The evolution of Radiation Therapy Oncology Group (RTOG) protocols for nonsmall cell lung cancer

Nonstandard Fractionation Schedules in Radiation Therapy of Head and Neck Cancer: A Review

The authors present an updated review of the clinical trials on hyperfractionated and accelerated fractionation schedules in radiotherapy of head and neck cancer. The available results in terms of survival and local control, and acute and late toxicity data are summarized in order to show the current status of this research field. The new breed of fractionation schedules that are on study, designed on the ground of new rationales, are presented as well. Finally, an introductory overview of combination therapy including non standard fractionation radiotherapy associated with chemotherapy is reported70.

Radiation therapy in locally advanced non-small-cell lung cancer: an overview of dose/fractionation strategies to improve outcomes

SUMMARY Local disease control and survival rates of locally advanced non-small-cell lung cancer patients are still poor, even with the best combination of chemotherapy and radiotherapy. Radiotherapy dose is believed to play a major role in controlling local disease, due a steep dose–response relationship for lung cancer, and therefore there is a strong biological rationale to escalate/accelerate the dose. In previous years, several prospective trials explored this option and obtained contrasting results, and recent technical advances in radiotherapy raise the issue of which approach should be considered the most appropriate for future studies. In this article, we briefly review selected prospective Phase I–III trials testing escalation/altered fractionation and focus on future perspectives in this field.

Toxicity and outcome of a phase II trial of taxane-based neoadjuvant chemotherapy and 3-dimensional, conformal, accelerated radiotherapy in locally advanced nonsmall cell lung cancer

BACKGROUND

The objective of this study was to evaluate prospectively the acute and late adverse effects of taxane/carboplatin neoadjuvant chemotherapy and 3-dimensional, conformal radiotherapy in patients with locally advanced nonsmall cell lung cancer (NSCLC).

METHODS

Forty-two patients were entered into a nonrandomized Phase II study of continuous, hyperfractionated, accelerated radiotherapy (CHART) week-end less (CHARTWEL) to a dose of 60 grays (Gy). Three cycles of chemotherapy were given over 9 weeks before radiotherapy. Dose escalation with paclitaxel was from 150 mg/m2 to 225 mg/m2. Systemic toxicity to chemotherapy was monitored throughout. Radiation-induced, early, adverse effects were assessed during the first 9 weeks from the start of radiotherapy, and late effects were assessed from 3 months onward. Overall survival, disease-free survival, and locoregional tumor control also were monitored.

RESULTS

Twenty percent of patients failed to receive chemotherapy as planned, primarily because of neutropenia. The incidence of Dische Dictionary Grade >or=2 and Grade >or=3 dysphagia was 57.5% and 10%, respectively, with an average duration of 1.2 weeks and 1.5 days, respectively. By 9 weeks, <3% of patients were symptomatic; and, eventually, all acute reactions were healed, and there has been no evidence of consequential damage. At 6 months, the actuarial incidence of moderate-to-severe pneumonitis was 10%. During this time, all patients were free of severe pulmonary complications. Actuarial estimates of Grade >or=2 late lung dysfunction were 3% at 1 year, 10% at 2 years, and remained at this level thereafter. The actuarial 3-year locoregional control and overall survival rates were 54% and 45%, respectively.

CONCLUSIONS

Neoadjuvant chemotherapy followed by 3-dimensional, conformal CHARTWEL 60-Gy radiotherapy in patients with advanced NSCLC was feasible and was tolerated well. Historic comparisons indicated that locoregional tumor control is not compromised by the use of conformal techniques.

Effect of overall treatment time on outcomes after concurrent chemoradiation for locally advanced non-small-cell lung carcinoma: analysis of the Radiation Therapy Oncology Group (RTOG) experience

PURPOSE

To determine whether overall treatment time affects outcomes after definitive concurrent chemoradiotherapy for locally advanced non-small-cell lung carcinoma (NSCLC).

METHODS AND MATERIALS

Data were analyzed from 3 prospective Radiation Therapy Oncology Group trials (RTOG 91-06, 92-04, and 94-10) in which immediate concurrent chemoradiation (cisplatin-based) was the primary therapy for good-performance status Stage III (and selected inoperable Stage II) NSCLC. "Short" overall treatment time (per protocol) was defined as completing treatment within 5 days of plan; other patients were considered to have had "prolonged" treatment time (protocol violation); treatment time was also analyzed as a continuous variable in a multivariate model. Actuarial analysis was performed for overall survival, progression-free survival, freedom from local-regional progression, and toxicity.

RESULTS

A total of 474 patients were analyzed. Median follow-up for surviving patients was 6.1 years. Treatment time was delivered per protocol in 387 (82%), whereas 87 patients (18%) had a prolonged treatment time. Long treatment time was significantly associated with severe acute esophagitis. Median survival was slightly better in patients completing treatment on time (19.5 months vs. 14.8 months), but this did not reach statistical significance (p = 0.15) in the univariate analysis. However, in the multivariate analysis of treatment time as a continuous variable, prolonged treatment time was significantly associated with poorer survival (p = 0.02), indicating a 2% increase in the risk of death for each day of prolongation in therapy. Histology (squamous fared worse) and performance status were also significant in the multivariate model.

CONCLUSIONS

This retrospective analysis demonstrates a correlation between prolonged overall radiotherapy treatment time and survival in patients with locally advanced NSCLC, even when concurrent chemotherapy is used. Further study of novel radiation-chemotherapy dose/fractionation regimens is warranted.

Two commonly used neoadjuvant chemoradiotherapy regimens for locally advanced stage III non–small cell lung carcinoma: long-term results and associations with pathologic response

BACKGROUND

We performed this study to determine the outcomes (pathologic response, survival, local-regional control, and toxicity) in patients treated with neoadjuvant chemoradiotherapy and planned operation for stage IIIA non-small cell lung carcinoma.

METHODS

Patients treated from 1993 to 2000 with neoadjuvant chemoradiotherapy and a predetermined plan for subsequent surgical resection for stage III non-small cell lung carcinoma were analyzed. All patients underwent pretreatment evaluation at the university's Multidisciplinary Lung Cancer Center. Most patients (87%) had complete mediastinoscopy staging, and all were believed to be poor candidates for up-front operation because of bulky extent of disease. The radiotherapy program used conventional, 2-dimensionally planned treatment to 45 to 54 Gy in 1.8- to 2-Gy fraction size. Concurrent chemotherapy consisted of etoposide/cisplatin or carboplatin/paclitaxel. Study end points included resectability, pathologic response, local-regional control, survival, and toxicity. An exploratory comparison between pathologic response and long-term survival was performed. An exploratory comparison between older chemotherapy (etoposide/cisplatin) and third-generation chemotherapy (carboplatin/paclitaxel) was also performed.

RESULTS

Of 53 patients, 45 (85%) were deemed surgical candidates after induction therapy. Twenty-two (42% of the initial cohort) patients had a major pathologic response to stage 0, I, or II disease. The 5-year actuarial survival was 31%. Major pathologic response was associated with improved survival (48% vs 24%; P =.027). The overall rate of early death potentially related to therapy in this series was 9%; this mostly occurred in patients who underwent right pneumonectomy. There was no difference in efficacy or mortality between etoposide/cisplatin and radiotherapy versus carboplatin/paclitaxel and radiotherapy, although the latter regimen was associated with less grade 3 or higher acute toxicity necessitating interruption or hospitalization during neoadjuvant treatment (P =.02). In-field local control was achieved in 83% of all patients (90% of the patients who underwent resection). Brain metastases as the first site of treatment failure occurred in 23% of all patients.

CONCLUSIONS

Neoadjuvant concurrent chemoradiation delivers high resectability, major pathologic response rate, and excellent local-regional control, with encouraging long-term survival considering the patient population studied. Major pathologic response correlates with long-term survival. Neoadjuvant carboplatin/paclitaxel and radiotherapy is an appropriate framework on which to add new therapies.

Portal imaging to assess set-up errors, tumor motion and tumor shrinkage during conformal radiotherapy of non-small cell lung cancer

PURPOSE

To investigate patient set-up, tumor movement and shrinkage during 3D conformal radiotherapy for non-small cell lung cancer.

MATERIALS AND METHODS

In 97 patients, electronic portal images (EPIs) were acquired and corrected for set-up using an off-line correction protocol based on a shrinking action level. For 25 selected patients, the orthogonal EPIs (taken at random points in the breathing cycle) throughout the 6-7 week course of treatment were assessed to establish the tumor position in each image using both an overlay and a delineation technique. The range of movement in each direction was calculated. The position of the tumor in the digitally reconstructed radiograph (DRR) was compared to the average position of the lesion in the EPIs. In addition, tumor shrinkage was assessed.

RESULTS

The mean overall set-up errors after correction were 0, 0.6 and 0.2 mm in the x (left-right), y (cranial-caudal) and z (anterior-posterior) directions, respectively. After correction, the standard deviations (SDs) of systematic errors were 1.4, 1.5 and 1.3 mm and the SDs of random errors were 2.9, 3.1 and 2.0 mm in the x-, y- and z-directions, respectively. Without correction, 41% of patients had a set-up error of more than 5 mm vector length, but with the set-up correction protocol this percentage was reduced to 1%. The mean amplitude of tumor motion was 7.3 (SD 2.7), 12.5 (SD 7.3) and 9.4 mm (SD 5.2) in the x-, y- and z-directions, respectively. Tumor motion was greatest in the y-direction and in particular for lower lobe tumors. In 40% of the patients, the projected area of the tumor regressed by more than 20% during treatment in at least one projection. In 16 patients it was possible to define the position of the center of the tumor in the DRR. There was a mean difference of 6 mm vector length between the tumor position in the DRR and the average position in the portal images.

CONCLUSIONS

The application of the correction protocol resulted in a significant improvement in the set-up accuracy. There was wide variation in the observed tumor motion with more movement of lower lobe lesions. Tumor shrinkage was observed. The position of the tumor on the planning CT scan did not always coincide with the average position as measured during treatment.

Subsets more likely to benefit from surgery or prophylactic cranial irradiation after chemoradiation for localized non-small-cell lung cancer

After chemoradiation for localized non-small-cell lung cancer, surgery and prophylactic cranial irradiation (PCI) have been used as additional therapies. Less than a third of patients develop brain recurrences, or have local recurrence as their sole initial site of recurrence; these are groups that would benefit from PCI or surgery, respectively. Pretreatment identification of patients more likely to benefit from surgery or PCI would be useful. A retrospective analysis of 80 patients was performed to determine prognostic factors for such patterns of failure. Twenty-nine patients were subsequently selected for surgery in a nonrandomized manner. Seventeen patients had isolated local initial recurrence and 15 had brain recurrences. In multivariable analysis, female gender and elevated LDH were found to be risk factors for brain recurrence. In the subset with stage III disease (n = 76), squamous cell histology was a risk factor for isolated initial local recurrence in both univariable and multivariable analysis. It is possible to identify subsets that may show increased benefit from PCI or surgery.

Comorbidity and Karnofksy performance score are independent prognostic factors in stage III non-small-cell lung cancer: an institutional analysis of patients treated on four RTOG studies

PURPOSE

To determine the prognostic role of comorbidity in Stage III non-small cell lung cancer (NSCLC) treated definitively with radiotherapy alone.

METHODS AND MATERIALS

A total of 112 patients with clinical Stage III NSCLC (American Joint Commission on Cancer 1997) enrolled in four Radiation Therapy Oncology Group studies (83-11, 84-03, 84-07, and 88-08 nonchemotherapy arms) at a single institution were analyzed retrospectively for overall survival (OS) and comorbidity. Of the 112 patients, 105 (94%) completed their assigned radiotherapy. The median assigned dose was 50.4 Gy to the lymphatics (range 45-50.4 Gy) and 70.2 Gy to the primary tumor (range 60-79.2 Gy). Comorbidity was rated retrospectively using the Cumulative Illness Rating Scale for Geriatrics (CIRS-G) and Charlson scales. Karnofsky performance scores (KPSs) and weight loss were prospectively recorded. Because only 8 patients had a KPS of <70, these patients were combined with patients who had a KPS of 70. The OS of this group was compared with that of the patients with better KPSs (>70).

RESULTS

The median survival was 10.39 months (range 7.87-12.91). The 2-, 3-, and 5-year OS rate was 20.5%, 12.5%, and 7.1%, respectively. On univariate analysis, clinical stage (IIIA vs. IIIB) was found to be a statistically significant factor influencing OS (p = 0.026), and the histologic features, grade, tumor size as measured on CT scans, age, tobacco use, weight loss >or=5%, and total dose delivered to the primary tumor were not. A KPS of <or=70 (p = 0.001), the presence of a CIRS-G score of 4 (extremely severe; p = 0.0002), and a severity index of >2 (p <0.0001) were associated with statistically significant inferior OS. Multivariate analysis with clinical stage, KPS, and comorbidity (severity index) of all patients showed that a KPS <or=70 and severity index >2 were independently associated with inferior OS; clinical tumor stage was not found to be an independent prognostic factor.

CONCLUSION

KPS and comorbidity are important independent prognostic factors in Stage III NSCLC. Comorbidity should be included in protocols studying advanced stage NSCLC and used for stratification.

Randomized phase III trial of radiation treatment +/- amifostine in patients with advanced-stage lung cancer

PURPOSE

This multicenter trial investigated whether daily pretreatment with amifostine (A) could reduce the incidence of acute and late lung toxicity and esophagitis without affecting antitumor efficacy of radiation in advanced lung cancer.

PATIENTS AND METHODS

Radiotherapy (XRT) patients (n = 146) received a daily fraction of 2 Gy/5 days/week to a total of 55-60 Gy +/- amifostine 340 mg/m(2) administered daily 15 min before irradiation. Acute and late toxicities were graded from 0 to 4 according to the Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer system.

RESULTS

Ninety-seven patients were evaluated 2 months post-XRT for the incidence of pneumonitis; 43% (23/53) of patients in the XRT arm and 9% (4/44) in the A + XRT arm experienced > or = Grade 2 pneumonitis (p < 0.001) [corrected]. Forty-nine percent (26/53) of patients in the XRT arm and 16% (7/44) in the A+XRT arm demonstrated changes representative of > or = Grade 2 lung damage (p < 0.001). At 6 months, fibrosis was present in 53% (19/36) receiving XRT vs. 28% (9/32) receiving A+XRT (p < 0.05). Incidence of esophagitis > or = Grade 2 during Week 4 was 42% (31/73) in the XRT arm vs. 4% (3/73) in the A+XRT arm (p < 0.001). Among 97 patients evaluable for response 2 months after XRT, complete or partial response was present in 76% (40/53) of patients in the XRT arm and 75% (33/44) in the A+XRT arm (p = 1.0).

CONCLUSION

Amifostine reduces the incidence of pneumonitis, lung fibrosis, and esophagitis in radiotherapy patients with lung cancer without compromising antitumor efficacy.

Prospective evaluation of early lung toxicity following three-dimensional conformal radiation therapy in non-small-cell lung cancer: preliminary results

PURPOSE

Radiation pneumonitis is the restricting complication following lung cancer irradiation. The correlation between dose-volume histograms (DVHs) and pneumonitis, with a clinical, radiological, and respiratory function evaluation was assessed. Special endpoint was the evaluation of respiratory function after three-dimensional conformal radiotherapy (3D-CRT).

METHODS AND MATERIALS

Fifty-four patients with non metastatic non-small-cell lung cancer (NSCLC) were treated with a curative intent with 3D-CRT (66 Gy). Thirty-one patients were treated postoperatively (pneumonectomy in 9 patients) for residual tumor or massive nodal involvement (N2 or N3); 23 patients were treated with exclusive radiotherapy. Clinical evaluation, CT scan, and pulmonary functional tests were performed before and 6 weeks after irradiation. The DVHs were calculated applying lung density heterogeneity.

RESULTS

Twenty patients had radiation pneumonitis. Irradiation significantly decreased total lung capacity. Volume of the PTV2 (more than 200 cm(3)) was a significant prognostic factor for lung complication.

CONCLUSION

DVHs combined with initial pulmonary functional tests can predict pulmonary toxicity and could allow us to adjust volume that received total highest dose with acceptable toxicity.

Factors predicting severe radiation pneumonitis in patients receiving definitive chemoradiation for lung cancer

PURPOSE

To identify factors that may predict for severe radiation pneumonitis or pneumonopathy (RP), we reviewed a set of simple, commonly available characteristics.

METHODS AND MATERIALS

Medical records of 148 lung cancer patients with good performance status (ECOG 0-1) treated definitively with chemoradiation from 6/92-6/98 at the University of Pennsylvania were reviewed. Actuarial survival and the crude rate of severe radiation pneumonitis were determined as a function of several variables. Potential predictive factors examined included age, gender, histology, stage, pulmonary function, performance status (0 vs. 1), weight loss, tumor location, radiation dose, initial radiation field size, chemotherapy regimen, and timing of chemotherapy. Univariate analysis (log-rank test) was performed for each variable. Multivariate analysis was performed using linear regression.

RESULTS

Median survival for the entire cohort was 14.7 months. Four patients were inevaluable for pneumonitis due to early death from progressive disease. Of the remaining 144 evaluable patients, 12 (8.3%) experienced severe RP. The most significant factor predicting for severe RP was performance status (p < 0.003). The risk of severe RP was 16% for PS-1 patients vs. 2% for PS-0 patients. Women were significantly more likely to develop severe RP than men (p = 0.01). Among 67 patients for whom pre-radiation therapy pulmonary function data were available, forced expiratory volume of the lung in 1 second (FEV(1)) was also significant (p = 0. 03). No patient suffering severe RP had a pretreatment FEV(1) > 2.0 liters. The median radiation dose was 59.2 Gy and median initial radiation field size was 228 cm(2). Neither radiotherapy factor predicted for RP. Other factors studied, including chemotherapy drugs, and schedule, also were not significant predictors of severe RP.

CONCLUSIONS

Pretreatment performance status, gender, and FEV(1) are significant predictors of severe radiation pneumonopathy, at least when using conventional radiation fields and doses. Complex radiation dose-volume algorithms that attempt to predict lung complication probabilities should probably incorporate these simply obtained clinical parameters.

Optimization of beam weights in conformal radiotherapy planning of stage III non-small cell lung cancer: effects on therapeutic ratio

PURPOSE

To evaluate the effects of beam weight optimization for 3D conformal radiotherapy plans, with or without beam intensity modulation, in Stage III non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Ten patients with Stage III NSCLC were planned using a conventional 3D technique and a technique involving noncoplanar beam intensity modulation (BIM). Two planning target volumes (PTVs) were defined: PTV1 included macroscopic tumor volume and PTV2 included macroscopic and microscopic tumor volume. Virtual simulation defined the beam shapes and incidences as well as the wedge orientations (3D) and segment outlines (BIM). Weights of wedged beams, unwedged beams, and segments were determined by human trial and error for the 3D-plans (3D-manual), by a standard weight table (SWT) for the BIM-plans (BIM-SWT) and by optimization (3D-optimized and BIM-optimized) using an objective function with a biological and a physical component. The resulting non-optimized and optimized dose distributions were compared, using physical endpoints, after normalizing the median dose of PTV1 to 80 Gy.

RESULTS

Optimization improved dose homogeneity at the target for 3D- and BIM-plans and the minimum dose at PTV1. The minimum dose at PTV2 was decreased by optimization especially in 3D-plans. After optimization, the dose-volume histograms (DVHs) of lung and heart were shifted to lower doses for 80-90% of the organ volume. Since lung is the dose-limiting organ in Stage III NSCLC, an increased minimum dose at PTV1 together with a decreased dose at the main lung volume suggests an improved therapeutic ratio. Optimization allows 10% dose escalation for 3D-plans and 20% for BIM-plans at isotoxicity levels of lung and spinal cord. Upon dose escalation, esophagus may become the dose-limiting structure when PTV1 extends close to the esophagus.

CONCLUSIONS

Optimization using a biophysical objective function allowed an increase of the therapeutic ratio of radiotherapy planning for Stage III NSCLC.

[Radiotherapy for stage III, inoperable, asymptomatic small cell lung cancer. Final results of a prospective randomized study (240 patients)]

PURPOSE

To report the results of a prospective randomized study concerning the role of radiotherapy in the treatment of stage III, unresectable, asymptomatic non-small cell lung cancer.

MATERIAL AND METHODS

Between 1992 and 1996, 240 patients with stage III, unresectable, asymptomatic non-small cell lung cancer were enrolled in this study, and sequentially randomized to one of the three treatment arms: conventional irradiation, hypofractionated irradiation and control group. In the conventional irradiation arm (79 patients), a dose of 50 Gy in 25 fractions in five weeks was delivered to the primary tumor and the mediastinum. In the hypofractionated irradiation arm (81 patients), there were two courses of irradiation separated by an interval of four weeks. In each series, patients received 20 Gy in five fractions in five days, in the same treatment volume as the conventional irradiation group. In the control group arm, 80 patients initially did not receive radiotherapy and were only observed. Delayed palliative hypofractionated irradiation (20-25 Gy in four to five fractions in four to five days) was given to the primary tumor when major symptoms developed.

RESULTS

The two-year actuarial survival rates for patients in the conventional irradiation, hypofractionated irradiation and control group arms were 18%, 6% and 0%, with a median survival time of 12 months, nine months and six months respectively. The differences between survival rates were statistically significant at the 0.05 level.

CONCLUSION

Although irradiation provides good palliation, the results are disappointing. The comparison of conventional and hypofractionated irradiation shows an advantage for conventional schedules.

Is prolonged survival possible for patients with supraclavicular node metastases in non-small cell lung cancer treated with chemoradiotherapy?: Analysis of the Radiation Therapy Oncology Group experience

PURPOSE

To determine if patients with non-small cell lung carcinoma (NSCLC) and positive supraclavicular nodes (SN+) have a similar outcome to other patients with Stage IIIB NSCLC (SN-) when treated with modern chemoradiotherapy.

METHODS AND MATERIALS

Using the Radiation Therapy Oncology Group (RTOG) database, data were retrospectively analyzed from five RTOG trials studying chemoradiotherapy for NSCLC: 88-04, 88-08 (chemo-RT arm), 90-15, 91-06, 92-04. Comparisons were made between the SN+ and SN- subgroups with respect to overall survival, progression-free survival (PFS), and metastases-free survival (MFS) using the log rank test. Cox multivariate proportional hazards regression analysis was used to determine the effect of several potential confounding variables, including histology (squamous vs. nonsquamous), age (>60 vs. < or = 60), Karnofsky Performance Status (KPS) (<90 vs. > or = 90), weight loss (> or = 5% vs. <5%), and gender.

RESULTS

A total of 256 Stage IIIB patients were identified, of whom 47 had supraclavicular nodes (SN+) and 209 did not (SN-). Statistically significantly more SN+ patients had nonsquamous histology (p = 0.05); otherwise, known prognostic factors were well balanced. The median survival for SN+ patients was 16.2 months, vs. 15.6 months for SN- patients. The 4-year actuarial survival rates were 21% and 16% for SN+ and SN- patients respectively (p = 0.44). There was no statistically significant difference in the 4-year PFS rates (19% vs. 14%, p = 0.48). The Cox analysis did not show the presence or absence of supraclavicular nodal disease to be a prognostic factor for survival, MFS, or PFS. The only statistically significant factor on multivariate analysis was gender, with males having a 40% greater risk of mortality than females (p = 0.03). There were no clinically significant differences in toxicity when comparing SN+ vs. SN- patients. Among the 47 SN+ patients, there were no reported cases of brachial plexopathy or other > or = Grade 2 late neurologic toxicity.

CONCLUSIONS

When treated with modern chemoradiotherapy, the outcome for patients with supraclavicular metastases appears to be similar to that of other Stage IIIB patients. SN+ patients should continue to be enrolled in trials studying aggressive chemoradiotherapy regimens for locally advanced NSCLC.

Inhomogeneous target-dose distributions: a dimension more for optimization?

PURPOSE

To evaluate if the use of inhomogeneous target-dose distributions, obtained by 3D conformal radiotherapy plans with or without beam intensity modulation, offers the possibility to decrease indices of toxicity to normal tissues and/or increase indices of tumor control stage III non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Ten patients with stage III NSCLC were planned using a conventional 3D technique and a technique involving noncoplanar beam intensity modulation (BIM). Two planning target volumes (PTVs) were defined: PTV1 included macroscopic tumor volume and PTV2 included macroscopic and microscopic tumor volume. Virtual simulation defined the beam shapes and incidences as well as the wedge orientations (3D) and segment outlines (BIM). Weights of wedged beams, unwedged beams, and segments were determined by optimization using an objective function with a biological and a physical component. The biological component included tumor control probability (TCP) for PTV1 (TCP1), PTV2 (TCP2), and normal tissue complication probability (NTCP) for lung, spinal cord, and heart. The physical component included the maximum and minimum dose as well as the standard deviation of the dose at PTV1. The most inhomogeneous target-dose distributions were obtained by using only the biological component of the objective function (biological optimization). By enabling the physical component in addition to the biological component, PTV1 inhomogeneity was reduced (biophysical optimization). As indices for toxicity to normal tissues, NTCP-values as well as maximum doses or dose levels to relevant fractions of the organ's volume were used. As indices for tumor control, TCP-values as well as minimum doses to the PTVs were used.

RESULTS

When optimization was performed with the biophysical as compared to the biological objective function, the PTV1 inhomogeneity decreased from 13 (8-23)% to 4 (2-9)% for the 3D-(p = 0.00009) and from 44 (33-56)% to 20 (9-34)% for the BIM plans (p < 0. 00001). Minimum PTV1 doses (expressed as the lowest voxel-dose) were similar for both objective functions. The mean and maximum target doses were significantly higher with biological optimization for 3D as well as for BIM (all p values < 0.001). Tumor control probability (estimated by TCP1 x TCP2) was 4.7% (3D) and 6.2% (BIM) higher for biological optimization (p = 0.01 and p = 0.00002 respectively). NTCP(lung) as well as the percentage of lung volume exceeding 20 Gy was higher with the use of the biophysical objective function. NTCP(heart) was also higher with the use of the biophysical objective function. The percentage of heart volume exceeding 40 Gy tended to be higher but the difference was not significant. For spinal cord, the maximum dose as well as NTCP(cord) were similar for 3D plans (D(max): p = 0.04; NTCP: p = 0.2) but were significantly lower for BIM (D(max): p = 0.002; NTCP: p = 0.008) if the biophysical objective function was used.

CONCLUSIONS

When using conventional 3D techniques, inhomogeneous dose distributions offer the potential to further increase the probability of uncomplicated local control. When using techniques as BIM that would lead to large escalation of the median and maximum target doses, it seems indicated to limit target-dose inhomogeneity to avoid dose levels that are so high that the safety becomes questionable.

Hyperfractionated radiotherapy for clinical stage II non-small cell lung cancer

BACKGROUND AND PURPOSE

Patients with stage II non-small cell lung cancer who are not suitable for or refuse surgery are treated with radiotherapy, but the results reported so far are not satisfactory. To improve the prognosis of such patients, we have used hyperfractionated radiotherapy. In this paper, we retrospectively analyzed results of the treatment.

MATERIALS AND METHODS

Between 1988 and 1993, 67 patients were treated with hyperfractionated radiotherapy with 1.2 Gy twice daily to a total dose of 69.6 Gy. All patients were technically operable, but 43 had medical problems and 24 refused surgery. The median age and Karnofsky performance status score was 60 and 90 years, respectively. No patient received chemotherapy or immunotherapy. The median follow-up period was 61 months.

RESULTS

The median survival time and the 5-year survival rate were 27 months and 25% (standard error, SE, 6%), respectively. The 5-year local control rate was 44% (SE,7%). Univariate analysis of prognostic factors revealed that a higher Karnofsky performance status score, weight loss of < or =5% before treatment, and T1 stage were associated with better prognosis, and peripheral location was of borderline significance (P = 0.053). There were two bronchopulmonary and two esophageal acute grade 3 toxicities, and one bronchopulmonary and two esophageal late grade 3 toxicities. No grade 4 or 5 toxicity was observed.

CONCLUSION

These results are encouraging and further studies on the use of hyperfractionation seem to be warranted for stage II non-small cell lung cancer.

Conformal radiotherapy of Stage III non-small cell lung cancer: a class solution involving non-coplanar intensity-modulated beams

PURPOSE

We developed a semiautomatic class solution to irradiate centrally located Stage III non-small cell lung cancer (NSCLC), involving a beam intensity modulation technique and optimization using a biophysical cost function.

METHODS AND MATERIALS

Treatment for 10 patients with Stage III NSCLC was planned, using a conventional three- or four-beam three-dimensional (3D) technique and two techniques involving, respectively, seven (BIM1) and five (BIM2) noncoplanar beam incidences with intensity modulation. Two planning target volumes were defined: PTV1 included macroscopic tumor volume and PTV2 included macroscopic and microscopic disease. Beams were divided into beam parts (segments) and their outlines were defined during virtual simulation. Optimization using a biophysical cost function determined beam weights, segment weights, and wedge angles. Biological end points included tumor control probability of both target volumes (TCP1 and TCP2) and normal tissue complication probability (NTCP) of heart, lung, and spinal cord. The resulting uncomplicated local control probability (UCLP) was calculated. Physical end points included dose at PTV1 expressed as a dose minimum and dose maximum. Target-dose inhomogeneity was constrained in all plans.

RESULTS

Concerning tumor evaluation, TCP1 was 74% (range 54-89%) for the 3D plan, 78.0% (range 62-94%) for BIM1, and 86.0% (range 59-93%) for BIM2. TCP1*TCP2 was, respectively, 67.0% (range 39-81%), 73.0% (range 56-94%), and 81.0% (range 54-93%). Minimum doses to PTV1 were 85, 80, and 88 Gy with the three respective techniques, while dose maxima were 89, 101, and 100 Gy. NTCPs of lung were 45.0% (range 11-75%) for 3D, 19.5% (range 8-59%) for BIM1, and 24.5% (range 3-61%) for BIM2. NTCPs of heart and spinal cord were comparable for all techniques. ULCPs were 37.0% (range 9-73%), 52.5% (range 22-86%), and 60.0% (range 20-85%), respectively. Applying physical limits to ensure clinical safety, minimum doses at PTV1 were recalculated. These were 72, 71, and 74 Gy for 3D, BIM1, and BIM2, respectively.

CONCLUSION

The BIM2 plan is a candidate class solution for dose escalation studies in centrally located Stage III NSCLC.

High-dose radiation therapy alone for inoperable non-small cell lung cancer--experience with prolonged overall treatment times

The purpose of this study as to determine the impact of overall treatment time on long-term survival after high-dose radiation therapy alone for inoperable non-small cell lung cancer (NSCLC). Between 1978 and 1990, 229 patients with stage I-III disease and Karnofsky Performance Scores of 80-100 received a conventionally fractionated total dose of 70 Gy through a split-course technique. After a first treatment course of 40 or 50 Gy, a restaging was performed and only patients without any contraindications, such as newly diagnosed distant metastases or serious deterioration of performance status, were given a second course. In 83% of patients this break lasted for 4-6 weeks. Overall treatment time ranged between 7 and 24 weeks (median 12 weeks). Median follow-up time was 6.6 years (range 4.0-9.3 years). Actuarial overall survival rates at 2 and 5 years were 28% and 7% respectively. Complete radiological tumor response was observed in 31% of patients, and was found to be the strongest positive predictor of survival with 2- and 5-year rates of 50% and 12% respectively compared with 17% and 4% for patients without complete response. Treatment duration was not found to be a significant prognostic factor in univariate or multivariate analysis. For overall treatment times of 7-11 weeks (n = 50), 12 weeks (n = 79) and > 12 weeks (n = 100), 5-year survival was 4%, 6%, and 8%, respectively (p = 0.6). To conclude, in our experience and in contrast to other studies, prolonged overall treatment times in radiation therapy alone for inoperable NSCLC had no negative impact on long-term survival. It is hypothesized that accelerated tumor cell repopulation is absent in a significant number of these patients with the time-factor playing no apparent role for outcome of treatment.

A phase II trial, feasibility of combination of daily cisplatinum and accelerated radiotherapy via concomitant boost in stage III non-small cell lung cancer

PURPOSE

A prospective phase II trial was conducted by the Institute of Oncology, Istanbul University in December 1994 on patients with locally-advanced non-small cell lung cancer to assess acute toxicity and the feasibility of a combination of radiosensitizer and accelerated radiotherapy with concomitant boost.

MATERIALS AND METHODS

Patients were irradiated using 'large' fields (primary tumour and locoregional lymph nodes) with 1.8 Gy per fraction, five fractions a week. Reduced 'boost' fields (primary and involved nodes only) were also irradiated twice-weekly 1.8 Gy per fraction in ten fractions concomitantly 6 h after the administration of large field. Total radiation dose was 63 Gy in 5 weeks (45 Gy 'large' fields and 18 Gy 'boost'). The maximum allowed dose to the spinal cord was 3750 cGy. Cisplatinum, 6 mg/m2 was given daily just before 'large' field irradiation.

RESULTS

As of January 1997, 15 patients were evaluated (median follow-up of 12.5 months with a range of 5.5-23 months). The overall acute toxicity rate was 38% and Grade 3 acute toxicity was 8%. Grade 4 or greater acute toxicities were not observed. The overall rate of cisplatinum-induced nausea and vomiting was 80% (severe in 60%), but all were easily treated with antiemetics. Complete response rate (clinical and radiological) was 40% and an overall response rate was 73%. Median survival was 16 months and progression-free survival was 5.5 months (range of 2.5-21 months).

CONCLUSIONS

Toxicity was well tolerated and no treatment-related death occurred with this combined treatment regimen. Although it appears that better local control rates can be achieved, additional phase II/III studies are needed.

[Lung cancer--hopelessness in inoperability? A 10-year follow-up]

BACKGROUND

According to reports of Durrant et al. [19] and Berry et al. [5] it was concluded that non-operable non-small cell lung tumors cannot be cured. In this consequence initiation of radiotherapy was fixed at the beginning of symptoms. However, long-time survivors in our follow-up lead us to analyse not only quality of life and secondary therapeutic effects but also this special group with the results of the whole collective treated in the same period of interest.

PATIENTS AND METHODS

Between 1.1. 1981 and 31. 12. 1983 a number of 169 patients had been recommended for locoregional radiotherapy treatment of lung cancer; 145 patients received at least 50 Gy, 134 out of them 60 Gy or more. Men/female ratio was 137:8, median age was 65 (36 to 88) years. Classified according to the TN-stage there were 59 patients in T1-4 N0 and 86 patients in T1-4 N1-3 M0. Histologically: 98 squamous cell carcinomas, 23 adenocarcinomas, 9 large cell carcinomas and 15 specimens mixed from the named subgroup or rare histologies. Treatment concept including repetition of bronchoscopic evaluation after 60 Gy was prospectively discussed and fixed with our pneumologist. Radiation dose was given with a shrinking-field technique to mediastinum and primary. In case of macroscopically or microscopically persistence of tumor we continued radiation dose up to 80 Gy. Radiotherapy was not followed by chemotherapy. A telecobalt unit has been used for treatment due to the lack of high-voltage linear accelerators. In absence of a computer assisted planning system-a problem in most of the radiotherapeutic centers in this time-dose calculation was done by central beam planning of ICRU-point in the middle of the tumor respectively the center of target volume on the base of a cross section. Usually there was used a 3-field plan ap/pa opposite and an oblique field with an angle of 30 degrees from the ipsilateral back or ventral side, depending on the position of the tumor. Spinal cord was shielded to avoid a dose-more than 36 to 42 Gy. The longer distance and higher weightiness of the oblique fields had as consequence lung fibrosis in the irradiated lung area and a considerable higher maximal dose situated in the soft tissue and skin often followed by strong indurations in this area 1 to 3 years after radiation therapy without further limitations of quality of life.

RESULTS

From 145 patients with non-small cell lung cancer 64.1% (93/145) survived 6 months, 42.8% (62/145) 1 year, 19.3% (28/145) 2 years and 7.6% (11/145) 5 and 4.8 (7/145) more than 10 years. According to TN-stages T1-4 N0 collective had a survival rate of 67.8% (40/59) after half a year, 50.8% (30/59) after 1 year, 23.7% (14/59) after 2 and 11.9% (7/59) after 5 years. Treatment results by patients with positive lymph nodes T1-4 N1-3 after the same intervals are: 61.6% (53/86), 37.2% (32/86), 16.2% (14/86) respectively 4.7% (4/86). In the period 5 to 10 years after irradiation 4 patients died, 1 with local relapse, 2 with contralateral lung cancer-ipsilateral region was endoscopically and histologically free of tumor- and 1 patient in consequence of heart insufficiency of several years. Seven patients are still alive after 13 to 16 years. There is no sign of tumor in this group or any effects limitating their quality of life. Twenty-four patients received less than 50 Gy. All patients but 2 did not survive 6 months. One patient survived half a year and 1 patient 2 years.

CONCLUSIONS

The reported treatment results in a period with modest technological possibilities, a telecobalt unit, should encourage to a curative intention, when dissemination cannot be proved. If lung cancer is limited to the primary region with or without lymph node metastases the possibility of tumor elimination is small but feasible. If inoperable lung cancer is not curable, this mostly is not due to inability of locoregional radiotherapy, but rather can be seen as a lack of reliable and permanent elimination or prevention of

Hyperfractionated radiotherapy alone for clinical stage I nonsmall cell lung cancer

PURPOSE

Among patients with Stage I nonsmall cell lung cancer (NSCLC), those treated with conventional radiotherapy show poorer prognosis than those treated by surgery. To improve the prognosis of such patients, we have used hyperfractionated radiation therapy.

METHODS AND MATERIALS

Between 1988 and 1993, 49 patients were treated with hyperfractionated radiotherapy with 1.2 Gy twice daily to a total dose of 69.6 Gy. All patients were technically operable, but 29 had medical problems and 20 refused surgery. The median age and Karnofsky Performance Status was 63 years and 90, respectively. No patient received chemotherapy or immunotherapy. Prophylactic mediastinal irradiation was not given.

RESULTS

The median survival time was 33 months, and the 5-year survival rate was 30%. The rate at 5 years for freedom from each of relapse, local recurrence, mediastinal lymphnode metastasis, and distant metastasis was 41%, 55%, 89%, and 75%, respectively. Univariate analysis revealed that higher Karnofsky Performance Status score, absence of weight loss before treatment, and T1 stage were associated with better survival, although the T stage became insignificant on multivariate analysis. There were two Grade 3 acute toxicities and three Grade 3 late toxicities, but there was no Grade 4-5 toxicity.

CONCLUSION

The results of this study compare favorably with those of most previous studies employing conventional fractionation. Further studies on hyperfractionation seem to be warranted for Stage I NSCLC.

Hyperfractionation: where do we stand?

Hyperfractionation is generally expected to allow an escalation of total dose, thereby increasing tumour control rate, without increasing the risk of late complications. The purpose of this review is to assess the empirical evidence for this therapeutic gain from hyperfractionated radiotherapy. Although extensive clinical data have been accumulated until now, especially on treatment of head and neck cancer, the line of evidence is not consistent. The present analysis indicates that the dose per fraction generally used in standard radiotherapy is already a good choice.

[Induction chemotherapy followed by concomitant combined radiotherapy and chemotherapy in stage III non-small cell bronchial carcinoma]

PURPOSE

To determine the efficacy and safety of induction chemotherapy followed by concomitant chemoradiotherapy in the treatment of stage III non-small cell lung cancer and whether the response to induction chemotherapy can predict the response to subsequent chemoradiotherapy and survival.

MATERIALS AND METHODS

Between December 1987 and June 1993, 46 patients with previously untreated stage III non-small cell lung cancer received every 21 days induction chemotherapy (ICT) including three cycles of 5-fluorouracil (600 mg/m2/d in short infusion from d1 to d5), cisplatin (15 mg/m2/d from d1 to d5), etoposide (50 mg/m2/d from d1 to d5) and hydroxyurea (1,500 mg/d from d1 to d5). The first 21 patients also received bleomycin (3 mg/m2/d from d1 to d5). All patients received concomitant chemotherapy and had chest radiotherapy (CCRT). Patients received irradiation (65 Gy/33-6 fractions/7 weeks) on d25 after the third cycle of chemotherapy. Concomitant chemotherapy was composed of cisplatin (20 mg/m2) and 5-fluorouracil (500 mg/m2) that were administered each Monday and Thursday during radiotherapy. Maintenance chemotherapy consisted of thiotepa (10 mg/m2) and methotrexate (10 mg/m2) that were administered every 2 weeks for 6 months.

RESULTS

Pulmonary toxicity was observed in four out of 21 patients who had received bleomycin and subsequently developed pulmonary fibrosis, leading to death for two of them. ICT alone produced five complete responses (11%) and 13 partial responses (28%). The combination of chemotherapy and radiotherapy led to 19 complete responses (41%) and 14 partial responses (30%). Eighteen of the 18 responders (100%) to ICT responded to subsequent CCRT, of whom 13 (72%) became complete responders. Fifteen of the 28 non-responders to ICT (53%) responded to CCRT, six of them being complete responders (21%) (P < 0.001). The median overall survival rate was 17 months when considering all patients, 25 months in patients responding to ICT and 13 months in non-responders. The 2-year survival rates were 28, 55 and 11%, respectively (P < 0.05). ICT did not influence the rate of subsequent metastatic events. However, locoregional reprogression was lower in responders to ICT. The number of metastatic events was not significantly related to response to ICT. By contrast, the rate of local failure was higher when there was resistance to ICT (75% versus 39%). Out of the 19 complete responders to CCRT (13 responders to ICT and six non-responders to ICT), four developed secondary locoregional reprogression (21%) and six developed metastatic disease (31%). In complete responders to CCRT, the rate of locoregional failure was 15% in responders to ICT (2/13) and 33% (2/6) in non-responders to ICT. Four out of the 13 responders to CCRT after response to ICT (31%) and two out of the six complete responders to CCRT developed metastatic disease after non-response to ICT.

CONCLUSION

There is a statistically significant relationship not only between the response to ICT and the response to CCRT, but also between the response to ICT and the local outcome and survival.

High-dose, hyperfractionated, accelerated radiotherapy using a concurrent boost for the treatment of nonsmall cell lung cancer: unusual toxicity and promising early results

PURPOSE

The treatment of nonsmall cell lung cancer (NSCLC) with conventional radiotherapy (RT) results in inadequate local tumor control and survival. We report results of a Phase II trial designed to treat patients with a significantly increased total dose administered in a reduced overall treatment time using a hyperfractionated, accelerated treatment schedule with a concurrent boost technique.

METHODS AND MATERIALS

A total of 49 patients with unresectable Stage IIIA/IIIB (38 patients) or medically inoperable Stage I/II (11 patients) NSCLC were prospectively enrolled in this protocol. Radiation therapy was administered twice daily, 5 days/week with > 6 h between each treatment. The primary tumor and adjacent enlarged lymph nodes were treated to a total dose of 73.6 Gy in 46 fractions of 1.6 Gy each. Using a concurrent boost technique, electively irradiated nodal regions were simultaneously treated with a dose of 1.25 Gy/fraction for the first 36 fractions to a total dose of 45 Gy.

RESULTS

Median survival for the entire group of 49 patients is 15.3 months. Actuarial survival at 2 years is 46%: 60% for 11 Stage I/II patients, 55% for 21 Stage IIIA patients, and 26% for 17 Stage IIIB patients. The actuarial rate of freedom from local progression at 2 years is 64% for the entire group of 49 patients: 62% for Stage I/II patients, 70% for Stage IIIA patients, and 55% for Stage IIIB patients. Patients who underwent serial bronchoscopic reevaluation (4 Stage I/II, 8 Stage IIIA, and 6 Stage IIIB) have an actuarial rate of local control of 71% at 2 years. The median total treatment time was 32 days. Nine of 49 patients (18%) experienced Grade III acute esophageal toxicity. The 2-year actuarial risk of Grade III or greater late toxicity is 30%. The 2-year actuarial rate of severe-late pulmonary and skin-subcutaneous toxicity is 20% and 15%, respectively.

CONCLUSION

This treatment regimen administers a substantially higher biologically effective dose compared with conventional and pure hyperfractionation treatment schedules. The overall rate of acute and late toxicity was acceptable. Preliminary rates of overall survival and local control and freedom from local progression compare favorably to results reported with pure hyperfractionated radiotherapy and chemoradiotherapy.