Outcomes for oligometastatic head and neck cancer treated with stereotactic body radiotherapy: Results from an international multi-institutional consortium

BACKGROUND

We report the results of an international multi-institutional cohort of oligometastatic (OMD) head and neck cancer (HNC) patients treated with SBRT.

METHODS

Patients with OMD HNC (≤5 metastases) treated with SBRT between 2008 and 2016 at six institutions were included. Treated metastasis control (TMC), progression-free survival (PFS), and overall survival (OS) were analyzed by multivariable analysis (MVA).

RESULTS

Forty-two patients with 84 HNC oligometastases were analyzed. The TMC rate at 1 and 2 years were 80% and 66%, with a median time to recurrence of 10.1 months. The median PFS and OS were 4.7 and 23.3 months. MVA identified a PTV point maximum (BED)10 > 100 Gy as a predictor of improved TMC (HR = 0.31, p = 0.034), and a cumulative PTV > 48 cc as having worse PFS (HR = 2.99, p < 0.001).

CONCLUSION

Favorable TMC and OS was observed in OMD HNCs treated with SBRT.

Radiotherapy After Gross Total Resection of Skull Base Chordoma: A Surveillance, Epidemiology, and End Results Database Analysis of Survival Outcomes

OBJECTIVE

Skull base chordoma is a rare and locally destructive malignancy which presents unique therapeutic challenges. While achieving gross total resection (GTR) confers the greatest survival advantage, the role of adjuvant radiotherapy (RT) for patients who receive GTR remains unclear in the absence of prospective trials. Here, we aim to assess the effect of RT on survival outcomes in skull base chordoma patients who receive GTR by utilizing the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Patients with diagnostic, primary site, and resection codes specific for chordoma, skull base, and GTR, respectively, were queried in the SEER database (2000-2018). Kaplan-Meier curves (log-rank test) were constructed and Cox proportional hazards models were used to assess survival outcomes.

RESULTS

A total of 115 skull base chordomas undergoing GTR were identified, of which 37 (32%) received no RT and 78 (68%) received RT. Median follow-up was 55.00 months (range: 0.00-227.00). Overall survival (OS) of patients with GTR was 85% and 70% at 5 and 10 years, respectively. Multivariate Cox proportional hazard analysis among chordoma patients undergoing GTR found age ≥65 (P < 0.01) was associated with poorer OS outcomes. RT appeared to trend toward offering benefit in terms of OS in patients after GTR, however this did not achieve statistical significance in the adjusted model (HR = 0.51, CI = 0.23-1.16, P = 0.09). When comparing, disease-specific survival was also not improved in patients undergoing RT (HR = 0.58, CI = 0.23-1.46, P = 0.25).

CONCLUSIONS

It remains unclear whether RT after GTR of chordoma improved survival outcomes among SEER database patients.

NIMG-08. AN INTEGRATED INFORMATICS MODEL COMBINING CLINICAL FACTORS, RADIOMICS AND A NOVEL CONNECTOMICS FRAMEWORK TO DISTINGUISH PATHOLOGICALLY-PROVEN RADIONECROSIS FROM PROGRESSION IN TREATED BRAIN METASTASES

PURPOSE/OBJECTIVE(S)

To distinguish radionecrosis (RN) from true progression (TP) in brain metastases treated with stereotactic radiosurgery (SRS), we apply machine learning to create a multi-domain model that incorporates clinical factors, multiparametric radiomics(mpRads), and tumor connectomics, a novel MRI-based complex graph theory framework that describes the intricate network of relationships within the tumor and surrounding tissue.

MATERIALS/METHODS

Metastases treated with SRS that had pathologic confirmation of RN vs. TP after imaging progression were included from a single institution. Regions of interest were manually segmented using the single largest diameter of the T1 post-contrast(T1C) lesion plus the corresponding area of T2 FLAIR hyperintensity. We developed an Integrated Radiomics Informatics System (IRIS) based on an isomap support vector machine (IsoSVM) model to classify TP from RN using leave-one-out cross-validation (LOOCV). Class imbalance was resolved using differential misclassification weighting during model training using IRIS. Area under the receiver operating characteristic (AUC-ROC) and AUC-PR (precision recall) analysis were performed.

RESULTS

We analyzed 135 lesions in 110 patients. There were 43 cases (31.9%) of RN and 92 cases (68.1%) of TP. The top-performing connectomics features were degree centrality (increased with RN) and average path length (decreased with RN), suggesting greater “connectivity” and increased similarity in intralesional features between the T1C and FLAIR signal regions in RN cases. The top-performing radiomics feature was multidimensional entropy (increased in TP), demonstrating greater heterogeneity in TP cases. Finally, the top-performing clinical features were prior RT before SRS, histology, and treated lesion size. The LOOCV IsoSVM model successfully classified TP from RN with an AUC-ROC of 0.84 (95% CI: 0.77-0.90) and AUC-PR of 0.90 (95% CI: 0.82-0.95). The F1 score was 0.89.

CONCLUSION

Our novel machine-learning framework was able to efficiently combine features from multiple domains (i.e., radiomics, connectomics, and clinical factors) to distinguish pathologically-proven TP from RN with excellent discrimination.

[Place of 3D custom-made implants after failure of modeling steno-chondro-plasties]

Most common congenital malformation of the thorax, Pectus Excavatum affects about one in 500 people. Several surgical or medical techniques have been proposed. Some are followed by complications or insufficient results even though their constant functional value is highly controversial. Secondary surgery with a deep customized 3D elastomer implant, may be an elegant effective and safe solution compared to others; it allows a good aesthetic result expected by patients in the absence of any respiratory or cardio-vascular functional context.

RADI-22. Toxicity and local control outcomes for brain metastases managed with resection and aggressive reirradiation after initial radiosurgery failure

Objectives

To describe toxicity and tumor outcome after resection and aggressive re-irradiation (stereotactic radiosurgery(SRS) or brachytherapy) of brain metastasis that have pathologically confirmed recurrence after prior radiosurgery.

Methods

A retrospective chart review identified 40 lesions in 35 patients that were initially treated with SRS, then demonstrated evidence of recurrence with pathologic confirmation and underwent re-irradiation either with radiosurgery (n=28, 70%) or intracavitary brachytherapy with Cesium-131 seeds (n=12, 30%). Toxicity was measured by: steroids initiated or increased within 3 months, imaging evidence of treatment effect vs disease progression at any time point, further intervention for local recurrence or necrosis, and any grade 3/4 neurologic events. Local control (with failure defined by sustained progression on imaging or pathologic confirmation of tumor) was measured from time of retreatment.

Results

Median follow-up from time of re-irradiation was 11.8 months (range 1 – 89.7 months). Dose for repeat radiosurgery was 18–25 Gy in 1–5 fractions, and brachytherapy dose was 55–65 Gy at 5 mm depth. Twelve lesions subsequently had imaging evidence of radionecrosis vs. progression. Of these, eight underwent repeat resection with pathology demonstrating radiation necrosis in five patients (n=4 with SRS, n=1 with brachy) and tumor recurrence in 3 (n=2 with brachy, and n=1 with SRS). Toxicities included: Steroids, 14(35%); imaging progression/necrosis 12(30%); grade 3/4 event, 3(20%); and surgically confirmed radionecrosis 5(12.5%). Local control of retreated lesions at 6 months is 85.5%, and at 12 months is 79.3%, OS at 1 year is 52.5% and at 2 years 46.6%. Local control at one year for repeat stereotactic treatment was 82.9% and for Cs131 brachytherapy was 80.8%

Conclusions

Aggressive re-irradiation after resection for pathologic confirmation appears to be appropriately safe and effective for the majority of patients after local failure of initial radiosurgery.

RADI-23. Exploring the optimal timing of routine initial surveillance MRI following treatment of brain metastases with stereotactic radiosurgery: a comparison of two approaches

Purpose

To measure the value of early initial surveillance MRI scans in patients with brain metastases undergoing stereotactic radiosurgery (SRS), as MRI scans are a significant cost and patient stressor.

Methods

We identified a retrospective cohort of patients with brain metastases treated with SRS and followed at a single institution with scheduled 6-week or 12-week initial surveillance MRI. Imaging interval was based on policy of different providers. Outcome measures included new/progressive lesions, salvage treatment, detection of new lesions before symptoms, and use of surgical resection.

Results

Two hundred patients were included: 100 consecutive patients scanned with 6-week and 12-week imaging. Eighty-seven and 74 patients in each group had available follow-up imaging and were analyzed. Median time to MRI was 6.7 weeks and 13.5 (p<.001). No difference in primary site, prior SRS, number of treated brain metastases, or use of targeted therapy/immune checkpoint inhibitors was detected. A lower percentage of patients with 6-week MRI had controlled extracranial disease at initial treatment (30% vs 47%,p=.003). Twenty-eight percent with 6-week MRI had findings concerning for new/progressive disease, compared to 47% with 3-month MRI (p=0.01). Fifteen percent (10/87) with 6-week MRI underwent intervention (i.e. SRS, whole brain radiotherapy, or surgery) compared to 34% (20/74) with 12-week MRI (p=0.004). Of patients receiving SRS, a higher percentage had new/worsening neurologic symptoms (45% vs 30%) at follow-up although a lower percentage had new lesions >1cm (20% vs 50%) when discovered. One patient in each group underwent surgical salvage.

Conclusion

While shorter 6-week interval MRI surveillance post-SRS may detect new/progressive disease less frequently than 12-week MRI surveillance intervals, short interval MRI may be more likely to detect new/progressive lesions before symptoms develop. Surgical salvage was uncommon with either schedule. Further study may identify a high-risk subgroup who would benefit from early surveillance.

Development of new brain metastases in triple negative breast cancer

BACKGROUND

Brain metastases are common in patients with breast cancer, and those with triple negative status have an even higher risk. Triple negative status is currently not considered when managing brain metastases.

OBJECTIVE

To determine whether triple negative breast cancer (TNBC) patients with brain metastases have a higher burden of intracranial disease and whether WBRT has a survival benefit in this cohort of patients.

METHODS

We conducted a retrospective cohort study with 85 patients meeting the inclusion criteria.

RESULTS

25% of patients had TNBC. 95% of the patients in this study received SRS and 48% received WBRT. The average number of new brain metastases from time of initial brain imaging to radiation therapy was 0.67 ± 1.1 in the non-TNBC status patients and 2.6 ± 3.7 in the triple negative status patients (p = 0.001). A cox proportional hazards model showed that WBRT does not significantly affect overall survival in patients with TNBC (HR 1.48; 95% CI 0.47-4.67; p = 0.50).

CONCLUSION

Our findings highlight the highly aggressive intracranial nature of TNBC. The rate of new brain metastasis formation is higher in TNBC patients compared to non-TNBC patients. Furthermore, there is no survival benefit for WBRT in TNBC patients. These findings are relevant for clinicians planning brain radiation for TNBC patients as they may find more brain metastases at the time of brain radiation than they anticipated based on initial brain imaging.

NCOG-05. MANAGEMENT OF BRAIN METASTASIS IN TRIPLE NEGATIVE BREAST CANCER

Brain metastasis is common in patients with breast cancer, and those with triple negative status have an even higher risk. Stereotactic radiosurgery (SRS) is preferred to whole brain radiation therapy (WBRT) in most patients. However, triple negative status is currently not considered when determining optimal radiation therapy. Given the aggressive nature of triple negative breast cancer, we evaluated a role for WBRT for all patients in this cohort. We conducted a single-institution retrospective cohort study to determine whether triple negative patients with brain metastases have a higher burden of intracranial disease and whether type of initial radiation therapy affects overall survival for this cohort of patients. 85 patients met the inclusion criteria for this study. 25% of patients had triple negative breast cancer, of which 91% received SRS and 53% of patients received WBRT. The average number of new brain metastases from time of initial brain imaging to radiation therapy was 0.67 (St.Dev:1.1) in the non-triple negative status patients and 2.6 (St. Dev:3.7) in the triple negative status patients (p=0.001). Using a cox proportional hazards model, it was found that whole brain radiotherapy does not significantly affect overall survival in patients with triple negative breast cancer (p = 0.96). Our findings highlight the highly aggressive intracranial nature of triple negative breast cancer. Indeed, the rate of increase in brain metastases is significantly higher for triple negative patients compared to non-triple negative patients. As a result, we evaluated whether triple negative patients would benefit from whole brain radiation regardless of findings on initial brain imaging. Despite 53% of patients receiving WBRT, our investigation found that there is no additional benefit to WBRT in triple negative breast cancer patients. These results suggest a need to re-evaluate the role of WBRT in the management of triple negative breast cancer.

Traumatic thoracoabdominal hernia repair using a novel chest-wall reconstruction technique: a case report

Thoracoabdominal hernia following blunt trauma is extremely rare. Abdominal viscera are more likely to herniate into the thorax if there is traumatic diaphragmatic rupture. We report the case of a patient presenting with a traumatic thoracoabdominal hernia containing part of the right lobe of the liver and the hepatic flexure of the colon. The hernia migrated cranially, to protrude through a seventh intercostal defect despite the diaphragm remaining fully intact. The need for early multispecialty (thoracic and hepatobiliary) surgical repair is highlighted, with improvements in surgical outcome for a complex trauma case by using a novel chest-wall reconstruction technique.

Deferred Radiotherapy After Debulking of Non-functioning Pituitary Macroadenomas: Clinical Outcomes

Background: To describe the outcome for a cohort of patients with non-functioning pituitary macroadenomas (NFPMA), managed by debulking surgery with radiation therapy delayed until progression. Methods: Two hundred and sixty-seven patients were treated surgically for pituitary tumors at our institution between 1997 and 2005. One hundred and twenty-six patients met the inclusion criteria of NFPMA. They were followed for at least 2 years. Results: At presentation, 58% of patients had objectively decreased visual function, 66% had endocrine abnormalities, and 46% had headaches. Of the entire cohort, 75% of tumors abutted the optic chiasm and 87% had suprasellar extension. Over a median follow up of 112 months from surgery, 52% of patients had evidence of radiographic tumor progression, and 39% required additional treatment. There was a significant difference freedom from progression and in the number of patients receiving additional treatment with preoperative adenoma size of < 2 vs. ≥2 cm (p < 0.05). Conclusion: Close observation with radiation therapy delayed until the time of progression is an appropriate option for patients presenting with initial adenoma size < 2 cm, and can be considered for those with initial sizes up to 4 cm, as the majority of patients do not require further intervention for 10 or more years, thereby meaningfully postponing the risks of radiotherapy.

Distinguishing True Progression From Radionecrosis After Stereotactic Radiation Therapy for Brain Metastases With Machine Learning and Radiomics

PURPOSE

Treatment effect or radiation necrosis after stereotactic radiosurgery (SRS) for brain metastases is a common phenomenon often indistinguishable from true progression. Radiomics is an emerging field that promises to improve on conventional imaging. In this study, we sought to apply a radiomics-based prediction model to the problem of diagnosing treatment effect after SRS.

METHODS AND MATERIALS

We included patients in the Johns Hopkins Health System who were treated with SRS for brain metastases who subsequently underwent resection for symptomatic growth. We also included cases of likely treatment effect in which lesions grew but subsequently regressed spontaneously. Lesions were segmented semiautomatically on preoperative T1 postcontrast and T2 fluid-attenuated inversion recovery magnetic resonance imaging, and radiomic features were extracted with software developed in-house. Top-performing features on univariate logistic regression were entered into a hybrid feature selection/classification model, IsoSVM, with parameter optimization and further feature selection performed using leave-one-out cross-validation. Final model performance was assessed by 10-fold cross-validation with 100 repeats. All cases were independently reviewed by a board-certified neuroradiologist for comparison.

RESULTS

We identified 82 treated lesions across 66 patients, with 77 lesions having pathologic confirmation. There were 51 radiomic features extracted per segmented lesion on each magnetic resonance imaging sequence. An optimized IsoSVM classifier based on top-ranked radiomic features had sensitivity and specificity of 65.38% and 86.67%, respectively, with an area under the curve of 0.81 on leave-one-out cross-validation. Only 73% of cases were classifiable by the neuroradiologist, with a sensitivity of 97% and specificity of 19%.

CONCLUSIONS

Radiomics holds promise for differentiating between treatment effect and true progression in brain metastases treated with SRS. A predictive model built on radiomic features from an institutional cohort performed well on cross-validation testing. These results warrant further validation in independent datasets. Such work could prove invaluable for guiding management of individual patients and assessing outcomes of novel interventions.

Abstract 676: Preliminary investigation into the dosimetric impact of tumor treating field arrays on concurrent radiotherapy for newly-diagnosed glioblastoma

Rationale:

Glioblastoma (GBM) is the most common and deadly primary CNS malignancy in adults. The addition of tumor treating fields (TTFields), a non-invasive anti-mitotic therapy approved for use in newly-diagnosed or recurrent GBM, following standard resection and chemoradiation has been shown to significantly improve both overall and progression-free survival in a randomized phase III clinical trial.

Preclinical evidence suggests that TTFields may disrupt mitotic spindles and exhibit a similar synergism with radiotherapy (RT) to other microtubule inhibitors. The ability to treat patients concurrently with RT and TTFields is thus of considerable clinical interest. The TTFields device array applicator worn on the scalp may affect radiation dose distribution, an effect that may be mitigated but also be made more difficult to account for by the routine repositioning of the applicator during therapy to avoid skin toxicity. In preparation for a clinical trial, we have therefore undertaken a phantom investigation to evaluate the effect of varying TTFields array position on RT dosimetry and planning target volume (PTV) coverage.

Methods:

Radiation beams and contours were copied to an anthropomorphic phantom from the treatment plan of a newly-diagnosed GBM patient receiving standard adjuvant RT. Four CT scans of the phantom were employed: one lacking the TTFields array and three with the array placed in varying positions over the cranium of the phantom to simulate routine replacement and repositioning of the array as would occur in clinical use.

Dosimetric recalculations were then performed for each scan using the Philips Pinnacle treatment planning system and the dosimetric average of the three array positions was calculated using Varian Velocity software.

Results:

Recalculation of the treatment plan of our test patient onto the phantom wearing the TTFields array resulted in reduction of the isodose covering 95% of the PTV by 5.5 cGy/day over the course of treatment as compared to the phantom with no array (to 51.6 Gy from 53.4 Gy). This small difference in PTV coverage is unlikely to be of clinical significance, obviating the need for time-intensive replanning each time the skin position of the array has changed.

Conclusion:

We plan to confirm this novel finding by further investigating the impact of repositioning TTFields arrays on the radiation treatment plans of a larger, sequential cohort of newly-diagnosed GBM patients. These preliminary studies will ultimately be the foundation of a clinical trial evaluating the concurrent use of TTFields during standard radiotherapy.

Citation Format: Gregory C. Stachelek, Jimm Grimm, Joseph Moore, Juan F. Jackson, Kristin Redmond, Chetan Bettegowda, Lawrence Kleinberg. Preliminary investigation into the dosimetric impact of tumor treating field arrays on concurrent radiotherapy for newly-diagnosed glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 676.

Stereotactic spine radiosurgery: Review of safety and efficacy with respect to dose and fractionation

BACKGROUND

Stereotactic body radiotherapy (SBRT) is an emerging treatment option for spinal metastases with demonstrated efficacy in the upfront, postoperative, and re-treatment settings, as well as for tumor histologies considered radioresistant. Uncertainty exists regarding the optimal dose and fractionation schedule, with single and multifraction regimens commonly utilized.

METHODS

A literature search of the PubMed and Medline databases was conducted to identify papers specific to spine SBRT and the effect of varying dose/fractionation regimens on outcomes. Bibliographies of relevant papers were searched for further references, and international spine SBRT experts were consulted.

RESULTS

Local control rates generally exceed 80% at 1 year, while high rates of pain control have been attained. There is insufficient evidence to suggest superiority of either single or multiple fraction regimens with respect to local control and pain control. Low rates of toxicity have been reported, assuming strict dose constraints are respected. Radiation myelopathy may be the most morbid toxicity, although the rates are low. The risk of vertebral compression fracture appears to be associated with higher doses per fraction such as those used in single-fraction regimens. The Spinal Instability Neoplastic Score should be considered when evaluating patients for spine SBRT, and prophylactic stabilisation may be warranted. Pain flare is a relatively common toxicity which may be mediated with prophylactic dexamethasone. Because of the treatment complexity and potentially serious toxicities, strict quality assurance should occur at the organizational, planning, dosimetric, and treatment delivery levels.

CONCLUSION

Both single and multifraction regimens are safe and efficacious in spine SBRT for spinal metastases. There may be advantages to hypofractionated treatment over single-fraction regimens with respect to toxicity. Ongoing investigation is underway to define optimal dose and fractionation schedules.

Spinal metastases: multimodality imaging in diagnosis and stereotactic body radiation therapy planning

Due to increased effectiveness of cancer treatments and increasing survival rates, metastatic disease has become more frequent compared to the past, with the spine being the most common site of bony metastases. Diagnostic imaging is an integral part of screening, diagnosis and follow-up of spinal metastases. In this article, we review the principles of multimodality imaging for tumor detection with respect to their value for diagnosis and stereotactic body radiation therapy planning for spinal metastases. We will also review the current international consensus agreement for stereotactic body radiation therapy planning, and the role of imaging in achieving the best possible treatment plan.

A prospective study of cerebral, frontal lobe, and temporal lobe volumes and neuropsychological performance in children with primary brain tumors treated with cranial radiation

BACKGROUND

Cranial radiation therapy (RT) is an important component in the treatment of pediatric brain tumors. However, it can result in long-term effects on the developing brain. This prospective study assessed the effects of cranial RT on cerebral, frontal lobe, and temporal lobe volumes and their correlation with higher cognitive functioning.

METHODS

Ten pediatric patients with primary brain tumors treated with cranial RT and 14 age- and sex-matched healthy children serving as controls were evaluated. Quantitative magnetic resonance imaging and neuropsychological assessments (language, memory, auditory and visual processing, and vocabulary) were performed at the baseline and 6, 15, and 27 months after RT. The effects of age, the time since RT, and the cerebral RT dose on brain volumes and neuropsychological performance were analyzed with linear mixed effects model analyses.

RESULTS

Cerebral volume increased significantly with age in both groups (P = .01); this increase in volume was more pronounced in younger children. Vocabulary performance was found to be significantly associated with a greater cerebral volume (P = .05) and a lower RT dose (P = .003). No relation was observed between the RT dose and the cerebral volume. There was no difference in the corresponding neuropsychological tests between the 2 groups.

CONCLUSIONS

This prospective study found significant relations among the RT dose, cerebral volumes, and rate of vocabulary development among children receiving RT. The results of this study provide further support for clinical trials aimed at reducing cranial RT doses in the pediatric population. Cancer 2017;161-168. © 2016 American Cancer Society.

Timely stereotactic body radiotherapy (SBRT) for spine metastases using a rapidly deployable automated planning algorithm

Purpose/objectives

The complex planning and quality assurance required for spine SBRT are a barrier to implementation in time-sensitive or limited resource clinical situations. We developed and validated an automated inverse planning algorithm designed to streamline planning and allow rapid delivery of conformal single fraction spine SBRT using widely available technology.

Materials/methods

The Rapid Spine (RaSp) automated script successfully generated single fraction SBRT plans for fourteen complex spinal lesions previously treated at a single high-volume institution. Automated RaSp plans were limited to 5 beams with a total of 15 segments (allowing calculation-based verification) and optimized based on RTOG 0631 objectives. Standard single fraction (16 Gy) stereotactic IMRT plans were generated for the same set of complex spinal lesions and used for comparison. A conservative 2 mm posterior isocenter shift was used to simulate minor set-up error.

Results

Automated plans were generated in under 5 min from target definition and had a mean dose to the PTV of 1663 cGy (SD 131.5), a dose to 90 % of PTV (D90) of 1358 cGy (SD 111.0), and a maximum point dose (Dmax) to the PTV of 2055 cGy (SD 195.2) on average. IMRT plans took longer to generate but yielded more favorable dose escalation with a mean dose to the PTV of 1891 cGy (SD 117.6), D90 of 1731 cGy (SD 126.5), and Dmax of 2218 cGy (SD 195.7). A 2 mm posterior shift resulted in a 20 % (SD 10.5 %) increase in cord dose for IMRT plans and a 10 % (SD 5.3 %) increase for RaSp plans. The 2 mm perturbation caused 3 cord dose violations for the IMRT plans and 1 violation for corresponding RaSp plans.

Conclusion

The Rapid Spine plan method yields timely and dosimetrically reasonable SBRT plans which meet RTOG 0631 objectives and are suitable for rapid yet robust pretreatment quality assurance followed by expedited treatment delivery. RaSp plans reduce the tradeoff between rapid treatment and optimal dosimetry in urgent cases and limited resource situations.

Isolated anterior mediastinal tuberculosis in an immunocompetent patient

Background

The differential diagnosis of a mediastinal mass is a common challenge in clinical practice, with a wide range of differential diagnosis to be considered. One of the rarer causes is tuberculosis. Atypical presentations of tuberculosis are well documented in immunocompromised patients, but should also be considered in the immunocompetent.

Case presentation

This case outlines a previously healthy 22 year-old immunocompetent male presenting with worsening chest pain, positional dyspnea, dry cough and dysphagia. Chest x-ray showed evidence of an isolated anterior mediastinal mass, which was confirmed on computed tomography. A mediastinoscopy was diagnostic as histology revealed necrotizing granulomatous inflammation and the presence of acid-fast bacilli, indicating mediastinal tuberculosis.

Conclusion

Typically the underlying presentation of mediastinal tuberculosis is mediastinal lymphadenitis. This case was unusual in that we detected an isolated large anterior mediastinal mass accompanied by a relatively small burden of mediastinal lymphadenitis. Cases similar to this have been documented in immunosuppressed patients however in our case no evidence of immunosuppression was found. This case report emphasizes the importance that a detailed and logical pathway of investigation is pursued when encountering a mediastinal mass.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0175-7) contains supplementary material, which is available to authorized users.

Glioblastoma recurrence patterns near neural stem cell regions

PURPOSE

Glioblastoma (GBM) cancer stem cells and their neural stem cell counterparts are hypothesized to contribute to tumor progression. We examined whether GBM contrast enhancement contact with neurogenic regions (NR) affect recurrence patterns, as contrast enhancement reflects regions of blood-brain barrier breakdown.

METHODS

102 patients with primary GBM, treated at Johns Hopkins Hospital between 2006 and 2009, were included. All patients underwent surgical resection followed by adjuvant IMRT (60 Gy/30 fractions) and concomitant temozolomide. Initial and recurrent tumor distance from the subventricular zone (SVZ) or subgranular zone (SGZ) was measured. Tumors were categorized as NR contacting or non-contacting. The chi-square test was used to analyze the association between tumor contact and recurrence pattern.

RESULTS

49 of 102 (48.0%, 95% CI: 0.386-0.576) tumors contacted NRs at initial presentation, and, of these tumors, 49/49 (100%) contacted NRs at recurrence. Of 53 tumors that were initially non-contacting, 37/53 (69.8%, 95% CI: 0.565-0.804) recurred contacting NRs. In total, 86/102 (84.3%, 95% CI: 0.760-0.901) recurrent GBM contacted NRs compared with 49/102 (48%, 95% CI: 0.386-0.576) at initial presentation. Of the recurrent tumors that did not contact NRs, 16/53 (30.1%, 95% CI: 0.195-0.435) recurred medially toward NRs with a significant decrease in distance between tumor contrast enhancement and NRs. 16/49 (32.6%, 95% CI: 0.212-0.466) initially NR-contacting GBMs recurred out-of field while 7/53 (13.2%, 95% CI: 0.0655-0.248) initially non-contacting recurred out of the radiation treatment field (p=0.0315, Odds ratio: 3.19, 95% CI: 1.18-8.62).

CONCLUSIONS

GBM contrast-enhancing recurrence is significantly associated with proximity to NRs. NR-contacting initial tumors were more likely to recur out of radiation treatment fields.

The era of stereotactic body radiotherapy for spinal metastases and the multidisciplinary management of complex cases

Spinal metastases are increasingly becoming a focus of attention with respect to treating with locally "ablative" intent, as opposed to locally "palliative" intent. This is due to increasing survival rates among patients with metastatic disease, early detection as a result of increasing availability of spinal MRI, the recognition of the oligometastatic state as a distinct sub-group of favorable metastatic patients and the advent of stereotactic body radiotherapy (SBRT). Although conventionally fractionated radiation therapy has been utilized for decades, the rates of complete pain relief and local control for complex tumors are sub-optimal. SBRT has the advantage of delivering high total doses in few fractions (typically, 24 Gy in 1 or 2 fractions to 30-45 Gy in 5 fractions) that can be considered "ablative". With mature clinical experience emerging among early adopters, we are realizing beyond efficacy the limitations of spine SBRT. In particular, toxicities such as vertebral compression fracture, and epidural disease progression as the most common pattern of local tumor progression. As a result, the multidisciplinary evaluation of cases prior to SBRT is emphasized with the intent to identify patients who could benefit from surgical stabilization or down-staging of epidural disease. The purpose of this review is to provide an overview of the current literature with respect to outcomes, technical details for safe delivery, patient selection criteria, common and uncommon side effects of therapy, and the increasing use of minimally invasive surgical techniques that can improve both safety and local control.

First bilateral lobar lung transplant in Ireland: advanced operative strategies in lung transplantation

Lobar lung transplantation is an option that provides the possibility of transplantation of small size recipients with size-mismatch donor lungs by surgically reducing the size of donor lungs. We report our first experience of bilateral lobar lung transplantation of big donor lungs, in a small size urgently listed recipient, after size reduction. A 24 years old girl with end stage cystic fibrosis received the bilateral lobar lung transplant. She made very good recovery postoperatively and was discharged home two weeks following surgery.