Recurrence Risk Stratification for Women With FIGO Stage I Uterine Endometrioid Carcinoma Who Underwent Surgical Lymph Node Evaluation

OBJECTIVE

The aim of this study was to estimate the recurrence risk based on the number of prognostic factors for patients with stage I uterine endometrioid carcinoma (EC) who underwent surgical lymph node evaluation (SLNE) and were managed with observation.

METHODS

We queried our database for women with FIGO-2009 stage I EC who underwent surgical staging including SLNE. Multivariate analysis with stepwise model selection was used to determine independent risk factors for 5-year recurrence-free survival (RFS). Study groups based on risk factors were compared for RFS, disease-specific survival, and overall survival.

RESULTS

A total of 706 patients were identified: median age was 60 years (range, 30 to 93 y) and median follow-up was 120 months. Median number of examined lymph nodes was 8 (range, 1 to 66). 91% were stage IA, 75% had grade 1 and lymphovascular space invasion was detected in 6%. Independent predictors of 5-year RFS included age 60 years and above ( P =0.038), grade 2 ( P =0.003), and grade 3 ( P <0.001) versus grade 1. Five-year RFS for group 0 (age less than 60 y and grade 1) was 98% versus 92% for group 1 (either: age 60 y and older or grade 2/3) versus 84% for group 2 (both: age 60 y and above and grade 2/3), respectively ( P <0.001). Five-year disease-specific survival was 100% versus 98% versus 95%, ( P =0.012) and 5-year overall survival was 98% versus 90% versus 81%, for groups 0, 1, and 2, respectively ( P <0.001).

CONCLUSIONS

In patients with stage I EC who received SLNE and no adjuvant therapy, only age 60 years and above and high tumor grade were independent predictors of recurrence and can be used to quantify individualized recurrence risk, whereas lymphovascular space invasion was not an independent prognostic factor in this cohort.

Treatment Tolerance and Toxicity in Elderly Oropharyngeal Cancer Patients and Implication on Outcomes

PURPOSE/OBJECTIVE(S)

To investigate the tolerance level and toxicity for standard of care treatment for oropharyngeal cancer (OP) in elderly patients and their impact on outcomes.

MATERIALS/METHODS

Using our in-house head and neck cancer database, we looked for non-metastatic OP cases that received definitive treatment between 1/2009-6/2020. All patients received either definitive radiation therapy (RT) +/- concomitant systemic therapy (ST), or surgery followed by adjuvant RT or RT-ST. For the elderly (age at diagnosis ≥65 years) and young (<65 years) patients, we compared treatment package time (TPT) (time from surgery to RT conclusion) for adjuvant RT, total RT duration and unplanned RT interruptions. ST details and dose/protocol modifications were also compared. We evaluated worst grade of pain and mucositis, hospitalization for non-hydration causes and febrile neutropenia (FN) during RT. Feeding tube (FT) use and weight loss were compared. The independent effect of these indicators on locoregional (LRFS), distant (DRFS) recurrence free and overall (OS) survival was assessed using multivariate analyses (MVA).

RESULTS

A cohort of 326 patients was included: 36% elderly (n = 118) and 64% young (n = 208), with no differences in AJCC stage distribution (8th), treatment received and HPV status (HPV+ve: 73% vs 74.6%; p = 0.86). In 23.6 % who received adjuvant RT, median TPT was 86 (range 72-128) and 81 (65-137) days for elderly vs young (p = 0.27); whereas in the definitive RT cases 76.4%, total RT duration was 49 days for both age groups. Overall, prescribed RT course was not completed in 4% and unplanned RT interruptions occurred in 22.8% and both were non-significant between age groups. Among the 261 patients that received ST, elderly utilized more cetuximab (26 vs 12%; p = 0.007). For those who received cisplatin, 20% of elderly had cumulative dose <200 mg/m2 compared to 6% among the younger age group (p = 0.006); and cisplatin was changed to carboplatin or cetuximab in 18% vs 8% (p = 0.019). Delayed/cancelled cycles and dose reductions were similar. There were more hospitalizations (47% vs 27%; p<0.001) and a trend for more FN (9% vs 3%; p = 0.09) with older age, while worst pain and mucositis was similar. FTs were used more in elderly patients (64% vs 50%; p = 0.02), for a median of 97 vs 64 days (p = 0.31); of which 19.5% vs 11% (p = 0.28) were inserted before RT start. However, % weight loss was non-significant. On MVA, longer RT duration, FT use and hospitalizations predicted worse LRFS and DRFS; and they were prognostic for OS in addition to TPT >90 days (p<0.05 for all). Nevertheless, elderly vs young had non-significant 3-year LRFS (91% vs 90% and 67% vs 69%), DRFS (86% vs 90% and 79% vs 81%) & OS (85% vs 81% and 39% vs 52%) for HPV+ve and HPV-ve respectively (p>0.05).

CONCLUSION

Elderly patients with OP need more multi-disciplinary supportive care when receiving RT and concurrent ST. However, survival outcomes are equivalent to younger patients. Ongoing studies should enroll more elderly candidates and stratify endpoints with age.

The Prognostic Significance of the Depth of Cervical Stromal Invasion in Women With FIGO Stage II Uterine Endometrioid Carcinoma

OBJECTIVE

The objective of this study was to investigate the prognostic significance of the depth of cervical stromal invasion (CSI) in women with FIGO stage II uterine endometrioid adenocarcinoma (EC).

METHODS

Our database of women with EC was quired for patients with stage II EC. Pathologic slides were retrieved and reviewed by gynecologic pathologists to determine cervical stromal thickness and depth of CSI as a percentage of stromal thickness (%CSI). Kaplan-Meier, univariate, and multivariate analyses were used to compare recurrence-free, disease-specific (DSS), and overall survival (OS) between women who had<50% versus ≥50% CSI. Univariate and multivariate analyses were used to assess other prognostic variables associated with survival endpoints.

RESULTS

A total of 117 patients were included in our study who had hysterectomy between 1/1990 and 8/2021. Seventy-nine patients (68%) with <50% and 38 (32w%) with ≥50% CSI. After a median follow-up of 131 months, 5-year DSS was significantly worse for women with ≥50% CSI (78% vs. 91%; P =0.04). However, %CSI was not an independent predictor for any of the studied survival endpoints. Independent predictors of worse 5-year recurrence-free survival and DSS included FIGO grade 3 tumors ( P =0.02) and the presence of lymphovascular space invasion ( P =0.03). Grade 3 tumors were the only independent predictor of worse 5-year OS ( P =0.02).

CONCLUSIONS

Our results suggest that deep CSI is not an independent prognostic factor for survival endpoints in women with stage II uterine endometroid adenocarcinoma. The lack of independent prognostic significance of the depth CSI needs to be validated in a multi-institutional analysis.

The Prognostic Impact of Substantial Lymphovascular Space Invasion in Women with FIGO Stage I Uterine Endometrioid Carcinoma with Pathologically Negative Nodal Evaluation

PURPOSE/OBJECTIVE(S)

Substantiallymphovascular space invasion (LVSI) is an important predictor of lymph node involvement in women with endometrial carcinoma. However, its prognostic significance in women with stage I who had pathologic negative nodal evaluation (PNNE) was not fully evaluated. We aimed to evaluate the prognostic significance of substantial LVSI on recurrence-free (RFS), disease-specific (DSS) and overall survival (OS) in women with FIGO stage I uterine endometrioid adenocarcinoma (EC).

MATERIALS/METHODS

Our uterine cancer database was queried for women with stage I EC who had a hysterectomy and PNNE at our institution between 1/1990 and 11/2022. Postoperatively, patients were managed with observation or adjuvant radiation therapy (RT) with pelvic external beam RT or vaginal cuff brachytherapy (VB). Women with synchronous malignancies and those who received adjuvant chemotherapy were excluded. Pathologic specimens were retrieved and LVSI was quantified by Gynecology pathologists (none, focal or substantial). Patients' demographics, surgical and pathologic variables were analyzed. Predictors of RFS, DSS and OS using univariate (UVA) and multivariate analysis (MVA) were studied.

RESULTS

One thousand fifty-two patients were identified with a median age of 63 years and median follow-up of 9.7 years. Median number of examined lymph node (LN) were 9 (range 4-18). 907 patients (86.2%) had no LVSI, 87 (8.3%) had focal and 58 (5.5%) had substantial LVSI. In patients with focal LVSI, 32.2% received pelvic RT and 39.1% received VB. In patients with substantial LVSI, 20.7% received pelvic RT and 58.6% received VB.Recurrence was diagnosed in 86 patients (8.2%). While any LVSI was associated with tumor recurrence, there was no significant difference for the site of initial recurrence between patients with focal vs. substantial LVSI. 5-year RFS was 93.3% (95% CI 91.5-95.1), 76.8% (67.2-87.7) and 79.1% (67.6-95.3) for no, focal and substantial LVSI. The 5-year DSS was 97.6% (96.5-98.7), 83.5% (75-93.1), and 90% (81.8-99.9); and 5-year OS was 90.7% (88.7-92.8), 72.8% (62.9-84.2) and 86% (76.2-97.2), respectively. Independent predictors of worse 5-year RFS and DSS include any LVSI, age > 60 years, higher tumor grade. Independent predictors of worse 5- year OS include any LVSI, age > 60, high comorbidity burden, and higher tumor grade.

CONCLUSION

Our large data suggest similar recurrence-free, disease specific and OS for women with stage I uterine endometrioid carcinoma who had pathologically negative nodal evaluation and substantial or focal LVSI. There was no significant difference for the site of initial recurrence between patients with focal or substantial LVSI. Multi-institutional pooled analyses may be needed to validate our results.

Definitive and Salvage Radiotherapy Compared to Other Modalities for Laryngeal Carcinoma in Situ

PURPOSE/OBJECTIVE(S)

We sought to analyze survival endpoints for laryngeal carcinoma in situ (CIS) undergoing definitive radiotherapy (RT) compared to other modalities.

MATERIALS/METHODS

Usingour prospectively maintained head and neck cancer database, we identified laryngeal CIS patients treated between 6/2001 and 12/2021. We excluded low-grade dysplasia, CIS with any synchronous invasive squamous cell carcinoma (SCC) within 3 months of the initial CIS biopsy and cases with inadequate follow up. Patients were offered either definitive RT, CO2/KTP laser ablation, photodynamic therapy (PDT) or any sort of therapeutic excision. After first line treatment, follow-up includes visits every 3-6 months with laryngoscopy and biopsies as appropriate. For recurrent CIS beyond 6 months of first line treatment, we reported salvage therapies received and long-term outcomes were reported. Using Kaplan-Meier curves and log-rank test we investigated recurrence free (RFS), progression to invasive SCC free (IFS) and overall (OS) survival across treatment groups. Patients managed with salvage RT were compared to first line RT recipients.

RESULTS

Atotal of 85 CIS cases were included: median age 65 years (IQR: 55-74), 73 males (85%) and 70 white (82.4%). 86% had a history of smoking with median pack year of 38 (IQR: 20-55) and 66% had a history of alcohol use. CIS was glottic in most of the cases (90.6%: 66% unilateral, 21% bilateral & 13% involved commissure); with only 9.4% in the supraglottic region. RT was used in 49.4% (n = 42) after biopsy (55%) or surgery (45%) with median dose of 63 Gy/28 fractions, mainly by 3D conformal RT (76%). The remaining 50.6% (n = 43) got therapeutic excision alone (commonly microflap excision) (46.5%), CO2/KTP laser (32.6%) or PDT (20.9%). Demographics and clinicopathological details were non-different between RT and non-RT patients except for Charlson comorbidity index: median 2 (IQR 1-3) in non-RT vs 1 (IQR 0-2) in 1ry RT; p = 0.007. After a median follow-up of 4.8 years (IQR 3.5), 51.8% had recurrent disease, 21.2% progressed to invasive SCC and 9.4% had laryngectomies mainly for invasive SCC after RT. First line RT had improved 2-(83% vs 39%) and 5-(74% vs 22%) year RFS vs non-RT therapies (p<0.001). Nevertheless, 2- and 5-year IFS (89% vs 98% and 80% vs 79%) and OS (92% vs 93% and 81% vs 77%) were non-significant among both (p>0.05 for all). Among non-RT cases with CIS recurrences, 12/35 (34%) had salvage RT. Following RT, salvage RT patients had similar 2- and 5-year RFS (81% vs 83% and 81% vs 74%) and IFS (81% vs 89% and 81% vs 80%) compared to first line RT (p>0.05 for all). All cases with CIS recurrences were salvaged successfully with 100% living with no CIS at latest follow-up.

CONCLUSION

Laryngeal CIS can be treated with a wide range of modalities including 1ry RT which has better recurrence free survival. Nevertheless, non-RT recurrent CIS can be salvaged successfully with many options including RT with equivalent long-term results.

Feasibility of Using Zero-Shot Learning in Transformer-Based Natural Language Processing Algorithm for Key Information Extraction from Head and Neck Tumor Board Notes

PURPOSE/OBJECTIVE(S)

Natural language processing (NLP) technology has the potential to automate information aggregation and summarization in oncology. One example is the automation of patient registry creation. In this work, we aim to show (1) the feasibility of using modern NLP algorithms to extract key information from tumor board notes, and (2) the impact of prompt engineering on the quality of the results.

MATERIALS/METHODS

In this IRB-approved study, we obtained the texts of head and neck tumor board notes for 306 unique patients. Five key pieces of information used to create a patient registry were predefined: age, gender, tumor histology, tumor stage, and primary location. The NLP algorithm used was a modified Text-To-Text Transfer Transformer (T5) model that was initially trained on the Colossal Clean Crawled Corpus (C4) dataset and subsequently fine-tuned on the Stanford Question Answering Dataset (SQuAD) to perform the downstream task of extractive question answering. The NLP model and trained weights were obtained from the Hugging Face platform. During inference, the entire body of the tumor board note and a related question were fed as inputs, and the model predicted a sequence of texts in response to the question. Two sets of questions of similar semantic meanings were used. Questions in prompt set #1 included "What is the gender?", "What is the age?", "What is the type of carcinoma in pathological diagnosis?", "What is the stage?", and "Where is the carcinoma located at?". Questions in prompt set #2 include "Is the patient male or female?", "How old is the patient?", "What kind of cancer?", "What is the cancer stage?", and "What is the tumor location?". Each model-predicted response was compared to the ground truth extracted from the tumor board notes. A response was classified as true if it is consistent with the ground truth, otherwise, it was deemed false. The response accuracy for each question was subsequently calculated.

RESULTS

The median number of words in each tumor board note was 448 (range, 219 - 1505). The accuracy of the NLP algorithm for each question from either set is reported in Table 1. Algorithm performance is higher for extracting objective information such as age, gender, and histology. In addition, it was found that questions of similar semantic meanings but with different wording can lead to significantly different results.

CONCLUSION

We demonstrated that a transformer-based extractive question-answering NLP algorithm can be successfully used for extracting information from head and neck tumor board notes with zero-shot learning. Furthermore, our results highlight the significance of prompt engineering for applying NLP for this task. Future work on finetuning these algorithms to oncology-specific texts can potentially enhance algorithm performance for more difficult tasks.

Disease Characteristics, Treatment and Survival for Oropharyngeal Squamous Cell Carcinoma of Elderly

PURPOSE/OBJECTIVE(S)

Incidence of oropharyngeal cancers (OP) has been increasing over the past few decades, mainly driven by human papilloma virus (HPV) associated cancers in younger men. However, a large number of OP patients in recent years are ≥65 years of age. We wanted to determine if there is a difference in outcomes in elderly patients with OP as compared to younger patients.

MATERIALS/METHODS

We queried our institutional prospectively maintained head and neck cancer database for patients with non-metastatic OP treated between 1/2009-6/2020. We excluded patients who did not receive any definitive treatment. We analyzed clinicopathological and treatment characteristics for elderly (age at diagnosis ≥65 years) compared to young (<65 years) across HPV subtypes. We also studied survival endpoints among age groups using Kaplan-Meier curves and log-rank test. Independent predictors were estimated using multivariate (MVA) Cox regression models for each HPV subtype.

RESULTS

We identified 340 patients who met our inclusion criteria: elderly 123 (36%) and young 213 (64%). The proportion of elderly HPV+ve patients showed an increasing trend over the years studied. Median age was 70 years (range 65-91) in elderly and 56 years (38-64) in young (p<0.001); and HPV+ve/-ve were 73.2/26.8% vs 74.6/25.3% for both age groups respectively (p = 0.86). Elderly patients had higher Charlson Comorbidity Index (CCI) and included more divorcees (p<0.05). There were more elderly current/former smokers (97% vs 82%; p = 0.007) within HPV-ve cases. Definitive radiotherapy (RT) +/- systemic therapy (CRT) was utilized in 73.2% (n = 249), while the remainder had surgery +/- adjuvant RT/CRT. There was no difference with age for OP subsite, 8th edition AJCC stage and treatment received except for more use of cetuximab (22.5% vs 10.2%; p<0.001) and weekly cisplatin (32.4% vs 25.8%; p<0.001) among elderly patients. After a median follow up of 5.24 years (IQR: 3.53), 3-year overall (OS) (HPV+ve: 85 vs 81%; HPV-ve: 39 vs 52%), locoregional free (LRFS) (HPV+ve: 86 vs 90%; HPV-ve: 67 vs 69%) and distant metastasis free (DMFS) survival (HPV+ve: 91 vs 90%; HPV-ve: 79 vs 81%) were all non-significant for elderly vs young respectively. On MVA, CCI and AJCC stage for HPV+ve; and smoking, T-stage and lymphovascular space invasion for HPV- were associated with OS. For HPV+ve, AJCC stage, adjuvant vs definitive RT and treatment in later years were predictive of better LRFS, whereas smoking index and extracapsular space invasion were deterministic for DMFS. Interestingly, outcomes among those who received cetuximab was similar to those who received concurrent cisplatin for all endpoints.

CONCLUSION

We did not note any significant difference in outcomes among elderly patients treated for OP when compared to the younger patients when multi-disciplinary head and neck cancer care is provided. This was noted even though a significantly larger proportion of elderly patients received cetuximab concurrent with RT as opposed to standard of care cisplatin.

Cetuximab and anemia prevention in head and neck cancer patients undergoing radiotherapy

Background

Epidermal growth factor receptor (EGFR) activation is associated with increased production of interleukin 6 (IL6), which is intensified by radiotherapy (RT) induced inflammatory response. Elevated IL6 levels intensifies RT-induced anemia by upregulating hepcidin causing functional iron deficiency. Cetuximab, an EGFR inhibitor, has been associated with lower rates of anemia for locally advanced head and neck squamous cell carcinoma (HNSCC). We hypothesized that concomitant cetuximab could prevent RT-induced anemia.

Methods

We queried our institutional head and neck cancers database for non-metastatic HNSCC cases that received RT with concomitant cetuximab or RT-only between 2006 and 2018. Cetuximab was administered for some high-risk cases medically unfit for platinum agents per multidisciplinary team evaluation. We only included patients who had at least one complete blood count in the 4 months preceding and after RT. We compared the prevalence of anemia (defined as hemoglobin (Hb) below 12 g/dL in females and 13 g/dL in males) and mean Hb levels at baseline and after RT. Improvement of anemia/Hb (resolution of baseline anemia and/or an increase of baseline Hb ≥1 g/dL after RT), and overall survival (OS) in relation to anemia/Hb dynamics were also compared.

Results

A total of 171 patients were identified equally distributed between cetuximab-plus-RT and RT-only groups. The cetuximab-plus-RT group had more locally-advanced stage, oropharyngeal and high grade tumors (p < 0.001 for all). Baseline anemia/Hb were similar, however anemia after RT conclusion was higher in the cetuximab-plus-RT vs RT-only (63.5% vs. 44.2%; p = 0.017), with a mean Hb of 11.98 g/dL vs. 12.9 g/dL; p = 0.003, for both respectively. This contributed to significantly worse anemia/Hb improvement for cetuximab-plus-RT (18.8% vs. 37.2%; p = 0.007). This effect was maintained after adjusting for other factors in multivariate analysis. The prevalence of iron, vitamin-B12 and folate deficiencies; and chronic kidney disease, was non-different. Baseline anemia was associated with worse OS (p = 0.0052) for the whole study cohort. Nevertheless, improvement of anemia/Hb was only marginally associated with better OS (p = 0.068).

Conclusions

In contrast to previous studies, cetuximab was not associated with lower rates of anemia after RT for nonmetastatic HNSCC patients compared to RT-alone. Dedicated prospective studies are needed to elucidate the effect of cetuximab on RT-induced anemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09708-9.

Characterizing Sensitive Cardiac Substructure Excursion Due to Respiration

Purpose

Whole-heart dose metrics are not as strongly linked to late cardiac morbidities as radiation doses to individual cardiac substructures. Our aim was to characterize the excursion and dosimetric variation throughout respiration of sensitive cardiac substructures for future robust safety margin design.

Methods and Materials

Eleven patients with cancer treatments in the thorax underwent 4-phase noncontrast 4-dimensional computed tomography (4DCT) with T2-weighted magnetic resonance imaging in end-exhale. The end-exhale phase of the 4DCT was rigidly registered with the magnetic resonance imaging and refined with an assisted alignment surrounding the heart from which 13 substructures (chambers, great vessels, coronary arteries, etc) were contoured by a radiation oncologist on the 4DCT. Contours were deformed to the other respiratory phases via an intensity-based deformable registration for radiation oncologist verification. Measurements of centroid and volume were evaluated between phases. Mean and maximum dose to substructures were evaluated across respiratory phases for the breast (n = 8) and thoracic cancer (n = 3) cohorts.

Results

Paired t tests revealed reasonable maintenance of geometric and anatomic properties (P < .05 for 4/39 volume comparisons). Maximum displacements >5 mm were found for 24.8%, 8.5%, and 64.5% of the cases in the left-right, anterior-posterior, and superior-inferior axes, respectively. Vector displacements were largest for the inferior vena cava and the right coronary artery, with displacements up to 17.9 mm. In breast, the left anterior descending artery D_mean varied 3.03 ± 1.75 Gy (range, 0.53-5.18 Gy) throughout respiration whereas lung showed patient-specific results. Across all patients, whole heart metrics were insensitive to breathing phase (mean and maximum dose variations <0.5 Gy).

Conclusions

This study characterized the intrafraction displacement of the cardiac substructures through the respiratory cycle and highlighted their increased dosimetric sensitivity to local dose changes not captured by whole heart metrics. Results suggest value of cardiac substructure margin generation to enable more robust cardiac sparing and to reduce the effect of respiration on overall treatment plan quality.

Outcomes of Post-Operative Treatment with Concurrent Chemoradiotherapy (CRT) in High-Risk Resected Oral Cavity Squamous Cell Carcinoma (OCSCC): A Multi-Institutional Collaboration

Adjuvant chemoradiation (CRT), with high-dose cisplatin remains standard treatment for oral cavity squamous cell carcinoma (OCSCC) with high-risk pathologic features. We evaluated outcomes associated with different cisplatin dosing and schedules, concurrent with radiation (RT), and the effect of cumulative dosing of cisplatin. An IRB-approved collaborative database of patients (pts) with primary OCSCC (Stage I–IVB AJCC 7th edition) treated with primary surgical resection between January 2005 and January 2015, with or without adjuvant therapy, was established from six academic institutions. Patients were categorized by cisplatin dose and schedule, and resultant groups compared for demographic data, pathologic features, and outcomes by statistical analysis to determine disease free survival (DFS) and freedom from metastatic disease (DM). From a total sample size of 1282 pts, 196 pts were identified with high-risk features who were treated with adjuvant CRT. Administration schedule of cisplatin was not significantly associated with DFS. On multivariate (MVA), DFS was significantly better in patients without perineural invasion (PNI) and in those receiving ≥200 mg/m² cisplatin dose (p < 0.001 and 0.007). Median DFS, by cisplatin dose, was 10.5 (<200 mg/m²) vs. 20.8 months (≥200 mg/m²). Our analysis demonstrated cumulative cisplatin dose ≥200 mg/m² was associated with improved DFS in high-risk resected OCSCC pts.

Quantifying inter-fraction cardiac substructure displacement during radiotherapy via magnetic resonance imaging guidance

Purpose

Emerging evidence suggests cardiac substructures are highly radiosensitive during radiation therapy for cancer treatment. However, variability in substructure position after tumor localization has not been well characterized. This study quantifies inter-fraction displacement and planning organ at risk volumes (PRVs) of substructures by leveraging the excellent soft tissue contrast of magnetic resonance imaging (MRI).

Methods

Eighteen retrospectively evaluated patients underwent radiotherapy for intrathoracic tumors with a 0.35 T MRI-guided linear accelerator. Imaging was acquired at a 17–25 s breath-hold (resolution 1.5 × 1.5 × 3 mm³). Three to four daily MRIs per patient (n = 71) were rigidly registered to the planning MRI-simulation based on tumor matching. Deep learning or atlas-based segmentation propagated 13 substructures (e.g., chambers, coronary arteries, great vessels) to daily MRIs and were verified by two radiation oncologists. Daily centroid displacements from MRI-simulation were quantified and PRVs were calculated.

Results

Across substructures, inter-fraction displacements for 14% in the left–right, 18% in the anterior-posterior, and 21% of fractions in the superior-inferior were > 5 mm. Due to lack of breath-hold compliance, ~4% of all structures shifted > 10 mm in any axis. For the chambers, median displacements were 1.8, 1.9, and 2.2 mm in the left–right, anterior-posterior, and superior-inferior axis, respectively. Great vessels demonstrated larger displacements (> 3 mm) in the superior-inferior axis (43% of shifts) and were only 25% (left–right) and 29% (anterior-posterior) elsewhere. PRVs from 3 to 5 mm were determined as anisotropic substructure-specific margins.

Conclusions

This exploratory work derived substructure-specific safety margins to ensure highly effective cardiac sparing. Findings require validation in a larger cohort for robust margin derivation and for applications in prospective clinical trials.

Incorporating sensitive cardiac substructure sparing into radiation therapy planning

PURPOSE

Rising evidence suggests that cardiac substructures are highly radiosensitive. However, they are not routinely considered in treatment planning as they are not readily visualized on treatment planning CTs (TPCTs). This work integrated the soft tissue contrast provided by low-field MRIs acquired on an MR-linac via image registration to further enable cardiac substructure sparing on TPCTs.

METHODS

Sixteen upper thoracic patients treated at various breathing states (7 end-exhalation, 7 end-inhalation, 2 free-breathing) on a 0.35T MR-linac were retrospectively evaluated. A hybrid MR/CT atlas and a deep learning three-dimensional (3D) U-Net propagated 13 substructures to TPCTs. Radiation oncologists revised contours using registered MRIs. Clinical treatment plans were re-optimized and evaluated for beam arrangement modifications to reduce substructure doses. Dosimetric assessment included mean and maximum (0.03cc) dose, left ventricular volume receiving 5Gy (LV-V5), and other clinical endpoints. As metrics of plan complexity, total MU and treatment time were evaluated between approaches.

RESULTS

Cardiac sparing plans reduced the mean heart dose (mean reduction 0.7 ± 0.6, range 0.1 to 2.5 Gy). Re-optimized plans reduced left anterior descending artery (LADA) mean and LADA_0.03cc (0.0-63.9% and 0.0 to 17.3 Gy, respectively). LV_0.03cc was reduced by >1.5 Gy for 10 patients while 6 cases had large reductions (>7%) in LV-V5. Left atrial mean dose was equivalent/reduced in all sparing plans (mean reduction 0.9 ± 1.2 Gy). The left main coronary artery was better spared in all cases for mean dose and D_0.03cc . One patient exhibited >10 Gy reduction in D_0.03cc to four substructures. There was no statistical difference in treatment time and MU, or clinical endpoints to the planning target volume, lung, esophagus, or spinal cord after re-optimization. Four patients benefited from new beam arrangements, leading to further dose reductions.

CONCLUSIONS

By introducing 0.35T MRIs acquired on an MR-linac to verify cardiac substructure segmentations for CT-based treatment planning, an opportunity was presented for more effective sparing with limited increase in plan complexity. Validation in a larger cohort with appropriate margins offers potential to reduce radiation-related cardiotoxicities.

Evaluating compliance with process-related quality metrics and survival in oral cavity squamous cell carcinoma: Multi-institutional oral cavity collaboration study

BACKGROUND

Process-related measures have been proposed as quality metrics in head and neck cancer care. A recent single-institution study identified four key metrics associated with increased survival. This study sought to validate the association of these quality metrics with survival in a multi-institutional cohort.

METHODS

Multicenter retrospective study of patients with oral cavity squamous cell (1/2005-1/2015). Baseline patient and disease characteristics and compliance with quality metrics was evaluated. Association between compliance with quality metrics with overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) was evaluated using Cox proportional hazards models.

RESULTS

Failure to comply with two or more of the quality metrics was associated with worse OS, DFS, and DSS. Adherence to all or all but one of the quality metrics was found to be associated with improved survival.

CONCLUSIONS

Process-related quality metrics are associated with increased survival in patients with oral cavity squamous cell carcinoma in a multi-institutional cohort.

Correlation of normal lung density changes with dose after stereotactic body radiotherapy (SBRT) for early stage lung cancer

BACKGROUND AND PURPOSE

To investigate the correlation between normal lung CT density changes with dose accuracy and outcome after stereotactic body radiation therapy (SBRT) for patients with early stage non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Thirty-one patients (with a total of 33 lesions) with non-small cell lung cancer were selected out of 270 patients treated with SBRT at a single institution between 2003 and 2009. Out of these 31 patients, 10 patients had developed radiation pneumonitis (RP). Dose distributions originally planned using a 1-D pencil beam-based dose algorithm were retrospectively recomputed using different algorithms. Prescription dose was 48 Gy in 4 fractions in most patients. Planning CT images were rigidly registered to follow-up CT datasets at 3-9 months after treatment. Corresponding dose distributions were mapped from planning to follow-up CT images. Hounsfield Unit (HU) changes in lung density in individual, 5 Gy, dose bins from 5 to 45 Gy were assessed in the peri-tumoral region. Correlations between HU changes in various normal lung regions, dose indices (V20, MLD, generalized equivalent uniform dose (gEUD)), and RP grade were investigated.

RESULTS

Strong positive correlation was found between HU changes in the peri-tumoral region and RP grade (Spearman's r = 0.760; p < 0.001). Positive correlation was also observed between RP and HU changes in the region covered by V20 for all algorithms (Spearman's r ≥ 0.738; p < 0.001). Additionally, V20, MLD, and gEUD were significantly correlated with RP grade (p < 0.01). MLD in the peri-tumoral region computed with model-based algorithms was 5-7% lower than the PB-based methods.

CONCLUSION

Changes of lung density in the peri-tumoral lung and in the region covered by V20 were strongly associated with RP grade. Relative to model-based methods, PB algorithms over-estimated mean peri-tumoral dose and showed displacement of the high-dose region, which correlated with HU changes on follow-up CT scans.

Charlson Comorbidity score influence on prostate cancer survival and radiation-related toxicity

INTRODUCTION

In addition to survival endpoints, we explored the impact of Charlson Comorbidity-Index (CCI) on the acute and late toxicities in men with localized prostate cancer who received dose-escalated definitive radiotherapy (RT).

MATERIALS AND METHODS

CCI scores at diagnosis and survival outcomes were identified for men with intermediate/high-risk prostate cancer treated with RT (1/2007-12/2012). Study-cohort was accordingly grouped into no, mild and severe comorbidity (CCI-0, 1 or 2+). CCI-groups were compared for demographics, prognostic-factors; and RT-related toxicities based on RTOG/CTCAE criteria. Kaplan-Meier curves and Uni/multivariate (MVA) analyses were used to examine the influence of CCI-group on overall (OS), disease-specific (DSS) and biochemical-relapse free (BRFS) survival.

RESULTS

We included 257 patients with median age 73 years (48-85), 53% African-American and 67% had intermediate-risk. Median prostate RT-dose was 76 Gy; and 47% received androgen-deprivation therapy. CCI-0,1,2+ groups encompassed 76 (30%), 54 (21%) and 127 (49%) patients, respectively and were well-balanced. Ten and 15-years OS were significantly different (76% versus 46% versus 55% for 10-years OS and 53% versus 31% versus 14% for 15-years OS for CCI-0 versus CCI-1[HR:2.25; CI[1.31-3.87]] versus CCI-2+[HR:2.73; CI[1.73-4.31]]; p < 0.001. CCI-0 had better DSS than CCI-2+ (HR:2.23; CI[1.06-4.68]; p = 0.03) and BRFS was similar (p = 0.99). Late G2/3 RT-toxicities were more common in CCI-2+ (47%) than CCI-1 (44%) and CCI-0 (29%), p = 0.032; with non-different acute-toxicities (p = 0.62). On MVA, increased CCI was deterministic for OS (HR:3.65; CI [1.71:7.79]; p < 0.001) and was only marginal for DSS (HR:2.55; CI [0.98-6.6]; p = 0.05) with no impact on BRFS (p > 0.05).

CONCLUSIONS

Higher CCI is a significant predictor for late RT-related side-effects and shorter OS in men with localized prostate cancer. Baseline comorbidities should be considered during initial counseling and follow up visits.

Cardiac substructure segmentation with deep learning for improved cardiac sparing

PURPOSE

Radiation dose to cardiac substructures is related to radiation-induced heart disease. However, substructures are not considered in radiation therapy planning (RTP) due to poor visualization on CT. Therefore, we developed a novel deep learning (DL) pipeline leveraging MRI's soft tissue contrast coupled with CT for state-of-the-art cardiac substructure segmentation requiring a single, non-contrast CT input.

MATERIALS/METHODS

Thirty-two left-sided whole-breast cancer patients underwent cardiac T2 MRI and CT-simulation. A rigid cardiac-confined MR/CT registration enabled ground truth delineations of 12 substructures (chambers, great vessels (GVs), coronary arteries (CAs), etc.). Paired MRI/CT data (25 patients) were placed into separate image channels to train a three-dimensional (3D) neural network using the entire 3D image. Deep supervision and a Dice-weighted multi-class loss function were applied. Results were assessed pre/post augmentation and post-processing (3D conditional random field (CRF)). Results for 11 test CTs (seven unique patients) were compared to ground truth and a multi-atlas method (MA) via Dice similarity coefficient (DSC), mean distance to agreement (MDA), and Wilcoxon signed-ranks tests. Three physicians evaluated clinical acceptance via consensus scoring (5-point scale).

RESULTS

The model stabilized in ~19 h (200 epochs, training error <0.001). Augmentation and CRF increased DSC 5.0 ± 7.9% and 1.2 ± 2.5%, across substructures, respectively. DL provided accurate segmentations for chambers (DSC = 0.88 ± 0.03), GVs (DSC = 0.85 ± 0.03), and pulmonary veins (DSC = 0.77 ± 0.04). Combined DSC for CAs was 0.50 ± 0.14. MDA across substructures was <2.0 mm (GV MDA = 1.24 ± 0.31 mm). No substructures had statistical volume differences (P > 0.05) to ground truth. In four cases, DL yielded left main CA contours, whereas MA segmentation failed, and provided improved consensus scores in 44/60 comparisons to MA. DL provided clinically acceptable segmentations for all graded patients for 3/4 chambers. DL contour generation took ~14 s per patient.

CONCLUSIONS

These promising results suggest DL poses major efficiency and accuracy gains for cardiac substructure segmentation offering high potential for rapid implementation into RTP for improved cardiac sparing.

Application of radiomics for the prediction of HPV status for patients with head and neck cancers

PURPOSE

To perform radiomic analysis of primary tumors extracted from pretreatment contrast-enhanced computed tomography (CE-CT) images for patients with oropharyngeal cancers to identify discriminant features and construct an optimal classifier for the characterization and prediction of human papilloma virus (HPV) status.

MATERIALS AND METHODS

One hundred and eighty seven patients with oropharyngeal cancers with known HPV status (confirmed by immunohistochemistry-p16 protein testing) were retrospectively studied as follows: Group A: 95 patients (19HPV- and 76HPV+) from the MICAII grand challenge. Group B: 92 patients (52HPV- and 40HPV+) from our institution. Radiomic features (172) were extracted from pretreatment diagnostic CE-CT images of the gross tumor volume (GTV). Levene and Kolmogorov-Smirnov's tests with absolute biserial correlation (>0.48) were used to identify the discriminant features between the HPV+ and HPV- groups. The discriminant features were used to train and test eight different classifiers. Area under receiver operating characteristic (AUC), positive predictive and negative predictive values (PPV and NPV, respectively) were used to evaluate the performance of the classifiers. Principal component analysis (PCA) was applied on the discriminant feature set and seven PCs were used to train and test a generalized linear model (GLM) classifier.

RESULTS

Among 172 radiomic features only 12 radiomic features (from 3 categories) were significantly different (P < 0.05, |BSC| > 0.48) between the HPV+ and HPV- groups. Among the eight classifiers trained and applied for prediction of HPV status, the GLM showed the highest performance for each discriminant feature and the combined 12 features: AUC/PPV/NPV = 0.878/0.834/0.811. The GLM high prediction power was AUC/PPV/NPV = 0.849/0.731/0.788 and AUC/PPV/NPV = 0.869/0.807/0.870 for unseen test datasets for groups A and B, respectively. After eliminating the correlation among discriminant features by applying PCA analysis, the performance of the GLM was improved by 3.3%, 2.2%, and 1.8% for AUC, PPV, and NPV, respectively.

CONCLUSIONS

Results imply that GTV's for HPV+ patients exhibit higher intensities, smaller lesion size, greater sphericity/roundness, and higher spatial intensity-variation/heterogeneity. Results are suggestive that radiomic features primarily associated with the spatial arrangement and morphological appearance of the tumor on contrast-enhanced diagnostic CT datasets may be potentially used for classification of HPV status.

Impact of CT reconstruction algorithm on auto-segmentation performance

Model‐based iterative reconstruction (MBIR) reduces CT imaging dose while maintaining image quality. However, MBIR reduces noise while preserving edges which may impact intensity‐based tasks such as auto‐segmentation. This work evaluates the sensitivity of an auto‐contouring prostate atlas across multiple MBIR reconstruction protocols and benchmarks the results against filtered back projection (FBP). Images were created from raw projection data for 11 prostate cancer cases using FBP and nine different MBIR reconstructions (3 protocols/3 noise reduction levels) yielding 10 reconstructions/patient. Five bony structures, bladder, rectum, prostate, and seminal vesicles (SVs) were segmented using an auto‐segmentation pipeline that renders 3D binary masks for analysis. Performance was evaluated for volume percent difference (VPD) and Dice similarity coefficient (DSC), using FBP as the gold standard. Nonparametric Friedman tests plus post hoc all pairwise comparisons were employed to test for significant differences (P < 0.05) for soft tissue organs and protocol/level combinations. A physician performed qualitative grading of 396 MBIR contours across the prostate, bladder, SVs, and rectum in comparison to FBP using a six‐point scale. MBIR contours agreed with FBP for bony anatomy (DSC ≥ 0.98), bladder (DSC ≥ 0.94, VPD < 8.5%), and prostate (DSC = 0.94 ± 0.03, VPD = 4.50 ± 4.77% (range: 0.07–26.39%). Increased variability was observed for rectum (VPD = 7.50 ± 7.56% and DSC = 0.90 ± 0.08) and SVs (VPD and DSC of 8.23 ± 9.86% range (0.00–35.80%) and 0.87 ± 0.11, respectively). Over the all protocol/level comparisons, a significant difference was observed for the prostate VPD between BSPL1 and BSTL2 (adjusted P‐value = 0.039). Nevertheless, 300 of 396 (75.8%) of the four soft tissue structures using MBIR were graded as equivalent or better than FBP, suggesting that MBIR offered potential improvements in auto‐segmentation performance when compared to FBP. Future work may involve tuning organ‐specific MBIR parameters to further improve auto‐segmentation performance. Running title: Impact of CT Reconstruction Algorithm on Auto‐segmentation Performance.

Impact of smoking on pathological features in oral cavity squamous cell carcinoma

OBJECTIVES

We sought to determine whether smokers with oral cavity squamous cell carcinoma (OCSCC) have tumors with more adverse pathological features than in nonsmokers and whether or not these are predictive of outcomes.

MATERIALS AND METHODS

We retrospectively identified 163 patients with American Joint Committee on Cancer stages I-IVa OCSCC diagnosed between 2005 and 2015 and treated with curative intent. A pathological risk score (PRS) was calculated using the National Comprehensive Cancer Network adverse risk factors: positive margin, extracapsular extension of lymph node metastases, pT3 or pT4 primary, N2 or N3 nodal disease, perineural invasion, and lymphovascular space invasion. Multivariable models were constructed to determine the independent predictors of overall survival (OS), recurrence-free survival (RFS), and PRS.

RESULTS

A total of 108 (66.26%) were smokers and 55 nonsmokers. Three-year actuarial OS and RFS were 62% and 68% in smokers and 81% and 69% in nonsmokers, respectively (P = 0.06 and P = 0.63). Smokers were more likely to have advanced disease stage and tumors with aggressive pathological features than nonsmokers. Smokers had significantly worse PRS (mean ± standard deviation; 2.38 ± 2.19, median; 2.00) than nonsmokers (0.89 ± 1.21, 0.00) (P < 0.001). Older age, higher PRS, and smoking status were independent predictors of OS. Smoking or PRS did not predict for worse RFS. On multivariate analysis, independent predictors of PRS were smoking status and grade (P < 0.001).

CONCLUSION

In patients with OCSCC, smokers have more aggressive disease as evidenced by more adverse pathological features than nonsmokers. Moreover, smoking is an independent predictor of OS but not RFS. The PRS is a significant predictor of OS and needs validation in the future studies.

Outcomes of post-operative treatment with concurrent systemic therapy and radiotherapy (RT) in intermediate (INT) risk resected oral cavity squamous cell carcinoma (OCSCC): A multi-institutional collaboration

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Background: Patients (pts) with adverse pathologic factors in resected OCSCC excluding positive surgical margins or extranodal extension represent a group of INT risk disease. Though not standard of care, adjuvant CRT is often used in INT pts. We conducted a multi-institutional study to evaluate factors associated with improved outcomes in INT pts treated with or without chemotherapy. Methods: An IRB-approved collaborative database of patients with primary OCSCC (Stage I-IVB AJCC 7th edition) treated with primary surgical resection between 1/1/2005 and 1/1/2015 with or without adjuvant therapy was established from 6 academic institutions. Pts were categorized by pathologic features and adjuvant therapy. Kaplan Meier curves, log-rank p-values and multivariate analysis (MVA) were used to describe outcomes by treatment including locoregional control (LRC) and disease free survival (DFS). Results: From a total sample size of 1270 patients, 455 INT risk pts were treated with primary surgical resection and adjuvant therapy; 95 received CRT, 274 received RT alone, and 86 received RT without recorded chemotherapy. 49% of pts had perineural invasion (PNI), 24.8% lymphovascular space invasion, 21.5% poorly differentiated histology, 47.3% with pT3/4 disease, and 27.9% with > 2 lymph node positive (LN+). 55.8% of CRT pts were treated with cisplatin. > 2 LN+ was the only significant predictor of LRC (HR 1.49, p= 0.049). PNI and > 2 LN+ were significant predictors of DFS (HR 1.52, p= 0.003 and HR 1.76, p< 0.001). On MVA, after adjusting for > 2 LN+, treatment with cisplatin-RT was borderline significant for LRC (HR 0.52, p= 0.08). 3 year LRC in pts with > 2 LN+ was 84.4% in pts treated with cisplatin-RT compared with 64.9% for RT alone. Conclusions: The addition of cisplatin-based CRT to INT risk pts is controversial but among pts with > 2 LN+ there was a trend toward benefit. This study is limited by small numbers of pts treated with CRT, though these results highlight the need for further investigation in this population to identify INT pts who would benefit from adjuvant therapy intensification.

Outcomes of postoperative treatment with concurrent chemoradiotherapy (CRT) in high risk resected oral cavity squamous cell carcinoma (OCSCC): A multi-institutional collaboration

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Background: Adjuvant CRT with high-dose cisplatin remains standard treatment for OCSCC with high risk pathologic features of positive surgical margins (SM+) and/or extranodal extension (ENE). High-dose cisplatin is associated with significant toxicities, and alternative dosing schedules or treatments are used. We evaluated outcomes associated with different systemic therapies concurrent with RT and the effect of cumulative dosing of cisplatin. Methods: An IRB-approved collaborative database of patients (pts) with primary OCSCC (Stage I-IVB AJCC 7th edition) treated with primary surgical resection between 1/1/2005 and 1/1/2015 with or without adjuvant therapy was established from 6 academic institutions. Pts were categorized by systemic therapy received, and resultant groups compared for demographic data, pathologic features, and outcomes by t-test and Chi-squared tests. Kaplan-Meier curves, log-rank p-values, and multivariate analysis (MVA) for disease free survival (DFS) and freedom from metastatic disease (DM). Results: From a total sample size of 1282 pts, 196 pts were identified with high risk features (SM+, ENE) who were treated with adjuvant CRT. Median age was 56 years, 63.3% of pts were men, 81.1% were Caucasian, 70.9% had significant tobacco history. 35.7% of pts had SM+, 82.7% ENE, 65.3% with perineural invasion (PNI), 49% had lymphovascular space invasion (LVSI). There was a trend associating higher cisplatin dose delivered with improved locoregional control, DM, and overall survival (OS) (p-values 0.131, 0.084, and 0.187, respectively). DFS was significantly better with higher cisplatin dose (HR = 0.95 per 100 mg/m2 increase in cisplatin). Administration schedule of cisplatin (weekly versus high-dose) was not significantly associated with DFS. On MVA, PNI and higher cisplatin dose remained statistically significant for DFS (p < 0.001 and 0.007). Median OS by cisplatin dose was 10.5 ( < 200 mg/m2) vs. 20.8 months ( > / = 200 mg/m2). Conclusions: This multi-institutional analysis demonstrated cumulative cisplatin dose > / = 200 mg/m2 was associated with improved DFS in high risk resected OCSCC pts. It remains unclear by this analysis if cisplatin administration schedule has any prognostic implication. Further study is warranted to elucidate the optimal cisplatin schedule for this population.

The impact of Charlson Comorbidity Index on survival outcomes in men with prostate cancer who underwent definitive prostate radiotherapy

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Background: Life expectancy is very essential in deciding treatment options in men with prostate cancer (PCa); however, the impact of comorbidities on outcomes is not well-established. We investigated the influence of Charlson Comorbidity Index (CCI) on survival endpoints in men with localized PCa who were treated with prostate radiotherapy (RT). Methods: Men with intermediate and high risk PCa who were treated with definitive RT between 1/2007 and 12/2012 were included. Groups were created according to their baseline CCI score at diagnosis into no, mild and severe comorbidity (CCI 0, 1 or 2+). The groups were then compared based on patients’ characteristics and prognostic factors. Kaplan-Meier curves and Uni/multivariate analyses (MVA) were used to examine the impact of CCI groups on overall (OS), disease specific (DSS), and biochemical relapse free (BRFS) survival. Results: 257 patients were identified after excluding low risk, metastatic cases and those with inadequate follow up. Median follow-up was 92 months (range: 2-135) and median age was 73 years (range: 48-85). 53% of the cases were black and 67% were of intermediate risk. Median RT dose was 76 Gy and 47% received androgen deprivation therapy. CCI groups 0, 1 and 2+ encompassed 76 (30%), 54 (21%) and 127 (49%) patients, respectively. Groups were generally well-balanced. 10 and 15 years OS was significantly different across CCI groups (76% & 53%, 46% & 31% and 55% & 14%, for CCI-0, 1 and 2+ respectively; p < 0.001). CCI-0 had better DSS than CCI-2+ ( p = 0.03) with no difference for CCI-0 vs 1 ( p = 0.1). BRFS was non-different among CCI groups ( p = 0.99). On MVA, increased CCI was deterministic for OS ( p < 0.001) after adjusting for age, Gleason’s score and T-stage. For DSS, only age and T3 vs T1/2 were independently prognostic ( p < 0.001); whereas CCI-1 vs 0 was only marginal ( p = 0.05). Conclusions: Higher CCI was a significant predictor of shorter OS in intermediate and high-risk PCa. Baseline comorbidities should be taken into consideration during patient counselling for treatment options and in designing prospective trials for men with localized prostate cancer.

The effect of treatment package time in head and neck cancer patients treated with adjuvant radiotherapy and concurrent systemic therapy

Objectives

In patients with head and neck carcinoma, “treatment package time” (TPT) was proven to impact outcomes in cases receiving adjuvant radiotherapy alone. Its impact in patients receiving radiotherapy with concurrent systemic therapy has not been studied previously. The TPT influence on survival endpoints for patients treated with surgery followed by radiation and concurrent systemic therapy was analyzed.

Methods

Institutional database to identify head and neck carcinoma cases treated with definitive surgery followed by concomitant chemo(bio) radiotherapy (CRT) was used. TPT was the number of days elapsed between surgery and the last day of radiation. %FINDCUT SAS macro tool was used to search for the cutoff TPT that was associated with significant survival benefit. Kaplan–Meier curves, log-rank tests as well as univariate and multivariate analyses were used to assess overall survival (OS) and recurrence free survival (RFS).

Results

One hundred and three cases with a median follow up of 37 months were included in the study. Oropharyngeal tumors were 43%, oral cavity 40% and laryngeal 17% of cases. Concurrent systemic therapy included platinum and cetuximab in 72% and 28%, respectively. Optimal TPT was found to be < 100 days with significantly better OS (P = 0.002) and RFS (P = 0.043) compared to TPT ≥100 days. On multivariate analysis; TPT<100 days, extracapsular nodal extension, high-risk score, lymphovascular space and perineural invasion were independent predictors for worse OS (P < 0.05). T4, extracapsular nodal extension and high-risk score were all significantly detrimental to RFS (P < 0.05).

Conclusions

Addition of concomitant systemic therapy to adjuvant radiotherapy did not compensate for longer TPT in head and neck squamous cell carcinoma. Multidisciplinary coordinated care must be provided to ensure the early start of CRT with minimal treatment breaks.

Cardiac Substructure Segmentation and Dosimetry Using a Novel Hybrid Magnetic Resonance and Computed Tomography Cardiac Atlas

PURPOSE

Radiation dose to the heart and cardiac substructures has been linked to cardiotoxicities. Because cardiac substructures are poorly visualized on treatment-planning computed tomography (CT) scans, we used the superior soft-tissue contrast of magnetic resonance (MR) imaging to optimize a hybrid MR/CT atlas for substructure dose assessment using CT.

METHODS AND MATERIALS

Thirty-one patients with left-sided breast cancer underwent a T2-weighted MR imaging scan and noncontrast simulation CT scans. A radiation oncologist delineated 13 substructures (chambers, great vessels, coronary arteries, etc) using MR/CT information via cardiac-confined rigid registration. Ground-truth contours for 20 patients were inputted into an intensity-based deformable registration atlas and applied to 11 validation patients. Automatic segmentations involved using majority vote and Simultaneous Truth and Performance Level Estimation (STAPLE) strategies with 1 to 15 atlas matches. Performance was evaluated via Dice similarity coefficient (DSC), mean distance to agreement, and centroid displacement. Three physicians evaluated segmentation performance via consensus scoring by using a 5-point scale. Dosimetric assessment included measurements of mean heart dose, left ventricular volume receiving 5 Gy, and left anterior descending artery mean and maximum doses.

RESULTS

Atlas approaches performed similarly well, with 7 of 13 substructures (heart, chambers, ascending aorta, and pulmonary artery) having DSC >0.75 when averaged over 11 validation patients. Coronary artery segmentations were not successful with the atlas-based approach (mean DSC <0.3). The STAPLE method with 10 matches yielded the highest DSC and the lowest mean distance to agreement for all high-performing substructures (omitting coronary arteries). For the STAPLE method with 10 matches, >50% of all validation contours had centroid displacements <3.0 mm, with the largest shifts in the coronary arteries. Atlas-generated contours had no statistical difference from ground truth for left anterior descending artery maximum dose, mean heart dose, and left ventricular volume receiving 5 Gy (P > .05). Qualitative contour grading showed that 8 substructures required minor modifications.

CONCLUSIONS

The hybrid MR/CT atlas provided reliable segmentations of chambers, heart, and great vessels for patients undergoing noncontrast CT, suggesting potential widespread applicability for routine treatment planning.

Retroperitoneal Metastasis Abutting Small Bowel: A Novel Magnetic Resonance-Guided Radiation Approach

Stereotactic body radiation therapy (SBRT) is an option for selected patients with metastatic disease. However, sometimes these lesions are located in such close proximity to critical normal structures that the use of safe tumoricidal SBRT doses is not achievable. Here we present a case in which real-time imaging and tracking with a magnetic resonance linear accelerator (MR-LINAC) provided a novel treatment approach and enabled safe treatment of the tumor using SBRT. Our case is a 69-year-old female who presented with localized recurrent small cell lung cancer with a retroperitoneal (FDG-avid) soft tissue lesion measuring 2.4 x 4.1 cm that was causing pain and right hydronephrosis. A Food and Drug Administration (FDA)-approved MR-LINAC system was utilized for planning and the delivery of 21 Gy in three fractions to the retroperitoneal lesion planning target volume (PTV), limited by the neighboring small bowel tolerance. The gross tumor volume (GTV) itself received 27 Gy (9 Gy per fraction). Simulation was performed using a volumetric MR imaging study in treatment position co-registered to a 4D-computed tomography (CT) image set for contouring of the target and organs at risk (OAR). Treatment planning was performed using the primary CT dataset. We developed a reasonable SBRT treatment plan to deliver the prescribed dose without exceeding tolerance doses to the right kidney, the small bowel and all other OAR’s. Real-time MR imaging and tracking during treatment delivery enabled assessment of respiratory-induced target movement in relation to the small bowel and kidney. Gating was performed to halt treatment when PTV movement exceeded the 2-mm range as specified by the treating physician. The treatment course was concluded successfully. The patient denied any acute gastrointestinal or genitourinary toxicity. The pain was significantly improved within a short time following treatment. Follow-up CT showed a near complete response of the mass with total restoration of renal functions, allowing the ureteric stent to be removed. This response has been maintained for five months till the last follow-up. In conclusion, MR-guided planning and delivery using real-time MR imaging and tracking facilitated the treatment of the retroperitoneal mass accurately and efficiently with excellent clinical and radiological response and minimal to no toxicity. We would not discern it safe to treat this mass utilizing SBRT without this ability to accurately visualize the tumor boundary using magnetic resonance imaging (MRI), and offer tracking of the target within the millimeter of surrounding critical OAR’s.

The impact of lymphadenectomy on survival endpoints in women with early stage uterine endometrioid carcinoma: A matched analysis

OBJECTIVES

The role of pelvic lymphadenectomy (LA) in women with stage I endometrial carcinoma (EC) is controversial. The objective of this study is to investigate the prognostic impact of LA on survival endpoints in matched cohorts of women with stage I EC solely of endometrioid histology. Survival endpoints included recurrence-free (RFS), disease-specific (DSS) and overall survival (OS).

METHODS AND MATERIALS

Patients with FIGO stage I EC who underwent hysterectomy with LA as part of their surgical staging between 1/1990 and 6/2015 were matched to a similar group that underwent hysterectomy without lymphadenectomy (NLA), based on stage, grade and adjuvant management. Univariate and multivariate modeling with Cox regression analysis was carried out for predictors of survival endpoints.

RESULTS

870 women constituted the study cohort (435 in each group). Median number of dissected lymph node in the LA group was 9 (range, 5-75). There was no statistically significant difference between the two groups in regards to 5-year OS (87.2% for LA vs. 91.7% for NLA) (p=0.36), DSS 97.7% vs. 98% (p=0.54) and RFS (93.7% vs. 90% (p=0.08), respectively. Lymphadenectomy was not a predictor of any of the studied survival endpoints. On multivariate analysis for the entire cohort, older age, deep myometrial invasion and higher tumor grade were predictors of worse RFS. For DSS, higher tumor grade, lower uterine segment (LUS) involvement and FIGO stage IB were significant predictors of worse outcome. For OS, older age and LUS involvement were the only two independent predictors for shorter OS.

CONCLUSIONS

After matching for FIGO stage, grade and adjuvant management, it appears that lymphadenectomy in women with stage I EC does not impact survival endpoints.

Trends in the utilization of adjuvant vaginal brachytherapy in women with early-stage endometrial carcinoma: Results of an updated period analysis of SEER data

PURPOSE

Adjuvant vaginal brachytherapy (VB) is a well-established and effective radiation treatment modality in women with early-stage endometrial carcinoma. We sought to evaluate and update published trends in the utilization of VB vs. other radiation therapy modalities (pelvic external beam radiation therapy (EBRT) or the combination of VB and pelvic EBRT using the National Cancer Institute's Surveillance, Epidemiology, and End Results database.

METHODS AND MATERIALS

The Surveillance, Epidemiology, and End Results database was queried for adult females with histologically confirmed International Federation of Gynecology and Obstetrics 1988 Stage I-II endometrial carcinoma diagnosed from 1995 to 2012 and treated definitively with hysterectomy and adjuvant radiation therapy. Chi-square tests were used to assess differences by radiation type (VB, EBRT, and VB + EBRT) and various demographic and clinical variables.

RESULTS

We identified 15,201 patients that met inclusion criteria. There was a significant overall increase in the use of VB was observed from 17.1% in 1995-2000 compared to 57.1% in 2007-2012 (p < 0.0001). Similarly, there was a proportional decrease in the use of EBRT from 54.0% to 25.5% (p < 0.0001) as well as in the use of VB + EBRT from 28.9% to 17.4% during the same period (p < 0.0001). The observed increase in utilization of VB was not limited to any variables (age, race, histological type, International Federation of Gynecology and Obstetrics stage, and the status of lymph node dissection [yes or no]) or the number of dissected lymph nodes.

CONCLUSIONS

In this large national database set, there continues to be an increasing trend for the use of VB in the adjuvant setting in women with early-stage endometrial carcinoma.