Factors Associated With Severe Acute Esophagitis From Hyperfractionated Radiotherapy With Concurrent Chemotherapy for Limited-Stage Small-Cell Lung Cancer

Predictive Modeling of Thoracic Radiotherapy Toxicity and the Potential Role of Serum Alpha-2-Macroglobulin

Background: To investigate the impact of alpha-2-macroglobulin (A2M), a suspected intrinsic radioprotectant, on radiation pneumonitis and esophagitis using multifactorial predictive models. Materials and Methods: Baseline A2M levels were obtained for 258 patients prior to thoracic radiotherapy (RT). Dose-volume characteristics were extracted from treatment plans. Spearman's correlation (Rs) test was used to correlate clinical and dosimetric variables with toxicities. Toxicity prediction models were built using least absolute shrinkage and selection operator (LASSO) logistic regression on 1,000 bootstrapped datasets. Results: Grade ≥2 esophagitis and pneumonitis developed in 61 (23.6%) and 36 (14.0%) patients, respectively. The median A2M level was 191 mg/dL (range: 94-511). Never/former/current smoker status was 47 (18.2%)/179 (69.4%)/32 (12.4%). We found a significant negative univariate correlation between baseline A2M levels and esophagitis (Rs = -0.18/p = 0.003) and between A2M and smoking status (Rs = 0.13/p = 0.04). Further significant parameters for grade ≥2 esophagitis included age (Rs = -0.32/p < 0.0001), chemotherapy use (Rs = 0.56/p < 0.0001), dose per fraction (Rs = -0.57/p < 0.0001), total dose (Rs = 0.35/p < 0.0001), and several other dosimetric variables with Rs > 0.5 (p < 0.0001). The only significant non-dosimetric parameter for grade ≥2 pneumonitis was sex (Rs = -0.32/p = 0.037) with higher risk for women. For pneumonitis D15 (lung) (Rs = 0.19/p = 0.006) and D45 (heart) (Rs = 0.16/p = 0.016) had the highest correlation. LASSO models applied on the validation data were statistically significant and resulted in areas under the receiver operating characteristic curve of 0.84 (esophagitis) and 0.78 (pneumonitis). Multivariate predictive models did not require A2M to reach maximum predictive power. Conclusion: This is the first study showing a likely association of higher baseline A2M values with lower risk of radiation esophagitis and with smoking status. However, the baseline A2M level was not a significant risk factor for radiation pneumonitis.

Once Daily High-dose Radiation (≥60 Gy) Treatment in Limited Stage Small Cell Lung Cancer

BACKGROUND

To investigate outcomes and prognostic factors in patients treated with once daily high-dose (≥60 Gy) radiation therapy (HDRT) and concurrent platinum-based chemotherapy in limited stage small cell lung cancer (LS-SCLC). While we await current phase III trials to determine optimal radiation dose fractionation schemes in LS-SCLC, we report our experience in LS-SCLC with once daily HDRT. We hypothesized that HDRT would achieve similar efficacy and tolerability as twice daily therapy.

METHODS

We conducted a single institution retrospective review of all patients with LS-SCLC who underwent curative intent treatment from 2005-2013. Patients treated with HDRT (≥60 Gy) and concurrent chemotherapy (cisplatin or carboplatin and etoposide) were included in our analysis. Clinicopathologic variables assessed include gender, performance status, time to treatment, response to treatment, toxicity, volumetric tumor response at 3 months, and use of prophylactic cranial irradiation (PCI).

RESULTS

42 patients with LS-SCLC who initiated concurrent chemoradiation from 2005 to 2013 were included in the analysis. 38 patients (90%) completed definitive treatment to the lung; 16 (38%) also completed PCI. Median failure free survival (FFS) and overall survival (OS) were 11.9 and 23.1 months, respectively. Two-year and 5-year OS rates were 47% (CI=30-62%) and 21% (CI=7-38%), respectively. On univariate analysis, PCI was associated with improved FFS but this was not significant (p=0.18). Gender was the only co-variate significantly associated with statistical differences in FFS (p=0.03) and OS (p=0.02). Grade 3 and 4 esophagitis were 10.5% and 2.6%, respectively. Pre-HDRT tumor volume and 3-month post-treatment tumor volume were both associated with FFS (p<0.01) but not OS.

CONCLUSIONS

In this single institution series, daily HDRT demonstrated a 2-year OS of 47% in LS-SCLC. This compares well to the historical survival of daily fractionation (47%) from INT 0096 reported by Turrisi et. al. Male gender was predictive of significantly worse FFS and OS. Once daily HDRT has similar OS to twice-daily radiation schemes; however, further studies assessing once daily HDRT for LS-SCLC are warranted.

Predictors for severe acute esophagitis in lung cancer patients treated with chemoradiotherapy: a systematic review

PURPOSE

To identify the risk factors for severe acute esophagitis (AE) in lung cancer patients undergoing chemoradiotherapy (CRT).

METHODS

Articles from PubMed, EMBASE, and the Cochrane Library were searched in August 2015. Articles reporting studies of the predictors for severe AE in lung cancer patients after CRT were included. Study quality was assessed using a modified quality assessment tool that was designed previously for an observational study. The effects of studies were combined with the study quality score using a best-evidence synthesis model. Severe AE incidence was also performed using the Metafor package of R-2.11.1.

RESULTS

A total of nine observational studies involving 1641 patients were included. The estimated incidence of severe AE was 14%. According to the best-evidence synthesis criteria, there were two strong-evidence risk factors for severe AE, which were the use of concurrent chemotherapy (CCT) and dose volume histogram (DVH). We also identified four limited-evidence risk factors.

CONCLUSIONS

More attention should be paid to the levels of patients' esophagus function. Although there is no conclusive evidence for severe AE in lung cancer patients after CRT, the above-mentioned factors provide evidence to guide clinicians as to which patients will have severe AE and to choose an optimal prophylactic strategy.

Advances in dosimetry and biological predictors of radiation-induced esophagitis

OBJECTIVE

To summarize the research progress about the dosimetry and biological predictors of radiation-induced esophagitis.

METHODS

We performed a systematic literature review addressing radiation esophagitis in the treatment of lung cancer published between January 2009 and May 2015 in the PubMed full-text database index systems.

RESULTS

Twenty-eight eligible documents were included in the final analysis. Many clinical factors were related to the risk of radiation esophagitis, such as elder patients, concurrent chemoradiotherapy, and the intense radiotherapy regimen (hyperfractionated radiotherapy or stereotactic body radiotherapy). The parameters including Dmax, Dmean, V20, V30, V50, and V55 may be valuable in predicting the occurrence of radiation esophagitis in patients receiving concurrent chemoradiotherapy. Genetic variants in inflammation-related genes are also associated with radiation-induced toxicity.

CONCLUSION

Dosimetry and biological factors of radiation-induced esophagitis provide clinical information to decrease its occurrence and grade during radiotherapy. More prospective studies are warranted to confirm their prediction efficacy.

Acute esophagitis for patients with local-regional advanced non small cell lung cancer treated with concurrent chemoradiotherapy

PURPOSE

Esophagitis is common in patients treated with definitive radiotherapy for local-regional advanced non small cell lung cancer (NSCLC). The purpose of this study was to estimate the dose-effect relationship using clinical and dosimetric parameters in patients receiving intensity modulated radiotherapy (IMRT) and concomitant chemotherapy (CCT).

METHODS

Between 2009 and 2013, 117 patients with stages IIB-IIIB NSCLC were treated in a multicenter randomized phase II trial with 2 cycles of induction chemotherapy followed by IMRT and CCT. The esophagitis was prospectively scored using the Common Toxicity Criteria 3.0. Clinical and dosimetric variables were analyzed for the correlation with grade ⩾2 esophagitis through logistic regression.

RESULTS

Grade 2 esophagitis was experienced by 31 (27%). All models including gender, institution, a dosimetric parameter and a position parameter were significantly associated with esophagitis. The two models using the relative esophagus volume irradiated above 40 Gy (V40, OR=2.18/10% volume) or the length of esophagus irradiated above 40 Gy (L40, OR=4.03/5 cm) were optimal. The upper part of esophagus was more sensitive and females experienced more toxicity than men.

CONCLUSION

V40 and L40 were most effective dosimetric predictors of grade ⩾2 esophagitis. The upper part of esophagus was more sensitive.

Incidence and predictors of severe acute esophagitis and subsequent esophageal stricture in patients treated with accelerated hyperfractionated chemoradiation for limited-stage small cell lung cancer

PURPOSE

Clinical and dosimetric predictors of severe (grade 3 or greater) acute esophageal toxicity and subsequent esophageal dilation were explored in patients with limited-stage small cell lung cancer treated with accelerated hyperfractionated chemoradiation.

METHODS AND MATERIALS

A total of 130 patients were identified who were treated to 45 Gy in 1.5-Gy twice-daily fractions with concurrent platinum-based chemotherapy between 2000 and 2009. Data on clinical, disease-related, and treatment-related variables were collected. Patients with percutaneous endoscopic gastrostomy tube insertion or intravenous hydration because of poor oral intake were designated as having acute grade 3 esophagitis. Univariate and multivariate analyses that associated treatment characteristics with esophagitis were assessed via logistic regression, and optimal cut points were identified with recursive partitioning analysis.

RESULTS

Twenty-five patients developed severe acute esophagitis, at a rate of 26% (18/69) in patients treated with earlier 3-dimensional conformal radiation therapy techniques and 11.5% (7/61) in patients treated with intensity modulated radiation therapy techniques and omission of elective nodal irradiation. The incidence of esophageal stricture was 6% overall (8 of 128 eligible) but 26% (6/23) among those who experienced prior grade 3 acute esophagitis and 2% (2/105) among those with acute esophagitis less than or equal to grade 2. Significant multivariate predictors of acute esophagitis were mean dose and volume of esophagus receiving at least 5% to 35% of the prescribed dose (V5 to V40). Patients with V5 ≥ 74% had a 44.4% risk of severe acute esophagitis (12/27) versus 12.6% (13/103) among those with V5 < 74%. V45 was the only dosimetric predictor for esophageal stricture, with 13.7% of patients in whom V45 was ≥37.5% requiring subsequent dilation.

CONCLUSIONS

Modern radiation techniques are associated with a lower frequency of severe acute esophagitis than previous paradigms. The proportion of esophagus receiving low- to moderate-range doses (mean, V5 through V40) predicts acute esophagitis, whereas the proportion of esophagus that receives high doses (V45) predicts the development of esophageal stricture that requires dilation. Patients who develop grade 3 acute esophagitis are at significant risk for subsequent esophageal stricture, whereas those with acute esophagitis of grade 2 or less display minimal risk.

Correlation of dosimetric and clinical factors with the development of esophagitis and radiation pneumonitis in patients with limited-stage small-cell lung carcinoma

BACKGROUND

The purpose of the study was to correlate clinical and dosimetric factors with the development of esophagitis and radiation pneumonitis in patients with limited-stage small-cell lung carcinoma (LS SCLC).

PATIENTS AND METHODS

One hundred eighteen patients who received curative intent chemoradiotherapy for LS SCLC and had electronically archived radiation treatment plans were included. The medical charts were reviewed for clinical data. The treatment plan was reviewed for critical structure delineation and dose delivered. Treatment planning data were analyzed using Computational Environment for Radiotherapy Research (V3.3). Dosimetric parameters were correlated with the risk of toxicity using Spearman rank correlation.

RESULTS

Radiotherapy dose was 40 Gy in 15 fractions (fx) (n = 80) and 45 Gy in 30 fractions twice per day (n = 38). The 6-month cumulative incidence of Grade ≥ 2 radiation pneumonitis was 6.5% and 7.9% for the 40 Gy/15 fx and 45 Gy/30 fx groups, respectively (P = .40). The 3-month cumulative incidence of Grade 3 esophagitis was 7.5% and 13.2% for the 40 Gy/15 fx and 45 Gy/30 fx groups, respectively (P = .31). Grade ≥ 3 pneumonitis was correlated with volume of lung receiving 20 Gy (V20) and mean lung dose. Grade ≥ 3 esophagitis was correlated with mean esophagus dose and minimum dose to the hottest 45% of the esophagus (D45).

CONCLUSION

Mean lung dose and V20 were significant predictors of radiation pneumonitis in LS SCLC. Mean esophageal dose and D45 were significant predictors of esophagitis. These 2 treatment schedules have similar toxicity profiles.

[Helical tomotherapy in the treatment of malignant pleural mesothelioma: The impact of low doses on pulmonary and oesophageal toxicity]

PURPOSE

To evaluate the adjuvant treatment of malignant pleural mesothelioma by helical tomotherapy and the impact of low doses on esophageal and pulmonary toxicity.

PATIENTS AND METHODS

Between June 2007 and May 2011, 29 patients diagnosed with malignant pleural mesothelioma received adjuvant radiotherapy by helical tomotherapy. The median age was 63 years (34-72). Histologically, 83 % of patients had epithelioid malignant pleural mesothelioma. Clinically, 45 % of patients were T3 and 55 % N0. Eighty six percent of the patients were treated by extrapleural pneumonectomy and 35 % received neoadjuvant chemotherapy with platinum and pemetrexed. The median dose in the pneumonectomy cavity was 50Gy at 2Gy/fraction.

RESULTS

The mean follow-up was 2.3 years after diagnosis. Overall survival at 1 and 2 years was 65 and 36 % respectively. The median survival from diagnosis was 18 months. Median lung volumes receiving 2, 5, 10, 13, 15 and 20Gy (V2, V5, V10, V13, V15 and V20) were 100, 98, 52, 36, 19 and 5 %. The median of the mean remaining lung dose was 11Gy. Two patients died of pulmonary complications, three patients had grade 3 lung toxicity, while esophageal grade 3-4 toxicity was observed in three other patients. No significant impact of clinical characteristics and dosimetric parameters were found on pulmonary toxicity, however a V10≥50 %, a V15≥15 % and mean lung dose of 10Gy or more had a tendency to be predictive of pulmonary toxicity (P<0.1). Moreover, in our analysis, the mean lung dose seems to have a significant impact on esophageal toxicity (P=0.03) as well as low doses to the controlateral lung: V5, V10 and V13 (P<0.05).

CONCLUSION

Helical tomotherapy is a promising technique in the multimodality treatment of malignant pleural mesothelioma. Low doses received by the contralateral lung appear to be the limiting factor. A dosimetric comparison with volumetric modulated arctherapy techniques would be interesting in this setting.

Once-daily radiotherapy to > or =59.4 Gy versus twice-daily radiotherapy to > or =45.0 Gy with concurrent chemotherapy for limited-stage small-cell lung cancer: a comparative analysis of toxicities and outcomes

PURPOSE

The aim of this study was to compare toxicities, disease control, survival outcomes, and patterns of failure between groups of limited-stage small-cell lung cancer patients treated with once-daily versus twice-daily radiotherapy and concurrent chemotherapy.

MATERIALS AND METHODS

This single-institution retrospective analysis included a comparison of two of radiotherapy regimens to planned doses of (1) > or =59.4 Gy at 1.8-2.0 Gy per once-daily fraction or (2) > or =45 Gy at 1.5 Gy per twice-daily fractions with concurrent platinum-based chemotherapy. Comparative analyses of toxicities and disease control were performed.

RESULTS

A total of 71 patients were included in the present study (17 once-daily, 54 twice-daily). Patient, tumor, staging, and treatment factors were similar between the two treatment groups. Median planned radiotherapy doses were 60 Gy (range 59.4-70.0 Gy) and 45 Gy (range 45-51 Gy) for the once-daily and twice-daily groups, respectively. Acute toxicities were similar between the groups ( approximately 20% grade 3 esophagitis). At a median survival follow-up of 26.2 months (range 3.4-85.5 months), 42 patients had died. The 2-year overall survival estimates were similar at 43% and 49% for the once-daily versus twice-daily groups, respectively. Isolated in-field failures were similar between the two groups ( approximately 17%).

CONCLUSION

The present analysis did not detect a statistically significant difference in acute toxicities, disease control, or survival outcomes in limited-stage small-cell lung cancer patients treated with concurrent chemotherapy and once-daily versus twice-daily radiotherapy.