The impact of regional nodal radiotherapy (dose/volume) on regional progression and survival in unresectable non-small cell lung cancer: an analysis of RTOG data

Comparison of Involved Field Radiotherapy versus Elective Nodal Irradiation in Stage IIIB/C Non-Small-Cell Lung Carcinoma Patients Treated with Concurrent Chemoradiotherapy: A Propensity Score Matching Study

Background

We retrospectively compared the incidence of isolated elective nodal failure (IENF) and toxicity rates and survival outcomes after elective nodal irradiation (ENI) versus involved-field RT (IFRT) by employing the propensity score matching (PSM) methodology in stage IIIB/C inoperable non-small-cell lung cancer (NSCLC) patients treated with definitive concurrent chemoradiotherapy (C-CRT).

Methods

Our PSM examination included 1048 stage IIIB/C NSCLC patients treated with C-CRT from January 2007 to December 2016: a total dose of 66 Gy (2 Gy/fraction) radiotherapy and 1–3 cycles of platinum-based doublet chemotherapy concurrently. The primary and secondary endpoints were the IENF and toxicity rates and survival outcomes after ENI versus IFRT, respectively. Propensity scores were calculated for each group to adjust for confounding variables and facilitate well-balanced comparability by creating 1 : 1 matched study groups.

Results

The median follow-up was 26.4 months for the whole study accomplice. The PSM analysis unveiled 1 : 1 matched 646 patients for the ENI (N = 323) and IFRT (N = 323) cohorts. Intergroup comparisons discovered that the 5-year isolated ENF incidence rates (3.4% versus 4.3%; P=0.52) and median overall survival (25.2 versus 24.6 months; P=0.69), locoregional progression-free survival (15.3 versus 15.1 months; P=0.52), and progression-free survival (11.7 versus 11.2 months; P=0.57) durations were similar between the ENI and IFRT cohorts, separately. However, acute grade 3-4 leukopenia (P=0.0012), grade 3 nausea-vomiting (P=0.006), esophagitis (P=0.003), pneumonitis (P=0.002), late grade 3-4 esophageal toxicity (P=0.038), and the need for hospitalization (P < 0.001) were all significantly higher in the ENI than in the IFRT group, respectively.

Conclusion

Results of the present large-scale PSM cohort established the absence of meaningful IENF or survival differences between the IFRT and ENI cohorts and, consequently, counseled the IFRT as the elected RT technique for such patients since ENI increased the toxicity rates.

Supraclavicular Recurrence in Completely Resected (y)pN2 Non-Small Cell Lung Cancer: Implications for Postoperative Radiotherapy

Background: The clinical value and delineation of clinical target volume (CTV) of postoperative radiotherapy (PORT) in completely resected (y)pN2 non-small cell lung cancer (NSCLC) remain controversial. Investigations specifically focusing on the cumulative incidence and prognostic significance of initial disease recurrence at the supraclavicular region (SCR) in this disease population are seldom reported.

Methods: Consecutive patients with curatively resected (y)pN2 NSCLC who received adjuvant chemotherapy from January 2013 to December 2018 at our cancer center were retrospectively examined. Disease recurrence at the surgical margin, ipsilateral hilum, and/or mediastinum was defined as loco-regional recurrence (LRR). Disease recurrence beyond LRR and SCR, was defined as distant metastasis (DM). Overall survival (OS1 and OS2) were calculated from surgery and disease recurrence to death of any cause, in the entire cohort and in patients with recurrent disease, respectively.

Results: Among the 311 patients enrolled, PORT without elective supraclavicular nodal irradiation (ESRT) was performed in 94 patients and neoadjuvant chemotherapy was administered in 31 patients. With a median follow-up of 26 months, 203 patients developed recurrent disease, including 27 SCRs, among which 16 were without DM and 22 involved the ipsilateral supraclavicular region. The 1, 3, and 5-year cumulative incidence of SCR were 6.53, 13.0, and 24.7%, respectively. Chosen DM as a competing event, cN2, ypN2, not receiving lobectomy, and negative expression of CK7 were significantly associated with SCR using the univariate competing risk analysis, while ypN2 was identified as the only independent risk factor of SCR (p = 0.012). PORT significantly reduced LRR (p = 0.031) and prolonged OS1 (p = 0.018), but didn't impact SCR (p = 0.254). Pattern of failure analyses indicated that the majority of LRRs developed within the actuarial or virtual CTV of PORT, and 15 of the 22 ipsilateral SCRs could be covered by the virtual CTV of proposed ESRT. In terms of OS2, patients who developed SCR but without DM had intermediate prognosis, compared with those who had DM (p = 0.009) and those who had only LRR (p = 0.048).

Conclusions: SCR is not uncommon and has important prognostic significance in completely resected (y)pN2 NSCLC. The clinical value of PORT and ESRT in such patients need to be further investigated.

ICORG 06-35: a prospective evaluation of PET-CT scan in patients with non-operable or non-resectable non-small cell lung cancer treated by radical 3-dimensional conformal radiation therapy: a phase II study

BACKGROUND

Radiotherapy (RT) is a key treatment modality in the curative treatment of patients with non-small cell lung cancer (NSCLC). Incorrect definition of the gross, or clinical, target volume is a common source of error which can lead to a reduced probability of tumour control.

OBJECTIVE

This was a pilot and a phase II study. The pilot evaluated the technical feasibility of integrating positron emission tomography-computed tomography (PET-CT) fusion. The primary outcome of the phase II study was to evaluate the safety of PET-CT scan-based RT by evaluating the rate of loco-regional recurrence outside the PET-CT planning target volume (PTV) but within conventional 3-D PTV.

METHODS

Patients underwent standard post-treatment follow-up, including repeated three monthly CT scans of the thorax. In case of loco-regional recurrence, three categories were considered, with only extra-PET scan PTV and intra-CT scan PTV recurrences considered as a failure. Our hypothesis was that the rate of these events would be < 10%.

RESULTS

Twelve patients were recruited; the study closed early due to poor recruitment. The primary endpoint of the pilot was met; it was feasible to deliver a PET-CT-based plan to ≥ 60% of patients. Two patients had intra-PET scan PTV recurrences, six had extra-PET scan PTV and extra-CT, and three patients had both. Another patient had extra-PET scan PTV and extra-CT as well as extra-PET scan PTV and intra-CT scan PTV recurrence.

CONCLUSION/ADVANCES IN KNOWLEDGE

PET-based planning has the potential to reduce radiation treatment volumes because of the avoidance of mediastinal lymph nodes that are PET negative.

The dosimetric effects of limited elective nodal irradiation in volumetric modulated arc therapy treatment planning for locally advanced non-small cell lung cancer

OBJECTIVE

Contemporary radiotherapy guidelines for locally advanced non-small cell lung carcinoma (LA-NSCLC) recommend omitting elective nodal irradiation, despite the fact that evidence supporting this came primarily from older reports assessing comprehensive nodal coverage using 3D conformal techniques. Herein, we evaluated the dosimetric implications of the addition of limited elective nodal irradiation (LENI) to standard involved field irradiation (IFI) using volumetric modulated arc therapy (VMAT) planning.

METHOD

Target volumes and organs-at-risk (OARs) were delineated on CT simulation images of 20 patients with LA-NSCLC. Two VMAT plans (IFI and LENI) were generated for each patient. Involved sites were treated to 60 Gy in 30 fractions for both IFI and LENI plans. Adjacent uninvolved nodal regions, considered high risk based on the primary tumor site and extent of nodal involvement, were treated to 51 Gy in 30 fractions in LENI plans using a simultaneous integrated boost approach.

RESULTS

All planning objectives for PTVs and OARs were achieved for both IFI and LENI plans. LENI resulted in significantly higher esophagus Dmean (15.3 vs. 22.5 Gy, p < 0.01), spinal cord Dmax (34.9 vs. 42.4 Gy, p = 0.02) and lung Dmean (13.5 vs. 15.9 Gy, p = 0.02), V20 (23.0 vs. 27.9%, p = 0.03), and V5 (52.6 vs. 59.4%, p = 0.02). No differences were observed in heart parameters. On average, only 32.2% of the high-risk nodal volume received an incidental dose of 51 Gy when untargeted in IFI plans.

CONCLUSION

The addition of LENI to VMAT plans for LA-NSCLC is feasible, with only modestly increased doses to OARs and marginal expected increase in associated toxicity.

Radiotherapy in Italy for Non-Small Cell Lung Cancer: Patterns of Care Survey

Aims and Background

Surveys in clinical practice are useful to find how current clinical approaches follow recommendations from evidence-based medicine, to stimulate discussion in a multidisciplinary team, and to hypothesize collaborative multi-centric trials. To assess management strategies for the use of radiotherapy in the treatment of lung cancer in Italy, in 2009, the Italian Society of Radiation Oncology Lung Cancer Study Group proposed the survey to all Italian radiation oncology institutions. Results were compared with literature data and international reports.

Study Design

Questionnaires on patterns of care of non-small cell lung cancer were sent to radiation oncology centers active at June 2009 and evaluated data recorded in 2008.

Results

A total of 65 of 143 Italian centers responded to the questionnaire. The responding centers reflect the distribution of radiotherapy centers throughout the country. Of the treated patients, 55.2% were stage III, and most cases had a good performance status. FDG-PET was routinely used by 51% of centers for diagnostic and contouring phases. Postoperative radiotherapy was prescribed to pN1 and pN2 patients in 42.2% and 98.5%, respectively. The possible use of neo-adjuvant concomitant chemoradiation was declared by 70% of responders. A sequential chemoradiation approach was actually used in 43.6% of cases, induction chemotherapy followed by concomitant radiochemotherapy in 42.4%, and upfront concomitant radiochemotherapy in only 14%. In 53% of the institutions, patients have a clinical examination by a radiation oncologist only after the beginning of chemotherapy and in 82.4% of cases they have already received 2–4 cycles of chemotherapy. Most of the institutions exclude elective nodal irradiation from routine application. Total dose and fractionation in adjuvant, neoadjuvant, curative and palliative settings confirm literature data. There were significant differences in treatment planning constraints applied for lung, esophageal and cardiac tissues. Of the responding centers, 41% had stereotactic therapy for primary inoperable lung cancer and for metastatic lesions.

Conclusions

In Italy, daily practice differs in some ways from the evidence supported by the results of meta-analyses/clinical trials as regards concurrent chemoradiation approaches. It could be postulated that there is an urgent need for groups that collaborate with the other societies involved in the treatment of non-small cell lung cancer in order to offer the best therapy to our patients.

Role of Computed Tomographyand [18F] Fluorodeoxyglucose Positron Emission Tomography Image Fusion in Conformal Radiotherapy of Non-Small Cell Lung Cancer: A Comparison with Standard Techniques with and without Elective Nodal Irradiation

Aims and background

Mediastinal elective node irradiation (ENI) in patients with non-small cell lung cancer candidate to radical radiotherapy is controversial. In this study, the impact of co-registered [18F]fluorodeoxyglucose-positron emission tomography (PET) and standard computed tomography (CT) on definition of target volumes and toxicity parameters was evaluated, by comparison with standard CT-based simulation with and without ENI.

Methods

CT-based gross tumor volume (GTVCT) was first contoured by a single observer without knowledge of PET results. Subsequently, the integrated GTV based on PET/CT coregistered images (GTVPET/CT) was defined. Each patient was planned according to three different treatment techniques: 1) radiotherapy with ENI using the CT data set alone (ENI plan); 2) radiotherapy without ENI using the CT data set alone (no ENI plan); 3) radiotherapy without ENI using PET/CT fusion data set (PET plan). Rival plans were compared for each patient with respect to dose to the normal tissues (spinal cord, healthy lungs, heart and esophagus).

Results

The addition of PET-modified TNM staging in 10/21 enrolled patients (48%); 3/21 were shifted to palliative treatment due to detection of metastatic disease or large tumor not amenable to high-dose radiotherapy. In 7/18 (39%) patients treated with radical radiotherapy, a significant (≥25%) change in volume between GTVCT and GTVPET/CT was observed. For all the organs at risk, ENI plans had dose values significantly greater than no-ENI and PET plans. Comparing no ENI and PET plans, no statistically significant difference was observed, except for maximum point dose to the spinal cord Dmax, which was significantly lower in PET plans. Notably, even in patients in whom PET/CT planning resulted in an increased GTV, toxicity parameters were fairly acceptable, and always more favorable than with ENI plans.

Conclusions

Our study suggests that [18F]-fluorodeoxyglucose-PET should be integrated in no-ENI techniques, as it improves target volume delineation without a major increase in predicted toxicity.

An individualized radiation dose escalation trial in non-small cell lung cancer based on FDG-PET imaging

AIM

The aim of the study was to assess the feasibility of an individualized 18F fluorodeoxyglucose positron emission tomography (FDG-PET)-guided dose escalation boost in non-small cell lung cancer (NSCLC) patients and to assess its impact on local tumor control and toxicity.

PATIENTS AND METHODS

A total of 13 patients with stage II-III NSCLC were enrolled to receive a dose of 62.5 Gy in 25 fractions to the CT-based planning target volume (PTV; primary turmor and affected lymph nodes). The fraction dose was increased within the individual PET-based PTV (PTV_PET) using intensity modulated radiotherapy (IMRT) with a simultaneous integrated boost (SIB) until the predefined organ-at-risk (OAR) threshold was reached. Tumor response was assessed during follow-up by means of repeat FDG-PET/computed tomography. Acute and late toxicity were recorded and classified according to the CTCAE criteria (Version 4.0). Local progression-free survival was determined using the Kaplan-Meier method.

RESULTS

The average dose to PTV_PET reached 89.17 Gy for peripheral and 75 Gy for central tumors. After a median follow-up period of 29 months, seven patients were still alive, while six had died (four due to distant progression, two due to grade 5 toxicity). Local progression was seen in two patients in association with further recurrences. One and 2-year local progression free survival rates were 76.9% and 52.8%, respectively. Three cases of acute grade 3 esophagitis were seen. Two patients with central tumors developed late toxicity and died due to severe hemoptysis.

CONCLUSION

These results suggest that a non-uniform and individualized dose escalation based on FDG-PET in IMRT delivery is feasible. The doses reached were higher in patients with peripheral compared to central tumors. This strategy enables good local control to be achieved at acceptable toxicity rates. However, dose escalation in centrally located tumors with direct invasion of mediastinal organs must be performed with great caution in order to avoid severe late toxicity.

Involved field radiotherapy (IFRT) versus elective nodal irradiation (ENI) for locally advanced non-small cell lung cancer: a meta-analysis of incidence of elective nodal failure (ENF)

Background and purpose

The use of involved field radiotherapy (IFRT) has generated concern about the increasing incidence of elective nodal failure (ENF) in contrast to elective nodal irradiation (ENI). This meta-analysis aimed to provide more reliable and up-to-date evidence on the incidence of ENF between IFRT and ENI.

Materials and methods

We searched three databases for eligible studies where locally advanced non-small cell lung cancer (NSCLC) patients received IFRT or ENI. Outcome of interest was the incidence of ENF. The fixed-effects model was used to pool outcomes across the studies.

Results

There were 3 RCTs and 3 cohort studies included with low risk of bias. There was no significant difference in incidence of ENF between IFRT and ENI either among RCTs (RR = 1.38, 95 % CI: 0.59–3.25, p = 0.46) or among cohort studies (RR = 0.99, 95 % CI: 0.46–2.10, p = 0.97). There was also no significant difference in incidence of ENF between IFRT and ENI when RCTs and cohort studies were combined (RR = 1.15, 95 % CI: 0.65–2.01, p = 0.64). I² of test for heterogeneity was 0 %.

Conclusion

This meta-analysis provides more reliable and stable evidence that there is no significant difference in incidence of ENF between IFRT and ENI.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-016-0698-3) contains supplementary material, which is available to authorized users.

Regional Lymph Node Uptake of [(18)F]Fluorodeoxyglucose After Definitive Chemoradiation Therapy Predicts Local-Regional Failure of Locally Advanced Non-Small Cell Lung Cancer: Results of ACRIN 6668/RTOG 0235

PURPOSE

The American College of Radiology Imaging Network (ACRIN) 6668/Radiation Therapy Oncology Group (RTOG) 0235 study demonstrated that standardized uptake values (SUV) on post-treatment [(18)F]fluorodeoxyglucose-positron emission tomography (FDG-PET) correlated with survival in locally advanced non-small cell lung cancer (NSCLC). This secondary analysis determined whether SUV of regional lymph nodes (RLNs) on post-treatment FDG-PET correlated with patient outcomes.

METHODS AND MATERIALS

Included for analysis were patients treated with concurrent chemoradiation therapy, using radiation doses ≥60 Gy, with identifiable FDG-avid RLNs (distinct from primary tumor) on pretreatment FDG-PET, and post-treatment FDG-PET data. ACRIN core laboratory SUV measurements were used. Event time was calculated from the date of post-treatment FDG-PET. Local-regional failure was defined as failure within the treated RT volume and reported by the treating institution. Statistical analyses included Wilcoxon signed rank test, Kaplan-Meier curves (log rank test), and Cox proportional hazards regression modeling.

RESULTS

Of 234 trial-eligible patients, 139 (59%) had uptake in both primary tumor and RLNs on pretreatment FDG-PET and had SUV data from post-treatment FDG-PET. Maximum SUV was greater for primary tumor than for RLNs before treatment (P<.001) but not different post-treatment (P=.320). Post-treatment SUV of RLNs was not associated with overall survival. However, elevated post-treatment SUV of RLNs, both the absolute value and the percentage of residual activity compared to the pretreatment SUV were associated with inferior local-regional control (P<.001).

CONCLUSIONS

High residual metabolic activity in RLNs on post-treatment FDG-PET is associated with worse local-regional control. Based on these data, future trials evaluating a radiation therapy boost should consider inclusion of both primary tumor and FDG-avid RLNs in the boost volume to maximize local-regional control.

[Forty years of progress in the therapeutic management of lung cancer]

This article reviews and describes the progress made in the therapeutic management of patients suffering from a lung cancer, outlining the major improvements made and suggesting some perspectives for the future.

Measurement of intra-fraction displacement of the mediastinal metastatic lymph nodes using four-dimensional CT in non-small cell lung cancer

Objective

To measure the intra-fraction displacements of the mediastinal metastatic lymph nodes by using four-dimensional CT (4D-CT) in non-small cell lung cancer (NSCLC).

Materials and Methods

Twenty-four patients with NSCLC, who were to be treated by using three dimensional conformal radiation therapy (3D-CRT), underwent a 4D-CT simulation during free breathing. The mediastinal metastatic lymph nodes were delineated on the CT images of 10 phases of the breath cycle. The lymph nodes were grouped as the upper, middle and lower mediastinal groups depending on the mediastinal regions. The displacements of the center of the lymph node in the left-right (LR), anterior-posterior (AP), and superior-inferior (SI) directions were measured.

Results

The mean displacements of the center of the mediastinal lymph node in the LR, AP, and SI directions were 2.24 mm, 1.87 mm, and 3.28 mm, respectively. There were statistically significant differences between the displacements in the SI and LR, and the SI and AP directions (p < 0.05). For the middle and lower mediastinal lymph nodes, the displacement difference between the AP and SI was statistically significant (p = 0.005; p = 0.015), while there was no significant difference between the LR and AP directions (p < 0.05).

Conclusion

The metastatic mediastinal lymph node movements are different in the LR, AP, and SI directions in patients with NSCLC, particularly for the middle and lower mediastinal lymph nodes. The spatial non-uniform margins should be considered for the metastatic mediastinal lymph nodes in involved-field radiotherapy.

Quantification of incidental mediastinal and hilar irradiation delivered during definitive stereotactic body radiation therapy for peripheral non-small cell lung cancer

To determine the amount of incidental radiation dose received by the mediastinal and hilar nodes for patients with non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). Fifty consecutive patients with NSCLC, treated using an SBRT technique, were identified. Of these patients, 38 had a prescription dose of 60 Gy in 20-Gy fractions and were eligible for analysis. For each patient, ipsilateral upper (level 2) and lower (level 4) paratracheal, and hilar (level 10) nodal regions were contoured on the planning computed tomography (CT) images. Using the clinical treatment plan, dose and volume calculations were performed retrospectively for each nodal region. SBRT to upper lobe tumors resulted in an average total ipsilateral mean dose of between 5.2 and 7.8 Gy for the most proximal paratracheal nodal stations (2R and 4R for right upper lobe lesions, 2L and 4L for left upper lobe lesions). SBRT to lower lobe tumors resulted in an average total ipsilateral mean dose of between 15.6 and 21.5 Gy for the most proximal hilar nodal stations (10R for right lower lobe lesions, 10 l for left lower lobe lesions). Doses to more distal nodes were substantially lower than 5 Gy. The often substantial incidental irradiation, delivered during SBRT for peripheral NSCLC of the lower lobes to the most proximal hilar lymph nodes may be therapeutic for low-volume, subclinical nodal disease. Treatment of peripheral upper lobe lung tumors delivers less incidental irradiation to the paratracheal lymph nodes with lower likelihood of therapeutic benefit.

[Radiotherapy of lung cancer: Any room left for elective mediastinal irradiation in 2011?]

Traditionally, the target volumes of curative-intent radiotherapy for non-small cell lung cancer include all uninvolved mediastinal nodes. However, an improvement in tumour control requires an increase of the total dose to the macroscopic target volume. This is only achievable if the irradiation of the organs at risk is reduced, i.e. elective irradiation of the mediastinum is omitted. The available data suggest that elective mediastinal irradiation may be safely omitted, provided that an adequate staging procedure, including FDG PET-CT, has been performed.

Thoracic radiotherapy for mediastinal nodal recurrence

Radiotherapy has been used to treat loco-regional recurrences located at various intra-thoracic sites, but long-term survival of these patients has been rarely observed. We report herein a lung adenocarcinoma patient with locoregional recurrence, who was successfully treated with high-dose radiotherapy. The patient could survive with no evidence of recurrence 5 years after thoracic irradiation. It is probably safe to administrate high-dose radiotherapy for some loco-regional recurrent patients with favorable prognostic factors such as good PS, no body weight loss. Further studies will be required to define a favorable subset of patients most likely to benefit from an aggressive approach.

Risk of isolated nodal failure for non-small cell lung cancer (NSCLC) treated with the elective nodal irradiation (ENI) using 3D-conformal radiotherapy (3D-CRT) techniques--a retrospective analysis

PURPOSE

To estimate retrospectively the rate of isolated nodal failures (INF) in NSCLC patients treated with the elective nodal irradiation (ENI) using 3D-conformal radiotherapy (3D-CRT).

MATERIALS/METHODS

One hundred and eighty-five patients with I-IIIB stage treated with 3D-CRT in consecutive clinical trials differing in an extent of the ENI were analyzed. According to the extent of the ENI, two groups were distinguished: extended (n = 124) and limited (n = 61) ENI. INF was defined as regional nodal failure occurring without local progression. Cumulative Incidence of INF (CIINF) was evaluated by univariate and multivariate analysis with regard to prognostic factors.

RESULTS

With a median follow up of 30 months, the two-year actuarial overall survival was 35%. The two-year CIINF rate was 12%. There were 16 (9%) INF, eight (6%) for extended and eight (13%) for limited ENI. In the univariate analysis bulky mediastinal disease (BMD), left side, higher N stage, and partial response to RT had a significant negative impact on the CIINF. BMD was the only independent predictor of the risk of incidence of the INF (p = 0.001).

CONCLUSIONS

INF is more likely to occur in case of more advanced nodal status.

Intra and interfraction mediastinal nodal region motion: implications for internal target volume expansions

The purpose of this study was to determine the intra and interfraction motion of mediastinal lymph node regions. Ten patients with nonsmall-cell lung cancer underwent controlled inhale and exhale computed tomography (CT) scans during two sessions (40 total datasets) and mediastinal nodal stations 1-8 were outlined. Corresponding CT scans from different sessions were registered to remove setup error and, in this reference frame, the centroid of each nodal station was compared for right-left (RL), anterior-posterior (AP), and superior-inferior (SI) displacement. In addition, an anisotropic volume expansion encompassing the change of the nodal region margins in all directions was used. Intrafraction displacement was determined by comparing same session inhale-exhale scans. Interfraction reproducibility of nodal regions was determined by comparing the same respiratory phase scans between two sessions. Intrafraction displacement of centroid varied between nodal stations. All nodal regions moved posteriorly and superiorly with exhalation, and inferior nodal stations showed the most motion. Based on anisotropic expansion, nodal regions expanded mostly in the RL direction from inhale to exhale. The interpatient variations in intrafraction displacement were large compared with the displacements themselves. Moreover, there was substantial interfractional displacement ( approximately 5 mm). Mediastinal lymph node regions clearly move during breathing. In addition, deformation of nodal regions between inhale and exhale occurs. The degree of motion and deformation varies by station and by individual. This study indicates the potential advantage of characterizing individualized nodal region motion to safely maximize conformality of mediastinal nodal targets.

[Stage IIIA and IIIB non-small cell lung cancer: results of chemotherapy combined with radiation therapy and analysis of prognostic factors]

OBJECTIVE

Most patients with stage III non-small cell lung cancer (NSCLC) are not candidates for surgery but can benefit from chemotherapy combined with radiation therapy. The objective of the present study was to analyze the results of sequential chemotherapy and radiation therapy and the prognostic value of initial clinical and laboratory variables.

PATIENTS AND METHODS

We carried out a retrospective study of 92 patients with stage III NSCLC treated with a sequential regimen of chemotherapy (carboplatin-etoposide, carboplatin-gemcitabine, and carboplatin-paclitaxel), and radiation therapy (6000 cGy in daily doses of 200 cGy, 5 d/wk). Response to therapy, overall survival, and the prognostic value of epidemiological, clinical, and laboratory variables were evaluated using univariate and multivariate analyses.

RESULTS

Median survival time was 14 months, with a 3-year survival rate of 16.1%. Poor performance status (score of 2 on the Eastern Cooperative Oncologic Group [ECOG] scale), anemia, and elevated serum concentrations of carcinoembryonic antigen were predictive of poorer survival in the multivariate analysis. In the univariate analysis, weight loss and diagnosis before the year 2000 were also associated with poorer prognosis (P<.01). TNM stage was not significantly correlated (P=.08). Toxicity was low, with 1 death and few cases of grade 3 or 4 toxicity according to World Health Organization criteria.

CONCLUSIONS

The use of chemotherapy combined with radiation therapy should be considered contraindicated in cases of poor performance status (ECOG scale score of 2). Weight loss, an elevated serum concentration of carcinoembryonic antigen, and a hemoglobin concentration of 12 g/dL or less carry a poor prognosis.

Involved-field radiation therapy for inoperable non small-cell lung cancer

PURPOSE

Dose escalation has been shown to improve local control in non-small-cell lung cancer (NSCLC) treated with definitive radiation therapy, but with increased complications. We implemented the use of involved-field radiotherapy (IFRT) in an effort to reduce toxicity while treating the gross tumor to higher doses. This analysis reports failure rates in uninvolved nodal regions with the use of IFRT.

PATIENTS AND METHODS

A total of 524 patients with NSCLC treated with three-dimensional conformal radiotherapy at Memorial Sloan-Kettering Cancer Center between 1991 and 2005 were reviewed. Only lymph node regions initially involved with tumor by either biopsy or radiographic criteria were included in the clinical target volume. Elective nodal failure (ENF) was defined as a recurrence in an initially uninvolved lymph node in the absence of local failure.

RESULTS

Only 32 patients (6.1%) with ENF were identified. The 2-year actuarial rates of elective nodal control and primary tumor control were 92.4% and 51%, respectively, with a median follow-up of 41 months in survivors. In patients who achieved local disease control, the 2-year elective nodal control rate was 91%. The median time to ENF was 6 months (range, 0 to 56 months). Many patients experienced treatment failure in multiple lymph node regions simultaneously.

CONCLUSION

The use of IFRT did not cause a significant amount of failure in lymph node regions not included in the tumor volume. Therefore, IFRT remains an acceptable method of treatment that allows for dose escalation while minimizing toxicity.

Improved local control without elective nodal radiotherapy in patients with unresectable NSCLC treated by 3D-CRT

To investigate the influence of prophylactic elective nodal irradiation on the therapeutic results of definitive radiotherapy for patients with stage IIIA or stage IIIB unresectable non-small-cell lung cancer, 55 patients with clinically inoperable advanced non-small-cell lung cancer were studied. After four cycles of induction chemotherapy, the patients were divided into two groups at random. In one group, the elective nodal irradiation was included in clinical tumor volume (CTV) of definitive radiotherapy (ENI group); and in the other group, elective nodal irradiation was not included in CTV (non-ENI group). For the patients in the ENI group, the mean prescription dose for gross tumor volumes was 58.4 Gy, while for the patients in the non-ENI group, it was 65.8 Gy (P < 0.05). The responsive rates were 45.8% and 74.0% (P < 0.05), and the rate of the elective nodal failure (ENF) was 4.2% and 11.1%, respectively. Kaplan-Meier analysis showed that the mean local-progression-free survival time was 11.0 and 15.0 months, and one-year local-failure rates were 51.9% and 24.5% (P < 0.05). The median overall survival time was 13.0 and 15.0 months, respectively (P = 0.084). The one-year survival rates were 55.7% and 72.5%, and two-year survival rates were 0% and 19.9%. There was no significant difference in the occurrences of radiation-associated complications between the two groups. Our results showed that omitting elective nodal irradiation did not result in a high incidence of elective nodal failure. On the contrary, it decreased local failure by increasing prescription doses to the primary diseases and lymphadenopaphy, and thereby it may further prolong the patients' survival.

[Progress in radiation therapy and integration in Tenon hospital (AP-HP) of new advances in routine practices of radiotherapy for non-small-cell lung cancer]

Much progress has been made in recent years in administration modalities for external radiotherapy of non-small-cell lung carcinoma. Three-dimensional conformal radiotherapy with or without intensity modulation, with respiratory gated radio-therapy (4D radiotherapy), and image-guided radiotherapy (IGRT) can be considered as a third revolution in radiation therapy after total dose fractionation and the development of megavoltage radiation therapy equipment. We describe progress in the three-dimensional radiotherapy technique and the integration of this technique in the department of Radiation Oncology at Tenon hospital (AP-HP).

Cancers bronchiques : la radiothérapie prophylactique des aires ganglionnaires a-t-elle encore une place ?

The use of conformal radiotherapy in lung cancer has considerably evolved with the advent of improved staging technologies and methods of radiation delivery. Patients with limited disease, inoperable for medical reasons, may be treated with conformal radiotherapy alone; patients with more advanced disease are treated with combined chemo-radiotherapy. If local control may be improved by radiotherapy dose escalation according to several studies, toxicity and more particularly pulmonary toxicity seems to be related to radiation volume. Thus the use of elective nodal irradiation is being questioned. Data for early stage (stage I) non-small-cell lung cancer treated with conformal radiotherapy or stereotactic hypofractionated radiotherapy strongly supports the use of smaller fields that do not incorporate elective nodal regions; local control and survival rates approach those of surgical series. In locally advanced non-small cell lung cancer, eliminating elective nodal irradiation allows to maximize tumor dose and minimize normal tissue toxicity in combined modality treatments; results are encouraging. The use of staging modalities such as positron emission tomography and eventually oesophageal ultrasonography is increasing, allowing to encompass the tumor volume with more accuracy. Several studies have confirmed that involved-field irradiation results into a regional nodal rate of less than 10%. Further larger-scale studies would be needed to definitely establish "no elective nodal irradiation" as a standard in non-small cell lung cancer. There are very few data concerning small cell lung cancer.

Induction cisplatin-gemcitabine-paclitaxel plus concurrent radiotherapy and gemcitabine in the multimodality treatment of unresectable stage IIIB non-small cell lung cancer

BACKGROUND

To evaluate feasibility and safety of induction three-drugs combination chemotherapy and concurrent radio-chemotherapy in stage IIIB NSCLC.

PATIENTS AND METHODS

Patients with stage IIIB NSCLC were treated with three courses of induction chemotherapy, cisplatin 50 mg/m(2), paclitaxel 125 mg/m(2) and gemcitabine 1000 mg/m(2) on days 1,8 of every 21 day cycle. Patients without distant progressive disease were then treated with radiotherapy and concurrent weekly gemcitabine (250 mg/m(2)). Toxicity and response of radio-chemotherapy treatment have been assessed.

RESULTS

Between Jan 01 and Nov 02, 46 patients were enrolled. Grade 3+ hematological and non-hematological toxicity during the induction phase were 41.3% and 13.1%, respectively. In 38 patients a Clinical Response or Stable Disease was recorded and these patients underwent to concurrent radio-chemotherapy. Grade 3+ hematological and non-hematological toxicities were 8.2% in this group. Further response was observed in 66% of patients. Overall median survival time was 17.8 months, with a 3-year survival rates of 23%.

CONCLUSION

Three-drugs induction chemotherapy and concurrent radio-chemotherapy with weekly gemcitabine in locally advanced stage IIIB NSCLC is feasible and safe.

Omission of elective node irradiation on basis of CT-scans in patients with limited disease small cell lung cancer: a phase II trial

PURPOSE

To evaluate the patterns of recurrence when elective node irradiation was omitted in patients with limited disease small cell lung cancer (LD-SCLC).

METHODS

A prospective phase II study was undertaken in 27 patients with LD-SCLC without detectable distant metastases on CT scan. Chest radiotherapy to a dose of 45 Gy in 30 fractions in 3 weeks (1.5 Gy BID with 6 - 8 h interval) was delivered concurrently with carboplatin and etoposide chemotherapy. Chest radiation started after a mean time of 17.7 days +/- 9.7 days (SD) (range: 0-33 days) after the beginning of chemotherapy. Only the primary tumour and the positive nodal areas on the pre-treatment CT scan were irradiated. A total of five chemotherapy cycles were administered, followed by prophylactic cranial irradiation (PCI) in patients without disease progression. Isolated nodal failure was defined as recurrence in the regional nodes outside of the clinical target volume, in the absence of in-field failure.

RESULTS

After a median time of 18 months post-radiotherapy, 7 patients (26%, 95% CI 19.5-42.5%) developed a local recurrence. Three patients (crude rate 11%, 95% CI 2.4-29%), developed an isolated nodal failure, all of them in the ipsilateral supraclavicular fossa. The median actuarial overall survival was 21 months (95% CI 15.3-26.7), and the median actuarial progression free survival was 16 months (95% CI 6.5-25.5). Eight patients developed an acute, reversible grade 3 (CTC 3.0) radiation oesophagitis (30%, 95% CI 14-50%).

CONCLUSIONS

Because of the small sample size, no definitive conclusions can be drawn. However, the omission of elective nodal irradiation on the basis of CT scans in patients with LD-SCLC resulted in a higher than expected rate of isolated nodal failures in the ipsilateral supraclavicular fossa. The incidence of acute, reversible oesophagitis was in the same range as reported with elective nodal fields. The safety of selective nodal irradiation in NSCLC should not be extrapolated to patients with LD-SCLC until more data are available. In the mean time, elective nodal irradiation should only be omitted in clinical trials.

Chemo-radiotherapy in non-small cell lung cancer: the role of gemcitabine

Gemcitabine (2'-2'-difluorodeoxycytidine) is a well-known cytotoxic drug and a potent radio-enhancer. We herein report the in vitro evidence of its activity, and the clinical experiences when this drug is administered concurrently with radiation. The phase I-II trials are analyzed, focusing on the recent ability to deliver irradiation with low incidence of side effects.

Probability of mediastinal involvement in non–small-cell lung cancer: a statistical definition of the clinical target volume for 3-dimensional conformal radiotherapy?

PURPOSE

Conformal irradiation (3D-CRT) of non-small-cell lung carcinoma (NSCLC) is largely based on precise definition of the nodal clinical target volume (CTVn). A reduction of the number of nodal stations to be irradiated would facilitate tumor dose escalation. The aim of this study was to design a mathematical tool based on documented data to predict the risk of metastatic involvement for each nodal station.

METHODS AND MATERIALS

We reviewed the large surgical series published in the literature to identify the main pretreatment parameters that modify the risk of nodal invasion. The probability of involvement for the 17 nodal stations described by the American Thoracic Society (ATS) was computed from all these publications. Starting with the primary site of the tumor as the main characteristic, we built a probabilistic tree for each nodal station representing the risk distribution as a function of each tumor feature. Statistical analysis used the inversion of probability trees method described by Weinstein and Feinberg. Validation of the software based on 134 patients from two different populations was performed by receiver operator characteristic (ROC) curves and multivariate logistic regression.

RESULTS

Analysis of all of the various parameters of pretreatment staging relative to each level of the ATS map results in 20,000 different combinations. The first parameters included in the tree, depending on tumor site, were histologic classification, metastatic stage, nodal stage weighted as a function of the sensitivity and specificity of the diagnostic examination used (positron emission tomography scan, computed tomography scan), and tumor stage. Software is proposed to compute a predicted probability of involvement of each nodal station for any given clinical presentation. Double cross validation confirmed the methodology. A 10% cutoff point was calculated from ROC and logistic model giving the best prediction of mediastinal lymph node involvement.

CONCLUSION

To more accurately define the CTVn in NSCLC three-dimensional conformal radiotherapy, we propose a software that evaluates the risk of mediastinal lymph node involvement from easily accessible individual pretreatment parameters.

Re-Examining the Role of Elective Nodal Irradiation

OBJECTIVE

Elective nodal irradiation (ENI) of regional lymphatics has been a foundational paradigm for radiation oncologists in the treatment of nonsmall-cell lung cancer (NSCLC), but its utility has recently been called into question. This review summarizes the controversies surrounding ENI and reviews the therapeutic options available to treat regional lymphatics in NSCLC.

METHODS

Local failure after conventional radiotherapy (RT) occurs in 40% to 80% of patients fueling the investigation of more aggressive RT regimens. As the dose is increased and accelerated the volume of normal lung tissue treated becomes a limiting factor. Thus elimination of ENI followed by further dose escalation has become a commonly pursued solution. When ENI is excluded, treatment is restricted to clinically positive disease and negative lymph node stations are left untreated.

RESULTS

Radiographic and surgical data suggest our ability to determine the true extent of disease is imperfect and therefore the elimination of ENI likely leaves microscopic NSCLC untreated.

CONCLUSIONS

At our institution we have concluded that the prophylactic treatment of regional lymph nodes is best reserved for patients most likely to achieve local control and are designing treatment protocols including chemotherapy to take advantage of this improvement in local control.

Impact of intensity-modulated radiation therapy as a boost treatment on the lung–dose distributions for non–small-cell lung cancer

PURPOSE

To investigate the feasibility of intensity-modulated radiotherapy (IMRT) as a method of boost radiotherapy after the initial irradiation by the conventional anterior/posterior opposed beams for centrally located non-small-cell lung cancer through the evaluation of dose distributions according to the various boost methods.

METHODS AND MATERIALS

Seven patients with T3 or T4 lung cancer and mediastinal node enlargement who previously received radiotherapy were studied. All patients underwent virtual simulation retrospectively with the previous treatment planning computed tomograms. Initial radiotherapy plans were designed to deliver 40 Gy to the primary tumor and involved nodal regions with the conventional anterior/posterior opposed beams. Two radiation dose levels, 24 and 30 Gy, were used for the boost radiotherapy plans, and four different boost methods (a three-dimensional conformal radiotherapy [3DCRT], five-, seven-, and nine-beam IMRT) were applied to each dose level. The goals of the boost plans were to deliver the prescribed radiation dose to 95% of the planning target volume (PTV) and minimize the volumes of the normal lungs and spinal cord irradiated above their tolerance doses. Dose distributions in the PTVs and lungs, according to the four types of boost plans, were compared in the boost and sum plans, respectively.

RESULTS

The percentage of lung volumes irradiated >20 Gy (V20) was reduced significantly in the IMRT boost plans compared with the 3DCRT boost plans at the 24- and 30-Gy dose levels (p = 0.007 and 0.0315 respectively). Mean lung doses according to the boost methods were not different in the 24- and 30-Gy boost plans. The conformity indexes (CI) of the IMRT boost plans were lower than those of the 3DCRT plans in the 24- and 30-Gy plans (p = 0.001 in both). For the sum plans, there was no difference of the dose distributions in the PTVs and lungs according to the boost methods.

CONCLUSIONS

In the boost plans the V20s and CIs were reduced significantly by the IMRT plans, but in the sum plans the effects of IMRT on the dose distributions in the tumor and lungs, like CI and V20, were offset. Therefore, to keep the beneficial effect of IMRT in radiotherapy for lung cancer, it would be better to use IMRT as a whole treatment plan rather than as a boost treatment.

Treatment-related esophagitis

Current therapeutic approaches for lung cancer favor treatment intensification, with the presumption that dose-intense chemotherapy regimens and/or higher radiation therapy (RT) doses or novel fractionation schemes will result in increased patient survival. Also, the trend for non-operative therapy has favored concurrent over sequential regimens. The incidence of severe acute esophagitis in patients treated for lung cancer with standard (once daily) RT alone is 1.3%, and induction chemotherapy increases the risk of severe acute esophagitis slightly over that of standard RT alone. In contrast, a strong radiosensitizing effect of chemotherapy given concurrently with standard thoracic RT (chemoRT) is associated with an incidence of severe esophagitis of 14% to 49%. Acute esophagitis may be severe and disabling, and result in hospitalization, placement of a feeding tube in the stomach or intravenous feedings, and steady supportive care. Also, RT may need to be halted temporarily to allow for healing of the esophageal lining; treatment breaks in turn decrease survival of patients with unresectable lung cancer. Therefore, esophagitis as a dose-limiting toxicity of chemoRT may have a direct impact on tumor control and survival. Aggressive types of RT fractionation have also been associated with worsening esophagitis grades and duration. Moreover, it is commonly assumed in the radiation oncology clinic that the longer the length of the esophagus segment included in the RT field the higher the probability of esophageal toxicity, although differing opinions are commonly expressed. Recent advances in 3-dimensional conformal RT allow a unique chance to gain volumetric data pertaining to organ damage rather than rely on older estimates based on organ length (eg, esophagus) or portion (ie, lung, spinal cord). The Radiation Therapy Oncology Group (RTOG) conducted a large phase III, randomized study RTOG 98-01 examining chemoRT with or without the amifostine (Ethyol; MedImmune, Inc, Gaithersburg, MD), a cyto- and radioprotectant in locally advanced non-small cell lung cancer (n = 243). While amifostine did not significantly reduce severe esophagitis based on National Cancer Institute Common Toxicity Criteria and weekly physician dysphagia logs, swallowing dysfunction over time (based on patient diaries, the equivalent of Esophagitis Index) was significantly lower in the amifostine arm ( P = .03). Therefore, significant progress has been accomplished in our understanding of the basis of esophageal injury resulting from thoracic RT, and future effort may find other effective strategies to either minimize or eliminate esophagitis.

Concurrent chemoradiotherapy with low dose weekly gemcitabine in stage III non-small cell lung cancer

Background

Combined chemoradiotherapy (CRT) is the treatment of choice for stage III NSCLC. Gemcitabine (G) is a novel deoxycitidine analogue that has been proven to be a potent radiosensitizer. Twenty-two consecutive patients were treated with concurrent CRT to demonstrate the tolerability and efficacy of low dose G given weekly as radiosensitizer in stage III NSCLC.

Methods

Patients with KPS ≥70, adequate bone marrow reserve, with no prior radiotherapy (RT) and surgery were included. Eighteen patients had received prior induction chemotherapy (CT). G (75 mg/m²/week) was infused over 1 hour for 6 weeks. Thoracic RT was given two hours later over 6 weeks at 1.8 Gy/day fractions (total dose of 61.2 Gy). Pulmonary toxicity was evaluated with computed tomography scans in 6 weeks.

Results

Median age was 60 years (range, 48–75), median follow-up was 15 months (range, 2–40). Sixty-eight percent of patients were male and median KPS score was 90. Conformal 3D-RT planning was used in 64% of patients. G was given for a median of 5 weeks (range 1–9). Twelve patients (54.6%) received all planned CT. G was stopped because of intolerance in 6 and death in 2 patients. Seven patients (31.8%) had radiation pneumonitis. Twenty patients were evaluated for overall response, 1 patient (4.5%) had clinical CR, 81.8% had PR while 9.5% had SD. Median overall survival (OS) was 14 ± 5 months (95% CI 3–25). One- and 2-year OS rates were 55% and 38%. Sixteen patients died of disease-related events (6 with progression of primary tumor, 8 due to metastatic disease), 2 patients died of other causes. One- and 2-year progression-free survival and local control rates were 56%, 27% and 79%, 51%, respectively.

Conclusion

G might be used as radiosensitizer for patients with stage III NSCLC who could not receive full doses CT with concurrent RT.

Selective mediastinal node irradiation based on FDG-PET scan data in patients with non–small-cell lung cancer: A prospective clinical study

PURPOSE

To evaluate the patterns of recurrence when selective mediastinal node irradiation based on FDG-PET scan data is used in patients with non-small-cell lung cancer (NSCLC).

METHODS AND MATERIALS

A prospective Phase I/II study was undertaken on 44 patients with NSCLC without detectable distant metastases on CT and FDG-PET scan, delivering either 61.2 Gy in 34 fractions over 23 days or 64.8 Gy in 36 fractions over 24 days (1.8 Gy b.i.d. with 8-h interval). Only the primary tumor and the positive mediastinal areas on the pretreatment FDG-PET scan were irradiated. Isolated nodal failure was defined as recurrence in the regional nodes outside of the clinical target volume, in the absence of in-field failure.

RESULTS

The CT and FDG-PET stage distribution was as follows: Stage I: 8 patients (18%) and 13 patients (29%); Stage II: 6 patients (14%) and 10 patients (23%); Stage IIIA: 15 patients (34%) and 7 patients (16%); Stage IIIB: 15 patients (34%) and 14 patients (32%), respectively. After a median follow-up time of 16 months (95% confidence interval [CI], 11-21 months) postradiotherapy, 11 patients (25%) developed a local recurrence. Only 1 patient (crude rate, 2.3%; upper bound of 95% CI, 10.3%), with a Stage II tumor on both CT and PET, developed an isolated nodal failure. The median actuarial overall survival was 21 months (95% CI, 14-28 months), and the median actuarial progression-free survival was 18 months (95% CI, 12-24 months).

CONCLUSIONS

Selective mediastinal node irradiation based on FDG-PET scan data in patients with NSCLC results in low isolated nodal failure rates. In the Phase I component of this trial, radiation dose escalation up to 64.8 Gy in 36 fractions over 24 days is feasible.

Phase II study of radiotherapy with three-dimensional conformal boost concurrent with paclitaxel and cisplatin for Stage IIIB non–small-cell lung cancer

PURPOSE

To evaluate the efficacy and toxicity of concurrent chemoradiotherapy with paclitaxel/cisplatin for Stage IIIB locally advanced non-small-cell lung cancer (NSCLC).

METHODS AND MATERIALS

Radiotherapy was administered to a total dose of 70.2 Gy (daily fraction of 1.8 Gy, 5 days/wk), over an 8-week period, combined with chemotherapy. The chemotherapy consisted of weekly 40 mg/m2 of paclitaxel plus 20 mg/m2 of cisplatin for 8 consecutive weeks. All patients received three-dimensional conformal radiotherapy (3D-CRT), based on computed tomography simulated planning after 41.4 Gy. The median follow-up period of survivors was 24 months.

RESULTS

Between January 2000 and October 2002, 135 patients with a median age of 60 years were enrolled and analyzed in this prospective trial. The overall response rate was 75% including 2 cases of complete response. The major patterns of failure were local failure and distant metastasis. The 2-year overall and progression-free survival rates were 37% and 18%, respectively. The median overall and progression-free survival times were 17 months and 9 months, respectively. Hematologic toxicity >Grade 2 was observed in 19% of patients and severe non-hematologic toxicity was infrequent.

CONCLUSIONS

Three-dimensional conformal radiotherapy, combined with paclitaxel and cisplatin chemotherapy, was associated with a satisfactory outcome with manageable toxicity. Further investigations are needed to improve the local control.

Strategies for enhanced radiation delivery in patients with lung cancer

Since the 1970s primary management for regionally advanced non-small cell lung cancer has shifted from radiotherapy alone to sequential chemoradiation to concurrent chemoradiation. The increase in survival with these approaches has been small; an approximately 3-4 month per decade increase in median survival. Future avenues to improve on these outcomes could involve: i)dose-intense radiotherapy; ii) better target delineation; and iii) combining molecularly targeted agents with optimised radiation therapy. However, to accomplish this, techniques to control tumour motion and decrease toxicity must be developed.

Are More Aggressive Therapies Able to Improve Treatment of Locally Advanced Non-Small Cell Lung Cancer: Combined Modality Treatment?

Non-small cell lung cancer continues to be a major oncologic problem, with approximately 3-month increase in median survival per decade since the 1970s. Thus, newer strategies are needed to improve outcomes in non-small cell lung cancer. New treatment strategies include optimizing and intensifying radiation therapy (RT) delivery, as well as improving systemic therapy with newly developed targeted agents. Three-dimensional treatment planning is a key technology for optimizing RT delivery. Additionally, improvements in radiation therapy will clearly require better target delineation and dose-intensification of RT. With newer, possibly less toxic agents such as the epidermal growth factor receptor inhibitors, RT and systemic therapy (with chemo- and/or targeted therapies) may be optimized in the concurrent setting, perhaps reserving more cytotoxic regimens either for the induction or maintenance settings.

How can we further improve radiotherapy for stage-III non-small-cell lung cancer?

Combined modality treatment in advanced NSCLC has produced some gain in treatment outcome. Local control as addressed by radiotherapy is still a significant site of failure. Doses higher than achieved by conventional conformal radiotherapy are shown to result in better control rates. Volume restriction seems to be the most important issue in dose escalation. Integration of PET imaging into target definition, omission of clinically uninvolved lymph-node areas and measures to decrease set-up and movement uncertainties are explored. Introduction of risk estimation based on dose-volume analysis for dose prescription may further optimise individual treatment.

A treatment planning study evaluating a 'simultaneous integrated boost' technique for accelerated radiotherapy of stage III non-small cell lung cancer

PURPOSE

As local tumour control is poor in stage III non-small cell lung cancer (NSCLC), a radiotherapy planning study was performed to evaluate the potential for treatment acceleration by using a simultaneous integrated boost (SIB) technique in patients who had completed induction chemotherapy.

METHODS AND MATERIALS

Co-registered pre- and post-chemotherapy planning CT scans from 10 patients who showed tumour regression after induction chemotherapy were used to compare different treatment schedules: (a) a sequential boost plan delivering, in 2 Gy per fraction, 50 Gy to the pre-chemotherapy tumour volume, followed by a sequential boost of 20 Gy to the post-chemotherapy tumour volume; (b) a SIB technique in which the pre- and post-chemotherapy tumour volumes were treated to different dose levels during each treatment fraction using identical total doses and number of fractions as above; (c) progressively more hypofractionated schedules that delivered the SIB technique in 25 and 20 once-daily fractions; (d) the actual clinical treatment plan in which 70 Gy was delivered to the pre-chemotherapy tumour volume in 35 daily fractions. Differences in the fractionation schemes used for these plans were accounted for by using the normalised total dose (NTD) for comparison, thereby assuming an alpha/beta ratio of 10 Gy for tumour and 3 Gy for normal tissues. The risk of normal tissue toxicity was estimated using the average lung NTD, the lung volume receiving NTD > 20 Gy, the oesophageal volume receiving NTD > 50 Gy, and the length of full circumference irradiated to at least 50 Gy.

RESULTS

With respect to the sequential boost technique, the SIB technique improved the sparing of the normal tissues in all patients. In most patients, the SIB plan could also be delivered in 25 fractions without increasing the estimated normal tissue toxicity. With SIB25, the mean lung NTD was reduced from 12.1 to 11.7 Gy, and the fraction of healthy lung tissue receiving NTD > 20 Gy by 2% on average. Although the length and volume of oesophagus irradiated to at least 50 Gy increased for some of the patients, the observed values were less than that was the case for the actual delivered treatment. However, special care should be taken to avoid exceeding the spinal cord tolerance in patients whose tumours are located close to the cord.

CONCLUSIONS

A SIB technique that delivers at least 50 Gy to the pre-chemotherapy tumour volume permits accelerated radiotherapy in patients with stage III NSCLC without increasing the expected risks of normal tissue toxicity. By reducing the overall treatment time, the SIB technique may improve local tumour control and survival.