Summary Background Head and neck cancers positive for human papillomavirus (HPV) are exquisitely radiosensitive. We investigated whether chemoradiotherapy with reduced-dose radiation would maintain ...survival outcomes while improving tolerability for patients with HPV-positive oropharyngeal carcinoma. Methods We did a single-arm, phase 2 trial at two academic hospitals in the USA, enrolling patients with newly diagnosed, biopsy-proven stage III or IV squamous-cell carcinoma of the oropharynx, positive for HPV by p16 testing, and with Zubrod performance status scores of 0 or 1. Patients received two cycles of induction chemotherapy with 175 mg/m2 paclitaxel and carboplatin (target area under the curve of 6) given 21 days apart, followed by intensity-modulated radiotherapy with daily image guidance plus 30 mg/m2 paclitaxel per week concomitantly. Complete or partial responders to induction chemotherapy received 54 Gy in 27 fractions, and those with less than partial or no responses received 60 Gy in 30 fractions. The primary endpoint was progression-free survival at 2 years, assessed in all eligible patients who completed protocol treatment. This study is registered with ClinicalTrials.gov , numbers NCT02048020 and NCT01716195. Findings Between Oct 4, 2012, and March 3, 2015, 45 patients were enrolled with a median age of 60 years (IQR 54–67). One patient did not receive treatment and 44 were included in the analysis. 24 (55%) patients with complete or partial responses to induction chemotherapy received 54 Gy radiation, and 20 (45%) with less than partial responses received 60 Gy. Median follow-up was 30 months (IQR 26–37). Three (7%) patients had locoregional recurrence and one (2%) had distant metastasis; 2-year progression-free survival was 92% (95% CI 77–97). 26 (39%) of 44 patients had grade 3 adverse events, but no grade 4 events were reported. The most common grade 3 events during induction chemotherapy were leucopenia (17 39%) and neutropenia (five 11%), and during chemoradiotherapy were dysphagia (four 9%) and mucositis (four 9%). One (2%) of 44 patients was dependent on a gastrostomy tube at 3 months and none was dependent 6 months after treatment. Interpretation Chemoradiotherapy with radiation doses reduced by 15–20% was associated with high progression-free survival and an improved toxicity profile compared with historical regimens using standard doses. Radiotherapy de-escalation has the potential to improve the therapeutic ratio and long-term function for these patients. Funding University of California.
To study the outcomes in patients treated for localized prostate cancer with 70 Gy delivered at 2.5-Gy/fraction within 5 weeks.
The study sample included all 770 consecutive patients with localized ...prostate cancer treated with hypofractionated intensity-modulated radiotherapy at the Cleveland Clinic between 1998 and 2005. The median follow-up was 45 months (maximum, 86). Both the American Society for Therapeutic Radiology and Oncology (ASTRO) biochemical failure definition and the alternate nadir + 2 ng/mL definition were used.
The overall 5-year ASTRO biochemical relapse-free survival rate was 82% (95% confidence interval, 79-85%), and the 5-year nadir + 2 ng/mL rate was 83% (95% confidence interval, 79-86%). For patients with low-risk, intermediate-risk, and high-risk disease, the 5-year ASTRO rate was 95%, 85%, and 68%, respectively. The 5-year nadir + 2 ng/mL rate for patients with low-, intermediate-, and high-risk disease was 94%, 83%, and 72%, respectively. The Radiation Therapy Oncology Group acute rectal toxicity scores were 0 in 51%, 1 in 40%, and 2 in 9% of patients. The acute urinary toxicity scores were 0 in 33%, 1 in 48%, 2 in 18%, and 3 in 1% of patients. The late rectal toxicity scores were 0 in 89.6%, 1 in 5.9%, 2 in 3.1%, 3 in 1.3%, and 4 in 0.1% (1 patient). The late urinary toxicity scores were 0 in 90.5%, 1 in 4.3%, 2 in 5.1%, and 3 in 0.1% (1 patient).
The outcomes after high-dose hypofractionation were acceptable in the entire cohort of patients treated with the schedule of 70 at 2.5 Gy/fraction.
To evaluate the early and late health-related quality of life (QOL) outcomes among prostate cancer patients following stereotactic body radiation therapy (SBRT).
Patient self-reported QOL was ...prospectively measured among 864 patients from phase 2 clinical trials of SBRT for localized prostate cancer. Data from the Expanded Prostate Cancer Index Composite (EPIC) instrument were obtained at baseline and at regular intervals up to 6 years. SBRT delivered a median dose of 36.25 Gy in 4 or 5 fractions. A short course of androgen deprivation therapy was given to 14% of patients.
Median follow-up was 3 years and 194 patients remained evaluable at 5 years. A transient decline in the urinary and bowel domains was observed within the first 3 months after SBRT which returned to baseline status or better within 6 months and remained so beyond 5 years. The same pattern was observed among patients with good versus poor baseline function and was independent of the degree of early toxicities. Sexual QOL decline was predominantly observed within the first 9 months, a pattern not altered by the use of androgen deprivation therapy or patient age.
Long-term outcome demonstrates that prostate SBRT is well tolerated and has little lasting impact on health-related QOL. A transient and modest decline in urinary and bowel QOL during the first few months after SBRT quickly recovers to baseline levels. With a large number of patients evaluable up to 5 years following SBRT, it is unlikely that unexpected late adverse effects will manifest themselves.
Abstract The ability of rare earth cerium oxide (CeO2 ) nanoparticles to confer radioprotection against gastrointestinal epithelium was examined. The pretreatment of normal human colon cells (CRL ...1541) with varying concentrations of CeO2 nanoparticles 24 hours before single-dose radiation exposure conferred protection from radiation-induced cell death by reducing the amount of reactive oxygen species produced and increasing the expression of superoxide dismutase 2 (SOD2), in a dose-dependent manner. In subsequent experiments athymic nude mice were pretreated with intraperitoneal injections of CeO2 nanoparticles before a single dose of radiation to the abdominal area. Immunohistochemical analysis show a decrease in TUNEL-and caspase 3–positive cells in the colonic crypt, 4 hours after radiation. In sharp contrast, a significant increase in SOD2 expression was observed. In the end, these studies suggest that CeO2 nanoparticles protect the gastrointestinal epithelium against radiation-induced damage by (1) acting as free-radical scavengers and (2) increasing the production of SOD2 before radiation insult. From the Clinical Editor In this study, the ability of rare earth cerium oxide (CeO2 ) nanoparticles to confer radioprotection was examined. The results suggest that CeO2 nanoparticles protect the gastrointestinal epithelium against radiation-induced damage both by acting as free-radical scavengers and by increasing the production of SOD2 before radiation insult.
To quantify and describe the real-time movement of the prostate gland in a large data set of patients treated with radiotherapy.
The Calypso four-dimensional localization system was used for target ...localization in 17 patients, with electromagnetic markers implanted in the prostate of each patient. We analyzed a total of 550 continuous tracking sessions. The fraction of time that the prostate was displaced by >3, >5, >7, and >10 mm was calculated for each session and patient. The frequencies of displacements after initial patient positioning were analyzed over time.
Averaged over all patients, the prostate was displaced >3 and >5 mm for 13.6% and 3.3% of the total treatment time, respectively. For individual patients, the corresponding maximal values were 36.2% and 10.9%. For individual fractions, the corresponding maximal values were 98.7% and 98.6%. Displacements >3 mm were observed at 5 min after initial alignment in about one-eighth of the observations, and increased to one-quarter by 10 min. For individual patients, the maximal value of the displacements >3 mm at 5 and 10 min after initial positioning was 43% and 75%, respectively.
On average, the prostate was displaced by >3 mm and >5 mm approximately 14% and 3% of the time, respectively. For individual patients, these values were up to three times greater. After the initial positioning, the likelihood of displacement of the prostate gland increased with elapsed time. This highlights the importance of initiating treatment shortly after initially positioning the patient.
Magnetic resonance imaging–guided adaptive radiotherapy would make available the best in anatomical and functional imaging during the course of radiation therapy. The possible methodology of magnetic ...resonance imaging–guided adapted radiotherapy and possible clinical applications are discussed.
Abstract Purpose The effectiveness of stereotactic body radiotherapy (SBRT) for localized prostate cancer is tested. Methods and materials A total of 1100 patients with clinically localized prostate ...cancer were enrolled in separate prospective phase 2 clinical trials of SBRT from 8 institutions during 2003–11 and pooled for analysis. SBRT using the CyberKnife delivered a median dose of 36.25 Gy in 4–5 fractions. Patients were low-risk (58%), intermediate-risk (30%) and high-risk (11%). A short-course of androgen deprivation therapy (ADT) was given to 14%. PSA relapse defined as a rise >2 ng/ml above nadir was analyzed with the Kaplan Meier method. Results With a median follow-up of 36 months there were 49 patients with PSA failure (4.5%), 9 of whom were subsequently determined to be benign PSA bounces. The 5-year biochemical relapse free survival (bRFS) rate was 93% for all patients; 95%, 83% and 78% for GS ⩽6, 7 and ⩾8, respectively ( p = 0.001), and 95%, 84% and 81% for low-, intermediate- and high-risk patients, respectively ( p < 0.001). No differences were observed with ADT ( p = 0.71) or as a function of total dose ( p = 0.17). A PSA bounce of >0.2 ng/ml was noted among 16% of patients. For 135 patients possessing a minimum of 5 years follow-up, the 5-year bRFS rate for low- and intermediate-risk patients was 99% and 93%, respectively. Conclusion PSA relapse-free survival rates after SBRT compare favorably with other definitive treatments for low and intermediate risk patients. The current evidence supports consideration of SBRT among the therapeutic options for these patients.
To investigate the dosimetric improvements in stereotactic body radiation therapy for patients with larger or central lung tumors using a highly noncoplanar 4π planning system.
This study involved 12 ...patients with centrally located or larger lung tumors previously treated with 7- to 9-field static beam intensity modulated radiation therapy to 50 Gy. They were replanned using volumetric modulated arc therapy and 4π plans, in which a column generation method was used to optimize the beam orientation and the fluence map. Maximum doses to the heart, esophagus, trachea/bronchus, and spinal cord, as well as the 50% isodose volume, the lung volumes receiving 20, 10, and 5 Gy were minimized and compared against the clinical plans. A dose escalation study was performed to determine whether a higher prescription dose to the tumor would be achievable using 4π without violating dose limits set by the clinical plans. The deliverability of 4π plans was preliminarily tested.
Using 4π plans, the maximum heart, esophagus, trachea, bronchus and spinal cord doses were reduced by 32%, 72%, 37%, 44%, and 53% (P≤.001), respectively, and R50 was reduced by more than 50%. Lung V20, V10, and V5 were reduced by 64%, 53%, and 32% (P≤.001), respectively. The improved sparing of organs at risk was achieved while also improving planning target volume (PTV) coverage. The minimal PTV doses were increased by the 4π plans by 12% (P=.002). Consequently, escalated PTV doses of 68 to 70 Gy were achieved in all patients.
We have shown that there is a large potential for plan quality improvement and dose escalation for patients with larger or centrally located lung tumors using noncoplanar beams with sufficient quality and quantity. Compared against the clinical volumetric modulated arc therapy and static intensity modulated radiation therapy plans, the 4π plans yielded significantly and consistently improved tumor coverage and critical organ sparing. Given the known challenges in central structure dose constraints in stereotactic body radiation therapy to the lung, 4π planning may increase efficacy and reduce toxicity.
To analyze changes in parotid gland dose resulting from anatomic changes throughout a course of radiotherapy in a cohort of head-and-neck cancer patients.
The study population consisted of 10 ...head-and-neck cancer patients treated definitively with intensity-modulated radiotherapy on a helical tomotherapy unit. A total of 330 daily megavoltage computed tomography images were retrospectively processed through a deformable image registration algorithm to be registered to the planning kilovoltage computed tomography images. The process resulted in deformed parotid contours and voxel mappings for both daily and accumulated dose-volume histogram calculations. The daily and cumulative dose deviations from the original treatment plan were analyzed. Correlations between dosimetric variations and anatomic changes were investigated.
The daily parotid mean dose of the 10 patients differed from the plan dose by an average of 15%. At the end of the treatment, 3 of the 10 patients were estimated to have received a greater than 10% higher mean parotid dose than in the original plan (range, 13-42%), whereas the remaining 7 patients received doses that differed by less than 10% (range, -6-8%). The dose difference was correlated with a migration of the parotids toward the high-dose region.
The use of deformable image registration techniques and daily megavoltage computed tomography imaging makes it possible to calculate daily and accumulated dose-volume histograms. Significant dose variations were observed as result of interfractional anatomic changes. These techniques enable the implementation of dose-adaptive radiotherapy.
PDF
