Target migration from re-inflation of adjacent atelectasis during lung stereotactic body radiotherapy

Stereotactic body radiotherapy (SBRT) is a widely accepted option for the treatment of medically inoperable early-stage non-small cell lung cancer (NSCLC). Herein, we highlight the importance of interfraction image guidance during SBRT. We describe a case of early-stage NSCLC associated with segmental atelectasis that translocated 15 mm anteroinferiorly due to re-expansion of the adjacent segmental atelectasis following the first fraction. The case exemplifies the importance of cross-sectional image-guided radiotherapy that shows the intended target, as opposed to aligning based on rigid anatomy alone, especially in cases associated with potentially “volatile” anatomic areas.

Comparison of outcomes between rectal squamous cell carcinoma and adenocarcinoma

Large, population-based analyses of rectal squamous cell carcinoma (SCC) have not been previously conducted. We assessed patterns of care, prognostic factors, and outcomes of rectal SCC and adenocarcinoma (AC) in population-based cohorts. Surveillance, Epidemiology, and End Results (SEER) registry searches were performed (1998-2011), producing 42,308 nonmetastatic rectal cancer patients (999 SCC and 41,309 AC). Patient, tumor, and treatment characteristics were compared. Based on risk factors, SCC/AC groups were subdivided into low-, intermediate-, and high-risk groups. Overall survival (OS) was compared between histological and risk groups using Kaplan-Meier method and log-rank test. Multivariate logistic regression models evaluated prognostic factors for 5-year survival. Cox regression modeling was performed on propensity-matched data. Rectal SCC, more common in females and associated with larger tumors of higher grade, was more often treated with radiotherapy (RT) than surgery. Surgery was associated with higher OS in AC but not SCC, and RT had proportionally greater benefits in SCC. These effects of RT and surgery were retained when stratified into risk groups (particularly high/intermediate-risk). Favorable prognostic factors for survival included younger age, non-black race, SCC histology, size ≤3.9 cm, localized stage, lower grade, surgery, and RT. For SCC, race, tumor grade, and surgery were not prognostic factors for survival. Cox regression modeling of propensity-matched data showed that AC histology increased risk of death versus SCC. In the largest analysis of rectal SCC to date, and in the notable absence (and unlikelihood) of prospective data, nonsurgical and RT-based treatment is recommended.

Effect of Akimbo versus Raised Arm Positioning on Breast and Cardiopulmonary Dosimetry in Pediatric Hodgkin Lymphoma

Purpose

In pediatric Hodgkin lymphoma (HL), radiotherapy (RT)-related late toxicities are a prime concern during treatment planning. This is the first study to examine whether arm positioning (raised versus akimbo) result in differential cardiopulmonary and breast doses in patients undergoing mediastinal RT.

Methods

Two treatment plans were made for each patient (akimbo/arms raised); treatment was per Children’s Oncology Group AHOD0031 protocol, including AP/PA fields. The anterior midline T6–T7 disk space was used as an anatomic reference of “midline.” Heart/lungs were contoured for each setup. For females, breasts were also contoured and nipple positions identified. Volumetric centers of contoured organs were defined and three-dimensional distances from “midline” were computed. Analyzed dosimetric parameters included V5 (volume receiving ≥5 Gy), V10, V15, V20, and mean dose. Statistics were performed using the Mann–Whitney test.

Results

Fifteen (6 females, 9 males) pediatric HL patients treated with mediastinal RT were analyzed. The median lateral distance from the breast center/nipple to “midline” with arms akimbo was larger than that with arms raised (8.6 vs. 7.7 cm left breast, p = 0.04; 10.7 vs. 9.2 cm left nipple, p = 0.04; 8.7 vs. 7.0 cm right breast, p = 0.004; 9.9 vs. 7.9 cm right nipple, p = 0.007). Raised arm position was associated with a median 2.8/3.0 cm decrease in breast/nipple separation, respectively. There were no significant differences in craniocaudal breast/nipple position based on arm positioning (p > 0.05). Increasing breast volume was correlated with larger arm position-related changes in breast/nipple separation (r = 0.74, p = 0.06/r = 0.85, p = 0.02). Akimbo positioning lowered median breast V5, V10, V15, and mean dose (p < 0.05), with no differences observed in patients with both mediastinal and axillary disease for any parameters (p > 0.05). Arm position had no significant effect on cardiopulmonary doses.

Conclusion

Akimbo arm positioning may be advantageous to decrease breast doses in female pediatric HL patients undergoing mediastinal RT, especially in the absence of axillary disease.

Radiation Therapy and Cardiac Death in Long-Term Survivors of Esophageal Cancer: An Analysis of the Surveillance, Epidemiology, and End Result Database

Objective

Radiation therapy (RT) for esophageal cancer often results in unintended radiation doses delivered to the heart owing to anatomic proximity. Using the Surveillance, Epidemiology, and End Results (SEER) database, we examined late cardiac death in survivors of esophageal cancer that had or had not received RT.

Methods

5,630 patients were identified that were diagnosed with esophageal squamous cell carcinoma (SCC) or adenocarcinoma (AC) from 1973–2012, who were followed for at least 5 years after therapy. Examined risk factors for cardiac death included age (≤55/56-65/66-75/>75), gender, race (white/non-white), stage (local/regional/distant), histology (SCC/AC), esophageal location (<18cm/18-24cm/25-32cm/33-40cm from incisors), diagnosis year (1973-1992/1993-2002/2003-2012), and receipt of surgery and/or RT. Time to cardiac death was evaluated using the Kaplan-Meier method. A Cox model was used to evaluate risk factors for cardiac death in propensity score matched data.

Results

Patients who received RT were younger, diagnosed more recently, had more advanced disease, SCC histology, and no surgery. The RT group had higher risk of cardiac death than the no-RT group (log-rank p<0.0001). The median time to cardiac death in the RT group was 289 months (95% CI, 255–367) and was not reached in the no-RT group. The probability of cardiac death increased with age and decreased with diagnosis year, and this trend was more pronounced in the RT group. Multivariate analysis found RT to be associated with higher probability of cardiac death (OR 1.23, 95% CI 1.03–1.47, HR 1.961, 95% CI 1.466–2.624). Lower esophageal subsite (33–40 cm) was also associated with a higher risk of cardiac death. Other variables were not associated with cardiac death.

Conclusions

Recognizing the limitations of a SEER analysis including lack of comorbidity accountability, these data should prompt more definitive study as to whether a possible associative effect of RT on cardiac death could potentially be a causative effect.

Atypical teratoid rhabdoid tumor: long-term survival after chemoradiotherapy

PURPOSE

Atypical teratoid rhabdoid tumors (ATRTs) arise from the central nervous system largely in the pediatric population. They portend a very poor prognosis with few long-term survivors. We describe a series of five cases at our institution.

METHODS

We conducted a retrospective chart review and clinical follow-up.

RESULTS

Three patients underwent chemoradiation after surgical resection; the two patients whose caretakers declined this therapy passed away soon after diagnosis. Chemoradiation included intravenous and intrathecal chemotherapy as well as intensity-modulated radiotherapy after resection. Of the patients receiving chemoradiation, two patients had infratentorial tumors, two had gross residual tumor after resection, and two were under the age of 3 years. The three patients receiving trimodality therapy remain clinically and symptomatically disease-free with follow-up times of 44, 46, and 55 months. Two of the patients have mild neuropsychiatric sequelae after therapy.

CONCLUSIONS

Long-term, high-volume trials of ATRT are currently not published. We offer experience in successful long-term survival of this tumor treated with chemoradiotherapy.