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1.
Curr Oncol ; 29(6): 3983-3995, 2022 05 31.
Article in English | MEDLINE | ID: mdl-35735427

ABSTRACT

Ambulatory cancer centers face a fluctuating patient demand and deploy specialized personnel who have variable availability. This undermines operational stability through the misalignment of resources to patient needs, resulting in overscheduled clinics, budget deficits, and wait times exceeding provincial targets. We describe the deployment of a Learning Health System framework for operational improvements within the entire ambulatory center. Known methods of value stream mapping, operations research and statistical process control were applied to achieve organizational high performance that is data-informed, agile and adaptive. We transitioned from a fixed template model by an individual physician to a caseload management by disease site model that is realigned quarterly. We adapted a block schedule model for the ambulatory oncology clinic to align the regional demand for specialized services with optimized human and physical resources. We demonstrated an improved utilization of clinical space, increased weekly consistency and improved distribution of activity across the workweek. The increased value, represented as the ratio of monthly encounters per nursing worked hours, and the increased percentage of services delivered by full-time nurses were benefits realized in our cancer system. The creation of a data-informed demand capacity model enables the application of predictive analytics and business intelligence tools that will further enhance clinical responsiveness.


Subject(s)
Ambulatory Care Facilities , Neoplasms , Humans , Neoplasms/therapy
2.
Radiol Case Rep ; 15(11): 2266-2270, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32983297

ABSTRACT

Stereotactic ablative radiotherapy (SABR) has emerged as an effective, noninvasive alternative to surgery in patients with oligometastatic disease. Historically, select patients with adrenal oligometastases have been treated with adrenalectomies which can offer durable local control and reasonable survival rates. SABR is a promising noninvasive treatment alternative to surgery capable of delivering ablative doses of radiation to the tumor with the goal of achieving durable local control of adrenal metastases. We report on a case of a patient who underwent initial surgical resection for a locally advanced lung adenocarcinoma and subsequently developed an early, biopsy-proven, oligometastatic recurrence in the adrenal gland. He underwent chemotherapy and SABR using CyberKnife to the adrenal metastasis and is in remission 7 years after treatment with no late toxicity. Fractionated SABR is an attractive noninvasive alternative to surgery for adrenal metastases. This case demonstrates that select patients with adrenal oligometastases, can achieve long-term remission and even cure following SABR.

3.
J Clin Oncol ; 37(15): 1316-1325, 2019 05 20.
Article in English | MEDLINE | ID: mdl-30943123

ABSTRACT

PURPOSE: Patients with centrally located early-stage non-small-cell lung cancer (NSCLC) are at a higher risk of toxicity from high-dose ablative radiotherapy. NRG Oncology/RTOG 0813 was a phase I/II study designed to determine the maximum tolerated dose (MTD), efficacy, and toxicity of stereotactic body radiotherapy (SBRT) for centrally located NSCLC. MATERIALS AND METHODS: Medically inoperable patients with biopsy-proven, positron emission tomography-staged T1 to 2 (≤ 5 cm) N0M0 centrally located NSCLC were accrued into a dose-escalating, five-fraction SBRT schedule that ranged from 10 to 12 Gy/fraction (fx) delivered over 1.5 to 2 weeks. Dose-limiting toxicity (DLT) was defined as any treatment-related grade 3 or worse predefined toxicity that occurred within the first year. MTD was defined as the SBRT dose at which the probability of DLT was closest to 20% without exceeding it. RESULTS: One hundred twenty patients were accrued between February 2009 and September 2013. Patients were elderly, there were slightly more females, and the majority had a performance status of 0 to 1. Most cancers were T1 (65%) and squamous cell (45%). Organs closest to planning target volume/most at risk were the main bronchus and large vessels. Median follow-up was 37.9 months. Five patients experienced DLTs; MTD was 12.0 Gy/fx, which had a probability of a DLT of 7.2% (95% CI, 2.8% to 14.5%). Two-year rates for the 71 evaluable patients in the 11.5 and 12.0 Gy/fx cohorts were local control, 89.4% (90% CI, 81.6% to 97.4%) and 87.9% (90% CI, 78.8% to 97.0%); overall survival, 67.9% (95% CI, 50.4% to 80.3%) and 72.7% (95% CI, 54.1% to 84.8%); and progression-free survival, 52.2% (95% CI, 35.3% to 66.6%) and 54.5% (95% CI, 36.3% to 69.6%), respectively. CONCLUSION: The MTD for this study was 12.0 Gy/fx; it was associated with 7.2% DLTs and high rates of tumor control. Outcomes in this medically inoperable group of mostly elderly patients with comorbidities were comparable with that of patients with peripheral early-stage tumors.


Subject(s)
Carcinoma, Non-Small-Cell Lung/radiotherapy , Lung Neoplasms/radiotherapy , Radiosurgery/methods , Aged , Aged, 80 and over , Dose Fractionation, Radiation , Dose-Response Relationship, Radiation , Female , Humans , Male , Middle Aged , Radiosurgery/adverse effects , Treatment Outcome
4.
Clin Transl Radiat Oncol ; 16: 28-33, 2019 May.
Article in English | MEDLINE | ID: mdl-30923751

ABSTRACT

•This study reports on the prognostic ability of haematological parameters for the largest known biopsy-proven stage-I medically inoperable cohort treated with SBRT.•After SBRT, the median values of Hb, ALC, ANC and TPC declined whereas the NLR and the PLR increased as compared to pre-SBRT.•Anemia along with other parameters was found to be a poor prognostic factor for local control despite treatment with SBRT to doses of >100 Gy BED10.•Simple and minimally invasive methods like a peripheral blood sample can provide prognostic information even for stage-I NSCLC patients.•Patient, tumor and treatment factors along with molecular markers should be used to create risk stratification models that can guide therapy.

5.
Clin Transl Radiat Oncol ; 15: 76-82, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30775562

ABSTRACT

BACKGROUND AND PURPOSE: There is conflicting evidence with respect to the correlation between neoadjuvant chemoradiation and anastomotic complications following trimodality therapy in patients with esophageal cancer. We aimed to analyze the relationship between their dosimetry and any resulting anastomotic complications. MATERIALS AND METHODS: The medical records of 51 consecutive patients who underwent trimodality therapy between 2007 and 2014 were retrospectively reviewed. We analyzed the differences in the mean dose received by regions of the esophagus relative to the landmark of the azygous vein and the stomach to correlate the development of an anastomotic complication using nonparametric rank-sum tests. RESULTS: Anastomotic leakage and stricture rates were 12% and 22%, respectively. Patients with anastomotic complications received a statistically significant higher mean dose to the esophagus at the level of the azygous vein (0.0 cm) and lower (up to -2.7 cm) (28.4-42.2 Gy vs. 10.3-27.6 Gy, p < 0.04). There were no differences noted in mean gastric doses. Median follow up time was 30.9 months. Median overall survival and disease free survival of our patient cohort was 34.4 months and 22.5 months, respectively. The development of an anastomotic complication did not affect survival outcomes. CONCLUSION: Patients who experienced anastomotic complication after trimodality therapy for esophageal cancer were more likely to have received a higher mean esophageal dose around the proximity of the azygous vein, where intrathoracic anastomoses most commonly occur. Communication between surgical and radiation oncologists regarding the anastomotic location may be an important consideration in planning for trimodality therapy in reducing potential anastomotic complications.

6.
Clin Lung Cancer ; 19(1): e11-e18, 2018 01.
Article in English | MEDLINE | ID: mdl-28711384

ABSTRACT

INTRODUCTION: Standard management of stage II non-small-cell lung cancer (NSCLC) is surgery, often followed by adjuvant chemotherapy. However, some patients do not undergo surgery for various reasons. We examined outcomes in this defined patient group. METHODS: We reviewed the records of patients with stage II NSCLC treated nonsurgically with curative intent from 2002 to 2012 across 3 academic cancer centers. Data collected included demographics, comorbidities, staging, treatments, and survival. The primary endpoint was overall survival (OS). We assessed factors associated with treatment choice and OS. RESULTS: A total of 158 patients were included: the median age was 74 years (range, 50-91 years), 44% were female, and 68% had a performance status of 0 to 1. The stage II groupings of the patients were T2b-T3 N0 in 55% and N1 in 45%. The most common reasons for inoperability were inadequate pulmonary reserve (27%) and medical comorbidities (24%). All patients received radical radiotherapy (RT) (median, 60 Gy [range, 48-75 Gy]). Seventy-three percent received RT alone; 24% received concurrent and 3% sequential chemoradiotherapy (CRT). In multivariate analyses, CRT was less likely in older patients (≥ 70 years) (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.11-0.70; P = .006) and in patients with higher (> 5) Charlson comorbidity scores (OR, 0.34; 95% CI, 0.13-0.90; P = .03) or normal (< 10 × 109/L) white blood cell counts (OR, 0.26; 95% CI, 0.09-0.73; P = .01). At the time of our analysis, 74% have died. The median OS was 22.9 months (range, 17.1-26.6 months). Patients who had undergone CRT had a significantly longer median OS than those receiving RT alone (39.1 vs. 20.5 months; P = .0019), confirmed in multivariate analysis (hazard ratio, 0.38; 95% CI, 0.21-0.69; P = .001). CONCLUSION: Nonsurgical approaches to management of stage II NSCLC are varied. Treatment with CRT was associated with significantly longer survival compared with RT alone. A randomized trial may be warranted.


Subject(s)
Age Factors , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Chemotherapy, Adjuvant , Lung Neoplasms/drug therapy , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/mortality , Female , Humans , Lung Neoplasms/mortality , Lung Neoplasms/radiotherapy , Male , Middle Aged , Neoplasm Staging , Radiotherapy , Survival Analysis , Treatment Outcome
7.
Clin Transl Radiat Oncol ; 5: 37-41, 2017 Aug.
Article in English | MEDLINE | ID: mdl-29594215

ABSTRACT

PURPOSE: In this single institution retrospective study of patients with stage I medically inoperable non-small cell lung cancer (NSCLC) treated with stereotactic ablative radiotherapy (SABR) we attempt to model overall survival (OS) using initial prognostic variables with specific attention on the Charlson co-morbidity index (CCI). METHODS: Between 2008 and 2013, 335 patients with medically inoperable stage I NSCLC were treated with SABR or hypofractionated radiotherapy (50-60 Gy in at least 5 Gy or 4 Gy fractions respectively) at our institution. Medical comorbidities and Charlson scores were determined by individual chart review. Patients were stratified into 3 groups based on the CCI score (0-1, 2-3, 4-9) and again based on the age-adjusted Charlson Comorbidity score (aCCI). Cumulative survival for each stratum was determined using the Kaplan-Meier method. Non-significant and confounding variables were identified and discounted from survival modeling. 3 sex stratified Cox regression models were tested: (1) aCCI with age and comorbidity combined; (2) age and CCI; (3) age alone, comorbidity removed. RESULTS: The median survival was 4.4 years and the median follow up 4.7 years. The median CCI and aCCI scores were 2 and 5 respectively. Patients with aCCI 7-12 had an increased hazard of death on univariate analysis HR 2.45 (1.15-5.22 95%CI, p = 0.02) and -excluding age as a competing variable- on multivariate analysis HR 2.25 (1.04-4.84 95%CI, p = 0.04). Patients with CCI 4-9 had an increased hazard of death on univariate analysis HR 1.57(1.30-2.90) but not on multivariate analysis. On formalized testing - with either continuous or categorical variables- all three survival models yielded similar coefficients of effect. CONCLUSION: We identify male gender, weight loss greater than 10% and age as independent prognostic factors for patients treated with medically inoperable NSCLC treated with SABR or hypofractionated radiotherapy. Based on our survival models, age alone can be used interchangeably with aCCI or CCI plus age with the same prognostic value. Age is more reliably recorded, less prone to error and therefore a more useful metric than Charlson score in this group of patients.

8.
Quant Imaging Med Surg ; 7(6): 614-622, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29312866

ABSTRACT

BACKGROUND: The prediction of local recurrence (LR) of stage I non-small cell lung cancer (NSCLC) after definitive stereotactic body radiotherapy (SBRT) remains elusive. The purpose of this study was to assess whether quantitative imaging features on pre-treatment computed tomography (CT) can predict LR beyond 18 (18F) fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT maximum standard uptake value (SUVmax). METHODS: This retrospective study evaluated 36 patients with 37 stage I NSCLC who had local tumor control (LC; n=19) and (LR; n=18). Textural features were extracted on pre-treatment CT. Mann-Whitney U tests were used to compare LC and LR groups. Receiver-operating characteristic (ROC) curves were constructed and the area under the curve (AUC) calculated with LR as outcome. RESULTS: Gray-level correlation and sum variance were greater in the LR group, compared with the LC group (P=0.02 and P=0.04, respectively). Gray-level difference variance was lower in the LR group (P=0.004). The logistic regression model generated using gray-level correlation and difference variance features resulted in AUC (SE) 0.77 (0.08) (P=0.0007). The addition of 18F-FDG PET/CT SUVmax did not improve the AUC (P=0.75). CONCLUSIONS: CT textural features were found to be predictors of LR of early stage NSCLC on baseline CT prior to SBRT.

9.
J Neurooncol ; 128(3): 431-6, 2016 07.
Article in English | MEDLINE | ID: mdl-27084705

ABSTRACT

We examined functional outcomes and quality of life of whole brain radiotherapy (WBRT) with integrated fractionated stereotactic radiotherapy boost (FSRT) for brain metastases treatment. Eighty seven people with 1-3 brain metastases (54/87 lung primary, 42/87 single brain metastases) were enrolled on this Phase II trial of WBRT (30 Gy/10) + simultaneous FSRT, (60 Gy/10). Median overall follow-up and survival was 5.4 months, 6 month actuarial intra-lesional control was 78 %; only 1 patient exhibited grade 4 toxicity (worsened seizures); most treatment related toxicity was grade 1 or 2; 2/87 patients demonstrated asymptomatic radiation necrosis on follow-up imaging. Mean (Min-Max) baseline KPS, Mini Mental Status Exam (MMSE) and FACT-BR quality of life were 83 (70-100), 28 (21-30) and 143 (98-153). Lower baseline MMSE (but not KPS or FACT-Br) was associated with worse survival after adjusting for age, number of metastases, primary and extra-cranial disease status. Crude rates of deterioration (>10 points decrease from baseline for KPS and FACT-Br, MMSE fall to <27) ranged from 26 to 38 % for KPS, 32-59 % for FACT-Br and 0-16 % for MMSE depending on the time-point assessed with higher rates generally noted at earlier time points (≤6 months post-treatment). Using a linear mixed models analysis, significant declines from baseline were noted for KPS and FACT-Br (largest effects at 6 weeks to 3 months) with no significant change in MMSE. The effects on function and quality of life of this integrated treatment of WBRT + simultaneous FSRT were similar to other published series combining WBRT + radiosurgery.


Subject(s)
Brain Neoplasms/radiotherapy , Brain Neoplasms/secondary , Radiosurgery , Adult , Aged , Aged, 80 and over , Brain Neoplasms/pathology , Female , Follow-Up Studies , Humans , Linear Models , Lung Neoplasms/pathology , Male , Middle Aged , Quality of Life , Radiosurgery/adverse effects , Radiosurgery/methods , Superior Sagittal Sinus , Survival Analysis , Treatment Outcome , Young Adult
10.
Lung Cancer ; 94: 74-80, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26973210

ABSTRACT

BACKGROUND AND OBJECTIVES: Standard management of stage II non-small cell lung cancer (NSCLC) is surgery, often followed by adjuvant chemotherapy. However, some patients do not undergo surgery for various reasons. The optimal non-surgical management of stage II NSCLC is undefined. We surveyed Canadian oncologists to understand current practices. MATERIALS AND METHODS: Canadian oncologists specializing in the management of lung cancer were invited by email to complete an anonymous, online survey developed by the research team. Physician demographics were recorded. Physicians were asked to comment on their practice and make treatment choices in eight clinical scenarios of inoperable stage II NSCLC. RESULTS: Responses were received from 81/194 physicians (42% response rate), 57% medical and 42% radiation oncologists. Most physicians (90%) had a practice with at least 25% lung cancer patients and 85% were based at an academic institution. Across eight clinical patient scenarios, radical therapy was selected 79-98% of the time. Radical radiotherapy alone and concurrent chemoradiotherapy were the preferred options for these patients, while sequential chemoradiation was less favoured. Nodal status (N0 vs N1) did not influence choice of therapy (p 0.31), but the reason for patient inoperability did (p<0.0001). There was no significant difference in choice of therapy when comparing responses between medical vs radiation oncologists, academic vs community physicians, and physicians with high vs low proportion of lung cancer patients. CONCLUSION: Most lung cancer physicians manage inoperable stage II NSCLC patients with curative intent, but consensus on how to optimally employ radiotherapy and/or chemotherapy is lacking. Future prospective, randomized trials are warranted.


Subject(s)
Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/therapy , Lung Neoplasms/pathology , Lung Neoplasms/therapy , Oncologists , Canada/epidemiology , Carcinoma, Non-Small-Cell Lung/epidemiology , Combined Modality Therapy , Disease Management , Health Care Surveys , Humans , Lung Neoplasms/epidemiology , Neoplasm Staging , Practice Patterns, Physicians'
11.
Pract Radiat Oncol ; 4(2): 82-89, 2014.
Article in English | MEDLINE | ID: mdl-24890348

ABSTRACT

PURPOSE: To standardize upper abdominal normal organ contouring guidelines for Radiation Therapy Oncology Group (RTOG) trials. METHODS AND MATERIALS: Twelve expert radiation oncologists contoured the liver, esophagus, gastroesophageal junction (GEJ), stomach, duodenum, and common bile duct (CBD), and reviewed and edited 33 additional normal organ and blood vessel contours on an anonymized patient computed tomography (CT) dataset. Contours were overlaid and compared for agreement using MATLAB (MathWorks, Natick, MA). S95 contours, defined as the binomial distribution to generate 95% group consensus contours, and normal organ contouring definitions were generated and reviewed by the panel. RESULTS: There was excellent consistency and agreement of the liver, duodenal, and stomach contours, with substantial consistency for the esophagus contour, and moderate consistency for the GEJ and CBD contours using a Kappa statistic. Consensus definitions, detailed normal organ contouring recommendations and high-resolution images were developed. CONCLUSIONS: Consensus contouring guidelines and a CT image atlas should improve contouring uniformity in radiation oncology clinical planning and RTOG trials.


Subject(s)
Digestive System/anatomy & histology , Digestive System/diagnostic imaging , Radiation Oncology/organization & administration , Radiation Oncology/standards , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy Planning, Computer-Assisted/standards , Tomography, X-Ray Computed/methods , Consensus , Humans
12.
World J Radiol ; 6(2): 18-25, 2014 Feb 28.
Article in English | MEDLINE | ID: mdl-24578789

ABSTRACT

The prognosis of patients with metastatic liver disease remains dismal with a median survival of only 6-12 mo. As 80%-90% of patients are not candidates for surgical therapy, there is a need for effective non-surgical therapies that would improve outcomes in these patients. The body of evidence related to the use of stereotactic ablative radiotherapy (SABR) in metastatic liver disease has substantially grown and evolved over the past decade. This review summarizes the current evidence supporting liver SABR with particular attention given to patient selection, target delineation, organ at risk dose volume constraints, response evaluation imaging and the various SABR techniques for delivering ablative radiotherapy to the liver. Even though it is unclear what dose-fractionation scheme, delivery system, concomitant therapy or patient selection strategy yields the optimum liver SABR outcomes, clear and growing evidence is available that SABR is a safe and effective therapy for the treatment of oligometastatic liver disease.

13.
Int J Radiat Oncol Biol Phys ; 88(2): 312-8, 2014 Feb 01.
Article in English | MEDLINE | ID: mdl-24411602

ABSTRACT

PURPOSE: The aim of this study was to determine whether the preradiation maximum standardized uptake value (SUVmax) of the primary tumor for [(18)F]-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) has a prognostic significance in patients with Stage T1 or T2N0 non-small cell lung cancer (NSCLC) treated with curative radiation therapy, whether conventional or stereotactic body radiation therapy (SBRT). METHODS AND MATERIALS: Between January 2007 and December 2011, a total of 163 patients (180 tumors) with medically inoperable histologically proven Stage T1 or T2N0 NSCLC and treated with radiation therapy (both conventional and SBRT) were entered in a research ethics board approved database. All patients received pretreatment FDG-PET / computed tomography (CT) at 1 institution with consistent acquisition technique. The medical records and radiologic images of these patients were analyzed. RESULTS: The overall survival at 2 years and 3 years for the whole group was 76% and 67%, respectively. The mean and median SUVmax were 8.1 and 7, respectively. Progression-free survival at 2 years with SUVmax <7 was better than that of the patients with tumor SUVmax ≥7 (67% vs 51%; P=.0096). Tumors with SUVmax ≥7 were associated with a worse regional recurrence-free survival and distant metastasis-free survival. In the multivariate analysis, SUVmax ≥7 was an independent prognostic factor for distant metastasis-free survival. CONCLUSION: In early-stage NSCLC managed with radiation alone, patients with SUVmax ≥7 on FDG-PET / CT scan have poorer outcomes and high risk of progression, possibly because of aggressive biology. There is a potential role for adjuvant therapies for these high-risk patients with intent to improve outcomes.


Subject(s)
Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Lung Neoplasms/diagnostic imaging , Positron-Emission Tomography/methods , Adult , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/mortality , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/radiotherapy , Carcinoma, Non-Small-Cell Lung/secondary , Disease Progression , Female , Fluorodeoxyglucose F18/pharmacokinetics , Humans , Lung Neoplasms/mortality , Lung Neoplasms/pathology , Lung Neoplasms/radiotherapy , Male , Middle Aged , Neoplasm Recurrence, Local , Prognosis , Radiopharmaceuticals/pharmacokinetics , Retrospective Studies , Treatment Outcome
14.
Int J Radiat Oncol Biol Phys ; 77(5): 1553-60, 2010 Aug 01.
Article in English | MEDLINE | ID: mdl-20605343

ABSTRACT

PURPOSE: To investigate the feasibility of modeling Stage III lung cancer tumor and node positions from anatomical surrogates. METHODS AND MATERIALS: To localize their centroids, the primary tumor and lymph nodes from 16 Stage III lung cancer patients were contoured in 10 equal-phase planning four-dimensional (4D) computed tomography (CT) image sets. The centroids of anatomical respiratory surrogates (carina, xyphoid, nipples, mid-sternum) in each image set were also localized. The correlations between target and surrogate positions were determined, and ordinary least-squares (OLS) and partial least-squares (PLS) regression models based on a subset of respiratory phases (three to eight randomly selected) were created to predict the target positions in the remaining images. The three-phase image sets that provided the best predictive information were used to create models based on either the carina alone or all surrogates. RESULTS: The surrogate most correlated with target motion varied widely. Depending on the number of phases used to build the models, mean OLS and PLS errors were 1.0 to 1.4 mm and 0.8 to 1.0 mm, respectively. Models trained on the 0%, 40%, and 80% respiration phases had mean (+/- standard deviation) PLS errors of 0.8 +/- 0.5 mm and 1.1 +/- 1.1 mm for models based on all surrogates and carina alone, respectively. For target coordinates with motion >5 mm, the mean three-phase PLS error based on all surrogates was 1.1 mm. CONCLUSIONS: Our results establish the feasibility of inferring primary tumor and nodal motion from anatomical surrogates in 4D CT scans of Stage III lung cancer. Using inferential modeling to decrease the processing time of 4D CT scans may facilitate incorporation of patient-specific treatment margins.


Subject(s)
Four-Dimensional Computed Tomography/methods , Lung Neoplasms/diagnostic imaging , Lymph Nodes/diagnostic imaging , Movement , Respiration , Algorithms , Feasibility Studies , Female , Humans , Least-Squares Analysis , Lung/diagnostic imaging , Lung Neoplasms/pathology , Lymph Nodes/pathology , Male , Models, Biological , Neoplasm Staging , Nipples/diagnostic imaging , Sternum/diagnostic imaging , Xiphoid Bone/diagnostic imaging
15.
Int J Radiat Oncol Biol Phys ; 75(4): 1092-7, 2009 Nov 15.
Article in English | MEDLINE | ID: mdl-19327915

ABSTRACT

PURPOSE: Respiratory-gated radiotherapy allows for the reduction of the toxicity associated with concomitant chemoradiotherapy, but the smaller fields used could increase the risk of missing the target. A prospective study was performed to evaluate the dosimetric consequences of time-trend changes in patients with lung cancer who were treated with concomitant chemoradiotherapy. METHODS AND MATERIALS: A total of 24 lung cancer patients eligible for chemoradiotherapy and gated delivery underwent four-dimensional computed tomography (4D-CT) after 15 fractions. This scan was co-registered with the initial planning 4D-CT and a new planning target volume (PTV) was generated on the basis of the tumor visualized after 15 fractions. Coverage of the repeat PTV was evaluated by applying the original plan to the second scan and recalculating the dose. Plan modification was triggered by a 5% reduction in the PTV included within the 95% isodose volume or an unacceptable increase in the critical organ dose. RESULTS: Of the 21 evaluable patients, 15 had an average reduction in the PTV of 8% after 30 Gy. The PTV increased in the remaining 6 patients, but the increase was >20% in only 1 patient. In the latter patient, disease progression was observed, and repeat planning was required. The plans created using the new PTV were acceptable in all the other patients. CONCLUSION: The role of adaptive radiotherapy appears limited when respiratory-gated radiotherapy is used to reduce the toxicity related to concomitant chemoradiotherapy. The use of more conformal treatment techniques might provide the rationale for repeat imaging as a method to identify patients at risk of dosimetric miss.


Subject(s)
Lung Neoplasms/drug therapy , Lung Neoplasms/radiotherapy , Radiotherapy, Conformal/methods , Aged , Algorithms , Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/radiotherapy , Combined Modality Therapy/methods , Female , Humans , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/pathology , Male , Middle Aged , Movement , Prospective Studies , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted/methods , Respiration , Tomography, X-Ray Computed/methods , Tumor Burden
16.
Int J Radiat Oncol Biol Phys ; 74(4): 1092-9, 2009 Jul 15.
Article in English | MEDLINE | ID: mdl-19095370

ABSTRACT

PURPOSE: The motion of mediastinal lymph nodes may undermine local control with involved-field radiotherapy. We studied patterns of nodal and tumor motion in 41 patients with lung cancer. METHODS AND MATERIALS: Four-dimensional (4D) computed tomography planning scans were retrospectively evaluated to identify patients with clearly visible mediastinal lymph nodes. One hundred nodes from 14 patients with Stage I and 27 patients with Stage III were manually contoured in all 4D computed tomography respiratory phases. Motion was derived from changes in the nodal center-of-mass position. Primary tumors were also delineated in all phases for 16 patients with Stage III disease. Statistical analysis included a multivariate mixed-effects model of grouped data. RESULTS: Average 3D nodal motion during quiet breathing was 0.68 cm (range, 0.17-1.64 cm); 77% moved greater than 0.5 cm, and 10% moved greater than 1.0 cm. Motion was greatest in the lower mediastinum (p = 0.002), and nodes measuring 2 cm or greater in diameter showed motion similar to that in smaller nodes. In 11 of 16 patients studied, at least one node moved more than the corresponding primary tumor. No association between 3D primary tumor motion and nodal motion was observed. For mobile primary tumors, phase offsets between the primary tumor and nodes of two or more and three or more phases were observed for 33% and 12% of nodes, respectively. CONCLUSIONS: Mediastinal nodal motion is common, with phase offsets seen between the primary tumor and different nodes in the same patient. Patient-specific information is needed to ensure geometric coverage, and adaptive strategies based solely on the primary tumor may be misleading.


Subject(s)
Lung Neoplasms/diagnostic imaging , Lymph Nodes/diagnostic imaging , Mediastinum/diagnostic imaging , Movement , Respiration , Aged , Female , Humans , Lung Neoplasms/pathology , Lymph Nodes/pathology , Male , Middle Aged , Multivariate Analysis , Radiotherapy Planning, Computer-Assisted/methods , Retrospective Studies , Tomography, X-Ray Computed/methods
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