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Lack of survival benefit following adjuvant radiation in patients with retroperitoneal sarcoma: A SEER analysis

BACKGROUND The benefit of radiation therapy (RT) among patients with retroperitoneal sarcoma (RPS) is controversial. We performed a retrospective analysis of the effect of RT on survival among RPS patients using a nationwide cancer registry. METHODS Utilizing data from the Surveillance, Epidemiology, and End Results (SEER) database, we identified 2308 cases of RPS from 1988 to 2004. We excluded 773 cases for age < 18, identification by autopsy only, absence of histologic confirmation, presence of metastatic disease, or lack of surgical intervention. Overall survival (OS) and disease-specific survival (DSS) were estimated using the Kaplan-Meier method. Multivariate analysis was performed using a Cox proportional hazards model, adjusting for significant covariables. RESULTS Among 1535 patients who met entry criteria, RT was administered to 373 patients (24.3%). The majority of RT (n = 300, 80.4%) was administered postoperatively. Median OS was 60 and 60 mo, respectively, for patients receiving and not receiving RT (P = 0.59). Median DSS was 86 and 117 mo, respectively, for patients receiving and not receiving RT (P = 0.84). On multivariate analysis, younger age, female gender, low and intermediate histologic grade, liposarcoma histology, tumor size 5-10 cm, and completeness of resection all independently predicted better OS and DSS, while RT did not (HR for OS with RT 0.92, 95% CI 0.78-1.09 and HR for DSS with RT 0.96, 95% CI 0.78-1.17). On subgroup analysis by histology, patients with malignant fibrous histiocytoma (MFH) receiving RT demonstrated statistically improved OS (P = 0.002) and DSS (P = 0.01), respectively. CONCLUSIONS With the possible exception of MFH, postoperative RT offers no survival benefit in RPS. Further studies are necessary to determine if the selective application of RT is indicated.

Development of a standardized method for contouring the lumbosacral plexus: A preliminary dosimetric analysis of this organ at risk among 15 patients treated with intensity-modulated radiotherapy for lower gastrointestinal cancers and the incidence of radiation-induced lumbosacral plexopathy

PURPOSE To generate a reproducible step-wise guideline for the delineation of the lumbosacral plexus (LSP) on axial computed tomography (CT) planning images and to provide a preliminary dosimetric analysis on 15 representative patients with rectal or anal cancers treated with an intensity-modulated radiotherapy (IMRT) technique. METHODS AND MATERIALS A standardized method for contouring the LSP on axial CT images was devised. The LSP was referenced to identifiable anatomic structures from the L4-5 interspace to the level of the sciatic nerve. It was then contoured retrospectively on 15 patients treated with IMRT for rectal or anal cancer. No dose limitations were placed on this organ at risk during initial treatment planning. Dosimetric parameters were evaluated. The incidence of radiation-induced lumbosacral plexopathy (RILSP) was calculated. RESULTS Total prescribed dose to 95% of the planned target volume ranged from 50.4 to 59.4 Gy (median 54 Gy). The mean (± standard deviation [SD]) LSP volume for the 15 patients was 100 ± 22 cm(3) (range, 71-138 cm(3)). The mean maximal dose to the LSP was 52.6 ± 3.9 Gy (range, 44.5-58.6 Gy). The mean irradiated volumes of the LSP were V40Gy = 58% ± 19%, V50Gy = 22% ± 23%, and V55Gy = 0.5% ± 0.9%. One patient (7%) was found to have developed RILSP at 13 months after treatment. CONCLUSIONS The true incidence of RILSP in the literature is likely underreported and is not a toxicity commonly assessed by radiation oncologists. In our analysis the LSP commonly received doses approaching the prescribed target dose, and 1 patient developed RILSP. Identification of the LSP during IMRT planning may reduce RILSP. We have provided a reproducible method for delineation of the LSP on CT images and a preliminary dosimetric analysis for potential future dose constraints.

Interstitial brachytherapy as boost for locally advanced T4 head and neck cancer

PURPOSE Locally advanced squamous cell cancers of the head and neck (SCCHN) with bone and cartilage invasion (BCI) or those with soft-tissue invasion (STI) have been treated with resection followedup with chemoradiotherapy (CRT) or definitive CRT. However, locoregional recurrence remained a large component of treatment failure. High-dose-rate interstitial brachytherapy (BT) has been used for dose escalation to further prevent local relapse. This is a review of our experience. METHODS AND MATERIALS T4N0-3M0 locally advanced oral cavity and oropharyngeal squamous cell carcinoma (SCCA) patients underwent definitive CRT or radiotherapy (RT) followedup with brachytherapy (BT). RT doses ranged from 45 to 50.4Gy. The patients were reassessed at this dose and if response was inadequate, patients underwent BT. BT doses ranged from 24 to 30Gy at 3-4Gy per fraction BID with 6h in between fractions. Concurrent chemotherapy was platinum based. RESULTS Twenty patients were treated with CRT or RT alone followed by BT. Thirteen patients had STI and 7 had BCI; 14 patients were treated with CRT followed by BT; and 6 patients were treated with RT alone followed by BT. Five-year locoregional control was 61%. Five-year overall survival was 29%. When we excluded the patients treated with RT alone, 5-year overall survival was 36%. Nodal status was the only prognostic factor. CONCLUSIONS This study suggests CRT followedup with BT for patients with T4 locally advanced SCCHN of the oral cavity, and oropharynx is a feasible treatment option. In patients with poor response to CRT, BT may be used for dose escalation to increase locoregional control.

Treatment outcomes of T4 locally advanced head and neck cancers with soft tissue invasion or bone and cartilage invasion.

Purpose/Objective(s):T4 locally advanced squamous cell cancers of the head and neck (SCCHN) with bone and cartilage invasion (BCI) traditionally have been treated with resection followed up with chemoradiotherapy (CRT). Because the organ preservation trials, more patients with BCI, as well as those with soft tissue invasion (STI), have been treated with definitive CRT. This is a review of our experience. Materials/Methods:We performed a retrospective review of patients who underwent definitive CRT or radical resection followed up with postoperative CRT for T4N0-3M0 locally advanced SCCHN. We analyzed outcomes based on STI/BCI and types of treatment. Radiotherapy doses ranged from 59.4 to 72 Gy. Concurrent chemotherapy was platinum based in all CRT patients. Results:From 1995 to 2006, 101 patients with locally advanced SCCHN were treated definitively. Of these, 51 had STI and 50 had BCI. Of the 51 patients with STI, 42 were treated with CRT, 5 patients were treated with resection followed by CRT, and 4 patients were treated with radiotherapy alone. Of the 50 patients with BCI, 26 patients were treated with CRT, 20 patients were treated with radical resection followed by radiotherapy or CRT, and 4 patients were treated with radiotherapy alone. Five-year local-regional control was 51% and 43% for STI and BCI patients treated with CRT, respectively, and 44% for BCI treated with radical resection. Five-year overall survival was 23%, 51%, and 28% for STI treated with CRT, BCI treated with CRT, and BCI treated with radical resection. Outcomes were not statistically different between these groups. Conclusions:This study suggests similar outcomes for CRT or resection followed up with chemoradiotherapy for patients with locally advanced SCCHN with BCI. Concurrent CRT may be viable alternative to upfront resection in these patients. Further studies should be performed to validate these provocative findings.

Prognostic significance of bone or cartilage invasion of locally advanced head and neck cancers.

Purpose/Objective(s):Locally advanced squamous cell cancers of the head and neck with bone and cartilage invasion (BCI) traditionally have been treated with resection followed up with radiotherapy or less commonly definitive chemoradiotherapy (CRT). However, it is unclear whether bone or cartilage invasion confers a worse prognosis in comparison with each other. Materials/Methods:T4N0–3M0 squamous cell cancers of the head and neck patients underwent CRT or radical resection followed up with postoperative CRT. Oral cavity, oropharynx, laryngeal and hypopharyngeal squamous cell cancers were included. Radiotherapy ranged from 59.4 to 72 Gy. Concurrent chemotherapy was platinum based. Results:Forty-six patients with BCI were treated. When treated with CRT, 5-year local control was 55% and 43% for BCI, respectively (P = 0.23). Five-year overall survival for these patients was 54% and 29% for BCI, respectively (P = 0.99). When treated with upfront resection, 5-year local control was not significantly different (P = 0.60) nor was 5-year overall survival (P = 0.15). Conclusions:This study suggests similar outcomes between patients with bone or cartilage invasion treated with upfront CRT or resection followed by CRT. Concurrent CRT may be viable alternative to resection in patients with either bone or cartilage invasion.

Addition of a third field significantly increases dose to the brachial plexus for patients undergoing tangential whole-breast therapy after lumpectomy.

Our goal was to evaluate brachial plexus (BP) dose with and without the use of supraclavicular (SCL) irradiation in patients undergoing breast-conserving therapy with whole-breast radiation therapy (RT) after lumpectomy. Using the standardized Radiation Therapy Oncology Group (RTOG)-endorsed guidelines delineation, we contoured the BP for 10 postlumpectomy breast cancer patients. The radiation dose to the whole breast was 50.4 Gy using tangential fields in 1.8-Gy fractions, followed by a conedown to the operative bed using electrons (10 Gy). The prescription dose to the SCL field was 50.4 Gy, delivered to 3-cm depth. The mean BP volume was 14.5 ± 1.5 cm(3). With tangential fields alone, the median mean dose to the BP was 0.57 Gy, the median maximum dose was 1.93 Gy, and the irradiated volume of the BP receiving 40, 45, and 50 Gy was 0%. When the third (SCL field) was added, the dose to the BP was significantly increased (P = .01): the median mean dose to the BP was 40.60 Gy, and the median maximum dose was 52.22 Gy. With 3-field RT, the median irradiated volume of the BP receiving 40, 45, and 50 Gy was 83.5%, 68.5%, and 24.6%, respectively. The addition of the SCL field significantly increases dose to the BP. The possibility of increasing the risk of BP morbidity should be considered in the context of clinical decision making.

SU‐FF‐T‐176: Rectal and Bladder Dose in Relationship to PTV Percentage Coverage in Prostate IMRT

Purpose: To study the relationship between percentage coverage of planning target volume (PTV) in prostate cancerIMRT and dose received by normal critical structures Method and Materials: Five patients with early stage prostate cancer were selected for this retrospective planning study. For 4 of 5 patients, PTV contains clinical target volume (CTV), which is the prostate gland, plus 0.8 cm uniform margin. For the fifth patient, PTV is formed by expanding CTV (prostate plus 1 cm proximal seminal vesicle) with 0.8 cm uniform margin. The prescription is 74 Gy for the first four patients and 79.2 Gy (last patient) prescribed to 95% iso dose line and dose normalization is to isocenter. For each patient, seven different plans were generated using Varian Eclipse treatment planning system version 8.1 for 18 MV photon beams from Varian 2100C: one 6‐field conformal plan and six 7‐field IMRT plans with PTV volume coverage raging from 99.5% to 95%. IMRT plans were optimized by iterations to reach the targeted coverage of PTV. Results: A linear correlation between the volume receiving 70 Gy in percentage or cc and PTV volume coverage from 99.5% to 95% has been found for both balder and rectum with R2 better than 0.95 for bladder and 0.91 for rectum for the first four patients. A generalized relationship can be written as V 70 ( cc )= k * PTV (%)+ b (1). All patients have a similar linear slope for bladder (average slope is 0.867±0.083 (SD)) and a slightly different slope for rectum (average slope is 0.545±0.230 (SD)). In equation (1), interception b is dependant of structure volume (bladder and rectum). Conclusions: Volume received 70 Gy by bladder and rectum in IMRT plans for prostate as CTV may have a linear relationship with PTV coverage ranging from 99.5% to 95%. One may use this relationship to guide in treatment planning process.