Radiation treatment of lung cancer—Patterns of Practice in Canada

Dose and Fractionation in Radiation Therapy of Curative Intent for Non-Small Cell Lung Cancer: Meta-Analysis of Randomized Trials

PURPOSE

The optimum dose and fractionation in radiation therapy of curative intent for non-small cell lung cancer remains uncertain. We undertook a published data meta-analysis of randomized trials to examine whether radiation therapy regimens with higher time-corrected biologically equivalent doses resulted in longer survival, either when given alone or when given with chemotherapy.

METHODS AND MATERIALS

Eligible studies were randomized comparisons of 2 or more radiation therapy regimens, with other treatments identical. Median survival ratios were calculated for each comparison and pooled.

RESULTS

3795 patients in 25 randomized comparisons of radiation therapy dose were studied. The median survival ratio, higher versus lower corrected dose, was 1.13 (95% confidence interval [CI] 1.04-1.22) when radiation therapy was given alone and 0.83 (95% CI 0.71-0.97) when it was given with concurrent chemotherapy (P for difference=.001). In comparisons of radiation therapy given alone, the survival benefit increased with increasing dose difference between randomized treatment arms (P for trend=.004). The benefit increased with increasing dose in the lower-dose arm (P for trend=.01) without reaching a level beyond which no further survival benefit was achieved. The survival benefit did not differ significantly between randomized comparisons where the higher-dose arm was hyperfractionated and those where it was not. There was heterogeneity in the median survival ratio by geographic region (P<.001), average age at randomization (P<.001), and year trial started (P for trend=.004), but not for proportion of patients with squamous cell carcinoma (P=.2).

CONCLUSIONS

In trials with concurrent chemotherapy, higher radiation therapy doses resulted in poorer survival, possibly caused, at least in part, by high levels of toxicity. Where radiation therapy was given without chemotherapy, progressively higher radiation therapy doses resulted in progressively longer survival, and no upper dose level was found above which there was no further benefit. These findings support the consideration of further radiation therapy dose escalation trials, making use of modern treatment methods to reduce toxicity.

Pattern of use of radiotherapy for lung cancer: a descriptive study

BACKGROUND

Lung cancer remains one of the most prevalent forms of cancer. Radiotherapy, with or without other therapeutic modalities, is an effective treatment. Our objective was to report on the use of radiotherapy for lung cancer, its variability in our region, and to compare our results with the previous study done in 2004 (VARA-I) in our region and with other published data.

METHODS

We reviewed the clinical records and radiotherapy treatment sheets of all patients undergoing radiotherapy for lung cancer during 2007 in the 12 public hospitals in Andalusia, an autonomous region of Spain. Data were gathered on hospital, patient type and histological type, radiotherapy treatment characteristics, and tumor stage.

RESULTS

610 patients underwent initial radiotherapy. 37% of cases had stage III squamous cell lung cancer and were treated with radical therapy. 81% of patients with non-small and small cell lung cancer were treated with concomitant chemo-radiotherapy and the administered total dose was ≥60 Gy and ≥45 Gy respectively. The most common regimen for patients treated with palliative intent (44.6%) was 30 Gy. The total irradiation rate was 19.6% with significant differences among provinces (range, 8.5-25.6%; p<0.001). These differences were significantly correlated with the geographical distribution of radiation oncologists (r=0.78; p=0.02). Our results were similar to other published data and previous study VARA-I.

CONCLUSIONS

Our results shows no differences according to the other published data and data gathered in the study VARA-I. There is still wide variability in the application of radiotherapy for lung cancer in our setting that significantly correlates with the geographical distribution of radiation oncologists.

Has the practice of radiation oncology for locally advanced and metastatic non-small-cell lung cancer changed in Canada?

Aim

Previous surveys have revealed wide variations in the management by radiation oncologists of non-small-cell lung cancer (nsclc) in Canada. The aim of the present study was to determine the current patterns of practice for locally advanced and metastatic nsclc among Canadian radiation oncologists.

Materials and Methods

An online survey was distributed electronically to all members of the Canadian Association of Radiation Oncologists. Those who treat lung cancer were invited to participate. The survey consisted of three scenarios focusing on areas of nsclc treatment in which the radiotherapy (rt) regimen that provides the best therapeutic ratio is unclear.

Results

Replies from 41 respondents were analyzed. For an asymptomatic patient with stage iiib nsclc unsuitable for radical treatment, 22% recommended immediate rt, and 78% recommended rt only if the patient were to become symptomatic. Those who believed that immediate rt prolongs survival were more likely to recommend it (p = 0.028). For a patient with a bulky stage iiib tumour and good performance status, 39% recommended palliative treatment, and 61% recommended radical treatment (84% concurrent vs. 16% sequential chemoradiation at 60–66 Gy in 30–33 fractions). Those who believed that chemoradiation has a greater impact on survival were more likely to recommend it (p < 0.001). For a symptomatic patient with stage iv nsclc, 54% recommended external-beam rt (ebrt) alone, 41% recommended other modalities (brachytherapy, endobronchial therapy, or chemotherapy) with or without ebrt, and 5% recommended best supportive care. A majority (76%) prescribed 20 Gy in 5 fractions for ebrt.

Conclusions

Compared with previous surveys, more radiation oncologists now offer radical treatment for locally advanced nsclc. Management of nsclc in Canada may be evidence-based, but perception by radiation oncologists of the treatment’s impact on survival also influences treatment decisions.

Patterns of care study for brachytherapy: results of the questionnaire for the years 2002 and 2007 in The Netherlands

Purpose

The goal of the ESTRO Patterns of Care study for Brachytherapy in Europe (PCBE) 2002 was to develop an aid to analyse brachytherapy practices. A 2^nd version of the PCB questionnaire was created for 2007. Data over 2007 were collected at the radiotherapy institutions in The Netherlands and compared with those from 2002. The aim of this study is to describe national brachytherapy practices, to demonstrate trends, and to provide data for rational health care planning.

Material and methods

Data were collected using a web-based questionnaire. For each centre, a local coordinator, responsible for coordinating the questionnaires and support of the further analysis was assigned. Data from the national cancer incidence registry was used for comparison with the data from the 21 Dutch departments.

Results

There was a decrease in low-dose rate equipment in parallel to an increase in both pulsed-dose rate and high-dose rate equipment. The use of 3D CT and MR based imaging techniques showed a slow rise. The most common clinical procedures were for prostate, gynaecological, and oesophageal tumours. A large increase (146%) in permanent implant prostate applications using 125I seeds was observed. The numbers of oesophageal and gynaecological treatments remained stable. There is concern on the low numbers of cases treated in some institutions for a few complex treatment sites. For head and neck, anal canal, paediatrics, bladder and eye interventions it ranged from 3-20 patients per year per institution.

Conclusions

The increase in number of patient treated with brachytherapy is in accordance with the increases in cancer incidence. The percentage of all radiotherapy patients treated with brachytherapy (approximately 5%) remained stable. The survey identified certain trends in resources and techniques, as well as areas of expected improvement and possible gain in clinical outcome. Data reported from this survey can be used for further planning of resources, facilities and concentration of a low-volume specialised and complex treatments.

Patterns of care for lung cancer in radiation oncology departments of Turkey

PURPOSE

To determine the patterns of care for lung cancer in Turkish radiation oncology centers.

METHODS AND MATERIALS

Questionnaire forms from 21 of 24 (87.5%) centers that responded were evaluated.

RESULTS

The most frequent histology was non-small cell lung cancer (NSCLC) (81%). The most common postoperative radiotherapy (RT) indications were close/(+) surgical margins (95%) and presence of pN2 disease (91%). The most common indications for postoperative chemotherapy (CHT) were ">/= IB" disease (19%) and the presence of pN2 disease (19%). In Stage IIIA potentially resectable NSCLC, the most frequent treatment approach was neoadjuvant concomitant chemoradiotherapy (CHRT) (57%). In Stage IIIA unresectable and Stage IIIB disease, the most frequent approach was definitive concomitant CHRT (91%). In limited SCLC, the most common treatment approach was concomitant CHRT with cisplatin+etoposide for cycles 1-3, completion of CHT to cycles 4-6, and finally prophylactic cranial irradiation in patients with complete response (71%). Six cycles of cisplatin + etoposide CHT and palliative thoracic RT, when required, was the most commonly used treatment (81%) in extensive SCLC. Sixty-two percent of centers did not have endobronchial brachytherapy (EBB) facilities.

CONCLUSION

There is great variation in diagnostic testing, treatment strategies, indications for postoperative RT and CHT, RT features, and EBB availability for LC cases. To establish standards, national guidelines should be prepared using a multidisciplinary approach.

Three-dimensional non-coplanar conformal radiotherapy yields better results than traditional beam arrangements for adjuvant treatment of gastric cancer

PURPOSE

The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields.

METHODS AND MATERIALS

A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field "box" was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test.

RESULTS

The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan.

CONCLUSION

Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical practice.

Resources and management strategies for the use of radiotherapy in the treatment of lung cancer in Central and Eastern European countries: Results of an International Atomic Energy Agency (IAEA) survey

PURPOSE

To assess resources and management strategies for the use of radiotherapy (RT) in the treatment of lung cancer in developing Central and Eastern European countries.

MATERIALS/METHODS

Questionnaires on patterns of care of NSCLC and SCLC were sent to radiation oncologists of Central and Eastern Europe. Comparisons were made between two groups of countries-ex-USSR states and other Eastern and Central European countries.

RESULTS

Twenty-four out of twenty-eight surveyed countries responded. There were significant differences in access to modern treatment facilities (3D planning systems, number of linear accelerators), percentage of patients with lung cancer receiving radiotherapy, schedules of palliative RT, use of postoperative RT for early stages between both analysed groups of countries. 3D systems were in use in 25% of centres for an entire treatment, in 28% for a part of the treatment, and in 47% curative RT was 2D planned. Sequential chemo-RT was the most common approach to radical management of NSCLC, followed by RT alone and concomitant chemo-RT; median percentages of patients receiving respective treatments per centre were 57%, 30%, and 10%. For SCLC, the concurrent approach was declared by 56%, and the sequential approach by 42% of responders.

CONCLUSIONS

Patterns of care of lung cancer in the analysed countries differed in some part from existing, evidence-based data on lung cancer. In particular, this difference was observed between ex-USSR countries and the rest of European developing countries in the equipment available and specific diagnostic and treatment parameters in radiotherapy of lung cancer, the latter group's practices more resembling those of developed European countries.

Intensity modulated radiation therapy with irregular multileaf collimated field: a dosimetric study on the penumbra region with different leaf stepping patterns

Using a Varian 21 EX linear accelerator with a multileaf collimator (MLC) of 120 leaves, the penumbra regions of beam profiles within an irregular multileaf collimated fields were studied. MLC fields with different leaf stepping angles from 21.8 degrees to 68.2 degrees were used. Beam profiles in different directions: (1) along the cross-line and in-line axis, (2) along the leaf stepping edges of the field, and (3) parallel to the stepping edges but in the middle of the field, were measured and calculated using Kodak XV radiographic film and Pinnacle3 treatment planning system version 7.4f. These beam profiles were measured and calculated at source to axis distance= 100 cm with 5 cm of solid water slab on top. On the one hand, for both cross-line and in-line beam profiles, the penumbra widths of 20%-80% did not vary with the leaf stepping angles and were about 0.4 cm. On the other hand, the penumbra widths of 10%-90% of the above two profiles varied with the stepping angles and had maximum widths of about 1.9 cm (cross-line) and 1.65 cm (in-line) for stepping angles of 38.7 degrees and 51.3 degrees , respectively. For profiles crossing the "rippled" stepping edges of the field, the penumbra widths (10%-90%) at the regions between two opposite leaves (i.e., profile end at the Y1/Y2 jaw position) decreased with the stepping angles. At the penumbra regions between two leaf edges with the tongue-and-groove structure of the same bank (i.e., profile end at the X1/X2 jaw position), the penumbra widths increased with the stepping angles. When the penumbra widths were measured between two opposite leaf edges and at corners between two leaves, the widths first decreased with the stepping angles and then increased beyond the minimum width point at stepping angle of 45 degrees. The penumbra width (10%-90%) measured at the leaf edge was larger than that at the corner. For the beam profiles calculated using Pinnacle3, it is found that the results agreed well with the measurements along the cross-line and in-line axis, while there was a deviation for the profiles along the leaf stepping edge of the field compared to the film measurements. The measured results in this study can help us to understand the dosimetric effect of the leaf stepping (due to finite leaf width), tongue-and-groove and rounded leaf end structure in the penumbra region of an irregular MLC field. A more dedicated penumbra model can be developed for the treatment planning system.

Practical integration of [18F]-FDG-PET and PET-CT in the planning of radiotherapy for non-small cell lung cancer (NSCLC): The technical basis, ICRU-target volumes, problems, perspectives

The value of positron emission tomography using [18F]-fluoro-deoxy-glucose (FDG-PET) for pretherapeutic evaluation of patients with non-small cell lung cancer (NSCLC) is beyond doubt. Due to the increasing availability of PET and PET-CT scanners the method is now widely available, and its technical integration has become possible for radiotherapy planning systems. Due to the depiction of malignant tissue with high diagnostic accuracy, the use of FDG-PET in radiotherapy planning of NSCLC is very promising. However, by uncritical application, PET could impair rather than improve the prognosis of patients. Therefore, in the present paper we give an overview of technical factors influencing PET and PET-CT data, and their consequences for radiotherapy planning. We further review the relevant literature concerning the diagnostic value of FDG-PET and on the integration of FDG-PET data in RT planning for NSCLC. We point out the possible impact in gross tumor volume (GTV) definition and describe methods of target volume contouring of the primary tumor, as well as concepts for the integration of diagnostic information on lymph node involvement into the clinical target volume (CTV), and the possible implications of PET data on the definition of the planning target volume (PTV). Finally, we give an idea of the possible future use of tracers other than [18F]-FDG in lung cancer.

Spanish patterns of care for 3D radiotherapy in non–small-cell lung cancer

PURPOSE

Curative radiotherapy for non-small-cell lung cancer is a difficult challenge, despite the use of conformal radiotherapy. Optimal three-dimensional delineation of treatment volumes is essential for improvement of local control and for limiting of tissue toxicity.

MATERIAL AND METHODS

A planning course on clinical practice of lung cancer was held in Barcelona. A questionnaire was given concerning (1) patient positioning, (2) planning-computed tomography scan, (3) accounting for tumor mobility, (4) investigative-procedure respiration-gated radiotherapy and breath-holding maneuvers, (5) generation of target volumes, (6) treatment planning, and (7) treatment delivery. This questionnaire was made to determine the Spanish application of European recommendations.

RESULTS

On the negative side, 1 hospital did not use three-dimensional tools, less than 50% used immobilization devices, and 55.6% used computed tomography slices of greater than 5 mm. On the positive side, 70.4% did not use standard margins for gross target volume derived from a computed tomography scan, 92.6% agreed with the inclusion of Naruke anatomic criteria of 1 cm or more in gross target volume planning, and 75% used V20 to estimate the risk of pneumonitis.

CONCLUSIONS

This study is the first validation of European recommendations for treatment planning and execution of radiotherapy in lung cancer. The main conclusion is the need to improve the negative aspects determined.

Can the use of amifostine improve cure rates for patients with advanced non-small cell lung cancer?

Concurrent chemoradiation, probably plus systemic chemotherapy, currently offers the best treatment strategy in stage IIIA/IIIB non-small cell lung cancer. However, such approaches do not control local disease well, perhaps because of inadequate radiation dose. While few studies have explored higher than standard radiation doses (ie, 60 Gy), the major fear is that higher doses increase patient morbidity without improving cure rates. A University of North Carolina (Chapel Hill, NC) phase I/II trial suggests that at least 74 Gy can be given safely to patients with cytotoxic drugs, with a suggestion of improved survival. Moreover, other trial data have suggested that the cytoprotective and radioprotective agent amifostine can be used to reduce esophagitis and possibly pneumonitis in patients treated with conventional radiation doses. We describe herein a proposed clinical trial designed to test: (1) the hypothesis that higher radiation doses can lead to a survival advantage in patients with non-small cell lung cancer, and (2) the value of amifostine as a cytoprotective agent in the high-radiation dose range.