Association of adjuvant radiation and survival in human papilloma virus-positive oropharynx squamous cell carcinoma with lymphovascular invasion as the sole adverse pathologic feature.

BACKGROUND: Postoperative radiotherapy radiation therapy (PORT) for early-stage human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) with positive lymphovascular invasion (LVI) has an unclear association with overall survival (OS). METHODS: This retrospective cohort study queried the National Cancer Database for surgically treated, T1-2, N0-1 HPV+ OPSCC from 2010 to 2019. Primary exposures were LVI and PORT, and the main outcome was 5-year OS. Odds ratios and hazard ratios (HR) with 95% confidence intervals (CIs) were generated using multivariable models and Cox proportional hazard models, respectively. RESULTS: Of 2768 patients, average age was 59.3 years, 2207 (79.7%) were male, and 386 (13.9%) had LVI. Of patients with LVI as their sole adverse pathologic feature, 220 (57.0%) received PORT, which was not associated with 5-year OS (HR, 1.13; CI, 0.65-1.19). CONCLUSIONS: Patients with surgically treated, early-stage HPV+ OPSCC and positive LVI as their only pathologic adverse feature may not require PORT.

Primary and adjuvant intensity-modulated radiotherapy in oropharyngeal carcinoma patients from a single institution.

BACKGROUND: To retrospectively access outcome, adverse events and prognostic factors in oropharyngeal carcinoma (OPC) patients treated with intensity-modulated radiotherapy (IMRT). METHODS: Ninety-eight OPC patients were treated between 2000 and 2015. Thirty-three patients received definitive and 65 adjuvant radiotherapy. Seventy-one percent had simultaneous chemotherapy. Patients were systematically followed up (mean 114 months, range 19-197 months). Statistical analysis used Kaplan-Meier method, Cox regression analysis, and log-rank test. Adverse events were classified according to common toxicity criteria version (CTCAE) 4.03. RESULTS: The 1-, 5-, and 10-year overall survival rates in the adjuvant vs. definitive cohort were 90.8% vs. 66.7%, 67.4% vs. 33.1%, and 57.7% vs. 16.5%. Survival in the adjuvant cohort was significantly longer than in the definitive cohort (P < 0.00005). Patients <65 years had a significantly longer survival than older patients. Locoregional tumor control rates after 1-, 5-, and 10 years in the adjuvant vs. definitive cohort were 90.2% vs. 66.7%, 82.2% vs 45.4%, and 72.1% vs. 30.3%. Locoregional tumor control in the adjuvant cohort was significantly longer than in the definite cohort (P < 0.005). Distant metastases were diagnosed in 20.4% of all patients. Most patients had mild CTCAE grade 1 and 2 adverse events and mild late adverse events including xerostomia, dysphagia, and lymphedema. CONCLUSION: Intensity-modulated radiotherapy for OPC is an important part of the treatment algorithm alone and in particular after surgery while the additional benefits of chemotherapy might be age dependent. Despite advanced tumor stages, nearly half of our patients were alive in the long term. The majority of patients had relatively mild chronic adverse events.

Obstructive sleep apnea syndrome: A frequent and difficult-to-detect complication of radiotherapy for oropharyngeal cancers.

This pilot study reveals a higher prevalence of obstructive sleep apnea syndrome (OSAS) in patients treated for oropharyngeal squamous cell carcinoma with radiotherapy compared to the general population. OSAS indicators such as the Epworth Sleepiness Scale seem insufficient in the diagnostic approach to OSAS in this population and systematic screenings should be considered.

Oncological results of salvage treatment in patients with oropharynx carcinoma treated with radiotherapy.

OBJECTIVE: To evaluate the possibilities of salvage after local recurrence in patients with oropharyngeal carcinomas treated with radiotherapy, and to analyse the prognostic factors related to the final control of the disease. METHODS: Retrospective study of 596 patients with oropharyngeal carcinoma treated with radiotherapy during the period 1991-2018. RESULTS: One hundred and eighty-one patients (30.4%) had a local recurrence. Of the patients with a local recurrence, 51 (28.2%) were treated with salvage surgery. Variables that were associated with the patient not receiving salvage surgery were age greater than 75 years, tumour location in the posterior hypopharyngeal wall, an initial tumour extent cT4, and a recurrence-free interval of less than 6 months. Five-year specific survival of patients treated with salvage surgery was 19.1% (95% CI: 7.3%-30.9%). Variables that were related to specific survival were extent of recurrence and status of resection margins. Final tumour control was not achieved in any of the patients with extensive recurrence (rpT3-4, n = 25) or positive resection margins (n = 22). CONCLUSION: Patients with oropharyngeal carcinomas treated with radiotherapy with local tumour recurrence have a limited prognosis. Most patients (71.8%) were not considered candidates for salvage surgery. The 5-year specific survival of patients treated with salvage surgery was 19.1%.

Vision Transformer-Based Multilabel Survival Prediction for Oropharynx Cancer After Radiation Therapy.

PURPOSE: A reliable and comprehensive cancer prognosis model for oropharyngeal cancer (OPC) could better assist in personalizing treatment. In this work, we developed a vision transformer-based (ViT-based) multilabel model with multimodal input to learn complementary information from available pretreatment data and predict multiple associated endpoints for radiation therapy for patients with OPC. METHODS AND MATERIALS: A publicly available data set of 512 patients with OPC was used for both model training and evaluation. Planning computed tomography images, primary gross tumor volume masks, and 16 clinical variables representing patient demographics, diagnosis, and treatment were used as inputs. To extract deep image features with global attention, we used a ViT module. Clinical variables were concatenated with the learned image features and fed into fully connected layers to incorporate cross-modality features. To learn the mapping between the features and correlated survival outcomes, including overall survival, local failure-free survival, regional failure-free survival, and distant failure-free survival, we employed 4 multitask logistic regression layers. The proposed model was optimized by combining the multitask logistic regression negative-log likelihood losses of different prediction targets. RESULTS: We employed the C-index and area under the curve metrics to assess the performance of our model for time-to-event prediction and time-specific binary prediction, respectively. Our proposed model outperformed corresponding single-modality and single-label models on all prediction labels, achieving C-indices of 0.773, 0.765, 0.776, and 0.773 for overall survival, local failure-free survival, regional failure-free survival, and distant failure-free survival, respectively. The area under the curve values ranged between 0.799 and 0.844 for different tasks at different time points. Using the medians of predicted risks as the thresholds to identify high-risk and low-risk patient groups, we performed the log-rank test, the results of which showed significantly larger separations in different event-free survivals. CONCLUSION: We developed the first model capable of predicting multiple labels for OPC simultaneously. Our model demonstrated better prognostic ability for all the prediction targets compared with corresponding single-modality models and single-label models.

Long-term follow-up of osteoradionecrosis of the mandible.

AIM: Investigating the prevalence of mandibular ORN in a single Swedish Oncology Center. METHODS: A total of 450 patients, treated with radiotherapy for squamous cell carcinoma in the oropharynx between 2004 and 2014 were included. Three different techniques of radiotherapy were studied. ORN diagnosis was set when clinical signs according to Marx were observed, or if radiological signs were staged according to Schwartz and Kagan. RESULTS: Using the staging system, 90 patients (20%) were diagnosed with ORN. The mean age of the ORN patients was 56.6 years, the older the patient the lower the risk of developing ORN (p = .01). The risk of developing ORN for patients receiving Intensity Modulated Radiotherapy was lower compared to patients treated with the other techniques in the multivariable analysis. Brachytherapy significantly increases the risk of ORN. The risk of ORN increased by 8% each year after radiation (p = .04). The mean time to the ORN diagnosis was 3.9 years. In the multivariate analysis, the risk of ORN increased by 13% each year after radiation (p = .0013). CONCLUSION: The mean radiation dose was of greater importance for the risk of ORN than the maximum dose. Elderly people with oropharyngeal cancer were less prone to develop ORN.

The development of a decision aid for patients with operable oropharyngeal carcinoma in the Netherlands - A mixed methods study.

OBJECTIVE: The aim of this project is to create an interactive online patient decision aid (PDA) for oropharyngeal cancer (OPSCC) patients, eligible for transoral (robotic) surgery with an ultimate goal to assist both physicians and patients in making treatment choices. MATERIALS AND METHODS: Following the International Patient Decision Aid Standards, a mixed-methods approach was employed. The study involved semi-structured in-depth interviews with patients and physicians, thinking-out-loud sessions, and study-specific questionnaires. Thematic coding and analysis were conducted on verbatim transcriptions of audio-recorded interviews. RESULTS: The PDA drafts were evaluated by twenty OPSCC survivors and twenty multidisciplinary specialists. Significant revisions were made after phase 1 to enhance readability and reduce text, whilst incorporating videos and graphics. Following all phases, both patients and specialists rated the PDA as comprehensible, feasible, and a valuable addition to regular counseling. CONCLUSION: This study showcases the development of a PDA for early stage oropharyngeal cancer patients considering surgery and radiotherapy options. The decision aid emphasizes the disparities in short- and long-term side effects between the two treatments. Patients and physicians found the decision aid to be understandable, user-friendly, and helpful for future patients. The PDA is available on https://beslissamen.nl/.

Outcomes of definitive local therapy with intensity-modulated radiation therapy in elderly patients ≥70 years with HPV-associated oropharyngeal cancer.

The incidence of human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) is increasing among elderly (≥70 years) patients and the optimal treatment approach is not known. In this study, we aimed to determine disease and toxicity outcomes in an elderly HPV-OPSCC population primarily treated with a chemoradiation (CRT) approach. We identified 70 elderly HPV-OPSCC patients who were treated with either surgery, radiotherapy, or CRT between 2011 and 2021. Time-to-event analysis for overall survival (OS), progression-free survival (PFS), and local control (LC) were conducted using the Kaplan-Meier method. Univariate and multivariable cox regression models were used to estimate the hazard ratio associated with covariates. The median follow-up for our cohort was 43.9 months. Of the 70 elderly patients, 55 (78.6%) receive CRT and 15 (22.4%) received RT alone. Two patients underwent TORS resection. Of the 55 patients treated with CRT, the most common systemic agents were weekly carboplatin/taxol (n = 18), cetuximab (n = 17), and weekly cisplatin (n = 11). The 5-year OS, PFS, and LC were 57%, 52%, and 91%, respectively. On univariate analysis, Eastern Cooperative Oncology Group performance status and Charlson Comorbidity Index (CCI) were significant predictors of OS, while on multivariate analysis only CCI was a significant predictor of OS (p = 0.006). The rate of late peg tube dependency, osteoradionecrosis, and aspiration was 10%, 4%, and 4%, respectively. Definitive local therapy in elderly HPV-OPSCC patients is associated with excellent LC and a low rate of late toxicities. Prospective studies are needed to further stratify subgroups of elderly patients who may benefit from aggressive definitive local therapy.

Impact of mandated drug monitoring on opioid use during highly conformal radiotherapy for oropharynx cancer.

BACKGROUND: Prescription drug monitoring programs (PDMPs) have proliferated due to increasing opioid-related deaths. We evaluated acute opioid use changes for 64 patients treated with highly conformal radiotherapy (RT) following a state-mandated PDMP. METHODS: Patients receiving proton therapy (PT) (n=40), intensity-modulated RT (IMRT) (n=14), or both (n=10) were divided into preintervention (n=26) and postintervention cohorts (n=38); records were reviewed retrospectively under an institutional review board (IRB)-approved tracking protocol. Dosages prescribed during acute therapy (during RT-3 months post-RT) and patient-reported pain (Defense and Veterans Pain Rating Scale) were endpoints. Dosages were treated as responses in Chi-square tests (three-level ordinal response). RESULTS: Overall, 72% (n=46) received opioids; of which 22% (n=10) of all patients and 10% (n=2) of opioid-naive patients continued analgesic management 3 months post-RT. Median total doses were 975 and 1,025 morphine milligram equivalents (MME) in pre- and postintervention groups, with no significant differences in MME prescribed (P=0.8) or uncontrolled pain (P=0.3). Statistically significant factors were tonsil primaries (P<0.01) and alcohol use (P=0.02). Uncontrolled pain episodes during and post-RT did not vary per cohort (P=0.19). CONCLUSIONS: PDMP use was not associated with management changes in patient-reported acute pain during RT (IMRT or PT). Following highly conformal RT, few patients remained on narcotics 3 months post-RT.

NTCP modelling of xerostomia after radiotherapy for oropharyngeal cancer using the PRO-CTCAE and CTCAE scoring systems at different time-points post-RT.

PURPOSE: This study aims at determining the parameter values of three normal tissue complication probability (NTCP) models for the contralateral parotid gland, contralateral submandibular gland (SMG) and contralateral salivary glands regarding the endpoint of xerostomia 6-24 months after radiotherapy for oropharynx cancer. METHODS: The treatment and outcome data of 231 patients with favorable risk, HPV-associated oropharyngeal squamous cell carcinoma are analyzed. 60 Gy intensity modulated radiotherapy was delivered to all the patients. The presence and severity of xerostomia was recorded (pre- and post- radiotherapy) by the PRO-CTCAE and the CTCAE scoring systems. In both scoring systems, patients with a change in symptom severity (from baseline) of ≥ 2 were considered responders. RESULTS: Xerostomia was observed in 61.3 %, 39.2 %, 28.6 % and 27.0 % of the patients based on the PRO-CTCAE scoring system at 6-, 12-, 18- and 24-months post-RT, respectively. The AUCs of the contralateral salivary glands ranged between 0.58-0.64 in the LKB model with the gEUD ranging between 20.3 Gy and 24.7 Gy. CONCLUSIONS: Based on the PRO-CTCAE scores, mean dose < 22 Gy, V50 < 10 % for the contralateral salivary glands and mean dose < 18 Gy, V45 < 10 % for the contralateral parotid were found to significantly reduce by a factor of 2-3 the risk for radiation induced xerostomia that is observed at 6-24 months post-RT, respectively. Also, gEUD < 22 Gy to the contralateral salivary glands and < 18 Gy to the contralateral parotid was found to significantly reduce the risk for radiation induced xerostomia that is observed at 6-24 months post-RT by 2.0-2.3 times.

Conventional Therapies of Oral Cancers: Highlights on Chemotherapeutic Agents and Radiotherapy, Their Adverse Effects, and the Cost Burden of Conventional Therapies.

Oral cancer (OC) is increasing worldwide, and it is mostly present to clinic in the late-stage of disease. Cancer of the lips, tongue, hard palate, upper and lower gingiva, buccal mucosa, and retromolar trigone are all included in the category of oral cavity cancer. Disease symptomatology and pathological grading decides the course of treatment. Several treatment modalities either alone in combinations may be utilized for oral squamous cell carcinoma (OSCC), including surgery, radiotherapy (external beam radiotherapy/brachytherapy), and adjuvant systemic therapy (chemotherapy or immunotherapy). Cancer patients also face a greater risk of oral side effects from chemotherapy, such as slowed tissue healing, bone, and salivary gland damage and disintegration, and disruption of the normal bacterial balance in the mouth. Consequently, the economic burden of the salivary gland, oral cavity, and oropharyngeal cancers must be also known for budget allocation, designing different programs and management strategies targeting oral cancers by any healthcare institutes. This article provides a summary of the most recent research that supports the use of chemotherapy for patients with advanced illness both alone and in conjunction with radiation including its adverse events and cost burden for oral cancers.

The application of 3D-printed oral stents in intensity-modulated radiotherapy for oropharyngeal cancer and their dosimetric effect on organs at risk.

BACKGROUND: This study investigates the accuracy of 3D-printed dental stents in intensity-modulated radiotherapy (IMRT) for oropharyngeal cancer (OPC) and their dosimetric effects on normal tissues. METHODS: We selected 60 patients with OPC who underwent IMRT in the Department of Oncology, Special Medical Center of Army Medical University. These patients were randomly assigned into 3D-printed oral stent, simple glass bottle, and nonstent groups (20 patients/group). The positioning error was analyzed with the onboard imaging system once a week after 5 fractions of IMRT. The conformity index (CI), homogeneity index (HI), radiation dose of organs at risk (OARs), and oral mucosal reaction were compared among the three groups. RESULTS: No significant difference was observed in the conformity and uniformity of the target dose and the dose received by the spinal cord, larynx, and bilateral parotid glands among the three groups (P > 0.05). Meanwhile, the dose received by the upper cheek, hard palate, and soft palate of patients was significantly lower in the 3D-printed oral stent group than in the nonstent group (P < 0.05) but insignificantly different between the 3D-printed oral stent and simple glass bottle groups (P > 0.05). When compared with the nonstent group, the simple glass bottle group showed a markedly lower dose received by the upper cheek (P < 0.05) and an insignificantly different dose received by the hard palate and soft palate (P > 0.05). According to Common Terminology Criteria for Adverse Events v.5.0, the adverse response rate of the hard palate mucosa was lower in the 3D-printed oral stent group than in the simple glass bottle and nonstent groups (P < 0.05). CONCLUSIONS: For OPC patients undergoing IMRT, the application of 3D-printed oral stents can significantly reduce the exposure dose of the upper cheek and hard palate and decrease the occurrence of adverse events such as oral mucositis although it cannot affect the positioning error.

Homologous platelet gel on radiation-induced dermatitis in a patient receiving head and neck radiotherapy plus cetuximab: A case report.

INTRODUCTION: Acute radiodermatitis is a significant complication of cancer radiotherapy, and platelet-based therapies are emerging as potential new treatments. MAIN SYMPTOMS AND IMPORTANT CLINICAL FINDINGS: In this report, we present the case of a patient with head and neck cancer undergoing radiotherapy combined with the monoclonal antibody cetuximab. After 4 weeks of this treatment, the patient developed cutaneous radiation dermatitis. Despite receiving standard treatment with corticosteroids and emollient cream, the lesion did not improve. MAIN DIAGNOSIS: cutaneous radiation dermatitis on head and neck cancer patient. THERAPEUTIC INTERVENTIONS: Topical application of platelet gel was initiated on the wound. From the second week of radiotherapy to the 4th week, homologous platelet-rich plasma was applied on the dermatitis using a bandage, 4 times a day. OUTCOMES: The topical treatment with homologous platelet gel resulted in complete healing of the radiodermatitis, including restoration of the epidermis, reepithelialization, and reduction in associated pain. CONCLUSION: homologous platelet gel might be an alternative to standard treatment of radiation dermatitis.

Importance of the Number and Location of Lymph Node Metastasis in Oropharyngeal Cancer.

BACKGROUND/AIM: The 8th edition of the American Joint Committee on Cancer staging system classifies oropharyngeal cancer (OPC) by the expression of p16. The discrepancy observed in this system between pathological and clinical N-stages in p16-positive OPC has provoked controversy. Therefore, this study investigated prognostic factors not included in the new staging system for p16-positive OPC patients. PATIENTS AND METHODS: Patients with non-metastatic OPC receiving radiotherapy were reviewed. Clinical lymph node statuses were reassessed based on contrast-enhanced computed tomography and fluorodeoxyglucose positron emission tomography. Overall survival (OS) and cause-specific survival (CSS) were analyzed using multivariate analyses to adjust baseline imbalances. RESULTS: In total, 166 OPC patients were reviewed. Among them, 81 patients with p16-positive were analyzed. Three or more lymph node metastases (LNM) were observed in 21 p16-positive OPCs. Retropharyngeal lymph node metastasis (Rp) was found in 12. Three-year OS, CSS, and progression-free survival rates in p16-positive patients were 76, 88, and 81%, respectively. In multivariate analyses of p16-positive OPC, LNM ≥3 was a prognostic factor of OS (hazard ratio=9.30, p<0.001) and CSS (hazard ratio=17.80, p=0.005). Rp was associated with poor CSS (hazard ratio=8.73, p=0.03). In N0-1 p16-positive patients, LNM ≥3 trended to be associated with poor OS (hazard ratio=3.93, p=0.06). CSS in patients with Rp was unfavorable (hazard ratio=70.16, p=0.05). CONCLUSION: LNM ≥3 and Rp may be predictive of OS and CCS in p16-positive OPC. These are also possibly used to subcategorize p16-positive cN0-1 OPC. Further validation of lymph node staging is needed to refine the clinical staging system.

Survival and Swallowing Function after Primary Radiotherapy versus Transoral Robotic Surgery for Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma.

INTRODUCTION: The aim of this study was to investigate the impact of primary transoral robotic surgery (TORS) versus radiotherapy (RT) on progression-free survival (PFS), overall survival (OS), and 1-year swallowing function for patients with early-stage HPV-associated oropharyngeal squamous cell carcinoma (OPSCC). METHODS: Patients with stage I-II (AJCC 8th Ed.) HPV-associated OPSCC treated with TORS followed by risk-adapted adjuvant therapy or (chemo)radiotherapy between 2014 and 2019 were identified. PFS, OS, and swallowing outcomes including gastrostomy tube (GT) use/dependence, and Functional Oral Intake Scale (FOIS) change over 1 year were compared. RESULTS: One hundred sixty-seven patients were analyzed: 116 treated with TORS with or without adjuvant RT and 51 treated with RT (50 chemoRT). The RT group had more advanced tumor/nodal stage, higher comorbidity, and higher rates of concurrent chemotherapy. There were no differences in 3-year PFS (88% TORS vs. 75% RT) or OS (90% vs. 81%) between groups, which persisted after adjusting for stage, age, and comorbidity. GT use/dependence rates were higher in the RT group. Mean (SD) FOIS scores in the TORS group were 6.9 (0.4) at baseline and 6.4 (1.0) at 1 year, compared with 6.7 (0.6) and 5.6 (1.7) for the RT group. Only clinical nodal stage was found to be significantly associated with FOIS change from baseline to 1 year. CONCLUSION: There were no differences in PFS or OS between patients treated with primary TORS or RT for early-stage HPV-associated OPSCC. Clinical N2 status is associated with FOIS change at 1 year and may be the major factor affecting long-term swallowing function, irrespective of primary treatment modality.

A comparison of loco-regional relapse pattern in HPV positive vs negative oropharyngeal cancers following radiotherapy; relation to pretreatment FDG-PET and radiotherapy target volumes.

BACKGROUND: Previous studies have shown that a large proportion of relapses in head-and neck squamous cell carcinoma (HNSCC) following radiotherapy (RT) occur in the pretreatment FDG-PET avid volume (GTV-PET). The aim of the current work was to see if this was valid also in an oropharynx squamous cell carcinoma (OPSCC) only population, and to compare the loco-regional relapse pattern between HPV positive and HPV negative patients. MATERIAL AND METHODS: Among 633 OPSCC patients treated between 2009 and 2017, 46 patients with known HPV (p16) status and isolated loco-regional relapse were included. Oncologists contoured relapse volumes (RV) on relapse scans (PET/CT, CT or MR), which were thereafter deformed to match the anatomy of the planning CTs. The point of origin (center of volume) of the deformed RVs were determined and analyzed in relation to the RT target volumes (GTV-PET, GTV and CTVs). The relapse pattern was compared between HPV positive and HPV negative patients using Fischer's exact test. RESULTS: Sixty RVs were contoured in the 46 patients. 55% (95% CI 44-67%) of relapses originated in GTV-PET, while the other RT volumes harbored 12% (5-20%) (GTV), 18% (9-28%) (high risk CTV) and 5% (0-11%) (low risk CTV) of relapses. Six relapses were found outside the RT target volumes. No significant difference in relapse pattern between HPV positive and HPV negative patients was found (p = .95). CONCLUSION: There were no signs of difference in loco-regional relapse pattern between HPV positive and HPV negative patients. In agreement with previous findings, GTV-PET was the most frequent RT target volume of relapse.

Proton therapy and oral mucositis in oral & oropharyngeal cancers: outcomes, dosimetric and NTCP benefit.

INTRODUCTION: Radiation-induced oral mucositis (RIOM), is a common, debilitating, acute side effect of radiotherapy for oral cavity (OC) and oropharyngeal (OPx) cancers; technical innovations for reducing it are seldom discussed. Intensity-modulated-proton-therapy (IMPT) has been reported extensively for treating OPx cancers, and less frequently for OC cancers. We aim to quantify the reduction in the likelihood of RIOM in treating these 2 subsites with IMPT compared to Helical Tomotherapy. MATERIAL AND METHODS: We report acute toxicities and early outcomes of 22 consecutive patients with OC and OPx cancers treated with IMPT, and compare the dosimetry and normal tissue complication probability (NTCP) of ≥ grade 3 mucositis for IMPT and HT. RESULTS: Twenty two patients, 77% males, 41% elderly and 73% OC subsite, were reviewed. With comparable target coverage, IMPT significantly reduced the mean dose and D32, D39, D45, and D50, for both the oral mucosa (OM) and spared oral mucosa (sOM). With IMPT, there was a 7% absolute and 16.5% relative reduction in NTCP for grade 3 mucositis for OM, compared to HT. IMPT further reduced NTCP for sOM, and the benefit was maintained in OC, OPx subsites and elderly subgroup. Acute toxicities, grade III dermatitis and mucositis, were noted in 50% and 45.5% patients, respectively, while 22.7% patients had grade 3 dysphagia. Compared with published data, the hospital admission rate, median weight loss, feeding tube insertion, unplanned treatment gaps were lower with IMPT. At a median follow-up of 15 months, 81.8% were alive; 72.7%, alive without disease and 9%, alive with disease. CONCLUSION: The dosimetric benefit of IMPT translates into NTCP reduction for grade 3 mucositis compared to Helical Tomotherapy for OPx and OC cancers and encourages the use of IMPT in their management.

Evaluation treatment planning system for oropharyngeal cancer patient using machine learning.

Oropharyngeal cancer (OPC) comprises a group of various malignant tumours that grow in the throat, larynx, mouth, sinuses, and nose. THE RESEARCH AIMS: to investigate the performance of the OPC VMAT model by comparison to clinical plans in terms of dosimetric parameters and normal tissue complication probabilities. PURPOSE: Tune the model which at least matches the performance of clinical created photon treatment plans and analyse and find the most appropriate strategic plan scheme for OPC. METHODS AND MATERIALS: The machine learning (ML) plans are compared to the reference plans (clinical plans) based on dose constraints and target coverage. VMAT oropharynx ML model of Raystation development 11B version (non-clinical) was used. A model was trained by using different modalities. A different strategy of machine learning and clinical plans was performed for five patients. The dose Prescribed for OPC is 70 Gy, 2 Gy per fraction (2Gy/Fx). The PTV was derived for the primary tumour and secondary tumour, PTV+7000 cGy and PTV_5425 cGy volumetric modulated arc therapy (VMAT) were used with beams performing a full 360° rotation around the single isocenter. RESULTS: Organs at risk were observed that the volume of L-Eye in clinical plan (AF) for the case1 treatment planning could be successfully used ensuring efficiency and lower than MLVMAT and MLVMAT-org plans were 372 cGy, 697 cGy and 667 cGy respectively, while showed case2, case3, case4 and case5 are better to protect the critical organs in ML plan compare with a clinical plan. DHI for the PTV-7000 and PTV-5425 is between 1 and 1.34, While DCI for PTV-7000 and PTV-5425 is between 0.98 and 1.