Rahul D. Tendulkar

Prediction of Chest Wall Toxicity From Lung Stereotactic Body Radiotherapy (SBRT)

PURPOSE To determine patient, tumor, and treatment factors related to the development of late chest wall toxicity after lung stereotactic body radiotherapy (SBRT). METHODS AND MATERIALS We reviewed a registry of 134 patients treated with lung SBRT to 60 Gy in 3 fractions who had greater than 1 year of clinical follow-up and no history of multiple treatments to the same lobe (n = 48). Patients were treated as per Radiation Therapy Oncology Group Protocol 0236 without specific chest wall avoidance criteria. The chest wall was retrospectively contoured. Thirty-two lesions measured less than 3 cm, and sixteen measured 3 to 5 cm. The median planning target volume was 29 cm(3). RESULTS With a median follow-up of 18.8 months, 10 patients had late symptomatic chest wall toxicity (4 Grade 1 and 6 Grade 2) at a median of 8.8 months after SBRT. No patient characteristics (age, diabetes, hypertension, peripheral vascular disease, or body mass index) were predictive for toxicity, whereas there was a trend for continued smoking (p = 0.066; odds ratio [OR], 4.4). Greatest single tumor dimension (p = 0.047; OR, 2.63) and planning target volume (p = 0.040; OR, 1.04) were correlated with toxicity, whereas distance from tumor edge to chest wall and gross tumor volume did not reach statistical significance. Volumes of chest wall receiving 30 Gy (V30) through 70 Gy (V70) were all highly significant, although this correlation weakened for V65 and V70 and maximum chest wall point dose only trended to significance (p = 0.06). On multivariate analysis, tumor volume was no longer correlated with toxicity and only V30 through V60 remained statistically significant. CONCLUSIONS Tumor size and chest wall dosimetry are correlated to late chest wall toxicity. Only chest wall V30 through V60 remained significant on multivariate analysis. Restricting V30 to 30 cm(3) or less and V60 to 3 cm(3) or less should result in a 10% to 15% risk of late chest wall toxicity or lower.

Contemporary Update of a Multi-Institutional Predictive Nomogram for Salvage Radiotherapy After Radical Prostatectomy

PURPOSE We aimed to update a previously published, multi-institutional nomogram of outcomes for salvage radiotherapy (SRT) following radical prostatectomy (RP) for prostate cancer, including patients treated in the contemporary era. METHODS Individual data from node-negative patients with a detectable post-RP prostate-specific antigen (PSA) treated with SRT with or without concurrent androgen-deprivation therapy (ADT) were obtained from 10 academic institutions. Freedom from biochemical failure (FFBF) and distant metastases (DM) rates were estimated, and predictive nomograms were generated. RESULTS Overall, 2,460 patients with a median follow-up of 5 years were included; 599 patients (24%) had a Gleason score (GS) ≤ 6, 1,387 (56%) had a GS of 7, 244 (10%) had a GS of 8, and 230 (9%) had a GS of 9 to 10. There were 1,370 patients (56%) with extraprostatic extension (EPE), 452 (18%) with seminal vesicle invasion (SVI), 1,434 (58%) with positive surgical margins, and 390 (16%) who received ADT (median, 6 months). The median pre-SRT PSA was 0.5 ng/mL (interquartile range, 0.3 to 1.1). The 5-yr FFBF rate was 56% overall, 71% for those with a pre-SRT PSA level of 0.01 to 0.2 ng/mL (n = 441), 63% for those with a PSA of 0.21 to 0.50 ng/mL (n = 822), 54% for those with a PSA of 0.51 to 1.0 ng/mL (n = 533), 43% for those with a PSA of 1.01 to 2.0 ng/mL (n = 341), and 37% for those with a PSA > 2.0 ng/mL (n = 323); P < .001. On multivariable analysis, pre-SRT PSA, GS, EPE, SVI, surgical margins, ADT use, and SRT dose were associated with FFBF. Pre-SRT PSA, GS, SVI, surgical margins, and ADT use were associated with DM, whereas EPE and SRT dose were not. The nomogram concordance indices were 0.68 (FFBF) and 0.74 (DM). CONCLUSION Early SRT at low PSA levels after RP is associated with improved FFBF and DM rates. Contemporary nomograms can estimate individual patient outcomes after SRT in the modern era.

Preoperative Breast Magnetic Resonance Imaging in Early Breast Cancer : Implications for Partial Breast Irradiation

Accelerated partial breast irradiation (APBI) of patients with early breast cancer is being investigated on a multi‐institutional protocol National Surgical Adjuvant Breast and Bowel Project (NSABP) B‐39/RTOG 0413. Breast magnetic resonance imaging (MRI) is more sensitive than mammography (MG) and may aid in selection of patients appropriate for PBI.

Impact of postmastectomy radiation on locoregional recurrence in breast cancer patients with 1-3 positive lymph nodes treated with modern systemic therapy.

PURPOSE Postmastectomy radiation therapy (PMRT) remains controversial for patients with 1-3 positive lymph nodes (LN+). METHODS AND MATERIALS We conducted a retrospective review of all 369 breast cancer patients with 1-3 LN+ who underwent mastectomy without neoadjuvant systemic therapy between 2000 and 2007 at Cleveland Clinic. RESULTS We identified 271 patients with 1-3 LN+ who did not receive PMRT and 98 who did receive PMRT. The median follow-up time was 5.2 years, and the median number of LN dissected was 11. Of those not treated with PMRT, 79% received adjuvant chemotherapy (of whom 70% received a taxane), 79% received hormonal therapy, and 5% had no systemic therapy. Of the Her2/neu amplified tumors, 42% received trastuzumab. The 5-year rate of locoregional recurrence (LRR) was 8.9% without PMRT vs 0% with PMRT (P=.004). For patients who did not receive PMRT, univariate analysis showed 6 risk factors significantly (P<.05) correlated with LRR: estrogen receptor/progesterone receptor negative (hazard ratio [HR] 2.6), lymphovascular invasion (HR 2.4), 2-3 LN+ (HR 2.6), nodal ratio >25% (HR 2.7), extracapsular extension (ECE) (HR 3.7), and Bloom-Richardson grade III (HR 3.1). The 5-year LRR rate was 3.4% (95% confidence interval [CI], 0.1%-6.8%] for patients with 0-1 risk factor vs 14.6% [95% CI, 8.4%-20.9%] for patients with ≥2 risk factors (P=.0006), respectively. On multivariate analysis, ECE (HR 4.3, P=.0006) and grade III (HR 3.6, P=.004) remained significant risk factors for LRR. The 5-year LRR was 4.1% in patients with neither grade III nor ECE, 8.1% with either grade III or ECE, and 50.4% in patients with both grade III and ECE (P<.0001); the corresponding 5-year distant metastasis-free survival rates were 91.8%, 85.4%, and 59.1% (P=.0004), respectively. CONCLUSIONS PMRT offers excellent control for patients with 1-3 LN+, with no locoregional failures to date. Patients with 1-3 LN+ who have grade III disease and/or ECE should be strongly considered for PMRT.

Stereotactic Radiosurgery for Single Brainstem Metastases: The Cleveland Clinic Experience

PURPOSE To assess the imaging and clinical outcomes of patients with single brainstem metastases treated with stereotactic radiosurgery (SRS). MATERIALS AND METHODS We retrospectively reviewed the data from patients with single brainstem metastases treated with SRS. Locoregional control and survival were calculated using the Kaplan-Meier method. Prognostic factors were assessed using a Cox proportional hazards model. RESULTS Between 1997 and 2007, 43 patients with single brainstem metastases were treated with SRS. The median age at treatment was 59 years, the median Karnofsky performance status was 80, and the median follow-up was 5.3 months. The median dose was 15 Gy (range, 9.6-24), and the median conformality and heterogeneity index was 1.7 and 1.9, respectively. The median survival was 5.8 months from the procedure date. Of the 33 patient with post-treatment imaging available, a complete radiographic response was achieved in 2 (4.7%), a partial response in 8 (18.6%), and stable disease in 23 (53.5%). The 1-year actuarial rate of local control, distant brain control, and overall survival was 85%, 38.3%, and 31.5%, respectively. Of the 43 patients, 8 (19%) died within 2 months of undergoing SRS, and 15 (36%) died within 3 months. On multivariate analysis, greater performance status (hazard ratio [HR], 0.95, p = .004), score index for radiosurgery (HR, 0.7; p = .004), graded prognostic assessment score (HR, 0.48; p = .003), and smaller tumor volume (HR, 1.23, p = .002) were associated with improved survival. No Grade 3 or 4 toxicities were observed. CONCLUSION The results of our study have shown that SRS is a safe and effective local therapy for patients with brainstem metastases.

Relationship of Imaging Frequency and Planning Margin to Account for Intrafraction Prostate Motion: Analysis Based on Real-Time Monitoring Data

PURPOSE Correction for intrafraction prostate motion becomes important for hypofraction treatment of prostate cancer. The purpose of this study was to estimate an ideal planning margin to account for intrafraction prostate motion as a function of imaging and repositioning frequency in the absence of continuous prostate motion monitoring. METHODS AND MATERIALS For 31 patients receiving intensity modulated radiation therapy treatment, prostate positions sampled at 10 Hz during treatment using the Calypso system were analyzed. Using these data, we simulated multiple, less frequent imaging protocols, including intervals of every 10, 15, 20, 30, 45, 60, 90, 120, 180, and 240 seconds. For each imaging protocol, the prostate displacement at the imaging time was corrected by subtracting prostate shifts from the subsequent displacements in that fraction. Furthermore, we conducted a principal component analysis to quantify the direction of prostate motion. RESULTS Averaging histograms of every 240 and 60 seconds for all patients, vector displacements of the prostate were, respectively, within 3 and 2 mm for 95% of the treatment time. A vector margin of 1 mm achieved 91.2% coverage of the prostate with 30 second imaging. The principal component analysis for all fractions showed the largest variance in prostate position in the midsagittal plane at 54° from the anterior direction, indicating that anterosuperior to inferoposterior is the direction of greatest motion. The smallest prostate motion is in the left-right direction. CONCLUSIONS The magnitudes of intrafraction prostate motion along the superior-inferior and anterior-posterior directions are comparable, and the smallest motion is in the left-right direction. In the absence of continuous prostate motion monitoring, and under ideal circumstances, 1-, 2-, and 3-mm vector planning margins require a respective imaging frequency of every 15, 60, and 240 to account for intrafraction prostate motion while achieving adequate geometric target coverage for 95% of the time.

Risk Factors for Complications of Radiation Therapy on Tissue Expander Breast Reconstructions

Abstract:  Radiation therapy has been shown to increase complication rates of tissue expander/implant breast reconstructions. The purpose of this study was to evaluate patient characteristics to assess their impact on complications. A retrospective review of patients who underwent mastectomy plus tissue expander/implant reconstruction from January 2000 to December 2006 was performed. The main outcome of interest was the development of postoperative complications. Analyses were performed to detect risk factors for complications. A total of 560 patients were included in the study. A total of 385 patients underwent unilateral and 174 underwent bilateral tissue expander/implant reconstructions, for a total of 733 reconstructions. A total complication rate of 31.8% and a major complication rate of 24.4% were calculated. The risk factors associated with a significantly increased incidence of complications were age greater than 50 years, body mass index (BMI) greater than 30, and radiation. Women younger than 50 years had a complication rate of 28.4%, whereas women older than 50 years had a complication rate of 37.0%. Women with a BMI less than 30 had a complication rate of 27.5%, whereas women with a BMI greater than 30 had a complication rate of 49%. The major complication rate in nonradiated and radiated patients was 21.2% and 45.4%, respectively. Despite higher complication rates, tissue expander/implant reconstructions were successful in 70.1% of radiated patients. Based on this study, the ideal radiated patient would have a BMI less than 30 and be younger than 50 years of age to maximize the likelihood of a successful tissue expander/implant reconstruction.

Irradiation of Pediatric High-Grade Spinal Cord Tumors

PURPOSE To report the outcome using radiation therapy (RT) for pediatric patients with high-grade spinal cord tumors. METHODS AND MATERIALS A retrospective chart review was conducted that included 17 children with high-grade spinal cord tumors treated with RT at St. Jude Childrens Research Hospital between 1981 and 2007. Three patients had gross total resection, 11 had subtotal resection, and 3 underwent biopsy. The tumor diagnosis was glioblastoma multiforme (n = 7), anaplastic astrocytoma (n = 8), or anaplastic oligodendroglioma (n = 2). Seven patients received craniospinal irradiation (34.2-48.6 Gy). The median dose to the primary site was 52.2 Gy (range, 38-66 Gy). RESULTS The median progression-free and overall survivals were 10.8 and 13.8 months, respectively. Local tumor progression at 12 months (79% vs. 30%, p = 0.02) and median survival (13.1 vs. 27.2 months, p = 0.09) were worse for patients with glioblastoma multiforme compared with anaplastic astrocytoma or oligodendroglioma. The median overall survival was shorter for patients when failure included neuraxis dissemination (n = 8) compared with local failure alone (n = 5), 9.6 vs. 13.8 months, p = 0.08. Three long-term survivors with World Health Organization Grade III tumors were alive with follow-up, ranging from 88-239 months. CONCLUSIONS High-grade spinal cord primary tumors in children have a poor prognosis. The propensity for neuraxis metastases as a component of progression after RT suggests the need for more aggressive therapy.

Long-term efficacy and toxicity of low-dose-rate 125 I prostate brachytherapy as monotherapy in low-, intermediate-, and high-risk prostate cancer

PURPOSE/OBJECTIVES To report long-term efficacy and toxicity for a single-institution cohort of patients treated with low-dose-rate prostate brachytherapy permanent implant (PI) monotherapy. METHODS AND MATERIALS From 1996 to 2007, 1989 patients with low-risk (61.3%), intermediate-risk (29.8%), high-intermediate-risk (4.5%), and high-risk prostate cancer (4.4%) were treated with PI and followed up prospectively in a registry. All patients were treated with (125)I monotherapy to 144 Gy. Late toxicity was coded retrospectively according to a modified Common Terminology Criteria for Adverse Events 4.0 scale. The rates of biochemical relapse-free survival (bRFS), distant metastasis-free survival (DMFS), overall survival (OS), and prostate cancer-specific mortality (PCSM) were calculated. We identified factors associated with late grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicity, bRFS, DMFS, OS, PCSM, and incontinence. RESULTS The median age of the patients was 67 years, and the median overall and prostate-specific antigen follow-up times were 6.8 years and 5.8 years, respectively. The overall 5-year rates for bRFS, DMFS, OS, and PCSM were 91.9%, 97.8%, 93.7%, and 0.71%, respectively. The 10-year rates were 81.5%, 91.5%, 76.1%, and 2.5%, respectively. The overall rates of late grade ≥3 GU and GI toxicity were 7.6% and 0.8%, respectively. On multivariable analysis, age and prostate length were significantly associated with increased risk of late grade ≥3 GU toxicity. The risk of incontinence was highly correlated with both pre-PI and post-PI transurethral resection of the prostate. CONCLUSIONS Prostate brachytherapy as monotherapy is an effective treatment for low-risk and low-intermediate-risk prostate cancer and appears promising as a treatment for high-intermediate-risk and high-risk prostate cancer. Significant long-term toxicities are rare when brachytherapy is performed as monotherapy.

Alignment focus of daily image guidance for concurrent treatment of prostate and pelvic lymph nodes.

PURPOSE To determine the dosimetric impact of daily imaging alignment focus on the prostate soft tissue versus the pelvic bones for the concurrent treatment of the prostate and pelvic lymph nodes (PLN) and to assess whether multileaf collimator (MLC) tracking or adaptive planning (ART) is necessary with the current clinical planning margins of 8 mm/6 mm posterior to the prostate and 5 mm to the PLN. METHODS AND MATERIALS A total of 124 kilovoltage cone-beam computed tomography (kV-CBCT) images from 6 patients were studied. For each KV-CBCT, 4 plans were retrospectively created using an isocenter shifting method with 2 different alignment focuses (prostate, PLN), an MLC shifting method, and the ART method. The selected dosimetric endpoints were compared among these plans. RESULTS For the isoshift contour, isoshift bone, MLC shift, and ART plans, D99 of the prostate was ≥97% of the prescription dose in 97.6%, 73.4%, 98.4%, and 96.8% of 124 fractions, respectively. Accordingly, D99 of the PLN was ≥97% of the prescription dose in 98.4%, 98.4%, 98.4%, and 100% of 124 fractions, respectively. For the rectum, D5 exceeded 105% of the planned D5 (and D5 of ART plans) in 11% (4%), 10% (2%), and 13% (5%) of 124 fractions, respectively. For the bladder, D5 exceeded 105% of the planned D5 (and D5 of ART) plans in 0% (2%), 0% (2%), and 0% (1%) of 124 fractions, respectively. CONCLUSION For concurrent treatment of the prostate and PLN, with a planning margin to the prostate of 8 mm/6 mm posterior and a planning margin of 5 mm to the PLN, aligning to the prostate soft tissue can achieve adequate dose coverage to the both target volumes; aligning to the pelvic bone would result in underdosing to the prostate in one-third of fractions. With these planning margins, MLC tracking and ART methods have no dosimetric advantages.