Intensity modulated radiation therapy with simultaneous integrated boost based dose escalation on neoadjuvant chemoradiation therapy for locally advanced distal esophageal adenocarcinoma

Effect of SIB-IMRT-based selective dose escalation of local tumor on the prognosis of patients with esophageal cancer

BACKGROUND

To investigate the effect of SIB-IMRT-based selective dose escalation to local tumor on the prognosis of patients with esophageal cancer (EC).

METHODS

A total of 302 EC patients were enrolled. The prognostic factors of the entire group were initially analyzed, and the composition ratios of the two groups and the different doses of each fraction for PTV were compared. The propensity-score matching (PSM) was carried out (1:1 ratio), and the prognostic factors for the two groups were analyzed according to the results of COX.

RESULTS

The median overall survival (OS) for all patients was 30.0 months (23.495-36.505 months), and the median disease-free survival (DFS) was 21.3 months (7.698-24.902 months). In multivariate analysis, chemotherapy, cTNM stage and dose-per-fraction for the PTV were independent prognostic factors for OS (P = 0.013, 0.000, 0.028) and DFS (P = 0.033, 0.000, 0.047). Multivariate analysis of patients after PSM revealed that cTNM staging and dose-per-fraction were the independent prognostic factors for OS (P = 0.000, 0.015). Chemotherapy, cTNM staging and dose-per-fraction for the PTV were the independent prognostic factors for DFS (P = 0.025, 0.010, 0.015). There was no significant difference in grade ≥ 2 acute toxicities between the two groups. A subgroup analysis of patients with a single dose of 2 Gy and > 2 Gy in the SIB-IMRT group showed that OS and DFS of the latter were significantly better than those of the former.

CONCLUSION

The selective dose escalation to local tumors based on SIB-IMRT technique can improve the survival of patients received radical radiotherapy without increasing toxicities.

Radiation Pneumonitis after Intensity-Modulated Radiotherapy for Esophageal Cancer: Institutional Data and a Systematic Review

Radiation pneumonitis (RP) is a serious complication that can occur after thoracic radiotherapy. The goal of this study is to investigate the incidence of RP after radiochemotherapy with intensity modulated radiotherapy (IMRT) in patients with esophageal cancer and correlate this with dose volume histogram (DVH) related parameters. For this purpose, the clinical course of 73 patients was evaluated and irradiation doses to the lungs were extracted from radiotherapy treatment plans. Furthermore, a systematic review on this topic was conducted across PubMed. In our institutional cohort, Common Terminology Criteria for Adverse Events (CTCAE) grade II or higher RP occurred in four patients (5.5%). The systematic review identified 493 titles of which 19 studies reporting 874 patients qualified for the final analysis. No grade IV or V RP after radiochemotherapy with IMRT for esophageal cancer was reported in the screened literature. Grade II or higher RP is reported in 6.6% of the patients. A higher incidence can be seen with increasing values for lung V20. In conclusion, our institutional data and the literature consistently show a low incidence of symptomatic RP after radiochemotherapy in patients with esophageal cancer treated with IMRT. However, efforts should be made to keep the lung V20 below 23% and specific caution is warranted in patients with pre-existing lung conditions.

Different definitions of esophagus influence esophageal toxicity prediction for esophageal cancer patients administered simultaneous integrated boost versus standard-dose radiation therapy

We aim to evaluate whether different definitions of esophagus (DEs) impact on the esophageal toxicity prediction for esophageal cancer (EC) patients administered intensity-modulated radiation therapy with simultaneous integrated boost (SIB-IMRT) vs. standard-dose IMRT (SD-IMRT). The esophagus for 21 patients diagnosed with primary EC were defined in the following four ways: the whole esophagus, including the tumor (ESO_whole); ESO_whole within the treatment field (ESO_infield); ESO_infield, excluding the tumor (ESO_{infield-tumor}) and ESO_whole, excluding the tumor (ESO_whole-tumor). The difference in the dose variation, acute esophageal toxicity (AET) and late esophageal toxicity (LET) of four DEs were compared. We found that the mean esophageal dose for ESO_whole, ESO_infield, ESO_{infield-tumor} and ESO_whole-tumor were increased by 7.2 Gy, 10.9 Gy, 4.6 Gy and 2.0 Gy, respectively, in the SIB-IMRT plans. Radiobiological models indicated that a grade ≥ 2 AET was 2.9%, 3.1%, 2.2% and 1.6% higher on average with the Kwint model and 14.6%, 13.2%, 7.2% and 3.4% higher with the Wijsman model for the four DEs. A grade ≥ 3 AET increased by 4.3%, 7.2%, 4.2% and 1.2%, respectively. Additionally, the predicted LET increased by 0.15%, 0.39%, 1.2 × 10⁻²% and 1.5 × 10⁻³%. Our study demonstrates that different DEs influence the esophageal toxicity prediction for EC patients administered SIB-IMRT vs. SD-IMRT treatment.

Local Control and Toxicity of a Simultaneous Integrated Boost for Dose Escalation in Locally Advanced Esophageal Cancer: Interim Results from a Prospective Phase I/II Trial

INTRODUCTION

Approximately 50% of recurrences after standard-dose chemoradiation for locally advanced esophageal cancer occur within the gross tumor volume (GTV). In this prospective phase I/II clinical trial, we explored the use of a simultaneous integrated boost (SIB) dose to the GTV.

METHODS

Forty-four patients with unresectable esophageal cancer received chemoradiation with an SIB of 58.8 to 63 Gy to the GTV and 50.4 Gy to the planning target volume, all in 28 fractions, with 5 weeks of concurrent docetaxel and fluorouracil or capecitabine. The end points were maximum tolerated dose, time to local failure, and clinical response.

RESULTS

Excluding those with less than 6 months of follow-up, 38 patients were evaluated at the time of analysis. The median age was 65 years (range 37-84). Most patients (71%) were men; 84% had T3 disease, 37% had N1 disease, 26% had N2 disease, 13% had M1 disease, and 50% had adenocarcinoma. The maximum tolerated SIB dose was 63 Gy. None experienced Common Terminology Criteria for Adverse Events grade 4 or 5 toxicity. At a median follow-up time of 13.3 months (range 1.2-36.2), 11 (29%) had local failure (median time to local failure 2.5 months [range 1.5-23.9]). A comparison with 97 similar patients who received 50.4 Gy without an SIB showed that the SIB reduced the local failure rate for patients with node-positive disease (13% versus 56%, p = 0.04), adenocarcinoma (26% versus 59%, p = 0.02), or stage III-IV disease (29% versus 55%, p = 0.04).

CONCLUSIONS

SIB intensity-modulated radiation therapy to gross primary disease may improve local control for patients with unresectable locally advanced esophageal cancer, especially those with adenocarcinoma.

Advances in Radiotherapy Management of Esophageal Cancer

Radiation therapy (RT) as part of multidisciplinary oncologic care has been marked by profound advancements over the past decades. As part of multimodality therapy for esophageal cancer (EC), a prime goal of RT is to minimize not only treatment toxicities, but also postoperative complications and hospitalizations. Herein, discussion commences with the historical approaches to treating EC, including seminal trials supporting multimodality therapy. Subsequently, the impact of RT techniques, including three-dimensional conformal RT, intensity-modulated RT, and proton beam therapy, is examined through available data. We further discuss existing data and the potential for further development in the future, with an appraisal of the future outlook of technological advancements of RT for EC.