Neural network dose prediction for cervical brachytherapy: Overcoming data scarcity for applicator-specific models.

BACKGROUND: 3D neural network dose predictions are useful for automating brachytherapy (BT) treatment planning for cervical cancer. Cervical BT can be delivered with numerous applicators, which necessitates developing models that generalize to multiple applicator types. The variability and scarcity of data for any given applicator type poses challenges for deep learning. PURPOSE: The goal of this work was to compare three methods of neural network training-a single model trained on all applicator data, fine-tuning the combined model to each applicator, and individual (IDV) applicator models-to determine the optimal method for dose prediction. METHODS: Models were produced for four applicator types-tandem-and-ovoid (T&O), T&O with 1-7 needles (T&ON), tandem-and-ring (T&R) and T&R with 1-4 needles (T&RN). First, the combined model was trained on 859 treatment plans from 266 cervical cancer patients treated from 2010 onwards. The train/validation/test split was 70%/16%/14%, with approximately 49%/10%/19%/22% T&O/T&ON/T&R/T&RN in each dataset. Inputs included four channels for anatomical masks (high-risk clinical target volume [HRCTV], bladder, rectum, and sigmoid), a mask indicating dwell position locations, and applicator channels for each applicator component. Applicator channels were created by mapping the 3D dose for a single dwell position to each dwell position and summing over each applicator component with uniform dwell time weighting. A 3D Cascade U-Net, which consists of two U-Nets in sequence, and mean squared error loss function were used. The combined model was then fine-tuned to produce four applicator-specific models by freezing the first U-Net and encoding layers of the second and resuming training on applicator-specific data. Finally, four IDV models were trained using only data from each applicator type. Performance of these three model types was compared using the following metrics for the test set: mean error (ME, representing model bias) and mean absolute error (MAE) over all dose voxels and ME of clinical metrics (HRCTV D90% and D2cc of bladder, rectum, and sigmoid), averaged over all patients. A positive ME indicates the clinical dose was higher than predicted. 3D global gamma analysis with the prescription dose as reference value was performed. Dice similarity coefficients (DSC) were computed for each isodose volume. RESULTS: Fine-tuned and combined models showed better performance than IDV applicator training. Fine-tuning resulted in modest improvements in about half the metrics, compared to the combined model, while the remainder were mostly unchanged. Fine-tuned MAE = 3.98%/2.69%/5.36%/3.80% for T&O/T&R/T&ON/T&RN, and ME over all voxels = -0.08%/-0.89%/-0.59%/1.42%. ME D2cc were bladder = -0.77%/1.00%/-0.66%/-1.53%, rectum = 1.11%/-0.22%/-0.29%/-3.37%, sigmoid = -0.47%/-0.06%/-2.37%/-1.40%, and ME D90 = 2.6%/-4.4%/4.8%/0.0%. Gamma pass rates (3%/3 mm) were 86%/91%/83%/89%. Mean DSCs were 0.92%/0.92%/0.88%/0.91% for isodoses ≤ 150% of prescription. CONCLUSIONS: 3D BT dose was accurately predicted for all applicator types, as indicated by the low MAE and MEs, high gamma scores and high DSCs. Training on all treatment data overcomes challenges with data scarcity in each applicator type, resulting in superior performance than can be achieved by training on IDV applicators alone. This could presumably be explained by the fact that the larger, more diverse dataset allows the neural network to learn underlying trends and characteristics in dose that are common to all treatment applicators. Accurate, applicator-specific dose predictions could enable automated, knowledge-based planning for any cervical brachytherapy treatment.

Phase II Trial of Cisplatin, Gemcitabine, and Intensity-Modulated Radiation Therapy for Locally Advanced Vulvar Squamous Cell Carcinoma: NRG Oncology/GOG Study 279.

PURPOSE: To assess efficacy and toxicity of cisplatin (C) and gemcitabine (G) with intensity-modulated radiation therapy (IMRT) in patients with locally advanced vulvar cancer not amenable to surgery. METHODS: Patients enrolled in a single-arm phase II study. Pretreatment inguinal-femoral nodal assessment was performed. Sixty-four Gy IMRT was prescribed to the vulva, with 50-64 Gy delivered to the groins/low pelvis. Radiation therapy (RT) plans were quality-reviewed pretreatment. C 40 mg/m2 and G 50 mg/m2 were administered once per week throughout IMRT. Complete pathologic response (CPR) was the primary end point. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and adverse events were assessed with Common Terminology Criteria for Adverse Events v 4.0. RESULTS: Fifty-seven patients enrolled, of which 52 were evaluable. The median age was 58 years (range, 25-58), and 94% were White. Forty (77%) had stage II or III disease, and all had squamous histology. A median of six chemotherapy cycles (range, 1-8) were received. Eighty-five percent of RT plans were quality-reviewed with 100% compliance to protocol. Seven patients came off trial because of toxicity or patient withdrawal. Of 52 patients available for pathologic assessment, 38 (73% [90% CI, 61 to 83]) achieved CPR. No pelvic exenterations were performed. With a median follow-up of 51 months, the 12-month PFS was 74% (90% CI, 62.2 to 82.7) and the 24-month OS was 70% (90% CI, 57 to 79). The most common grade 3 or 4 adverse events were hematologic toxicity and radiation dermatitis. There was one grade 5 event unlikely related to treatment. CONCLUSION: Weekly C and G concurrent with IMRT sufficiently improved CPR in women with locally advanced vulvar squamous cell carcinoma not amenable to surgical resection.

Design and Material Characterization of an Inflatable Vaginal Dilator.

There are more than 13,000 new cases of cervical cancer each year in the United States and approximately 245,000 survivors. External beam radiation and brachytherapy are the front-line treatment modalities, and 60% of patients develop vaginal damage and constriction, i.e., stenosis of the vaginal vault, greatly impeding sexual function. The incidence of vaginal stenosis (VS) following radiotherapy (RT) for anorectal cancer is 80%. VS causes serious quality of life (QoL) and psychological issues, and while standard treatment using self-administered plastic dilators is effective, acceptance and compliance are often insufficient. Based on published patient preferences, we have pursued the design of a soft inflatable dilator for treating radiotherapy-induced vaginal stenosis (VS). The critical component of the novel device is the dilator balloon wall material, which must be compliant yet able to exert therapeutic lateral force levels. We selected a commercially available silicone elastomer and characterized its stress-strain characteristics and hyperelastic properties. These parameters were quantified using uniaxial tensile testing and digital image correlation (DIC). Dilator inflation versus internal pressure was modeled and experimentally validated in order to characterize design parameters, particularly the dilator wall thickness. Our data suggest that an inflatable silicone elastomer-based vaginal dilator warrants further development in the context of a commercially available, well-tolerated, and effective device for the graded, controlled clinical management of radiotherapy-induced VS.

The Next Chapter in Immunotherapy and Radiation Combination Therapy: Cancer-Specific Perspectives.

Immunotherapeutic agents have revolutionized cancer treatment over the past decade. However, most patients fail to respond to immunotherapy alone. A growing body of preclinical studies highlights the potential for synergy between radiation therapy and immunotherapy, but the outcomes of clinical studies have been mixed. This review summarizes the current state of immunotherapy and radiation combination therapy across cancers, highlighting existing challenges and promising areas for future investigation.

Computational and AI-driven 3D structural analysis of human papillomavirus (HPV) oncoproteins E5, E6, and E7 reveal significant divergence of HPV E5 between low-risk and high-risk genotypes.

There are over 220 identified genotypes of Human papillomavirus (HPV), and the HPV genome encodes 3 major oncogenes, E5, E6, and E7. Conservation and divergence in protein sequence and function between low-risk versus high-risk oncogenic HPV genotypes has not been fully characterized. Here, we used modern computational and structural folding algorithms to perform a comparative analysis of HPV E5, E6, and E7 between multiple low risk and high risk genotypes. We first identified significantly greater sequence divergence in E5 between low- and high-risk genotypes compared to E6 and E7. Next, we used AlphaFold to model the structure of papillomavirus proteins and complexes with high confidence, including some with no established consensus structure. We observed that HPV E5, but not E6 or E7, had a dramatically different 3D structure between low-risk and high-risk genotypes. To our knowledge, this is the first comparative analysis of HPV proteins using Alphafold artificial intelligence (AI) system. The marked differences in E5 sequence and structure in high-risk HPVs may contribute in important and underappreciated ways to the development of HPV-associated cancers.

Durvalumab versus placebo with chemoradiotherapy for locally advanced cervical cancer (CALLA): a randomised, double-blind, phase 3 trial.

BACKGROUND: Concurrent chemoradiotherapy has been the standard of care for locally advanced cervical cancer for over 20 years; however, 30-40% of treated patients have recurrence or progression within 5 years. Immune checkpoint inhibition has improved outcomes for patients with PD-L1 positive metastatic or recurrent cervical cancer. We assessed the benefit of adding durvalumab, a PD-L1 antibody, with and following chemoradiotherapy for locally advanced cervical cancer. METHODS: The CALLA randomised, double-blind, phase 3 trial included 105 hospitals across 15 countries. Patients aged at least 18 years with previously untreated locally advanced cervical cancer (adenocarcinoma, squamous, or adenosquamous; International Federation of Gynaecology and Obstetrics [FIGO] 2009 stage IB2-IIB lymph node positive, stage ≥III any lymph node status) and WHO or Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned (1:1) through an interactive web response system using a permuted block size of 4 to receive durvalumab (1500 mg intravenously once every 4 weeks) or placebo with and following chemoradiotherapy, for up to 24 cycles. Chemoradiotherapy included 45 Gy external beam radiotherapy at 5 fractions per week concurrent with intravenous cisplatin (40 mg/m2) or carboplatin (area under the concentration-time curve 2) once weekly for 5 weeks, followed by image-guided brachytherapy (high-dose rate, 27·5-30 Gy or low-dose/pulse-dose rate, 35-40 Gy). Randomisation was stratified by disease stage status (FIGO stage and node status) and geographical region. Chemoradiotherapy quality was continuously reviewed. The primary endpoint was progression-free survival, assessed by the investigator using Response Evaluation Criteria in Solid Tumors, version 1.1, in the intention-to-treat population. Safety was assessed in patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03830866. FINDINGS: Between Feb 15, 2019, and Dec 10, 2020, 770 women were randomly assigned (385 to durvalumab and 385 to placebo; median age 49 years [IQR 41-57]). Median follow-up was 18·5 months (IQR 13·2-21·5) in the durvalumab group and 18·4 months (13·2-23·7) in the placebo group. At data cutoff, median progression-free survival had not been reached (95% CI not reached-not reached) for either group (HR 0·84; 95% CI 0·65-1·08; p=0·17); 12-month progression-free survival was 76·0% (71·3-80·0) with durvalumab and 73·3% (68·4-77·5) with placebo. The most frequently reported grade 3-4 adverse events in both groups were anaemia (76 [20%] of 385 in the durvalumab group vs 56 [15%] of 384 in the placebo group) and decreased white blood cells (39 [10%] vs 49 [13%]). Serious adverse events occurred for 106 (28%) patients who received durvalumab and 89 (23%) patients who received placebo. There were five treatment-related deaths in the durvalumab group (one case each of urinary tract infection, blood loss anaemia, and pulmonary embolism related to chemoradiotherapy only; one case of endocrine disorder related to durvalumab only; and one case of sepsis related to both durvalumab and chemoradiotherapy). There was one treatment-related death in the placebo group (pneumonia related to chemoradiotherapy). INTERPRETATION: Durvalumab concurrent with chemoradiotherapy was well tolerated in participants with locally advanced cervical cancer, however it did not significantly improve progression-free survival in a biomarker unselected, all-comers population. Concurrent durvalumab plus chemoradiotherapy warrants further exploration in patients with high tumoral PD-L1 expression. Rigorous monitoring ensured high chemoradiotherapy compliance with advanced technology and allowed patients to receive optimal care. FUNDING: AstraZeneca.

A practical guide to hybrid interstitial/intracavitary brachytherapy for locally-advanced cervical cancer.

PURPOSE: In select cases of locally advanced cervical cancer, a hybrid brachytherapy (HBT) approach consisting of a combined intracavitary (IC)/insterstitial (IS) implant can yield improved target coverage and/or decreased organ at risk dose compared to IC techniques while limiting invasiveness compared to IS techniques. METHODS AND MATERIALS: The technique involves placement of transvaginal and/or perineal needles in addition to the tandem and ring/ovoids using either a specialized applicator or free-hand placement. Following applicator and needle placement, brachytherapy may then be planned using principles similar to IC or IS techniques. During treatment planning, it can be helpful to obtain both MRI and CT imaging, as plastic MRI-compatible needles do not show up well on MRI. RESULTS: In patients where acceptable target coverage cannot be achieved using IC alone or doses to nearby OAR are too high, HBT should be evaluated. HBT can improve both dose to target and OAR while sparing patients the morbidity of perineal template-based interstitial brachytherapy. Specific scenarios where HBT may be preferred include bulky residual primary tumor especially with poor response to EBRT, extension into the lateral parametrium, vaginal extension of tumor, and an asymmetric target. Use of HBT can typically permit extension of dose coverage by an additional 1-2 cm beyond what can be achieved with an IC alone technique. CONCLUSION: HBT allows for improved therapeutic ratio by improving target volume coverage and/or lowering doses to OARs. Brachytherapists should be trained on the practical aspects of administering HBT to be able to offer a less invasive and impactful treatment option when appropriate.

Forecasting patient-specific dosimetric benefit from daily online adaptive radiotherapy for cervical cancer.

Objective. Adaptive Radiotherapy (ART) is an emerging technique for treating cancer patients which facilitates higher delivery accuracy and has the potential to reduce toxicity. However, ART is also resource-intensive, Requiring extra human and machine time compared to standard treatment methods. In this analysis, we sought to predict the subset of node-negative cervical cancer patients with the greatest benefit from ART, so resources might be properly allocated to the highest-yield patients.Approach. CT images, initial plan data, and on-treatment Cone-Beam CT (CBCT) images for 20 retrospective cervical cancer patients were used to simulate doses from daily non-adaptive and adaptive techniques. We evaluated the coefficient of determination (R2) between dose and volume metrics from initial treatment plans and the dosimetric benefits to theBowelV40Gy,BowelV45Gy,BladderDmean,andRectumDmeanfrom adaptive radiotherapy using reduced 3 mm or 5 mm CTV-to-PTV margins. The LASSO technique was used to identify the most predictive metrics forBowelV40Gy.The three highest performing metrics were used to build multivariate models with leave-one-out validation forBowelV40Gy.Main results. Patients with higher initial bowel doses were correlated with the largest decreases in BowelV40Gyfrom daily adaptation (linear best fit R2= 0.77 for a 3 mm PTV margin and R2= 0.8 for a 5 mm PTV margin). Other metrics had intermediate or no correlation. Selected covariates for the multivariate model were differences in the initialBowelV40GyandBladderDmeanusing standard versus reduced margins and the initial bladder volume. Leave-one-out validation had an R2of 0.66 between predicted and true adaptiveBowelV40Gybenefits for both margins.Significance. The resulting models could be used to prospectively triage cervical cancer patients on or off daily adaptation to optimally manage clinical resources. Additionally, this work presents a critical foundation for predicting benefits from daily adaptation that can be extended to other patient cohorts.

A randomized patient education trial investigating treatment-related distress and satisfaction with the use of an at-home gynecologic brachytherapy educational video.

BACKGROUND: Physician explanation of gynecologic brachytherapy can be overwhelming or induce patient anxiety, and may be time-constrained given clinical limitations. We report the first randomized trial of an educational video intervention in gynecologic brachytherapy on patient-reported outcomes. METHODS: Between February 2020 and January 2022, 80 gynecologic cancer patients prescribed brachytherapy were randomly assigned to either standard informed consent (Arm A) or a supplemental 16 min brachytherapy educational video (https://vimeo.com/403385455/d0716e3cc8) via the internet (Arm B). Primary outcome was treatment-related distress (National Comprehensive Cancer Network (NCCN) distress scale scored 0 (no distress) to 10 (maximum distress)). Secondary outcome was patient satisfaction (summated Likert-scale scored 11-55). Surveys were administered at baseline, after first treatment, and prior to brachytherapy completion. RESULTS: All patients completed the prescribed brachytherapy. In Arm B, 19/40 (48%) patients and 10/40 (25%) patients' family/friends viewed the video. For patients that completed all surveys (Arm A n=29, Arm B n=28), there was no difference between arms in the sociodemographic, clinical, or treatment variables. Distress scores were low at baseline (Arm A median 4, Arm B median 4, p=0.65) and there was no detectable change in distress between arms on surveys 1 and 2 (ß 0.36, p=0.67) or surveys 1 and 3 (ß -1.02, p=0.29) in multivariable analysis. Satisfaction scores were high at baseline (Arm A median 54, Arm B median 54.5, p=0.64) and there was no detectable change in satisfaction between arms on surveys 1 and 2 (ß 0.22, p=0.93) or surveys 1 and 3 (ß 0.63, p=0.85) in multivariable analysis. CONCLUSIONS: Among patients randomized to an educational video tool for gynecologic brachytherapy, approximately 50% of the cohort and 25% of the cohort's family/friends used the video. Overall, patients had low distress scores and high satisfaction scores with no significant differences between the standard and video intervention arms. Further work is needed to understand factors contributing to gynecologic brachytherapy anxiety. TRIAL REGISTRATION NUMBER: NCT04363957.

Automated treatment planning framework for brachytherapy of cervical cancer using 3D dose predictions.

Objective. To lay the foundation for automated knowledge-based brachytherapy treatment planning using 3D dose estimations, we describe an optimization framework to convert brachytherapy dose distributions directly into dwell times (DTs).Approach. A dose rate kerneld(r,θ,φ)was produced by exporting 3D dose for one dwell position from the treatment planning system and normalizing by DT. By translating and rotating this kernel to each dwell position, scaling by DT and summing over all dwell positions, dose was computed (Dcalc). We used a Python-coded COBYLA optimizer to iteratively determine the DTs that minimize the mean squared error betweenDcalcand reference doseDref, computed using voxels withDref80%-120% of prescription. As validation of the optimization, we showed that the optimizer replicates clinical plans whenDref= clinical dose in 40 patients treated with tandem-and-ovoid (T&O) or tandem-and-ring (T&R) and 0-3 needles. Then we demonstrated automated planning in 10 T&O usingDref= dose predicted from a convolutional neural network developed in past work. Validation and automated plans were compared to clinical plans using mean absolute differences (MAD=1N∑n=1Nabsxn-xn') over all voxels (xn= Dose,N= #voxels) and DTs (xn= DT,N= #dwell positions), mean differences (MD) in organD2ccand high-risk CTV D90 over all patients (where positive indicates higher clinical dose), and mean Dice similarity coefficients (DSC) for 100% isodose contours.Main results. Validation plans agreed well with clinical plans (MADdose= 1.1%, MADDT= 4 s or 0.8% of total plan time,D2ccMD = -0.2% to 0.2% and D90 MD = -0.6%, DSC = 0.99). For automated plans, MADdose= 6.5% and MADDT= 10.3 s (2.1%). The slightly higher clinical metrics in automated plans (D2ccMD = -3.8% to 1.3% and D90 MD = -5.1%) were due to higher neural network dose predictions. The overall shape of the automated dose distributions were similar to clinical doses (DSC = 0.91).Significance. Automated planning with 3D dose predictions could provide significant time savings and standardize treatment planning across practitioners, regardless of experience.

Outcomes from a 3-fraction high-dose-rate brachytherapy regimen for patients with cervical cancer.

PURPOSE: To estimate local control, survival, and toxicity associated with a 3-fraction (3F) image-guided brachytherapy (IGBT) regimen compared to longer fraction (LF) for cervical cancer. METHODS: 150 patients treated between 2015-2020 with 3F (24Gy in 3 fractions) or LF (28...30 Gy in 4-5 fractions) were reviewed. The primary outcome was 2-year local failure. We compared overall survival (OS), disease-free survival (DFS), hospitalizations, and toxicity. RESULTS: There were 32 patients in the 3F group and 118 in the LF group, with a median follow up of 22 months. The 3F had worse performance status (p = 0.01) but otherwise similar characteristics. The 2-year local failure rate was 3.6% (95% CI 0%, 10.6%) for 3F, and 7.5% (95% CI 2.4%, 12.6%) for LF. The univariable hazard ratio (HR) for local failure for 3F was 0.43 (0.05, 3.43; p = 0.43). Moreover, 2 of 32 (6.3%) 3F patients experienced Grade ...3 toxicity compared to 7 of 118 (5.9%) LF patients (p = 1.0), with no difference in hospitalization within 2 years (p = 0.66) and no treatment-related deaths. CONCLUSIONS: Local control was excellent, with long term survival and toxicity similar between the groups. These findings support consideration of 3F.

Dosimetric and feasibility evaluation of a CBCT-based daily adaptive radiotherapy protocol for locally advanced cervical cancer.

PURPOSE: Evaluate a cone-beam computed tomography (CBCT)-based daily adaptive platform in cervical cancer for multiple endpoints: (1) physics contouring accuracy of daily CTVs, (2) CTV coverage with adapted plans and reduced PTV margins versus non-adapted plans with standard-of-care (SOC) margins, (3) dosimetric improvements to CTV and organs-at-risk (OARs), and (4) on-couch time. METHODS AND MATERIALS: Using a Varian Ethos™ emulator and KV-CBCT scans, we simulated the doses 15 retrospective cervical cancer patients would have received with/without online adaptation for five fractions. We compared contours and doses from SOC plans (5-15 mm CTV-to-PTV margins) to adapted plans (3 mm margins). Auto-segmented CTVs and OARs were reviewed and edited by trained physicists. Physics-edited targets were evaluated by an oncologist. Time spent reviewing and editing auto-segmented structures was recorded. Metrics from the CTV (D99%), bowel (V45Gy, V40Gy), bladder (D50%), and rectum (D50%) were compared. RESULTS: The physician approved the physics-edited CTVs for 55/75 fractions; 16/75 required reductions, and 4/75 required CTV expansions. CTVs were encapsulated by unadapted, SOC PTVs for 56/75 (72%) fractions-representative of current clinical practice. CTVs were completely covered by adapted 3 mm PTVs for 71/75 (94.6%) fractions. CTV D99% values for adapted plans were comparable to non-adapted SOC plans (average difference of -0.9%), while all OAR metrics improved with adaptation. Specifically, bowel V45Gy and V40Gy decreased on average by 87.6 and 109.4 cc, while bladder and rectum D50% decreased by 37.7% and 35.8%, respectively. The time required for contouring and calculating an adaptive plan for 65/75 fractions was less than 20 min (range: 1-29 min). CONCLUSIONS: Improved dose metrics with daily adaption could translate to reduced toxicity while maintaining tumor control. Training physicists to perform contouring edits could minimize the time physicians are required at adaptive sessions improving clinical efficiency. All emulated adaptive sessions were completed within 30 min however extra time will be required for patient setup, image acquisition, and treatment delivery.

Underutilization of brachytherapy for cervical cancer in the United States.

Brachytherapy is a critical component of the definitive management of cervical cancer and allows for the safe delivery of about half of the total effective radiation dose needed for optimal outcomes. Moreover, the dose distribution of brachytherapy is highly conformal, allowing for a therapeutic index currently unmatched by alternative techniques. However, a modern brachytherapy program requires special equipment, infrastructure, and procedural expertise. Unfortunately, multiple lines of evidence suggest that brachytherapy is currently underutilized in the United States. In this review, we examine the importance of brachytherapy, contemporary recommendations, and avenues for growth.

Examining the Effect of Direct Patient Care for Medical Physicists: A Randomized Prospective Phase III Trial.

PURPOSE: Our purpose was to investigate the effect of physicist-patient consults on patient anxiety and patient satisfaction with a randomized prospective phase III clinical trial. METHODS AND MATERIALS: Sixty-six patients were randomly assigned to the physics direct patient care (PDPC) arm or the control arm of the trial. Patients assigned to the PDPC arm received 2 physicist-patient consults to educate them on the technical aspects of their radiation therapy, while patients assigned to the control arm received the standard of care (ie, standard radiation therapy workflow without any additional physicist-patient consults). Questionnaires were administered to all patients at 4 time points (after enrollment, after the simulation, after the first treatment, and after the last treatment) to assess anxiety and satisfaction. RESULTS: The decrease in anxiety for the PDPC arm, compared with the control arm, was statistically significant at the first treatment (P = .027) time point. The increase in technical satisfaction for the PDPC arm, compared with the control arm, was statistically significant at the simulation (P = .005), first treatment (P < .001), and last treatment (P = .002) time points. The increase in overall satisfaction for the PDPC arm, compared with the control arm, was statistically significant at the first treatment (P = .014) and last treatment (P = .001) time points. CONCLUSIONS: Physicist-patient consults improved the patient experience by decreasing anxiety and increasing satisfaction. Future work is needed to modify current radiation oncology workflows and medical physics responsibilities to allow all patients to benefit from this advancement in patient care.

Incomplete cisplatin regimens in chemoradiation and its effect on outcomes for locally advanced cervical cancer.

OBJECTIVE: To identify factors associated with receipt of incomplete cisplatin during chemoradiation for locally advanced cervical cancer and its impact on outcomes. METHODS: Patients with locally advanced cervical cancer treated with chemoradiation at our institution between November 2015 and August 2020 were retrospectively identified. Patients who received ≤4 cycles were identified as the 'incomplete' cohort and those who received 5-6 cycles as the 'complete' cohort. The primary endpoint of incomplete chemotherapy was evaluated with multivariable logistic regression. Secondary endpoints of locoregional failure, overall survival, and distant failure were evaluated in multivariable Cox and Fine-Gray models. RESULTS: Of 140 patients with locally advanced cervical cancer that underwent chemoradiation, 22 (15.7%) received an incomplete cisplatin regimen (8 with 0 cycles, 14 with 1-4 cycles). The most common reasons for receiving incomplete treatment were comorbidities/infections (41%), unmet laboratory parameters (27%), and cisplatin intolerance (14%). In multivariable models, only poor (2-4) Eastern Cooperative Oncology Group performance status was a significant predictor as these patients were 41 times more likely to receive incomplete chemotherapy (odds ratio (OR), 95% confidence interval (CI) 4.57 to 375.15, p<0.001). Median follow-up time was 20 months (range 4-64). In multivariable models, receipt of incomplete cisplatin was significantly associated with higher recurrence (locoregional failure hazard ratio (HR) 3.02, 95% CI 1.08 to 8.45, p=0.03; distant failure HR 2.71, 95% CI 1.13 to 6.47, p=0.02) and worse survival (overall survival HR 4.91, 95% CI 1.27 to 18.98, p=0.02). CONCLUSION: Incomplete cisplatin regimen was associated with worse oncologic outcomes. Poor performance status was the only factor associated with receiving an incomplete regimen. This notable proportion of patients may be a target for better tolerated novel targeted anticancer agents in order to improve outcomes.