/10.1186/s12885-024-12383-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://0-doi-org.brum.beds.ac.uk/10.1186/s12885-024-12383-7

Keywords