Relationship between dose-volume parameters and pulmonary complications after neoadjuvant chemoradiotherapy followed by surgery for lung cancer

Impact of the neutrophil-to-lymphocyte ratio on patients with locally advanced non-small cell lung cancer who suffer radiation pneumonitis during the course of induction chemoradiotherapy followed by surgery

PURPOSE

Radiation pneumonitis (RP) is an obstacle for patients after surgery following induction chemoradiotherapy for locally advanced non-small cell lung cancer (LA-NSCLC). We performed a comparative analysis of the association between clinicopathological factors, including the neutrophil-to-lymphocyte ratio (NLR) and prognosis, in LA-NSCLC patients with or without RP during induction chemoradiotherapy followed by surgery.

METHODS

The subjects of this analysis were 168 patients undergoing trimodality therapy for LA-NSCLC between January, 1999 and May, 2019. Patients were divided into two groups: the RP group (n = 41) and the non-RP group (n = 127). We compared the clinicopathological factors including the NLR between the groups and analyzed the association between the NLR and prognosis.

RESULTS

The RP group had more patients with tumors located in the lower lobe, more bilobar resections, shorter operative times, no implementation of postoperative adjuvant chemotherapy, and a higher postoperative NLR than the non-RP group. There were no significant differences in serious postoperative complications and the prognosis. Patients with a low postoperative NLR had a significantly better prognosis in the non-RP group, and a trend toward a better prognosis even in the RP group.

CONCLUSION

Postoperative NLR may be a useful prognostic factor, even for patients who suffer RP after trimodality therapy for LA-NSCLC.

Preliminary Study on the Effect of 4DCT-Ventilation-Weighted Dose on the Radiation Induced Pneumonia Probability (RIPP)

Purpose

The purpose of the present study was to evaluate the feasibility of using 4-dimensional computed tomography (4DCT)-ventilation-weighted dose analysis to predict radiation-induced pneumonia probability (RIPP).

Methods and Materials

The study population for this retrospective analysis included 16 patients with stage III lung cancer. Each patient's 4DCT images, including end-inhale and end-exhale sequences, were used for the deformable image registration, and the Hounsfield units (HU) density-change was used to calculate the ventilation. A previously established equation was used to convert the original dose (OD) D _{0, i} in the lungs in the original plan (OP) to the weighted-dose (WD) D _{w, i} in the weighted plan (WP). The patients were divided into 2 groups, one with radiation-induced pneumonia (RIP), and one without. The Spearman correlation analysis was used to analyze the correlation of RIP with ΔV₂₀ (ΔV _x = V _{w, x} in the WP - V _{0, x} in the OP), ΔMLD (ΔMLD = mean lung dose (MLD) in the WP - MLD in the OP), and ΔV₅.

Results

The results showed that 5 of the 16 patients were suffering from acute RIP, 4 of which had higher ΔV₂₀ and ΔMLD values than the rest of the patients. The results of the Spearman correlation analysis for those 4 patients were as follows: RIP vs. ΔV₂₀, r = 0.5123; RIP vs. ΔMLD, r = 0.5119; RIP vs. ΔV₅, r = 0.1904.

Conclusions

The 4DCT-ventilation-based weighted-dose analysis showed some correlation between RIPP and both ΔV₂₀ and ΔMLD, when comparing the weighted-dose and the conventional dose-volume histogram (DVH) analyses.

Dose-volume parameters predict radiation pneumonitis after induction chemoradiotherapy followed by surgery for non-small cell lung cancer: a retrospective analysis

Background

The relationship between lung dose-volume histogram (DVH) parameters and radiation pneumonitis (RP) associated with induction concurrent chemoradiotherapy (CCRT) followed by surgery in patients with non-small cell lung cancer (NSCLC) is unclear, particularly when concerning irradiation of the whole lung prior to resection. We performed this study to identify factors associated with grade ≥ 2 RP in such patients.

Methods

Patients who received induction CCRT (chemotherapy: cisplatin and docetaxel; radiotherapy: 46 Gy/23 fractions) between May 2003 and May 2017 were reviewed. The mean lung dose (MLD) and the percentage of the lung volume that received ≥5 Gy (V5) and ≥ 20 Gy (V20) were calculated. Factors associated with the development of grade ≥ 2 RP were analyzed.

Results

One hundred and eight patients were included in this study, 34 (31.5%) of whom experienced grade ≥ 2 RP. A V20 ≥ 21%, an MLD ≥10 Gy, and a lower lobe tumor location were significant predictors of grade ≥ 2 RP on univariate analysis (p = 0.007, 0.002, and 0.004, respectively). Moreover, an MLD ≥10 Gy and lower lobe location were significant predictors of grade ≥ 2 RP on multivariate analysis (p = 0.026 and 0.0043, respectively). The cumulative incidence rates of grade ≥ 2 RP at 6 months were 15.7 and 45.6% in patients with MLDs < 10 Gy and ≥ 10 Gy, respectively, and were 23.5 and 55.6% in patients with upper/middle lobe- vs. lower lobe-located tumors, respectively.

Conclusions

MLD and lower lobe location were predictors of grade ≥ 2 RP in patients who received induction CCRT. It is necessary to reduce the MLD to the greatest extent possible to prevent the occurrence of this adverse event.

Radiation pneumonitis in lung cancer treated with volumetric modulated arc therapy

Background

Few studies to date have assessed the incidence of radiation pneumonitis (RP) in lung cancer patients who have been treated with volumetric modulated arc therapy (VMAT). This study is aimed at reporting the RP incidence rate and the risk factors associated with a symptomatic RP in patients with lung cancer treated with VMAT.

Methods

A total of 77 consecutive lung cancer patients treated with VMAT from 2013 through 2015 were reviewed. RP severity was graded according to the Common Terminology Criteria for Adverse Events (CTCEA) v.4. Univariate and multivariate analyses were performed to identify the significant factors associated with RP.

Results

VMAT allowed us to achieve most planning objectives on the target volumes and organs at risk, for PTV V_95% =96.8%±3.1%, for lung V₅ =41.3%±8.7%, V₁₀ =30.0%±7.1%, V₂₀ =20.9%±5.7%, for heart V₅ =43.2%±29.9%, for esophagus V₆₀ =8.1%±12.9%. The maximum dose of spinal cord was 34.4±9.5 Gy. The overall incidence of symptomatic RP (grade ≥2 by CTCAE) was 28.6% in the entire cohort, and the rate of grade ≥3 RP was 11.7%. Based on the multivariate analysis, factors predictive of symptomatic RP included lung volume receiving ≥10 Gy (V₁₀) (P=0.019) and C-reactive protein changing level (P=0.013).

Conclusions

Our data showed that the incidence rate of RP was acceptable in lung cancer patients treated with VMAT. Additionally, we found that V₁₀ might be an important factor for predicting the development of RP when VMAT was used; but this observation needs to be validated in future studies.

Preoperative contralateral lung radiation dose is associated with postoperative pulmonary toxicity in patients with locally advanced non-small cell lung cancer treated with trimodality therapy

PURPOSE

In patients with non-small cell lung cancer (NSCLC) who undergo trimodality therapy (chemoradiation followed by surgical resection), it is unknown whether limiting preoperative radiation dose to the uninvolved lung reduces postsurgical morbidity. This study evaluated whether radiation fall-off dose parameters to the contralateral lung that is unaffected by NSCLC are associated with postoperative complications in NSCLC patients treated with trimodality therapy.

METHODS AND MATERIALS

We retrospectively reviewed NSCLC patients who underwent trimodality therapy between March 2008 and October 2016, with available restored digital radiation plans. Fischer's exact test was used to assess associations between patient and treatment characteristics and the development of treatment-related toxicity. Spearman rank correlation was used to measure the strength of association between dosimetric parameters.

RESULTS

Forty-six patients were identified who received trimodality therapy with intensity modulated radiation (median, 59.4 Gy; range, 45-70) and concurrent platinum doublet chemotherapy, followed by surgical resection. The median age was 64.9 years (range, 45.6-81.6). The median follow-up time was 1.9 years (range, 0.3-8.4). Twenty-four (52.2%) patients developed any-grade pulmonary toxicity and 14 (30.4%) patients developed grade 2+ pulmonary toxicity. There was an increased incidence of any-grade pulmonary toxicity in patients with contralateral lung volume receiving at least 20 Gy (V20) ≥7% compared with <7% (90%, n = 9 vs 41.7%, n = 15; P = .01). Similarly, contralateral lung V10 ≥20% was associated with an increased rate of any-grade pulmonary toxicity compared with V10 <20% (80%, n = 12 vs 38.7%, n = 12; P = .01). Pneumonectomy/bilobectomy was associated with grade 2+ pulmonary toxicity (P = .04).

CONCLUSIONS

Patients who received a higher radiation fall-off dose volume parameter (V20 ≥7% and V10 ≥20%) to the contralateral uninvolved lung had a higher incidence of any-grade postoperative pulmonary toxicity. Limiting radiation fall-off dose to the uninvolved lung may be an important modifiable radiation parameter in limiting postoperative toxicity in trimodality patients.

Occurrence of pneumonitis following radiotherapy of breast cancer - A prospective study

AIM

of this study is to determine the temporal resolution of therapy-induced pneumonitis, and to assess promoting factors in adjuvant treated patients with unilateral mammacarcinoma.

PATIENTS AND METHODS

A total of 100 post-surgery patients were recruited. The cohort was treated by 2 field radiotherapy (2FRT; breast and chest wall, N = 75), 3 field radiotherapy (3FRT; + supraclavicular lymphatic region, N = 8), or with 4 field radiotherapy (4FRT; + parasternal lymphatic region, N = 17). Ninety-one patients received various systemic treatments prior to irradiation. Following an initial screening visit post-RT, two additional visits after 12 and 25 weeks were conducted including radiographic examination. In addition, general anamnesis and the co-medication were recorded. The endpoint was reached as soon as a pneumonitis was developed or at maximum of six months post-treatment.

RESULTS

A pneumonitis incidence of 13% was determined. Of 91 patients with prior systemic therapy, 11 patients developed pneumonitis. Smoking history and chronic obstructive pulmonary disease (COPD) appeared to be positive predictors, whereas past pneumonia clearly promoted pneumonitis. Further pneumonitis-promoting predictors are represented by the applied field extensions (2 field radiotherapy [2FRT] < 3 field radiotherapy [3FRT] < 4 field radiotherapy [4FRT]) and the type of combined initial systemic therapies. As a consequence, all of the three patients in the study cohort treated with 4FRT and initial chemotherapy combined with anti-hormone and antibody protocols developed pneumonitis. A combination of the hormone antagonists tamoxifen and goserelin might enhance the risk for pneumonitis. Remarkably, none of the 11 patients co-medicated with statins suffered from pneumonitis.

CONCLUSIONS

The rapidly increasing use of novel systemic therapy schedules combined with radiotherapy (RT) needs more prospective studies with larger cohorts. Our results indicate that contribution to pneumonitis occurrence of various (neo)adjuvant therapy approaches followed by RT is of minor relevance, whereas mean total lung doses of >10 Gy escalate the risk of lung tissue complications. The validity of potential inhibitors of therapy-induced pneumonitis as observed for statin co-medication should further be investigated in future trials.