J.C. Ye

Equivalent Survival With Mastectomy or Breast-conserving Surgery Plus Radiation in Young Women Aged < 40 Years With Early-Stage Breast Cancer: A National Registry-based Stage-by-Stage Comparison.

BACKGROUND Studies have shown that young patients with early-stage breast cancer (BC) are increasingly undergoing mastectomy instead of breast-conserving therapy (BCT) consisting of lumpectomy and radiation. We examined the difference in outcomes in young women (aged < 40 years) who had undergone BCT versus mastectomy. MATERIALS AND METHODS The Surveillance, Epidemiology, and End Results database was queried for women aged < 40 years with stage I or II invasive BC treated with surgery from 1998 to 2003. Breast cancer-specific survival (BCSS) and overall survival (OS) were evaluated using Kaplan-Meier survival analysis and the log-rank test between treatment types. RESULTS Of the 7665 women, 3249 received BCT and 2627 underwent mastectomy without radiation. When separated by stage (I, IIA, and IIB), with a median follow-up duration of 111 months, the BCT and mastectomy-only groups showed no statistically significant differences in BCSS and OS. Overall, the age group of 35 to 39 years (66% of total) was associated with better 10-year BCSS (88%) and OS (86.1%) compared with the younger patients aged 20 to 34 years (34% of total). The latter group had a 10-year BCSS and OS of 84.1% and 82.3%, respectively (P < .001 for both BCSS and OS). However, when the patients of each age group were further subdivided by stage, the BCT group continued to show noninferior BCSS and OS compared with the mastectomy group in all subgroups. CONCLUSION The results of our study suggest that although young age might be a poor prognostic factor for BC, no evidence has shown that these patients will have better outcomes after mastectomy than after BCT.

Implications of previously undetected incidental findings on 3D CT simulation scans for radiation therapy

PURPOSE To determine the frequency of significant incidental findings on diagnostic quality simulation computed tomographic (CT) scans for radiotherapy planning. METHODS AND MATERIALS An institutional review board--approved retrospective review of radiation simulation CT scans with diagnostic radiology reports, performed between 2004 and 2006, was conducted to identify incidental findings, defined as previously unreported findings. An incidental finding was classified as a cancer-related finding (CRF) if it could potentially change the staging and treatment of the cancer. Other nonmalignant findings, not likely caused by cancer, were classified as noncancer findings (NCFs). RESULTS Of the 580 CT scans performed for radiation planning, 61 (11%) NCFs and 45 (8%) CRFs were identified. Common NCFs included degenerative bone changes (20%), diverticulosis (15%), and lung (11%), kidney (10%), thyroid (10%), and vascular (7%) abnormalities. Two of the vascular NCFs were thrombi requiring anticoagulation. The CRFs included suspected local recurrence (22%); lymphadenopathy (18%); significant progression of local disease (16%); distant metastasis to the liver (16%), bone (11%), and other sites (16%); and malignancy not evident (2%). Eight CRFs prompted additional workup, all with negative results, causing 2 treatment delays. Three CRFs warranted change of treatment without further imaging, including the use of induction chemotherapy before radiation, an increase in radiation dose, and proceeding with surgery up front followed by radiation. The remaining 34 CRFs did not require additional action because the abnormalities were already addressed by the planned treatment (33%), were believed to be benign with further review (29%), or would have been better evaluated by additional imaging that had been scheduled prior to radiation simulation (13%). Overall, 7 of 580 (1%) scans prompted treatment alterations, including 2 treatment delays. CONCLUSION A comprehensive review of radiation planning CT scans by diagnostic radiologists resulted in a significant change in medical or cancer management in only a small percentage of cases.

Daily patient setup error in prostate image guided radiation therapy with fiducial-based kilovoltage onboard imaging and conebeam computed tomography

BACKGROUND This study examined the interfraction setup error in patients undergoing prostate radiotherapy using fiducial markers and on-board imaging. METHODS Patients (n=53) were aligned to the treatment isocenter by laser followed by orthogonal kilovoltage (kV) radiographs to visualize bony anatomy and implanted fiducial markers. The magnitude and direction of couch shifts for isocenter correction required was determined by image registration for bony anatomy and fiducial markers. Twice weekly, 25 of the 53 patients also underwent conebeam computed tomography (CBCT) to measure any residual error in patient positioning. Based on individual coordinate shifts from CBCT, a net three-dimensional (3D) residual shift magnitude vector R was calculated. RESULTS The average couch shifts were 0.26 and 0.40 cm in inferior direction and 0.25 and 0.33 cm in superior direction for alignments made with bony anatomy and fiducial markers, respectively (P<0.0001). There were no significant differences noted in the vertical or lateral planes between the two image registration methods. In subset of 25 patients, no residual shift from fiducial plain film set up was required with CBCT matching in 66.5%, 52.4% and 57.9% of fractions for longitudinal, vertical and lateral planes, respectively, with majority (79%) of patients having a net residual 3D shifts of <0.3 cm. The use of CBCT increased average treatment time by approximately 6 min compared to kV radiographs alone. CONCLUSIONS The residual setup errors following daily kV image guided localization, as determined by CBCT, were small, which demonstrates high accuracy of kV localization when fiducial markers are present.

Integration of radiation and immunotherapy in breast cancer - Treatment implications

Radiation therapy (RT) has been successfully used in the treatment of breast cancer (BC) for over a century. While historically thought to be immunosuppressive, new data have shown that RT can work together with the immune system to eliminate cancer. It can cause immunogenic cell death and facilitate tumor neoantigen presentation and cross-priming of tumor-specific T-lymphocytes, turning irradiated tumor into an in-situ vaccine. Unfortunately, due to various immune escape mechanism put in place by the tumor, RT alone rarely results in a systemic response of metastatic disease sites (known as the abscopal effect). Immunotherapy, a series of agents designed to stimulate the immune system in order to generate tumor-specific immune response, is showing promise in treatment of various cancers, including BC, and can be an ideal complement to RT in stimulating a systemic immune response to reject the tumor cells. This review discusses the mechanisms in which RT can trigger an immune response for tumor rejection, and provide emerging preclinical and clinical data of combination immunoradiotherapy, and its potential in treating BC.

The relationship of dose to nerve volume in predicting pain recurrence after stereotactic radiosurgery in trigeminal neuralgia

OBJECTIVE Approximately 75%-92% of patients with trigeminal neuralgia (TN) achieve pain relief after Gamma Knife surgery (GKS), although a proportion of these patients will experience recurrence of their pain. To evaluate the reasons for durability or recurrence, this study determined the impact of trigeminal nerve length and volume, the nerve dose-volume relationship, and the presence of neurovascular compression (NVC) on pain outcomes after GKS for TN. METHODS Fifty-eight patients with 60 symptomatic nerves underwent GKS for TN between 2013 and 2015, including 15 symptomatic nerves secondary to multiple sclerosis (MS). High-resolution MRI was acquired the day of GKS. The median maximum dose was 80 Gy for initial GKS and 65 Gy for repeat GKS. NVC, length and volume of the trigeminal nerve within the subarachnoid space of the posterior fossa, and the ratio of dose to nerve volume were assessed as predictors of recurrence. RESULTS Follow-up was available on 55 patients. Forty-nine patients (89.1%) reported pain relief (Barrow Neurological Institute [BNI] Grades I-IIIb) after GKS at a median duration of 1.9 months. The probability of maintaining pain relief (BNI Grades I-IIIb) without requiring resumption or an increase in medication was 93% at 1 year and 84% at 2 years for patients without MS, and 68% at 1 year and 51% at 2 years for all patients. The nerve length, nerve volume, target distance from the brainstem, and presence of NVC were not predictive of pain recurrence. Patients with a smaller volume of nerve (< 35% of the total nerve volume) that received a high dose (≥ 80% isodose) were less likely to experience recurrence of their TN pain after 1 year (mean time to recurrence: < 35%, 32.2 ± 4.0 months; > 35%, 17.9 ± 2.8 months, log-rank test, χ2 = 4.3, p = 0.039). CONCLUSIONS The ratio of dose to nerve volume may predict recurrence of TN pain after GKS. Prospective studies are needed to determine the optimal dose to nerve volume ratio and whether this will result in longer pain-free outcomes.

Clinical Correlation of Previously Undetected Cancer-Related Incidental Findings on CT Planning Scans for Radiation Therapy

OBJECTIVE The purpose of our study was to determine the management and cancer outcome of incidental cancer-related findings reported on CT radiation treatment planning scans. MATERIALS AND METHODS We conducted a retrospective review of CT planning scans performed from 2004 to 2006 with diagnostic radiology reports. We previously found 45 (8%) cancer-related findings, defined as any previously unknown radiologic finding that could potentially change the staging or treatment of the cancer, in the 580 CT scans reviewed. This study further examines the cancer-related findings to identify their clinical significance, management, and cancer outcomes. RESULTS Eight (18%) of the 45 cancer-related findings prompted additional imaging, with negative findings and no cancer failure at the site of the cancer-related findings. Three (7%) cancer-related findings resulted in changes in cancer management without further imaging, including initiating induction chemotherapy instead of localized radiation, increasing the radiation dose to identified lymphadenopathy, and changing the sequence of local management to initial surgery followed by radiation. Two of these findings had local recurrence at the site of cancer-related findings. The remaining 34 (76%) cancer-related findings did not result in any additional action. With a median follow-up of 17 months (range, 2-67 months) from CT, there was a similar failure rate at the site of cancer-related findings in the groups without (15%) and with (18%) additional action. CONCLUSION In our series, cancer-related findings identified by diagnostic radiology review of radiation planning CT scans are associated with low incidence of cancer management changes and disease progression. However, the generalizability of this study is unclear because of the small number of cancer-related findings present.

In Regard to Ahmed et al.

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MO‐F‐108‐07: Impact of Additional Intensity Modulation On Arc‐Based Stereotactic Body Radiotherapy (SBRT) for Lung Cancer

PURPOSE A single-isocenter multi-segment dynamic conformal arc technique (SiMs-arc) has been used in our department in the past three years for efficient planning and delivery of over 200 lung SBRT treatments. The purpose of this study is to investigate the impact of additional intensity-modulation made available by Varian RapidArc on the dosimetric quality and delivery efficiency of arc-based lung SBRT. METHODS Four patients previously treated with lung SBRT using SiMs-arc were selected. SiMs-arc plans were generated with the isocenter located in the geometric center of patient axial plane (to allow for collision-free gantry rotation around the patient) and six 60°-arc segments spanning from 1° to 359°. Two RapidArc plans, one using the same arc geometry as SiMs-arc and the other using typical partial arcs (210°) with the isocenter inside PTV, were generated for each patient. All plans, generated using Eclipse V10.0, were normalized with PTV V100 to 95%. PTV coverage, dose to organs-at-risk and total MUs were compared to assess the impact of additional intensity-modulation provided in RapidArc. RESULTS RapidArc plans produced higher PTV D99 (by 1.0%-3.1%) and minimum dose (by 2.4% to 9.8%); better PTV conformality index (by 1%-8%); and less volume of 50% dose outside 2cm from PTV (by 0-20.8cc) than the corresponding SiMs-arc plans. No significant dose differences were observed for lungs, trachea, chest wall and heart. RapidArc using partial-arcs had lowest maximum dose to spinal cord. RapidArc plans required 1.5 to 1.91 times more MUs than SiMs-arc plans to deliver the same dose. CONCLUSION Additional intensity-modulation enlisted by RapidArc produces modest dosimetric improvements over conformal arcs for lung SBRT, but requires more MUs (by a factor > 1.5) to deliver. The dosimetric improvements, most notably in PTV minimum dose and in dose conformality for irregularly shaped PTVs, may outweigh the increased MUs in using RapidArc.

The growing importance of lesion volume as a prognostic factor in patients with multiple brain metastases treated with stereotactic radiosurgery

Stereotactic Radiosurgery (SRS) is considered standard of care for patients with 1–3 brain metastases (BM). Recent observational studies have shown equivalent OS in patients with 5+ BM compared to those with 2–4, suggesting SRS alone may be appropriate in these patients. We aim to review outcomes of patients treated with SRS with 2–4 versus 5+ BM. This analysis included consecutive patients from 1994 to 2015 treated with SRS. Of 1017 patients, we excluded patients with a single BM and patients without adequate survival data, resulting in 391 patients. All risk factors were entered into univariate analysis using Cox proportional hazards model, and significant factors were entered into multivariate analysis (MVA). We additionally analyzed outcomes after excluding patients with prior surgery or whole‐brain radiotherapy (WBRT). Median follow‐up was 7.1 months. Median KPS was 90, mean age was 59, and most common histologies were melanoma and lung. Median tumor volume was 3.41 cc. Patients with 2–4 BM had a median OS of 8.1 months compared to 6.2 months for those with 5+ BM (P = 0.0136). On MVA, tumor volume, KPS, and histology remained significant for OS, whereas lesion number did not. Similar results were found when excluding patients with prior surgery or WBRT. Rather than lesion number, the strongest prognostic factors for patients undergoing SRS were tumor volume >10 cc, KPS, and histology. BM number may therefore not be the most important criterion for candidacy for SRS. Patients with 5 or more BM should be considered for SRS.

Safety-Net Versus Private Hospital Setting for Brain Metastasis Patients Treated With Radiosurgery Alone: Disparities in Follow-Up Care and Outcomes

Stereotactic radiosurgery (SRS) alone is an increasingly accepted treatment for brain metastases, but it requires adherence to frequently scheduled follow‐up neuroimaging because of the risk of distant brain metastasis. The effect of disparities in access to follow‐up care on outcomes after SRS alone is unknown.