Current strategies for radiation therapy in non-small cell lung cancer

Reliability of Quantitative 18F-FDG PET/CT Imaging Biomarkers for Classifying Early Response to Chemoradiotherapy in Patients With Locally Advanced Non-Small Cell Lung Cancer

PURPOSE OF THE REPORT

We evaluated the reliability of 18F-FDG PET imaging biomarkers to classify early response status across observers, scanners, and reconstruction algorithms in support of biologically adaptive radiation therapy for locally advanced non-small cell lung cancer.

PATIENTS AND METHODS

Thirty-one patients with unresectable locally advanced non-small cell lung cancer were prospectively enrolled on a phase 2 trial (NCT02773238) and underwent 18F-FDG PET on GE Discovery STE (DSTE) or GE Discovery MI (DMI) PET/CT systems at baseline and during the third week external beam radiation therapy regimens. All PET scans were reconstructed using OSEM; GE-DMI scans were also reconstructed with BSREM-TOF (block sequential regularized expectation maximization reconstruction algorithm incorporating time of flight). Primary tumors were contoured by 3 observers using semiautomatic gradient-based segmentation. SUVmax, SUVmean, SUVpeak, MTV (metabolic tumor volume), and total lesion glycolysis were correlated with midtherapy multidisciplinary clinical response assessment. Dice similarity of contours and response classification areas under the curve were evaluated across observers, scanners, and reconstruction algorithms. LASSO logistic regression models were trained on DSTE PET patient data and independently tested on DMI PET patient data.

RESULTS

Interobserver variability of PET contours was low for both OSEM and BSREM-TOF reconstructions; intraobserver variability between reconstructions was slightly higher. ΔSUVpeak was the most robust response predictor across observers and image reconstructions. LASSO models consistently selected ΔSUVpeak and ΔMTV as response predictors. Response classification models achieved high cross-validated performance on the DSTE cohort and more variable testing performance on the DMI cohort.

CONCLUSIONS

The variability FDG PET lesion contours and imaging biomarkers was relatively low across observers, scanners, and reconstructions. Objective midtreatment PET response assessment may lead to improved precision of biologically adaptive radiation therapy.

Radiation dose effect in locally advanced non-small cell lung cancer

Radiation is the foundation of treatment for locally advanced non-small cell lung cancer (NSCLC), and as such, optimal radiation dose is essential for successful treatment. This article will briefly review biological considerations of radiation dose and their effect in the context of three-dimensional conformal radiation therapy (3D-CRT) including intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) for NSCLC. It will focus on literature review and discussions regarding radiation dose effect in locally advanced NSCLC including potential severe and lethal toxicities of high dose radiation given with concurrent chemotherapy. Potential new approaches for delivering safe and effective doses by individualizing treatment based on functional imaging are being applied in studies such as the PET boost trial and RTOG1106. The RTOG concept of delivering high dose radiation to the more resistant tumors with the use of isotoxic dose prescription and adaptive planning will also be discussed in detail.

Induction therapy followed by surgery for T3-T4/N0 non-small cell lung cancer: long-term results

BACKGROUND

The aim of this study was to analyze the impact of the induction chemoradiotherapy (IT) on the survival pattern in T3/T4-N0 non-small cell lung cancer (NSCLC) patients.

METHODS

The data of 71 patients treated from January 1992 to May 2007 were reviewed. Of these, 31 patients received IT prior to surgery (IT group: T3, 20 patients; and T4, 11 patients), and 40 directly underwent surgery (S group: T3, 34 patients; and T4, 6 patients). Survival rates were compared using the Kaplan-Meier analysis and the Cox proportional hazards models.

RESULTS

Mean ages were 62.5±9.9 years in the IT group and 67.7±7.1 in the S group. All patients but 1 completed the IT treatment and 27 patients (87%) were operated. A radical resection was possible in 21 patients (78%). In the IT group a complete pathologic response was obtained in 6 patients (22%), where 8 patients ended up in pI stage, 7 in pII stage, and 6 in pIII stage. The overall 5-year survival (long-term survival [LTS]) and disease-free 5-year survival (DFS) for the entire cohort were 40% and 34%, respectively. No significant differences were found when LTS in the IT group (44%) and in the S group (37%) were compared. At multivariate analysis, the completeness of resection was the only independent predictive factor (hazard ratio [HR]=5.18; 95% confidence interval [CI]=2.55 to 10.28) while Cox multivariate analysis (on the IT group only) confirmed the critical role of the pathologic downstaging (HR=4.62; 95% CI=1.54 to 13.89).

CONCLUSIONS

A multimodal strategy with IT treatment followed by surgery is a safe and reasonable treatment in T3/T4-N0 NSCLC patients, but no clear evidence of prognostic improvement may be assumed at the present time. Nevertheless, patients with radical resection and complete pathologic response have a very rewarding survival.

Results of curative radiation therapy with or without chemotherapy for stage III unresectable non-small cell lung cancer

PURPOSE

We retrospectively analyzed the patients who received curative radiotherapy for unresectable stage III NSCLC to investigate the impact of chemotherapy.

MATERIALS AND METHODS

From 1998 to 2001, the records of 224 patients who completed curative radiotherapy for NSCLC were reviewed. There were 210 males and 14 females, and their median age was 64 years (range 38 approximately 83). 54 patients had stage IIIA disease and 170 patients had stage IIIB disease. Conventional radiotherapy was given and the radiation dose ranged from 50 approximately 70 Gy with a median of 60 Gy, and chemotherapy was combined for 116 patients (52%).

RESULTS

The median survival, the 2-year, and 5-year actuarial survival rates of all 224 patients were 15 months, 30%, and 7%, respectively. The median survival of the patients with stage IIIA and IIIB disease were 21 months and 13 months, respectively (p=0.14). The median survival of patients who received chemoradiation was 18 months compared to 14 months for the patients who received RT alone (p=0.02). Among the chemoradiation group of patients, the median survival time of the patients who received 1 to 3 cycles of chemotherapy was 16 months and that for the patients who received more than 3 cycles was 22 months (p=0.07). We evaluated the effects of the timing of chemoradiation in 57 patients who received more than 3 cycles of chemotherapy. The median survival of the patients with the concurrent sequence was 25 months and that for the patients with the sequential chemotherapy was 19 months (p=0.81).

CONCLUSIONS

For advanced stage III non-small cell lung cancer patients who completed the curative radiotherapy, the addition of chemotherapy improved the survival compared to the patients who received radiotherapy alone.

Neoadjuvant concurrent radiochemotherapy in locally advanced (IIIA–IIIB) non-small-cell lung cancer: long-term results according to downstaging

BACKGROUND

To report the efficacy of induction treatment (IT) protocol with concurrent radiochemotherapy in locally advanced non-small-cell lung cancer (NSCLC), and to analyze downstaging as a surrogate end point.

PATIENTS AND METHODS

Patients with histo- or cytologically confirmed stage IIIA or IIIB NSCLC were treated according to an IT protocol followed by surgery. Downstaging was assessed for all resected patients.

RESULTS

In the period between February 1992 and July 2000, 92 patients were enrolled in the study (57 IIIA, 35 IIIB). Response was observed in 63 patients; 56 patients underwent radical resection. Patients downstaged to stage 0-I (DS 0-I) showed a statistically significant improved disease-free survival (26.2 months pStage 0-I versus 11.2 months pStage II-III; P=0.0116) and overall survival (median 32.5 months pStage 0-I versus 18.3 months pStage II-III; P=0.025). Patients with DS 0-I had a significantly lower probability (P=0.0353) of developing distant metastases estimated in 0.2963 odds ratio.

CONCLUSION

Neoadjuvant radiochemotherapy is feasible with good pathological DS results. Pathological downstaging was confirmed to have high predictive value. Its use is suggested in the short-term evaluation of induction protocols efficacy in locally advanced NSCLC.

Incidental surgical findings of a phase I trial of weekly gemcitabine and concurrent radiotherapy in patients with unresectable non-small cell lung cancer

OBJECTIVE

to report the surgical facts of unresectable patients with locally advanced non-small cell lung cancer (NSCLC) treated in a phase I trial with concurrent weekly gemcitabine and radiotherapy who achieved a clinical downstaging so as to re-enter resectability.

MATERIALS AND METHODS

from 3/99 to 11/00, 30 patients (ten stage IIIa, 16 IIIb and four IV) with histologically proven, unresectable NSCLC, were enrolled in this phase I trial. Gemcitabine was given weekly for 5 consecutive weeks as a 30-min intravenous infusion, at least 4 h before radiotherapy. Starting dose: 100 mg/m(2). Maximum tolerated dose (MTD): 350 mg/m(2). Radiotherapy total dose: 50.4 Gy (1.8 Gy/day) on primitive tumour and involved lymph nodes.

RESULTS

27 out of 30 patients (90%) were evaluable for clinical restaging (three patients who decided to continue their treatment elsewhere have been excluded). A major clinical response (partial+complete response) was observed in 17 out of 27 cases (62.9%). Clinical complete response rate was 3.7% (1/27) while partial response rate was 59.2% (16/27). Nine patients (33.4%) showed a clinical stable disease and one a disease progression (3.7%). Fourteen patients re-entered resectability and were operated upon: seven lobectomies; four bilobectomies; two pneumonectomies and one explorative thoracotomy. Mean operation duration time was 112 min; mean blood loss was 390 cc. Thirty-day morbidity and mortality were nil. Mean post-operative hospital stay was 6.8 days. A slight increase in operational technical difficulty was encountered. Definitive histology showed a pathologic downstaging of 71.4% (10/14). In four patients, only microscopic neoplastic remnants were found.

CONCLUSIONS

combined treatment with weekly gemcitabine and concurrent radiotherapy is feasible. In patients with advanced NSCLC who achieved a good clinical response and therefore were judged to be resectable, surgery was possible without any increase in thirty-day morbidity and mortality. Satisfactory pathologic results were obtained.

Optimizing radiation treatment plans for lung cancer using lung perfusion information

PURPOSE

To study the impact of incorporation of lung perfusion information in the optimization of radical radiotherapy (RT) treatment plans for patients with medically inoperable non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

The treatment plans for a virtual phantom and for five NSCLC patients with typical defects of pre-RT lung perfusion were optimized to minimize geometrically determined parameters as the mean lung dose (MLD), the lung volume receiving more than 20 Gy (V20), and the functional equivalent of the MLD, using perfusion-weighted dose-volume histograms. For the patients the (perfusion-weighted) optimized plans were compared to the clinically applied treatment plans.

RESULTS

The feasibility of perfusion-weighted optimization was demonstrated in the phantom. Using perfusion information resulted in an increase of the weights of those beams that were directed through the hypo-perfused lung regions both for the phantom and for the studied patients. The automatically optimized dose distributions were improved with respect to lung toxicity compared with the clinical treatment plans. For patients with one hypo-perfused hemi-thorax, the estimated gain in post-RT lung perfusion was 6% of the prescribed dose compared to the geometrically optimized plan. For patients with smaller perfusion defects, perfusion-weighted optimization resulted in the same plan as the geometrically optimized plan.

CONCLUSION

Perfusion-weighted optimization resulted in clinically well applicable treatment plans, which cause less radiation damage to functioning lung for patients with large perfusion defects.

Surgical results of maximal local-regional treatment (cisplatin-enhanced high-dose radiotherapy and adjuvant surgery) in initially non-resectable stage III lung cancer

We report the surgical short- and long-term results in 42 patients treated in a phase II trial with 50-60 Gy cisplatin-enhanced radiotherapy (RT) and adjuvant resection, for initially non-resectable stage III non-small cell lung cancer. Six of the 42 patients had a complete response, 31 a partial response and five stable disease at the presurgical clinical restaging. A complete pathologic response was observed in 19 cases (R0a surgery); 15 complete resections were performed due to persistent disease (R0b). There were eight non-radical operations (R+). Operative deaths were seen after right pneumonectomy (five cases) and in case of a non-radical operation after no response following the chemo-radiotherapy schedule (two cases). Surgery should be contraindicated in these cases. Overall eight-year-survival was 26% (37% in R0a and 27% in R0b patients). No patient with R+ surgery survived at the eighth year. A local progression as initial failure occurred in four of the 34 R0 patients, and in five of the eighth with a R+ procedure. Resection seems to improve local control, but its role needs further definition. However, advanced stage III patients treated only with a local therapy were not precluded from a long-term survival.

Phase I trial of weekly gemcitabine and concurrent radiotherapy in patients with inoperable non-small-cell lung cancer

PURPOSE

To report the evidence of a phase I trial planned to determine the maximum-tolerated dose (MTD) and related toxicity of weekly gemcitabine (GEM) and concurrent radiotherapy in patients with non--small-cell lung cancer (NSCLC). In addition, the response to treatment was evaluated and reported.

PATIENTS AND METHODS

Thirty-six patients with histologically confirmed NSCLC deemed unresectable because of advanced stage were observed and treated according to a combined chemoradiation protocol with GEM as chemotherapeutic agent. GEM was given weekly for 5 consecutive weeks as a 30-minute intravenous infusion concurrent with radiotherapy (1.8 Gy/d; total dose, 50.4 Gy). The initial dose was 100 mg/m(2). Pulmonary, esophageal, cardiac, hematologic, and skin toxicities were assessed. The dose of GEM was increased by 50 mg/m(2) up to a dose of 250 mg/m(2); an additional increase by 25 mg/m(2) up to the MTD was planned and realized. Three patients were enrolled for each dose level.

RESULTS

Dose-limiting toxicity was identified for the 375-mg/m(2) level with two episodes of grade 2 esophagitis and two of grade 3 pulmonary actinic interstitial disease. The weekly dose of GEM 350 mg/m(2) was well tolerated.

CONCLUSION

A weekly GEM dose of 350 mg/m(2) concurrent with radiotherapy was well tolerated. Promising results regarding response to treatment were observed and reported.

A palliative accelerated irradiation regimen for advanced non-small-cell lung cancer vs. conventionally fractionated 60 GY: results of a randomized equivalence study

PURPOSE

Radiation oncologists are often faced with patients with advanced non-small-cell lung cancer (NSCLC), who are not suitable candidates for state-of-the-art radical treatment, but who also are not judged to have a very short life expectancy. Some physicians treat these patients palliatively, whereas others advocate more intensive treatment. To find out if there is a substantial difference in outcome between these approaches, we performed a randomized prospective study.

METHODS AND MATERIALS

Between 1994 and 1998, 152 eligible patients with advanced NSCLC Stage III (n = 121) or minimal Stage IV (n = 31) were randomized to receive conventionally fractionated (cf; A: 60 Gy, 6 weeks, n = 79) or short-term treatment (PAIR; B: 32 Gy, 2 Gy b.i.d.; n = 73) of tumor and mediastinum.

RESULTS

One-year survival rate for all patients was 37% with no significant difference between the two treatment arms (A: 36%; B: 38%; p = 0.76). As far as can be judged from limited data available, palliation was adequate and similar for the two treatment arms. Apart from expected differences in the time course of esophagitis, acute side effects were moderate and equally distributed. No severe late effects were observed.

CONCLUSIONS

In the present randomized trial, survival and available data on palliation were not different after cf to 60 Gy compared to the palliative PAIR regimen. Therefore, for patients who are not suitable for radical treatment approaches, the prescription of a palliative short-term irradiation appears preferable compared to cf over several weeks.