Safety and Efficacy of Stereotactic Body Radiotherapy for Ultra-Central Thoracic Tumors

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is increasingly utilized in the management of ultra-central thoracic tumors, although concerns regarding significant toxicity remain. We sought to evaluate the toxicity and efficacy of SBRT to these tumors at our institution.

MATERIALS/METHODS

Patients with ultra-central lung tumors or nodes treated at our institution with SBRT between 2009 and 2019 were retrospectively reviewed. Ultra-central was defined as having the planning target volume (PTV) overlapping or abutting the central bronchial tree and/or esophagus. All SBRT plans were generated with homogenous dose distributions using target coverage objectives of ITV V100% >99%, PTV V95% >99%, and an ideal PTV Dmax <105% (strict <120%). All plans were reviewed in quality assurance rounds by a team of dosimetrists, physicists, and radiation oncologists. The primary endpoint was incidence of severe toxicity (ST), defined as SBRT-related grade ≥3 toxicities, graded using the Common Terminology Criteria for Adverse Events V5.0. Secondary endpoints included local failure (LF), progression-free survival (PFS) and overall survival (OS). Competing risk analysis was used to estimate incidence and predictors of ST and LF, with death as a competing risk. Kaplan-Meier method was used to estimate PFS and OS.

RESULTS

A total of 154 patients who received 162 ultra-central courses of SBRT were included, with a median follow-up of 21.5 months. Treatment intent was most commonly for oligoprogression (46%), oligometastasis (30%), followed by curative (20%). The most frequent tumor histologies were NSCLC (41%) and RCC (26%). SBRT prescription doses ranged from 30-55 Gy in 5 fractions (BED10 range 48-115 Gy). The most common prescription was 50 Gy in 5 fractions (42%). The cumulative incidence of ST was 8.9% at 3-years. The most common ST was pneumonitis (n = 4). Notable toxicities included bronchopleural fistula (n = 2, grade 3 and 4), bronchial stricture (n = 1, grade 3), and esophagitis leading to bleeding (n = 1, grade 4). There were no esophageal strictures or perforations, and no bronchial bleeds. There was 1 possible treatment related death from pneumonitis/pneumonia. Predictors of any ST included increased lung V5 Gy, decreased PTV V95%, and not having prior radiation therapy to the chest. The cumulative incidence of LF was 4.8%, 11% and 14% at 1-, 2-, and 3-years respectively. Predictors of LF included younger age, and greater volume of overlap between the PTV and esophagus. Median PFS was 8.4 months, while median OS was 3.7 years.

CONCLUSION

In one of the largest case series of ultra-central thoracic SBRT reported to date, homogenously prescribed SBRT plans were associated with relatively low rates of ST and LF across a variety of treatment indications. Predictors of ST should be interpreted recognizing the heterogeneity in toxicities observed. Identified predictors of both ST and LF can contribute to future work to optimize the therapeutic ratio in treatment of ultra-central thoracic tumors.

Toxicity and Efficacy of Multitarget Thoracic Stereotactic Body Radiation Therapy

PURPOSE

With the increasing use of stereotactic body radiation therapy (SBRT) for primary and metastatic cancer, use of multitarget thoracic (MTT) SBRT is rising. Given the limited safety and efficacy data, we report the experience of this strategy from a large academic center.

METHODS AND MATERIALS

Between 2012 and 2021, patients who received SBRT for ≥2 thoracic targets separated by ≤1 year were retrospectively reviewed. The primary endpoint was clinically significant radiation pneumonitis (CSRP) requiring steroids, oxygen, or intubation. Secondary endpoints included local failure (LF), initiation or change of systemic therapy (ICST), progression-free survival, and overall survival. Competing risk analysis was used to evaluate the cumulative incidence of CSRP, LF, and ICST. Univariate and multivariable analyses were performed to look for clinical and dosimetric predictive factors of CSRP and LF.

RESULTS

One hundred ninety patients (481 lesions) were treated with MTT SBRT with a median follow-up of 19.7 months. Indications for SBRT were oligometastases (n = 70; 36.8%), oligoprogression (n = 62; 32.6%), curative intent in patients with primary lung cancer (n = 37; 19.5%), and control of dominant areas of metastatic progression (n = 21; 11.0%). The number of irradiated tumors ranged from 2 to 7 and the majority of SBRT courses were delivered simultaneously (88.2%). Overall, 14 patients (7.4%) had CSRP, with 5 cases requiring oxygen. The cumulative incidence of CSRP at 6 and 12 months was 5.3% and 7.6%, respectively. The cumulative incidence of LF at 2 years was 10.5%. The cumulative incidence of ICST at 2 years was 41.1%. Median progression-free survival was 11.8 months and median overall survival was 51.3 months. On multivariable analysis, a higher lung V35_Gy (hazard ratio, 2.59; P = .02) was a statistically significant predictor of CSRP and colorectal histology predicted for higher LF (hazard ratio, 2.12; P = .02).

CONCLUSIONS

In one of the largest institutional series of MTT SBRT, rates of CSRP and LF were low. Optimizing plans to lower the lung V35_Gy may decrease the risk of CSRP.

Surgical, Radiation, and Systemic Treatments of Patients With Thymic Epithelial Tumors: A Systematic Review

INTRODUCTION

Thymic epithelial tumors are rare and are classified as thymoma, thymic carcinoma, and thymic neuroendocrine tumors. The objective of this systematic review was to evaluate the treatment options for patients with thymic epithelial tumors.

METHODS

This systematic review was developed by Ontario Health (Cancer Care Ontario)'s Program in Evidence-Based Care and by the Lung Cancer Disease Site Group. MEDLINE, EMBASE, and the Cochrane Library were searched for studies comparing surgical, radiotherapy, or systemic treatments against any combination of these treatments in patients with thymic epithelial tumors. Meta-analyses were conducted with clinically homogenous studies.

RESULTS

A total of 106 studies were included, mainly from observational studies. There was an overall survival benefit with postoperative radiotherapy for patients with thymic carcinoma (hazard ratio = 0.65, 95% confidence interval: 0.47-0.89) and for patients with thymoma (hazard ratio = 0.70, 95% confidence interval: 0.59-0.82), especially for those with a high risk for mortality. Patients with thymic carcinoma or thymoma had a response to chemotherapy. Selection bias affected the results for studies that evaluated neoadjuvant chemotherapy or minimally invasive surgical techniques. Furthermore, the overall survival benefit found for adjuvant chemotherapy may have been confounded by the administration of postoperative radiotherapy.

CONCLUSIONS

For patients with thymoma or thymic carcinoma, the literature is of low quality and subject to bias. There were overall survival benefits with postoperative radiotherapy. The results of this systematic review were used to inform treatment recommendations in a clinical practice guideline. Future large-scale prospective studies that control for confounders are needed.

Surgical, Radiation, and Systemic Treatments of Patients with Thymic Epithelial Tumours: A Clinical Practice Guideline

OBJECTIVE

The aim of this guideline was to provide recommendations for the most effective therapy for patients with thymic epithelial tumours, including thymoma, thymic carcinoma, and thymic neuroendocrine tumours. This guideline is intended to be used by all healthcare professionals managing patients with thymic epithelial tumours.

METHODS

The guideline was developed by Ontario Health (Cancer Care Ontario)'s Program in Evidence-Based Care and by the Lung Cancer Disease Site Group through a systematic review of the evidence, expert consensus, and formal internal and external reviews.

RESULTS

Evidence-based recommendations were developed to improve the management of patients with thymic epithelial tumours. The guideline includes recommendations for surgical, radiation, and systemic treatments for patients with thymoma, thymic carcinoma, and thymic neuroendocrine tumours separated by stage of disease using the TNM staging system. Recommendations for patients with thymic neuroendocrine tumours were endorsed from the 2021 National Comprehensive Cancer Network Neuroendocrine and Adrenal Tumors Guideline.

CONCLUSION

This guideline reflects the new staging system for patients with thymoma and thymic carcinoma and includes supporting evidence from the best available studies.

Stereotactic Radiotherapy for Pancreatic Cancer: A Single-Institution Experience

Introduction

Despite treatment advances, the prognosis of locally advanced pancreatic cancer is poor. Treatment remains varied and includes systemic and radiotherapy (RT). Stereotactic body radiotherapy (SBRT), highly conformal high-dose RT per fraction, is an emerging treatment option.

Materials and methods

We performed a single-institution retrospective review of patients with pancreatic adenocarcinoma treated with SBRT from 2015-2017. The median dose was 27 Gy (range: 21-36 Gy) in three fractions. Endpoints included local progression (RECIST 1.1; Response Evaluation Criteria in Solid Tumors 1.1), distant metastasis, overall survival, and toxicity.

Results

Forty-one patients were treated, with a median follow-up of eight months. Patients who received SBRT had unresectable (49%), metastatic (17%), or borderline resectable (7%) disease, declined surgery (17%), medically inoperable (7%), or developed local recurrence following the Whipple procedure (2%). The six-month and one-year rates of local progression-free survival, distant metastasis-free survival, and overall survival were 62% and 55%, 44% and 32%, and 70% and 49%, respectively. Five patients (12%) experienced seven late gastrointestinal (GI) grade 3 events.

Conclusion 

SBRT may be considered a treatment option to achieve local control of pancreatic cancer and is associated with a modest risk of severe late GI toxicities. Systemic therapies remain important, given the proportion of patients who develop distant metastases.

Stereotactic ablative radiotherapy for malignant mediastinal and hilar lymphadenopathy: a systematic review

Background

Stereotactic ablative radiotherapy (SABR) safety and efficacy for mediastinal and hilar lymphadenopathy (MHL) is not yet established, given its potential for toxicity due to the proximity to esophagus and proximal bronchial tree (PBT). This review summarized current reported outcomes of MHL SABR.

Methods

This systematic review, based on the PRISMA guidelines, was performed using MEDLINE® (PubMed®), EMBASE and Cochrane Library databases from inception until December 2018. Studies reporting outcomes from SABR specifically for MHL from all primary malignancies were included. Non- English studies, guidelines, reviews, non-peer reviewed correspondences were excluded. Only the most recent publication and/or largest cohort from a single institution would be included for analysis.

Results

From the 222 studies identified, 4 retrospective studies totaling 196 patients were included in the analysis. One study included a small number of patients receiving non-ablative doses of stereotactic radiotherapy (RT). Non-small cell lung cancer (NSCLC) was the most common primary (65%), followed by breast (8%). Median follow-up ranged between 12 and 32 months. Reported dose and fractionation ranged from 21 to 60 Gy in 3–11 fractions, with median BED10 ranged from 46–106 Gy10. Three studies reported local control (LC) rates: study 1, 97% (1-year) and 77% (5-year); study 4, 88% (2-year); and study 2, 69% (6-month) and 66% (16-month). Pooled grade 3–5 toxicity rate according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0 was 6% (n=11). Pooled SABR-related mortality (grade 5 toxicity) rate was 2% (n=4). Three SABR-related deaths from esophageal fistulae (2 to trachea, 1 to mediastinum) were reported, with all 3 having prior RT to the subcarinal nodes.

Conclusions

Our review suggested SABR for MHL to be feasible and effective, though there is a potential for serious toxicity especially in the re-irradiation scenario. Multi-institutional and/or prospective studies will help determine the therapeutic benefit of SABR in this high-risk treatment scenario.

Intensity Modulated Radiation Therapy Plus Etoposide/Cisplatin for Patients With Limited Advanced Unresectable Thymic Epithelial Tumors: A Prospective Phase 2 Study

PURPOSE

This prospective phase 2 study evaluated the efficacy and safety of intensity modulated radiation therapy plus etoposide/cisplatin (EP) for patients with unresectable thymic epithelial tumors (TETs).

METHODS AND MATERIALS

Patients with limited advanced unresectable TETs whose lesions could be encompassed within radiation fields were enrolled in this study. Two cycles of EP (75 mg/m² etoposide and 25 mg/m² cisplatin on days 1-3 and days 29-31) were administered concurrently with radiation therapy, followed by 2 cycles after radiation therapy. The primary endpoint was the objective response rate. The secondary endpoints were the progression-free survival rate, overall survival rate, and incidence of adverse events.

RESULTS

Fifty-six patients were enrolled between June 2011 and May 2018. Twenty-two and 34 patients had thymomas and thymic carcinomas, respectively. The median age was 52 (range, 21-76) years, and 30 patients (53.6%) were men. Eight patients (14.3%) had stage III tumors, 6 (10.7%) had stage IVA tumors, and 42 (75.0%) had stage IVB tumors. The objective response rate was 85.7% (95% confidence interval, 76.3%-95.2%). With a median follow-up of 46 (range, 7-101) months, the 1-, 2-, and 5-year progression-free survival rates were 66.1%, 48.0%, and 29.5%, and the 1-, 2-, and 5-year overall survival rates were 91.0%, 76.2%, and 56.2%, respectively. The most common grade 3 to 4 adverse event was leukopenia (42.9%). Pulmonary fibrosis was also observed (5.3%).

CONCLUSIONS

Because intensity modulated radiation therapy with EP is effective and safe for limited advanced unresectable TETs, it could be a suitable treatment option for such patients.

Surgery after chemoradiotherapy in patients with stage III (N2 or N3, excluding T4) non-small-cell lung cancer: a systematic review

Background

Chemoradiation with curative intent is considered the standard of care in patients with locally advanced, stage iii non-small-cell lung cancer (nsclc). However, some patients with stage iii (N2 or N3, excluding T4) nsclc might be eligible for surgery. The objective of the present systematic review was to investigate the efficacy of surgery after chemoradiotherapy compared with chemoradiotherapy alone in patients with potentially resectable locally advanced nsclc.

Methods

A search of the medline, embase, and PubMed databases sought randomized controlled trials (rcts) comparing surgery after chemoradiotherapy with chemoradiotherapy alone in patients with stage iii (N2 or N3, excluding T4) nsclc.

Results

Three included rcts consistently found no statistically significant difference in overall survival between patients with locally advanced nsclc who received surgery and chemoradiotherapy or chemoradiotherapy alone. Only one rct found that progression-free survival was significantly longer in patients treated with chemoradiation and surgery (hazard ratio: 0.77; 95% confidence interval: 0.62 to 0.96). In a post hoc analysis of the same trial, the overall survival rate was higher in the surgical group than in matched patients in a chemoradiation-only group if a lobectomy was performed (p = 0.002), but not if a pneumonectomy was performed. Furthermore, fewer treatment-related deaths occurred in patients who underwent lobectomy than in those who underwent pneumonectomy.

Conclusions

For patients with locally advanced nsclc, the benefits of surgery after chemoradiation are uncertain. Surgery after chemoradiation for patients who do not require a pneumonectomy might be an option.

Initial management of small-cell lung cancer (limited- and extensive-stage) and the role of thoracic radiotherapy and first-line chemotherapy: a systematic review

Background

Patients with limited-stage (ls) or extensive-stage (es) small-cell lung cancer (sclc) are commonly given platinum-based chemotherapy as first-line treatment. Standard chemotherapy for patients with ls sclc includes a platinum agent such as cisplatin combined with the non-platinum agent etoposide. The objective of the present systematic review was to investigate the efficacy of adding radiotherapy to chemotherapy in patients with es sclc and to determine the appropriate timing, dose, and schedule of chemotherapy or radiation for patients with sclc.

Methods

The medline and embase databases were searched for randomized controlled trials (rcts) comparing treatment with radiotherapy plus chemotherapy against treatment with chemotherapy alone in patients with es sclc. Identified rcts were also included if they compared various timings, doses, and schedules of treatment for patients with es sclc or ls sclc.

Results

Sixty-four rcts were included. In patients with ls sclc, overall survival was greatest with platinum-etoposide compared with other chemotherapy regimens. In patients with es sclc, overall survival was greatest with chemotherapy containing platinum-irinotecan than with chemotherapy containing platinum-etoposide (hazard ratio: 0.84; 95% confidence interval: 0.74 to 0.95; p = 0.006). The addition of radiation to chemotherapy for patients with es sclc showed mixed results. There was no conclusive evidence that the timing, dose, or schedule of thoracic radiation affected treatment outcomes in sclc.

Conclusions

In patients with ls sclc, cisplatin-etoposide plus radiotherapy should remain the standard therapy. In patients with es sclc, the evidence is insufficient to recommend the addition of radiotherapy to chemotherapy as standard practice to improve overall survival. However, on a case-by-case basis, radiotherapy might be added to reduce local recurrence. The most commonly used chemotherapy is platinum-etoposide; however, platinum-irinotecan can be considered.

Guideline for the Initial Management of Small Cell Lung Cancer (Limited and Extensive Stage) and the Role of Thoracic Radiotherapy and First-line Chemotherapy

AIMS

We investigated the efficacy of adding radiotherapy to chemotherapy in patients with extensive stage small cell lung cancer (ES-SCLC) and the appropriate timing, dose and schedule of treatment for patients with ES-SCLC or limited stage SCLC (LS-SCLC).

MATERIALS AND METHODS

The guideline was developed by Cancer Care Ontario's Program in Evidence-Based Care and by the Lung Cancer Disease Site Group through a systematic review of randomised controlled trials.

KEY RECOMMENDATIONS

In patients with LS-SCLC (stage I, II and III), the addition of thoracic radiotherapy to standard chemotherapy is recommended. However, there is no clear evidence to inform definitive recommendations for optimal timing, sequential versus concurrent therapies and optimal dose or regimen. In patients with LS-SCLC, etoposide-cisplatin is the preferred regimen for adults who are being treated with combined modality therapy with curative intent. In patients with ES-SCLC (stage IV), there is insufficient evidence to recommend the addition of thoracic radiotherapy to standard chemotherapy as a standard practice for survival benefit; however, it could be considered on a case-by-case basis to reduce local recurrence. In patients with ES-SCLC, a platinum agent plus etoposide is the preferred regimen for adult patients who are being treated with combined modality therapy. Cisplatin and irinotecan represents an alternative treatment option to this, but is associated with increased rates of adverse events such as diarrhoea.

How equitable is access to treatment for lung cancer patients? A population-based review of treatment practices in Ontario

Aim:

Guideline concordance is one of the metrics used by the Cancer Quality Council of Ontario and Cancer Care Ontario to assess the quality of cancer care and to drive quality improvement.

Materials & Methods:

The rates for lung cancer surgical resection and concordance with the Cancer Care Ontario postoperative adjuvant chemotherapy (AC) guideline were assessed by health region during two time periods (2010–2011 and 2012–2013) according to five equity measures (age, sex, neighborhood income, location of residence and size of immigrant population).

Results:

Of the patients with stage I/II NSCLC, 52.2% to 63.0% underwent surgical resection in the province of Ontario, Canada; for patients with stage IIIA disease, the rate was 26.4%. The probability of a surgical resection decreased substantially with age; only 26.9% of those with potentially resectable (stage I–IIIA) disease over 80 years underwent surgery. The use of postoperative AC increased modestly over the time of the study but the rate of use varied widely by health region (34.6 to 84.6%). Patients in rural areas were as likely to receive AC as urban dwellers; however, older aged patients (≥65 years) and those from the lowest income neighborhoods were significantly less likely to receive AC.

Conclusion:

Surgical rates and the use of AC vary by health region in Ontario and by age and level of neighborhood income despite universal access in a publicly funded health care system. The reasons for this variance are unclear but warrant further study.

Presented in part at the 15th World Conference on Lung Cancer, Sydney, Australia, 27–30 October 2013

Adjuvant Systemic Therapy and Adjuvant Radiation Therapy for Stage I to IIIA Completely Resected Non-Small-Cell Lung Cancers: American Society of Clinical Oncology/Cancer Care Ontario Clinical Practice Guideline Update

Purpose The panel updated the American Society of Clinical Oncology (ASCO) adjuvant therapy guideline for resected non-small-cell lung cancers. Methods ASCO convened an update panel and conducted a systematic review of the literature, investigating adjuvant therapy in resected non-small-cell lung cancers. Results The updated evidence base covered questions related to adjuvant systemic therapy and included a systematic review conducted by Cancer Care Ontario current to January 2016. A recent American Society for Radiation Oncology guideline and systematic review, previously endorsed by ASCO, was used as the basis for recommendations for adjuvant radiation therapy. An update of these systematic reviews and a search for studies related to radiation therapy found no additional randomized controlled trials. Recommendations Adjuvant cisplatin-based chemotherapy is recommended for routine use in patients with stage IIA, IIB, or IIIA disease who have undergone complete surgical resections. For individuals with stage IB, adjuvant cisplatin-based chemotherapy is not recommended for routine use. However, a postoperative multimodality evaluation, including a consultation with a medical oncologist, is recommended to assess benefits and risks of adjuvant chemotherapy for each patient. The guideline provides information on factors other than stage to consider when making a recommendation for adjuvant chemotherapy, including tumor size, histopathologic features, and genetic alterations. Adjuvant chemotherapy is not recommended for patients with stage IA disease. Adjuvant radiation therapy is not recommended for patients with resected stage I or II disease. In patients with stage IIIA N2 disease, adjuvant radiation therapy is not recommended for routine use. However, a postoperative multimodality evaluation, including a consultation with a radiation oncologist, is recommended to assess benefits and risks of adjuvant radiation therapy for each patient with N2 disease. Additional information is available at www.asco.org/lung-cancer-guidelines and www.asco.org/guidelineswiki .

Adjuvant Systemic Therapy and Adjuvant Radiation Therapy for Stage I to IIIA Completely Resected Non-Small-Cell Lung Cancers: American Society of Clinical Oncology/Cancer Care Ontario Clinical Practice Guideline Update

Purpose The panel updated the American Society of Clinical Oncology (ASCO) adjuvant therapy guideline for resected non-small-cell lung cancers. Methods ASCO convened an update panel and conducted a systematic review of the literature, investigating adjuvant therapy in resected non-small-cell lung cancers. Results The updated evidence base covered questions related to adjuvant systemic therapy and included a systematic review conducted by Cancer Care Ontario current to January 2016. A recent American Society for Radiation Oncology guideline and systematic review, previously endorsed by ASCO, was used as the basis for recommendations for adjuvant radiation therapy. An update of these systematic reviews and a search for studies related to radiation therapy found no additional randomized controlled trials. Recommendations Adjuvant cisplatin-based chemotherapy is recommended for routine use in patients with stage IIA, IIB, or IIIA disease who have undergone complete surgical resections. For individuals with stage IB, adjuvant cisplatin-based chemotherapy is not recommended for routine use. However, a postoperative multimodality evaluation, including a consultation with a medical oncologist, is recommended to assess benefits and risks of adjuvant chemotherapy for each patient. The guideline provides information on factors other than stage to consider when making a recommendation for adjuvant chemotherapy, including tumor size, histopathologic features, and genetic alterations. Adjuvant chemotherapy is not recommended for patients with stage IA disease. Adjuvant radiation therapy is not recommended for patients with resected stage I or II disease. In patients with stage IIIA N2 disease, adjuvant radiation therapy is not recommended for routine use. However, a postoperative multimodality evaluation, including a consultation with a radiation oncologist, is recommended to assess benefits and risks of adjuvant radiation therapy for each patient with N2 disease. Additional information is available at www.asco.org/lung-cancer-guidelines and www.asco.org/guidelineswiki .

Guideline for radiotherapy with curative intent in patients with early-stage medically inoperable non-small-cell lung cancer

OBJECTIVES

For this guideline, we investigated the effectiveness of radiotherapy with curative intent in medically inoperable patients with early-stage non-small-cell lung cancer (nsclc).

METHODS

The guideline was developed by Cancer Care Ontario's Program in Evidence-Based Care and by the Lung Cancer Disease Site Group through a systematic review of mainly retrospective studies, expert consensus, and formal internal and external reviews.

RECOMMENDATIONS

■ Stereotactic body radiation therapy (sbrt) with curative intent is an option that should be considered for patients with early-stage, node-negative, medically inoperable nsclc. Qualifying Statements■ Because of the high dose per fraction, the planning process and treatment delivery for sbrt require the use of advanced technology to maintain an appropriate level of safety. Consistent patient positioning and 4-dimensional analysis of tumour and critical structure motion during simulation and treatment delivery are essential.■ Preliminary results for proton-beam therapy have been promising, but the technique requires further clinical study.■ Recommended fractionation schemes for sbrt should result in a biologically effective dose of 100 or greater by the linear quadric model, choosing an α/β value of 10 [bed_10(LQ) ≥ 100]. Qualifying Statements■ Because of the increased risk of treatment-related adverse events associated with centrally located tumours, consideration of tumour size and proximity to critical central structures is required when determining the dose and fractionation.■ Examples of dose-fractionation schemes used in the included studies have been provided.■ Based on the current evidence and the opinion of the authors, radiation doses at bed_10(LQ) greater than 146 might significantly increase toxicity and should be avoided.■ Determination of the radiation bed by the linear quadratic model has limitations for the extreme hypofractionated schemes used in sbrt.

Immune Checkpoint Inhibitors for Patients With Advanced Non-Small-Cell Lung Cancer: A Systematic Review

Second-line treatment options are limited for patients with advanced non-small-cell lung cancer (NSCLC). Standard therapy includes the cytotoxic agents docetaxel and pemetrexed, and the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors erlotinib and gefitinib. Immune checkpoint inhibitors are a new class of treatment that have shown durable overall radiologic response rates and have been well tolerated. The objective of this systematic review was to investigate the efficacy of immune checkpoint inhibitors compared with other chemotherapies in patients with advanced NSCLC. Medline, Embase, and PubMed were searched for randomized controlled trials comparing treatment with immune checkpoint inhibitors against treatment with chemotherapy in patients with stage IIIB or IV NSCLC. Nine randomized controlled trials with 15 publications were included. A significant overall survival benefit of second-line nivolumab (nonsquamous: hazard ratio [HR] = 0.72, 95% confidence interval [CI], 0.60-0.77; P < .001; squamous: HR = 0.59, 95% CI, 0.44-0.79; P < .001) or second-line atezolizumab (HR = 0.73, 95% CI, 0.62-0.87; P = .0003) or second-line pembrolizumab (in patients with programmed cell death ligand 1 [PD-L1]-positive tumors) (pembrolizumab 2 mg/kg HR = 0.71, 95% CI, 0.58-0.88; P = .0008; pembrolizumab 10 mg/kg HR = 0.61, 95% CI, 0.49-0.75; P < .0001) or first-line pembrolizumab (HR = 0.60, 95% CI, 0.41-0.89; P = .005) compared with chemotherapy was found. The adverse effects were mainly higher in the chemotherapy arms. For patients with advanced stage IIIB/IV NSCLC, the improvement in overall survival outweighed the harms and supported the use of first-line pembrolizumab (in patients with ≥ 50% PD-L1-positive tumors) or second-line nivolumab, atezolizumab, or pembrolizumab (in patients with PD-L1-positive tumors).

A Phase II Trial of Erlotinib and Concurrent Palliative Thoracic Radiation for Patients With Non-Small-Cell Lung Cancer

BACKGROUND

The downstream signaling pathways of the epidermal growth factor receptor might influence radiation resistance. Data from preclinical work support the hypothesis that erlotinib concurrent with radiation therapy (RT) might increase cancer cell killing. The present trial was designed to examine the efficacy and toxicity of combined erlotinib and palliative chest thoracic RT in non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Patients with newly diagnosed stage III-IV (American Joint Committee on Cancer, version 6) or recurrent NSCLC received 3 weeks of erlotinib at a dose of 150 mg daily, starting 1 week before palliative thoracic RT to 30 Gy in 10 fractions within 2 weeks. The primary outcome was a change in the quality of life, as measured by the Lung Cancer Symptom Scale (LCSS) question on the "symptoms of lung cancer" from baseline to 4 weeks after treatment.

RESULTS

A total of 40 patients were recruited from 2 institutions. Of the 40 patients, 22 (55%) were men, with an average age of 71 years, and 60% had stage IV disease. A total of 26 patients (65%) completed the full course of erlotinib, and 35 (88%) completed the planned RT. Twenty-five patients (62.5%) reported LCSS scores at 4 weeks after treatment, with an average change (improvement) of -12.5 U (95% confidence interval, -23.0 to -1.9; 2P = .023). This was less than the a priori hypothesis of a change of -17.5 U. The median overall and progression-free survival was 5.2 and 3.2 months, respectively.

CONCLUSION

The present single-arm, phase II trial did not demonstrate additional symptomatic benefit from concurrent erlotinib therapy with standard palliative thoracic RT for patients with locally advanced or metastatic NSCLC.

Phase II study of accelerated hypofractionated three-dimensional conformal radiotherapy for stage T1-3 N0 M0 non-small cell lung cancer: NCIC CTG BR.25

BACKGROUND

A multi-institutional phase II trial was performed to assess a hypofractionated accelerated radiotherapy regimen for early stage non-small cell lung cancer (NSCLC) in an era when stereotactic body radiotherapy was not widely available.

METHODS

Eighty patients with biopsy-proven, peripherally located, T1-3 N0 M0 NSCLC were enrolled. Eligible patients received 60 Gy in 15 fractions using a three-dimensional conformal technique without inhomogeneity correction. The gross tumour volume (GTV) was the primary tumor only, and the planning target volume (PTV) margin was 1.0 to 1.5cm. The primary endpoint was the 2-year primary tumor control rate. Toxicities were measured using the Common Terminology Criteria for Adverse Events version 3.0.

RESULTS

The median follow-up of patients was 49 months (range = 21-63 months). The median age of patients was 75.9 years. The actuarial rate of primary tumor control was 87.4% (95% confidence interval [CI] = 76.2% to 93.5%) at 2 years. Overall survival was 68.7% (95% CI = 57.2% to 77.6%) at 2 years. The actuarial rates of developing regional and distant relapse at 2 years were 8.8% (95% CI = 4.1% to 18.7%) and 21.6% (95% CI = 13.5% to 33.5%), respectively. Tumor size greater than 3cm was associated with an increased risk of developing distant relapse (hazard ratio = 3.11; 95% CI = 1.30 to 7.42; two-sided log-rank test P = .007). The most common grade 3+ toxicities were fatigue (6.3%), cough (7.5%), dyspnea (13.8%), and pneumonitis (10.0%)

CONCLUSIONS

Conformal radiotherapy to a dose of 60 Gy in 15 fractions resulted in favorable primary tumor control and overall survival rates in patients with T1-3 N0 M0 NSCLC. Severe toxicities were uncommon with this relatively simple treatment technique.

Phase II study of accelerated hypofractionated three-dimensional conformal radiotherapy for stage T1-3 N0 M0 non-small cell lung cancer: NCIC CTG BR.25

BACKGROUND

A multi-institutional phase II trial was performed to assess a hypofractionated accelerated radiotherapy regimen for early stage non-small cell lung cancer (NSCLC) in an era when stereotactic body radiotherapy was not widely available.

METHODS

Eighty patients with biopsy-proven, peripherally located, T1-3 N0 M0 NSCLC were enrolled. Eligible patients received 60 Gy in 15 fractions using a three-dimensional conformal technique without inhomogeneity correction. The gross tumour volume (GTV) was the primary tumor only, and the planning target volume (PTV) margin was 1.0 to 1.5cm. The primary endpoint was the 2-year primary tumor control rate. Toxicities were measured using the Common Terminology Criteria for Adverse Events version 3.0.

RESULTS

The median follow-up of patients was 49 months (range = 21-63 months). The median age of patients was 75.9 years. The actuarial rate of primary tumor control was 87.4% (95% confidence interval [CI] = 76.2% to 93.5%) at 2 years. Overall survival was 68.7% (95% CI = 57.2% to 77.6%) at 2 years. The actuarial rates of developing regional and distant relapse at 2 years were 8.8% (95% CI = 4.1% to 18.7%) and 21.6% (95% CI = 13.5% to 33.5%), respectively. Tumor size greater than 3cm was associated with an increased risk of developing distant relapse (hazard ratio = 3.11; 95% CI = 1.30 to 7.42; two-sided log-rank test P = .007). The most common grade 3+ toxicities were fatigue (6.3%), cough (7.5%), dyspnea (13.8%), and pneumonitis (10.0%)

CONCLUSIONS

Conformal radiotherapy to a dose of 60 Gy in 15 fractions resulted in favorable primary tumor control and overall survival rates in patients with T1-3 N0 M0 NSCLC. Severe toxicities were uncommon with this relatively simple treatment technique.

A mixed methods approach to understand variation in lung cancer practice and the role of guidelines

INTRODUCTION

Practice pattern data demonstrate regional variation and lower than expected rates of adherence to practice guideline (PG) recommendations for the treatment of stage II/IIIA resected and stage IIIA/IIIB unresected non-small cell lung cancer (NSCLC) patients in Ontario, Canada. This study sought to understand how clinical decisions are made for the treatment of these patients and the role of PGs.

METHODS

Surveys and key informant interviews were undertaken with clinicians and administrators.

RESULTS

Participants reported favorable ratings for PGs and the evidentiary bases underpinning them. The majority of participants agreed more patients should have received treatment and that regional variation is problematic. Participants estimated that up to 30% of patients are not good candidates for treatment and up to 20% of patients refuse treatment. The most common barrier to implementing PGs was the lack of organizational support by clinical administrative leadership. There was concern that the trial results underpinning the PG recommendations were not generalizable to the typical patients seen in clinic. The qualitative analysis yielded five themes related to physicians' decision making: the unique patient, the unique physician, the family, the clinical team, and the clinical evidence. A dynamic interplay between these factors exists.

CONCLUSION

Our study demonstrates the challenges inherent in (i) the complexity of clinical decision making; (ii) how quality of care problems are perceived and operationalized; and (iii) the clinical appropriateness and utility of PG recommendations. We argue that systematic and rigorous methodologies to help decision makers mitigate or negotiate these challenges are warranted.

Neoadjuvant chemoradiotherapy and multivisceral resection for primary locally advanced adherent colon cancer: a single institution experience

BACKGROUND

Although there is an extensive body of literature on the role of neoadjuvant chemoradiotherapy (CRT) in the management of rectal cancer, its role in primary locally advanced adherent colon cancer (LAACC) is unclear.

OBJECTIVE

To analyzed the outcomes of neoadjuvant CRT and multivisceral resection in the management of LAACC patietns.

METHODS

We retrospectively reviewed our institutional Colorectal Carcinoma Database for 33 patients with potentially resectable, non-metastatic primary LAACC who received neoadjuvant CRT followed by multivisceral resection. CRT consisted of external beam radiation (45-50 Gy in 25 daily fractions) and concurrent 5-FU infusion (225 mg/m(2)/day).

RESULTS

There were 21 males and 12 females. Median age was 64 (31-83) and median follow-up was 36 months. All patients had microscopically clear resection margins (R0). Complete pathologic response was documented in 1 patient (3%) and 66% had ypT4b disease. Post-operative complications were observed in 36% of patients with no 30-day mortality. The 3-year overall survival and 3-year disease-free survival were 85.9% and 73.7% respectively. Two patients developed a local recurrence.

CONCLUSIONS

Neoadjuvant CRT and en-bloc multivisceral resection may result in high rates of R0 resection and excellent local control with acceptable morbidity and mortality in selected patients with LAACC.

Autocontouring and manual contouring: which is the better method for target delineation using 18F-FDG PET/CT in non-small cell lung cancer?

Previously, we showed that a CT window and level setting of 1,600 and -300 Hounsfield units, respectively, and autocontouring using an (18)F-FDG PET 50% intensity level correlated best with pathologic results. The aim of this study was to compare this autocontouring with manual contouring, to determine which method is better.

METHODS

Seventeen patients with non-small cell lung cancer underwent (18)F-FDG PET/CT before surgery. The maximum diameter on pathologic examination was determined. Seven sets of gross tumor volumes (GTVs) were defined. The first set (GTV(CT)) was contoured manually using only CT information. The second set (GTV(Auto)) was autocontoured using a 50% intensity level for (18)F-FDG PET images. The third set (GTV(Manual)) was manually contoured using a visual method on PET images. The other 4 sets combined CT and (18)F-FDG PET images fused to one another to become composite volumes: GTV(CT+Auto), GTV(CT+Manual), GTV(CT-Auto), and GTV(CT-Manual). To quantitate the degree to which CT and (18)F-FDG PET defined the same region of interest, a matching index was calculated for each case. The maximum diameter of GTV was compared with the maximum diameter on pathologic examination.

RESULTS

The median GTV(CT), GTV(Auto), GTV(Manual), GTV(CT+Auto), GTV(CT+Manual), GTV(CT-Auto), and GTV(CT-Manual) were 6.96, 2.42, 4.37, 7.46, 10.17, 2.21, and 3.38 cm(3), respectively. The median matching indexes of GTV(CT) versus GTV(CT+Auto), GTV(Auto) versus GTV(CT+Auto), GTV(CT) versus GTV(CT+Manual), and GTV(Manual) versus GTV(CT+Manual) were 0.86, 0.65, 0.88, and 0.81, respectively. Compared with the maximum diameter on pathologic examination, the correlations of GTV(CT), GTV(Auto), GTV(Manual), GTV(CT+Auto), and GTV(CT+Manual) were 0.87, 0.83, 0.93, 0.86, and 0.94, respectively.

CONCLUSION

The matching index was higher for manual contouring than for autocontouring using a 50% intensity level on (18)F-FDG PET images. When using a 50% intensity level to contour the target of non-small cell lung cancer, one should also consider using manual contouring of (18)F-FDG PET to check for any missed disease.

PET CT thresholds for radiotherapy target definition in non-small-cell lung cancer: how close are we to the pathologic findings?

PURPOSE

Optimal target delineation threshold values for positron emission tomography (PET) and computed tomography (CT) radiotherapy planning is controversial. In this present study, different PET CT threshold values were used for target delineation and then compared pathologically.

METHODS AND MATERIALS

A total of 31 non-small-cell lung cancer patients underwent PET CT before surgery. The maximal diameter (MD) of the pathologic primary tumor was obtained. The CT-based gross tumor volumes (GTV(CT)) were delineated for CT window-level thresholds at 1,600 and -300 Hounsfield units (HU) (GTV(CT1)); 1,600 and -400 (GTV(CT2)); 1,600 and -450 HU (GTV(CT3)); 1,600 and -600 HU (GTV(CT4)); 1,200 and -700 HU (GTV(CT5)); 900 and -450 HU (GTV(CT6)); and 700 and -450 HU (GTV(CT7)). The PET-based GTVs (GTV(PET)) were autocontoured at 20% (GTV(20)), 30% (GTV(30)), 40% (GTV(40)), 45% (GTV(45)), 50% (GTV(50)), and 55% (GTV(55)) of the maximal intensity level. The MD of each image-based GTV in three-dimensional orientation was determined. The MD of the GTV(PET) and GTV(CT) were compared with the pathologically determined MD.

RESULTS

The median MD of the GTV(CT) changed from 2.89 (GTV(CT2)) to 4.46 (GTV(CT7)) as the CT thresholds were varied. The correlation coefficient of the GTV(CT) compared with the pathologically determined MD ranged from 0.76 to 0.87. The correlation coefficient of the GTV(CT1) was the best (r=0.87). The median MD of GTV(PET) changed from 5.72 cm to 2.67 cm as the PET thresholds increased. The correlation coefficient of the GTV(PET) compared with the pathologic finding ranged from 0.51 to 0.77. The correlation coefficient of GTV(50) was the best (r=0.77).

CONCLUSION

Compared with the MD of GTV(PET), the MD of GTV(CT) had better correlation with the pathologic MD. The GTV(CT1) and GTV(50) had the best correlation with the pathologic results.

Positron emission tomography in staging early lung cancer: a randomized trial

BACKGROUND

Among patients with early-stage non-small cell lung cancer (NSCLC), preoperative imaging tests are important in defining surgical candidates.

OBJECTIVE

To assess whether whole-body positron emission tomography and computed tomography (PET-CT) plus cranial imaging correctly upstages cancer in more patients with NSCLC than does conventional staging plus cranial imaging.

DESIGN

Randomized clinical trial with recruitment from June 2004 to August 2007. The centralized, computer-generated, variable block size randomization scheme was stratified by treatment center and cancer stage. Participants, health care providers, and outcome assessors were not blinded to imaging modality assignment.

SETTING

8 hospitals and 5 PET-CT centers in academic institutions.

PATIENTS

Eligible patients were older than 18 years; had histologic or cytologic proof of stage I, II, or IIIA NSCLC on the basis of chest radiography and thoracic CT; and had a tumor considered to be resectable.

INTERVENTION

PET-CT or conventional staging (abdominal CT and bone scan). All patients also had cranial imaging using CT or magnetic resonance imaging.

MEASUREMENTS

The primary outcome was correct upstaging, thereby avoiding stage-inappropriate surgery. Secondary outcomes were incorrect upstaging and incorrect understaging.

RESULTS

170 patients were assigned to PET-CT and 167 to conventional staging. Eight patients (3 who had PET-CT and 5 who had conventional staging) did not have planned surgery. Disease was correctly upstaged in 23 of 167 PET-CT recipients and 11 of 162 conventional staging recipients (13.8% vs. 6.8%; difference, 7.0 percentage points [95% CI, 0.3 to 13.7 percentage points]), thereby sparing these patients from surgery. Disease was incorrectly upstaged in 8 PET-CT recipients and 1 conventional staging recipient (4.8% vs. 0.6%; difference, 4.2 percentage points [CI, 0.5 to 8.6 percentage points]), and it was incorrectly understaged in 25 and 48 patients, respectively (14.9% vs. 29.6%; difference, 14.7 percentage points [CI, 5.7 to 23.4 percentage points]). At 3 years, 52 patients who had PET-CT and 57 patients who had conventional staging had died.

LIMITATION

The relatively small sample and the fact that some patients did not have planned surgery limited the ability to determine precise differences in clinical outcomes that were attributable to testing strategies.

CONCLUSION

Preoperative staging with PET-CT and cranial imaging identifies more patients with mediastinal and extrathoracic disease than conventional staging, thereby sparing more patients from stage-inappropriate surgery, but the strategy also incorrectly upstaged disease in more patients.

Adjuvant radiotherapy for gastric cancer: A dosimetric comparison of 3-dimensional conformal radiotherapy, tomotherapy and conventional intensity modulated radiotherapy treatment plans

Some patients with gastric cancer benefit from post-operative chemo-radiotherapy, but adequately irradiating the planning target volume (PTV) whilst avoiding organs at risk (OAR) can be difficult. We evaluate 3-dimensional conformal radiotherapy (CRT), conventional intensity-modulated radiotherapy (IMRT) and helical tomotherapy (TT). TT, 2 and 5-field (F) CRT and IMRT treatment plans with the same PTV coverage were generated for 5 patients and compared. Median values are reported. The volume of left/right kidney receiving at least 20Gy (V20) was 57/51% and 51/60% for 2 and 5F-CRT, and 28/14% for TT and 27/19% for IMRT. The volume of liver receiving at least 30Gy (V30) was 45% and 62% for 2 and 5F-CRT, and 37% for TT and 35% for IMRT. With TT, 98% of the PTV received 95-105% of the prescribed dose, compared with 45%, 34% and 28% for 2F-CRT, 5F-CRT and IMRT respectively. Using conventional metrics, conventional IMRT can achieve comparable PTV coverage and OAR sparing to TT, but at the expense of PTV dose heterogeneity. Both irradiate large volumes of normal tissue to low doses. Additional studies are needed to demonstrate the clinical impact of these technologies.

18F-fluorodeoxyglucose positron emission tomography-computed tomography for suspected recurrent papillary thyroid cancer: early experience at Sunnybrook Health Sciences Centre

OBJECTIVES

To report the initial experience with combined 18F-fluorodeoxyglucose positron emission tomography (FDG PET)/computed tomography (CT) imaging for suspected recurrent papillary differentiated thyroid cancer (DTC) at Sunnybrook Health Sciences Centre (SHSC), Toronto.

DESIGN

Single institution retrospective study.

METHODS

Consecutive patients from SHSC who underwent FDG PET/CT imaging for suspected recurrent DTC over a period of 2.5 years were identified and their charts reviewed.

MAIN OUTCOME MEASURE

Qualitative appraisal of FDG PET/CT imaging in suspected recurrent DTC.

RESULTS

Sixteen patients (14F, 2M) were identified accounting for 17 FDG PET/CT scans. Three scans (18%) in 3 different patients were reported as suspicious for recurrent disease in the neck (1-3 lesions) and were considered "positive". All were subsequently confirmed pathologically (4-13 positive lymph nodes post operatively). Prior conventional imaging was abnormal in two patients. Two patients had an elevated non-stimulated thyroglobulin (TG) < 10 ng/mL (4.9 and 9.4). The remaining patient had a TG < 0.3 ng/mL but was anti-TG antibody positive (84 IUx10-3/L). With a median follow up of 15 months (range 7-36) there were no false positive or negative scans. Incidental pathology (breast cancer, large bowel polyps) was identified on a further 2/17 scans (12%).

CONCLUSIONS

FDG PET/CT imaging is able to detect recurrent DTC in patients with low TG levels. It can complement conventional imaging findings and exclude distant FDG-avid metastases prior to surgery. It may underestimate the number of positive lymph nodes in the neck. Occult pathology may be identified with whole body FDG PET/CT.

Phase III trial of maintenance gefitinib or placebo after concurrent chemoradiotherapy and docetaxel consolidation in inoperable stage III non-small-cell lung cancer: SWOG S0023

PURPOSE

Early clinical studies with gefitinib showed promising efficacy and mild toxicity in patients with advanced non-small-cell lung cancer (NSCLC). Thus, gefitinib was an ideal agent to evaluate in a maintenance setting in stage III disease.

PATIENTS AND METHODS

Untreated patients with stage III NSCLC, a performance score of 0 to 1, and adequate organ function were eligible. All patients received cisplatin 50 mg/m(2) on days 1 and 8 plus etoposide 50 mg/m(2) on days 1 to 5, every 28 days for two cycles with concurrent thoracic radiation (1.8- to 2-Gy fractions per day; total dose, 61 Gy) followed by three cycles of docetaxel 75 mg/m(2). Patients whose disease did not progress were randomly assigned to gefitinib 250 mg/d or placebo until disease progression, intolerable toxicity, or the end of 5 years. The planned sample size was 672 patients to confer power of 0.89 to detect a 33% increase over the expected median survival time of 21 months (one-sided P = .025, log-rank test). Random assignment was stratified by stage, histology, and measurable versus nonmeasurable disease.

RESULTS

Enrollment began in July 2001. An unplanned interim analysis conducted in April 2005 rejected the alternative hypothesis of improved survival at the P = .0015 level for 243 randomly assigned patients. The study closed, and preliminary results were reported. Now, with a median follow-up time of 27 months, median survival time was 23 months for gefitinib (n = 118) and 35 months for placebo (n = 125; two-sided P = .013). The toxic death rate was 2% with gefitinib compared with 0% for placebo.

CONCLUSION

In this unselected population, gefitinib did not improve survival. Decreased survival was a result of tumor progression and not gefitinib toxicity.

Cancer Care Ontario and American Society of Clinical Oncology adjuvant chemotherapy and adjuvant radiation therapy for stages I-IIIA resectable non small-cell lung cancer guideline

PURPOSE

To determine the role of adjuvant chemotherapy and radiation therapy in patients with completely resected stage IA-IIIA non-small-cell lung cancer (NSCLC).

METHODS

The Cancer Care Ontario Program in Evidence-Based Care and the American Society of Clinical Oncology convened a Joint Expert Panel in August 2006 to review the evidence and draft recommendations for these therapies.

RESULTS

Available data support the use of adjuvant cisplatin-based chemotherapy in completely resected NSCLC; however, the strength of the data and consequent recommendations vary by disease stage. Adjuvant radiation therapy appears detrimental to survival in stages IB and II, with a possible modest benefit in stage IIIA.

CONCLUSION

Adjuvant cisplatin-based chemotherapy is recommended for routine use in patients with stages IIA, IIB, and IIIA disease. Although there has been a statistically significant overall survival benefit seen in several randomized clinical trials (RCTs) enrolling a range of people with completely resected NSCLC, results of subset analyses for patient populations with stage IB disease were not significant, and adjuvant chemotherapy in stage IB disease is not currently recommended for routine use. To date, very few patients with stage IA NSCLC have been enrolled onto RCTs of adjuvant therapy; adjuvant chemotherapy is not recommended in these cases. Evidence from RCTs demonstrates a survival detriment for adjuvant radiotherapy with limited evidence for a reduction in local recurrence. Adjuvant radiation therapy appears detrimental to survival in stage IB and II, and may possibly confer a modest benefit in stage IIIA.

Randomized, double-blind, placebo-controlled trial of erythropoietin in non-small-cell lung cancer with disease-related anemia

PURPOSE

Previous trials have suggested a quality-of-life (QOL) improvement for anemic cancer patients treated with erythropoietin, but few used QOL as the primary outcome. We designed a trial to investigate the effects of epoetin alfa therapy on the QOL of anemic patients with advanced non-small-cell carcinoma of the lung (NSCLC).

PATIENTS AND METHODS

A multicenter, randomized, double-blind, placebo-controlled trial was conducted. The proposed sample size was 300 patients. Eligible patients were required to have NSCLC unsuitable for curative therapy and baseline hemoglobin (Hgb) levels less than 121 g/L. Patients were assigned to 12 weekly injections of subcutaneous epoetin alpha or placebo, targeting Hgb levels between 120 and 140 g/L. The primary outcome was the difference in the change in Functional Assessment of Cancer Therapy-Anemia scores between baseline and 12 weeks.

RESULTS

Reports of thrombotic events in other epoetin trials prompted an unplanned safety analysis after 70 patients had been randomly assigned (33 to the active arm and 37 to the placebo arm). This revealed a significant difference in the median survival in favor of the patients on the placebo arm of the trial (63 v 129 days; hazard ratio, 1.84; P = .04). The Steering Committee closed the trial. Patient numbers compromised the interpretation of the QOL analysis, but a positive Hgb response was noted with epoetin alfa treatment.

CONCLUSION

An unplanned safety analysis suggested decreased overall survival in patients with advanced NSCLC treated with epoetin alfa. Although infrequent, other similar reports highlight the need for ongoing trials evaluating erythropoietin receptor agonists to ensure that overall survival is monitored closely.

The role of high-dose-rate brachytherapy in the palliation of symptoms in patients with non-small-cell lung cancer: a systematic review

PURPOSE

This review addresses the role of high-dose-rate endobronchial brachytherapy (HDREB) for symptom palliation in patients with non-small-cell lung cancer.

METHODS AND MATERIALS

Relevant trials were identified through a systematic search of the literature.

RESULTS

Twenty-nine trials were eligible. Six randomized trials involved HDREB alone or with external beam radiation therapy (EBR) or laser therapy. Median and 1-year survival ranged from 4 to 10 months and from 11% to 38%, respectively. Symptoms controlled by HDREB were dyspnea, cough, chest pain, and hemoptysis. Fatal hemoptysis ranged from 7% to 22%. Better overall symptom palliation and fewer retreatments were required in previously untreated patients using EBR alone or EBR with HDREB.

CONCLUSIONS

EBR alone is more effective than HDREB for symptom palliation in previously untreated patients with endobronchial non-small-cell lung cancer. HDREB with EBR seems to provide better symptom relief than EBR alone. HDREB is recommended for symptomatic patients with recurrent endobronchial obstruction previously treated by EBR, providing it is technically feasible.

The role of radiation therapy in malignant pleural mesothelioma: a systematic review

INTRODUCTION

Radiation therapy may offer patients presenting with malignant pleural mesothelioma (MPM) symptom palliation and improvements in quality of life. This systematic review will address the role of radiation therapy in the management of MPM.

METHODS

A thorough systematic search of the literature was conducted for published articles and conference proceedings for applicable abstracts. Relevant trials were selected and assessed.

RESULTS

Three small randomized controlled trials compared prophylactic external beam radiation therapy to no radiation therapy for patients with thoracic tracts caused by drainage tubes or diagnostic procedures. None of those trials reported any serious adverse effects. A pooled analysis found no significant reduction in the frequency of procedure tract metastases. Four non-comparative studies have shown that hemithoracic irradiation alone resulted in significant toxicity, including radiation-induced pulmonary fibrosis, radiation pneumonitis, and bronchopleural fistula, without any survival benefit. Few of the identified studies reported on symptom control, and no studies included formal measures of quality of life.

CONCLUSION

There is limited evidence for the role of radiotherapy in the management of patients with MPM. Future studies including radiotherapy for the treatment of such patients should include formal measures of quality of life and symptom control.

Management of unresected stage III non-small cell lung cancer: a systematic review

PURPOSE

To conduct a systematic review to determine the most effective therapy for patients with unresected stage III non-small cell lung cancer.

METHODS

Relevant randomized trials and meta-analyses were identified through a systematic search of the literature.

RESULTS

Forty-seven trials and six meta-analyses were included. No statistically significant survival differences were detected for immediate versus delayed administration of radiotherapy or different doses of hyperfractionated radiotherapy. Three of 12 trials comparing various doses and schedules of radiotherapy detected a statistically significant survival advantage with higher radiation doses. All meta-analyses found a statistically significant survival advantage for chemoradiation, particularly platinum-based, compared with radiation alone. One meta-analysis and three trials comparing concurrent with sequential chemoradiation detected a statistically significant survival advantage with concurrent administration. Increased toxicities, especially esophagitis and hematologic events, were generally associated with concurrent chemoradiation. The survival advantage for concurrent platinum-based chemoradiation corresponds to a 4% absolute survival benefit at 2 years. With respect to trials comparing different chemotherapy regimens or schedules, there is insufficient evidence to determine which particular regimen or schedule is most effective.

CONCLUSION

Palliative radiotherapy can provide symptom relief for symptomatic patients with poor performance status. For patients with good performance status, chemoradiation improves survival compared with radiotherapy alone, particularly when the two modalities are administered concurrently. Sequential chemoradiation is a treatment option for borderline-status patients. Adequate assessment of performance status is important when evaluating treatment options for patients with unresected non-small cell lung cancer. Patients and physicians should have a full discussion of the benefits, limitations, and toxicities of therapy.

Reproducibility of lung tumor position and reduction of lung mass within the planning target volume using active breathing control (ABC)

PURPOSE

The active breathing control (ABC) device allows for temporary immobilization of respiratory motion by implementing a breath hold at a predefined relative lung volume and air flow direction. The purpose of this study was to quantitatively evaluate the ability of the ABC device to immobilize peripheral lung tumors at a reproducible position, increase total lung volume, and thereby reduce lung mass within the planning target volume (PTV).

MATERIALS AND METHODS

Ten patients with peripheral non-small-cell lung cancer tumors undergoing radiotherapy had CT scans of their thorax with and without ABC inspiration breath hold during the first 5 days of treatment. Total lung volumes were determined from the CT data sets. Each peripheral lung tumor was contoured by one physician on all CT scans to generate gross tumor volumes (GTVs). The lung density and mass contained within a 1.5-cm PTV margin around each peripheral tumor was calculated using CT numbers. Using the center of the GTV from the Day 1 ABC scan as the reference, the displacement of subsequent GTV centers on Days 2 to 5 for each patient with ABC applied was calculated in three dimensions.

RESULTS

With the use of ABC inspiration breath hold, total lung volumes increased by an average of 42%. This resulted in an average decrease in lung mass of 18% within a standard 1.5-cm PTV margin around the GTV. The average (+/- standard deviation) displacement of GTV centers with ABC breath hold applied was 0.3 mm (+/- 1.8 mm), 1.2 mm (+/- 2.3 mm), and 1.1 mm (+/- 3.5 mm) in the lateral direction, anterior-posterior direction, and superior-inferior direction, respectively.

CONCLUSIONS

Results from this study indicate that there remains some inter-breath hold variability in peripheral lung tumor position with the use of ABC inspiration breath hold, which prevents significant PTV margin reduction. However, lung volumes can significantly increase, thereby decreasing the mass of lung within a standard PTV.

Accelerated hypofractionation for early-stage non-small-cell lung cancer

PURPOSE

To describe the outcome of treating early-stage non-small-cell lung cancer (NSCLC) with an accelerated hypofractionated course of radiotherapy.

METHODS AND MATERIALS

A policy of treating early-stage NSCLC with a dose of 48 Gy in 12 once-daily fractions without elective irradiation of radiologically uninvolved regional nodes was adopted in 1996. We describe the outcome in 33 patients with NSCLC treated with this dose-fractionation schedule.

RESULTS

The median patient age was 72.0 years. Most patients (75.8%) were not surgical candidates because of medical comorbidities or old age. For staging, 97.0% underwent CT of the thorax, and mediastinoscopy was performed in 6.1%. All patients had Stage T1-T2N0, except for 4 patients with positive nodes based on pathologically involved or clinically enlarged lymph nodes adjacent to the primary tumor. The overall survival rate was 80.1% at 1 year and 46.0% at 2 years. The median survival was 22.6 months. The cause-specific survival rate was 89.8% at 1 year and 54.1% at 2 years. The recurrence-free survival rate was 66.4% at 1 year and 40.0% at 2 years. Lateral radiotherapy field margins of <2 cm predicted for inferior overall survival, cause-specific survival, and recurrence-free survival on univariate and multivariate analyses (p <0.05). The most commonly reported toxicities were acute dermatitis (30.3%) and late cutaneous/subcutaneous fibrosis (24.2%).

CONCLUSION

Accelerated hypofractionation for early-stage NSCLC appears to be safe and produces promising early results. Very small radiotherapy field margins may lead to an inferior outcome. Prospective studies are needed to determine the optimal dose-fractionation schedule.

The impact of (18)FDG-PET on target and critical organs in CT-based treatment planning of patients with poorly defined non-small-cell lung carcinoma: a prospective study

PURPOSE

To prospectively study the impact of coregistering (18)F-fluoro-deoxy-2-glucose hybrid positron emission tomographic (FDG-PET) images with CT images on the planning target volume (PTV), target coverage, and critical organ dose in radiation therapy planning of non-small-cell lung carcinoma.

METHODS AND MATERIALS

Thirty patients with poorly defined tumors on CT, referred for radical radiation therapy, underwent both FDG-PET and CT simulation procedures on the same day, in radiation treatment position. Image sets were coregistered using external fiducial markers. Three radiation oncologists independently defined the gross tumor volumes, using first CT data alone and then coregistered CT and FDG-PET data. Standard margins were applied to each gross tumor volume to generate a PTV, and standardized treatment plans were designed and calculated for each PTV. Dose-volume histograms were used to evaluate the relative effect of FDG information on target coverage and on normal tissue dose.

RESULTS

In 7 of 30 (23%) cases, FDG-PET information changed management strategy from radical to palliative. In 5 of the remaining 23 (22%) cases, new FDG-avid nodes were found within 5 cm of the primary tumor and were included in the PTV. The PTV defined using coregistered CT and FDG-PET would have been poorly covered by the CT-based treatment plan in 17--29% of cases, depending on the physician, implying a geographic miss had only CT information been available. The effect of FDG-PET on target definition varied with the physician, leading to a reduction in PTV in 24-70% of cases and an increase in 30-76% of cases. The relative change in PTV ranged from 0.40 to 1.86. On average, FDG-PET information led to a reduction in spinal cord dose but not in total lung dose, although large differences in dose to the lung were seen for a few individuals.

CONCLUSION

The coregistration of planning CT and FDG-PET images made significant alterations to patient management and to the PTV. Ultimately, changes to the PTV resulted in changes to the radiation treatment plans for the majority of cases. Where possible, we would recommend that FDG-PET data be integrated into treatment planning of non-small-cell lung carcinoma, particularly for three-dimensional conformal techniques.

Observer variation in contouring gross tumor volume in patients with poorly defined non-small-cell lung tumors on CT: the impact of 18FDG-hybrid PET fusion

PURPOSE

To quantify interobserver variation in gross tumor volume (GTV) localization using CT images for patients with non-small-cell lung carcinoma and poorly defined tumors on CT and to determine whether variability would be reduced if coregistered 2-[18F]fluoro-2-deoxy-d-glucose (FDG)-hybrid positron emission tomography (PET) with CT images were used.

METHODS AND MATERIALS

Prospectively, 30 patients with non-small-cell lung carcinoma had CT and FDG-hybrid PET examinations in radiation treatment position on the same day. Images were coregistered using eight fiducial markers. Guidelines were established for contouring GTVs. Three radiation oncologists performed localization independently. The coefficient of variation was used to assess interobserver variability.

RESULTS

The size of the GTV defined showed great variation among observers. The mean ratios of largest to smallest GTV were 2.31 and 1.56 for CT only and for CT/FDG coregistered data, respectively. The addition of PET reduced this ratio in 23 of 30 cases and increased it in 7. The mean coefficient of variation for GTV based on the combined modalities was significantly smaller (p < 0.01) than that for CT data only.

CONCLUSIONS

High observer variability in CT-based definition of the GTV can occur. A more consistent definition of the GTV can often be obtained if coregistered FDG-hybrid PET images are used.

Deep inspiration breath hold to reduce irradiated heart volume in breast cancer patients

PURPOSE

To evaluate the use of deep inspiration breath hold (DIBH) during tangential breast radiation therapy as a means of reducing irradiated cardiac volume.

METHODS AND MATERIALS

The Active Breathing Control (ABC) device designed at William Beaumont Hospital, Michigan was used to quantify the potential benefit of radiation delivery during DIBH for five left-sided breast cancer patients. This device initiates a breath hold at a predefined, reproducible lung volume. For each patient, two CT scans were acquired with and without breath hold, and virtual simulation was performed for regular tangent and wide-tangent techniques. The resulting dose-volume histograms were calculated, and the volume of heart irradiated to 25 Gy or more was assessed.

RESULTS

The influence of ABC on irradiated heart volumes varied considerably among the five patients. Three patients with substantial cardiac volume in the treatment field during normal respiration showed a significant dose-volume histogram reduction when deep inspiration was applied, with decreases in the heart volume receiving 25 Gy of more than 40 cc observed. For one patient, deep inspiration reduced irradiated cardiac volumes only with the wide-tangent technique, while one patient showed no substantial irradiated volume decrease.

CONCLUSION

A DIBH technique during tangential breast irradiation has the potential to significantly decrease irradiated cardiac volume for suitably selected patients. The magnitude of the impact of the breath hold application depends on patient anatomy, lung capacity, and pulmonary function.

The influence of patient geometry on the selection of chest wall irradiation techniques in post-mastectomy breast cancer patients

BACKGROUND AND PURPOSE

To evaluate three chest wall (CW) irradiation techniques: wide tangential photon beams, direct appositional electron field and electron arc therapy with regards to target coverage and normal tissue tolerance.

MATERIALS AND METHODS

Thirty-two post-mastectomy breast cancer patients were planned using three CW irradiation techniques. Computed tomography (CT) simulation was done on all patients and clinical target, heart and lung volumes were contoured. For each technique, dose distributions and dose-volume histograms (DVH) were calculated. Pass/fail criteria were applied based on volumetric target and critical structure dose coverage. Passing criteria for target was 95% of target receiving 95% of dose using a standard dose of 50 Gy/25 fractions, for heart </=10% volume receiving 50% dose (i.e. 25 Gy) and for lung </=25% volume ipsilateral lung receiving 50% dose (i.e. 25 Gy).

RESULTS

The number of patients optimally treated by each technique were as follows: wide tangential photon beams 23/32 (72%), direct appositional electron field 1/32 (3%), electron arc 4/32 (12.5%) and in 4/32 (12.5%) no technique was optimal. Geometric predictors for technique suitability include CW thickness, medial to lateral CW curvature, uniformity of superior to inferior CW curvature and length of mastectomy scar.

CONCLUSIONS

This study confirms the utility of CT planning and DVH analysis for treatment planning of breast cancer. Patient factors that predict for treatment technique suitability and aid in technique selection can be identified. In a small subset of patients, none of the currently studied techniques were optimal and more novel methods of chest wall irradiation are required.

Decreased levels of the cell-cycle inhibitor p27Kip1 protein: prognostic implications in primary breast cancer

Breast cancer is the second leading cause of cancer death in North American women. There is considerable need for reliable prognostic markers to assist clinicians in making management decisions. Although a variety of factors have been tested, only tumor stage, grade, size, hormone receptor status, and S-phase fraction are used on a routine basis. The cell cycle is governed by a family of cyclin-dependent kinases (cdks), which are regulated by associated cyclins and by phosphorylation. p27Kip1, a cyclin-dependent kinase inhibitor, regulates progression from G1 into S phase by binding and inhibiting cyclin/cdks. p27Kip1 protein levels and/or activity are upregulated by growth inhibitory cytokines including transforming growth factor-beta (TGF-beta) and, thus, provide an important link between extracellular regulators and the cell cycle. Loss of p27Kip1, a negative cell-cycle regulator, may contribute to oncogenesis and tumor progression. However, p27Kip1 mutations in human tumors are extremely rare. We have demonstrated by immunohistochemistry that p27Kip1 protein levels are reduced in primary breast cancers and that this is associated with tumor progression in both in situ and invasive lesions. This was confirmed by western analysis, reflected in increased G1/S-phase cyclin-dependent kinase activities and shown to be regulated posttranscriptionally by in situ hybridization. Furthermore, on multivariate analysis, low p27Kip1 is a predictor of reduced disease-free survival. This simple and reliable immunohistochemical assay may become a routine part of breast cancer evaluation and may influence patient management.

DNA double-strand break induction and rejoining as determinants of human tumour cell radiosensitivity. A pulsed-field gel electrophoresis study

Measurement of the surviving fraction after 2 Gy (SF2) may predict for local control of the tumour and patients cure, but clonogenic assays are unsuitable for wider clinical application. Promising results have been obtained using DNA damage assays such as pulsed-field gel electrophoresis, PFGE. In the current study, nine human tumour cell lines (SF2, range 0.08-0.62) were studied for DNA double-strand break (dsb) induction and six of these for dsb rejoining using PFGE. Differences in dsb induction, as the slope (+/- SEM) of DNA release per Gy, varied from 1.30 (0.05) to 2.42 (0.17). The dsb induction frequency varied from 3.55 (0.33) to 9.69 (2.18) dsb x 10(-9)/bp/Gy (21-56 dsb/Gy/cell). Variations in the half-time for fast phase (18-60 min) and slow phase (38-445 min) dsb rejoining were observed. Statistically significant correlations were found between SF2 and the slope of the DNA release curve (p = 0.003), DNA release after 10 Gy (p = 0.029) and 20 Gy (p = 0.011) and slow phase dsb rejoining (p = 0.012). While the underlying mechanisms of cell killing remain unclear, PFGF measurement of dsb induction and rejoining shows great potential as a predictive assay for intrinsic cellular radiosensitivity.