S. Faria

Randomized Phase III Noninferiority Study Comparing Two Radiotherapy Fractionation Schedules in Patients With Low-Risk Prostate Cancer

PURPOSE Conventional radiotherapy (C-RT) treatment schedules for patients with prostate cancer typically require 40 to 45 treatments that take place from > 8 to 9 weeks. Preclinical and clinical research suggest that hypofractionation-fewer treatments but at a higher dose per treatment-may produce similar outcomes. This trial was designed to assess whether the efficacy of a hypofractionated radiotherapy (H-RT) treatment schedule is no worse than a C-RT schedule in men with low-risk prostate cancer. PATIENTS AND METHODS A total of 1,115 men with low-risk prostate cancer were randomly assigned 1:1 to C-RT (73.8 Gy in 41 fractions over 8.2 weeks) or to H-RT (70 Gy in 28 fractions over 5.6 weeks). This trial was designed to establish (with 90% power and an α of .05) that treatment with H-RT results in 5-year disease-free survival (DFS) that is not worse than C-RT by more than 7.65% (H-RT/C-RT hazard ratio [HR] < 1.52). RESULTS A total of 1,092 men were protocol eligible and had follow-up information; 542 patients were assigned to C-RT and 550 to H-RT. Median follow-up was 5.8 years. Baseline characteristics were not different according to treatment assignment. The estimated 5-year DFS was 85.3% (95% CI, 81.9 to 88.1) in the C-RT arm and 86.3% (95% CI, 83.1 to 89.0) in the H-RT arm. The DFS HR was 0.85 (95% CI, 0.64 to 1.14), and the predefined noninferiority criterion that required that DFS outcomes be consistent with HR < 1.52 was met (P < .001). Late grade 2 and 3 GI and genitourinary adverse events were increased (HR, 1.31 to 1.59) in patients who were treated with H-RT. CONCLUSION In men with low-risk prostate cancer, the efficacy of 70 Gy in 28 fractions over 5.6 weeks is not inferior to 73.8 Gy in 41 fractions over 8.2 weeks, although an increase in late GI/genitourinary adverse events was observed in patients treated with H-RT.

Radiotherapy in the treatment of vertebral hemangiomas.

Symptomatic vertebral hemangiomas are not common. Although radiotherapy has been used as treatment, the data are sparse concerning total dose, fractionation and results. We report nine patients with vertebral hemangioma treated with 3000-4000 rad, 200 rad/day, 5 fractions per week, followed from 6 to 62 months. Seventy-seven percent had complete or almost complete disappearance of the symptoms. Radiotherapy schedules are discussed.

A Phase II Comparative Study of Gross Tumor Volume Definition With or Without PET/CT Fusion in Dosimetric Planning for Non-Small Cell Lung Cancer (NSCLC): Primary Analysis of Radiation Therapy Oncology Group (RTOG) 0515

BACKGROUND Radiation Therapy Oncology Group (RTOG) 0515 is a Phase II prospective trial designed to quantify the impact of positron emission tomography (PET)/computed tomography (CT) compared with CT alone on radiation treatment plans (RTPs) and to determine the rate of elective nodal failure for PET/CT-derived volumes. METHODS Each enrolled patient underwent definitive radiation therapy for non-small-cell lung cancer (≥ 60 Gy) and had two RTP datasets generated: gross tumor volume (GTV) derived with CT alone and with PET/CT. Patients received treatment using the PET/CT-derived plan. The primary end point, the impact of PET/CT fusion on treatment plans was measured by differences of the following variables for each patient: GTV, number of involved nodes, nodal station, mean lung dose (MLD), volume of lung exceeding 20 Gy (V20), and mean esophageal dose (MED). Regional failure rate was a secondary end point. The nonparametric Wilcoxon matched-pairs signed-ranks test was used with Bonferroni adjustment for an overall significance level of 0.05. RESULTS RTOG 0515 accrued 52 patients, 47 of whom are evaluable. The follow-up time for all patients is 12.9 months (2.7-22.2). Tumor staging was as follows: II = 6%; IIIA = 40%; and IIIB = 54%. The GTV was statistically significantly smaller for PET/CT-derived volumes (98.7 vs. 86.2 mL; p < 0.0001). MLDs for PET/CT plans were slightly lower (19 vs. 17.8 Gy; p = 0.06). There was no significant difference in the number of involved nodes (2.1 vs. 2.4), V20 (32% vs. 30.8%), or MED (28.7 vs. 27.1 Gy). Nodal contours were altered by PET/CT for 51% of patients. One patient (2%) has developed an elective nodal failure. CONCLUSIONS PET/CT-derived tumor volumes were smaller than those derived by CT alone. PET/CT changed nodal GTV contours in 51% of patients. The elective nodal failure rate for GTVs derived by PET/CT is quite low, supporting the RTOG standard of limiting the target volume to the primary tumor and involved nodes.

Hypofractionated Radiotherapy for Favorable Risk Prostate Cancer

PURPOSE Since the recognition that prostate cancer probably has a low alpha/beta ratio, hypofractionated radiotherapy has become an attractive treatment option for localized prostate cancer. However, there is little experience with the use of hypofractionation delivering a high biologically equivalent dose. We report our experience with high-dose hypofractionated radiotherapy. MATERIAL AND METHODS A total of 129 patients with favorable risk prostate cancer were treated with three-dimensional conformal radiotherapy treatment plans to the dose of 66 Gy in 22 fractions, prescribed at the isocenter. Planning target volume consisted of the prostate plus a uniform 7-mm margin, including the rectal margin. No patient received hormonal therapy. Toxicity was prospectively graded by the Common Toxicity Criteria version 3. Biochemical relapse was defined as postradiotherapy nadir prostate-specific antigen + 2 ng/mL. RESULTS With a median follow-up of 51 months, the 5-year actuarial biochemical control rate is 98%. The only 3 cases with biochemical failure did not have a clinical local relapse. More than 50% of patients did not develop acute toxicity. For late toxicity, the worst crude rate of Grade >or=2 genitourinary (GU) and gastrointestinal (GI) toxicity seen at any time during follow-up were 32% and 25%, respectively. There was no Grade 4 or 5 toxicity. At the last follow-up, persistent Grade >or=2 late GU and GI toxicity were 2% and 1.5%, respectively. CONCLUSIONS This hypofractionated regimen provides excellent biochemical control in favorable risk prostate cancer with an acceptable rate of late toxicity. Further studies exploring this hypofractionation regimen are warranted.

Defining Radiotherapy Target Volumes Using 18F-Fluoro-Deoxy-Glucose Positron Emission Tomography/Computed Tomography: Still a Pandora's Box?

PURPOSE We discuss the effect of (18)F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) data on target volume definition for radiotherapy planning. We compared the effect of various thresholding methods on the PET-based target volume vs. the standard CT-based tumor volume. METHODS AND MATERIALS Different thresholding methods were reviewed and compared to our PET-based gross tumor volume data obtained from a cohort of 31 non-small-cell lung carcinoma patients who had undergone preoperative PET/CT scans for staging. The feasibility and limitations of FDG-based PET/CT data on target volume delineation in radiotherapy planning have been demonstrated with frequently used approaches for target outlining such as the qualitative visual method and the fixed 15% or 40% of the maximal iso-uptake value threshold methods. RESULTS The relationship between PET-based and CT-based volumes generally suffers from poor correlation between the two image data sets, expressed in terms of a large statistical variation in gross tumor volume ratios, irrespective of the threshold method used. However, we found that the maximal signal/background ratios in non-small-cell lung carcinoma patients correlated well with the pathologic results, with an average ratio for adenocarcinoma, large cell carcinoma, and squamous cell carcinoma of 10.5 ± 3.5, 12.6 ± 2.8, and 14.1 ± 5.9, respectively. CONCLUSION The fluctuations in tumor volume using different quantitative PET thresholding approaches did not depend on the thresholding method used. They originated from the nature of functional imaging in general and PET imaging in particular. Functional imaging will eventually be used for biologically tailored target radiotherapy volume definition not as a replacement of CT- or magnetic resonance imaging-based anatomic gross tumor volumes but with the methods complementing each other in a complex mosaic of distinct biologic target volumes.

Risk of Hypogonadism From Scatter Radiation During Pelvic Radiation in Male Patients With Rectal Cancer

PURPOSE Recent studies have reported fluctuations in sex hormones during pelvic irradiation. The objective of this study was to observe the effects of radiation on hormonal profiles for two treatment modalities: conventional external beam radiotherapy (EBRT) and high-dose-rate brachytherapy (HDRBT) given neoadjuvantly for patients with rectal cancer. METHODS AND MATERIALS Routine serum follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels were collected from 119 consecutive male patients receiving either EBRT, using 45.0-50.4 Gy in 25-28 fractions with concurrent 5-fluorouracil chemotherapy or HDRBT using 26 Gy in 4 fractions. RESULTS Thirty patients with initially abnormal profiles were excluded. Profiles included in this study were collected from 51 patients treated with EBRT and 38 patients treated with HDRBT, all of whom had normal hormonal profiles before treatment. Mean follow-up times were 17 months for the entire patient cohort-14 and 20 months, respectively-for the EBRT and HDRBT arms. Dosimetry results revealed a mean cumulative testicular dose of 1.24 Gy received in EBRT patients compared with 0.27 Gy in the HDRBT group. After treatment, FSH and LH were elevated in all patients but were more pronounced in the EBRT group. The testosterone-to-LH ratio was significantly lower (p = 0.0036) in EBRT patients for tumors in the lower third of the rectum. The 2-year hypogonadism rate observed was 2.6% for HDRBT compared with 17.6% for EBRT (p = 0.09) for tumors in the lower two thirds of the rectum. CONCLUSION HDRBT allows better hormonal sparing than EBRT during neoadjuvant treatment of patients with rectal cancer.

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.

Absence of toxicity with hypofractionated 3-dimensional radiation therapy for inoperable, early stage non-small cell lung cancer.

PurposeHypofractionated radiotherapy may overcome repopulation in rapidly proliferating tumors such as lung cancer. It is more convenient for the patients and reduces health care costs. This study reports our results on patients with medically inoperable, early stage, non-small cell lung cancer (NSCLC) treated with hypofractionation.Materials and methodsStage T1-2N0 NSCLC patients were treated with hypofractionation alone, 52.5 Gy/15 fractions, in 3 weeks, with 3-dimensional conformal planning. T1-2N1 patients with the hilar lymphnode close to the primary tumor were also eligible for this treatment. We did not use any approach to reduce respiratory motion, but it was monitored in all patients. Elective nodal radiotherapy was not performed. Routine follow up included assessment for acute and late toxicity and radiological tumor response. Median follow up time was 29 months for the surviving patients.ResultsThirty-two patients with a median age of 76 years, T1 = 15 and T2 = 17, were treated. Median planning target volume (PTV) volume was 150cc and median V16 of both lungs was 13%. The most important finding of this study is that toxicity was minimal. Two patients had grade ≤ 2 acute pneumonitis and 3 had mild (grade 1) acute esophagitis. There was no late toxicity. Actuarial 1 and 2-year overall survival rates are 78% and 56%, cancer specific survival rates (CSS) are 90% and 74%, and local relapse free survival rates are 93% and 76% respectively.Conclusion3-D planning, involved field hypofractionation at a dose of 52.5 Gy in 15 daily fractions is safe, well tolerated and easy radiation treatment for medically inoperable lung cancer patients. It shortens by half the traditional treatment. Results compare favorably with previously published studies. Further studies are needed to compare similar technique with other treatments such as surgery and stereotactic radiotherapy.

Reporting Late Rectal Toxicity in Prostate Cancer Patients Treated With Curative Radiation Treatment

PURPOSE Long-term rectal toxicity is a concern for patients with prostate cancer treated with curative radiation. However, comparing results of late toxicity may not be straightforward. This article reviews the complexity of reporting long-term side effects by using data for patients treated in our institution with hypofractionated irradiation. METHODS AND MATERIALS Seventy-two patients with localized prostate cancer treated with hypofractionated radiotherapy alone to a dose of 66 Gy in 22 fractions were prospectively assessed for late rectal toxicity according to the Common Toxicity Criteria, Version 3, scoring system. Ninety percent of patients had more than 24 months of follow-up. Results are compared with data published in the literature. RESULTS We found an actuarial incidence of Grade 2 or higher late rectal toxicity of 27% at 30 months and a crude incidence of Grade 2 or higher late rectal toxicity of 18%. This was mostly severe toxicity documented during follow-up. The incidence of Grade 3 rectal toxicity at the last visit was 3% compared with 13% documented at any time during follow-up. CONCLUSION Comparison of late toxicity after radiotherapy in patients with prostate cancer must be undertaken with caution because many factors need to be taken into consideration. Because accurate assessment of late toxicity in the evaluation of long-term outcome after radiotherapy in patients with localized prostate cancer is essential, there is a need to develop by consensus guidelines for assessing and reporting late toxicity in this group of patients.

Phase II trial of short-course radiotherapy followed by delayed surgery for locoregionally advanced rectal cancer.

A prospective phase II study to investigate the feasibility and the rate of complete pathological response (ypT0) after short‐course radiotherapy (SCRT) followed by surgery at 8 weeks.