Effect of contrast medium on treatment modalities planned with different photon beam energies: a planning study.

BACKGROUND: Routinely, patient's planning scans are acquired after administration of iodinized contrast media but they will be treated in the absence of that. Similarly, high energy photons have a better penetrating power, while low energy photons will result in tighter dose distribution and negligible neutron contamination. The aim of the study was to investigate a suitable photon beam energy in the presence of intravenous contrast medium. MATERIALS AND METHODS: An indigenously made original-contrast (OC) phantom was mentioned as virtual-contrast (VC) and virtual-without-contrast (VWC) phantom were generated by assigning the Hounsfield Units (HU) to different structures. Intensity-modulated (IMRT) and volumetric-modulated-arc (VMAT) plans were generated as per criteria of the TG-119 protocol. RESULTS: It was observed that the maximum dose to the spinal cord was better with 6 mega-voltage (MV) in IMRT. The coverage of Prostate PTV (PR PTV) was similar with all the photon energies and was comparable with TG-119, except for original-contrast (OC) phantom using the VMAT technique. Homogeneity-index (HI) was comparatively better for VMAT plans. CONCLUSION: The contrast CT images lower the dose to targets. IMRT or VMAT plans, generated on such CT images will be delivered with higher doses than evaluated. However, the overdose remains non-significant.

Impact of acuros XB algorithm in deep-inspiration breath-hold (DIBH) respiratory techniques used for the treatment of left breast cancer.

AIM: To investigate the impact of Acuros XB (AXB) algorithm in the deep-inspiration breath-hold (DIBH) technique used for treatment of left sided breast cancer. BACKGROUND: AXB may estimate better lung toxicities and treatment outcome in DIBH. MATERIALS AND METHODS: Treatment plans were computed using the field-in-field technique for a 6 MV beam in two respiratory phases - free breathing (FB) and DIBH. The AXB-calculations were performed under identical beam setup and the same numbers of monitor units as used for AAA-calculation. RESULTS: Mean Hounsfield units (HU), mass density (g/cc) and relative electron density were -782.1 ±â€¯24.8 and -883.5 ±â€¯24.9; 0.196 ±â€¯0.025 and 0.083 ±â€¯0.032; 0.218 ±â€¯0.025 and 0.117 ±â€¯0.025 for the lung in the FB and DIBH respiratory phase, respectively. For a similar target coverage (p > 0.05) in the DIBH respiratory phase between the AXB and AAA algorithm, there was a slight increase in organ at risk (OAR) dose for AXB in comparison to AAA, except for mean dose to the ipsilateral lung. AAA predicts higher mean dose to the ipsilateral lung and lesser V20Gy for the ipsilateral and common lung in comparison to AXB. The differences in mean dose to the ipsilateral lung were 0.87 ±â€¯2.66 % (p > 0.05) in FB, and 1.01 ± 1.07% (p < 0.05) in DIBH, in V20Gy the differences were 1.76 ±â€¯0.83% and 1.71 ±â€¯0.82% in FB (p < 0.05), 3.34 ± 1.15 % and 3.24 ± 1.17 % in DIBH (p < 0.05), for the ipsilateral and common lung, respectively. CONCLUSION: For a similar target volume coverage, there were important differences between the AXB and AAA algorithm for low-density inhomogeneity medium present in the DIBH respiratory phase for left sided breast cancer patients. DIBH treatment in conjunction with AXB may result in better estimation of lung toxicities and treatment outcome.

Myxofibrosarcoma of Head and Neck Region - A Rare Case Report.

Myxofibrosarcoma (MFS) is a rare subtype of soft tissue sarcoma that usually occurs in the extremities of the body. Its location in the head and neck region is unique. Surgery is the primary treatment for all non-metastatic MFS. It has high rates of local recurrence and metastasis. Like other soft tissue sarcomas, the aim of adjuvant treatment is to decrease the chances of local recurrence or metastasis in MFS. Due to its rarity, there is a lack of data showing the benefit of adjuvant treatment in MFS of the head and neck region. We are presenting a case report and literature review on MFS in the head and neck.

Evaluation of the Treatment Planning and Delivery for Hip Implant Cases on Tomotherapy.

Purpose: The metal present in the implant creates artifacts during the treatment simulation, which impacts the treatment planning and delivery of the prescribed dose to the target and sparing normal tissues. This retrospective study evaluated the uncertainties in the planning and delivery of doses for prosthesis cases with dedicated phantom. Materials and Methods: In this retrospective study, 11 patients with a hip prosthesis having cervix carcinoma were selected. Two treatment plans were generated on treatment planning system (TPS) for each case. Plan_No_Res was without any beam restriction, and Plan_exit_only was the plan with restricted beam entry through the metallic implant. An indigenous phantom was utilized to verify the accuracy of the treatment. In the phantom, some groves were present, which could be filled by implants that mimic the patient's geometries, like left, right and bilateral femur implants. The delivered doses were recorded using optically stimulated luminescence dosimeters (OSLDs), which were placed at different positions in the phantom. The plans were further calculated using megavoltage computed tomography (MVCT) scans acquired during treatment. Results: The patient data showed no significant dose changes between the two planning methods. The treatment time increases from 412.18 ± 86.65 to 427.36 ± 104.80 with P = 0.03 for Plan_No_Res and Plan_exit_only, respectively. The difference between planned and delivered doses of various points across phantom geometries was within ± 9.5% in each case as left, right, and bilateral implant. The variations between OSLDs and MVCT calculated doses were also within ± 10.8%. Conclusion: The study showed the competency of tomotherapy planning for hip prosthesis cases. The phantom measurements demonstrate the errors in dosimetry near the implant material, suggesting the need for precise methods to deal with artifact-related issues.

Primary Oropharyngeal SMARCA4-Deficient Carcinoma: Expanding the Diagnostic Spectrum in Head and Neck Cancer.

With the advent of molecular immunohistochemistry and next generation sequencing, Switch/sucrose non-fermentable (SWI/SNF) chromatin remodeling complex altered tumors have gained recognition recently. SWI/SNF related, matrix associated, actin dependent regulator of chromatin subfamily B member 1 (SMARCB1) and SMARCA4 are the primary SWI/SNF components altered in several recently described undifferentiated malignancies in head and neck region with predilection for paranasal sinuses in SMARCB1-deficient tumors and nasal cavity in SMARCA4-deficient tumors. However, to the best of our knowledge, SMARCA4-deficient tumors of the oropharynx have not been described. We present an unusual case of SMARCA4-deficient carcinoma of the oropharynx (palatine tonsil) which is the first case in the literature, expanding the topographic distribution of SMARCA4-deficient tumors in the head and neck region and emphasizing the importance of BRG1 as an essential immunohistochemical marker for the diagnosis of this distinct entity.

Is it too early to recommend local treatment in oligometastatic non-small cell lung cancer: a plea for equipoise.

Oligometastatic non-small cell lung cancer (OMD NSCLC) has been proposed to bridge the spectrum between non-metastatic and widely metastatic states and is perceived as an opportunity for potential cure if removed. Twelve clinical trials on local treatment have been reported, yet none are conclusive. These trials informed the development of a joint clinical practice guideline by the American & European Societies for Radiation Oncology, which endorses local treatment for OMD NSCLC. However, the heterogeneity between prognostic factors within these trials likely influenced outcomes and can only support guidance at this time. Caution against an uncritical acceptance of the guideline is discussed, as strong recommendations are offered based on expert opinion and inconclusive evidence. The guideline is also examined by a patient's caregiver, who emphasizes that uncertain evidence impedes shared decision making.

Identification of variables and development of a prediction model for DIBH eligibility in left-sided breast cancer radiotherapy: a prospective cohort study with temporal validation.

OBJECTIVE: To identify variables associated with a patients' ability to reproducibly hold their breath for deep-inspiration breath-hold (DIBH) radiotherapy (RT) and to develop a predictive model for DIBH eligibility. METHODS: This prospective, single-institution, IRB-approved observational study included women with left-sided breast cancer treated between January 2023 and March 2024. Patients underwent multiple breath-hold sessions over 2-3 consecutive days. DIBH waveform metrics and clinical factors were recorded and analysed. Logistic mixed modelling was used to predict DIBH eligibility, and a temporal validation cohort was used to assess model performance. RESULTS: In total, 253 patients were included, with 206 in the model development cohort and 47 in the temporal validation cohort. The final logistic mixed model identified increasing average breath-hold duration (OR, 95% CI: 0.308, 0.104-0.910. p = 0.033) and lower amplitude (OR, 95% CI: 0.737, 0.641-0.848. p < 0.001) as significant predictors of DIBH eligibility. Increasing age was associated with higher odds of being ineligible for DIBH (OR, 95% CI: 1.040, 1.001-1.081. p = 0.044). The model demonstrated good discriminative performance in the validation cohort with an AUC of 80.9% (95% CI: 73.0-88.8). CONCLUSION: The identification of variables associated with DIBH eligibility and development of a predictive model has the potential to serve as a decision-support tool. Further external validation is required before its integration into routine clinical practice.

Cardiac markers in left-sided breast cancer patients receiving adjuvant radiotherapy: a prospective study.

OBJECTIVES: To investigate the association between radiotherapy (RT) and cardiac biomarkers in women with left-sided breast cancer. METHODS: This prospective observational study recruited patients with stage I-III left-sided breast cancer without coronary heart disease who required adjuvant RT. High-sensitivity troponin I(hsTnI), N-terminal pro-brain natriuretic peptide(NT-proBNP), and high-sensitivity C-reactive protein(hsCRP) levels were measured pre-RT, immediately after RT, and 3 months post-RT. Cardiac-sparing RT techniques were utilized (Field-in-Field IMRT/VMAT ± voluntary deep inspiration breath-hold). Statistical analyses were performed using non-parametric tests and multivariable quantile regression (QR). RESULTS: One hundred five patients completed the study, with 63 evaluable at three months post-RT. Pre- and post-RT biomarkers showed no significant differences. Median pre-RT and post-RT values were: hsTnI (0.012ng/mL; 0.012ng/mL), hsCRP (3.1 mg/L; 2.8 mg/L), and NT-proBNP (59pg/mL; 45pg/mL). Three months post-RT, hsTnI, hsCRP and NT-proBNP levels also showed no significant differences. Multivariable QR revealed no association between heart Dmean [median(IQR): 2.87 Gy (2.05-3.94)] and post-RT biomarkers. Age and BMI were associated with hsCRP and NT-proBNP, respectively. CONCLUSIONS: hsTnI, NT-proBNP, and hsCRP are not correlated with contemporary low cardiac exposure in left-sided breast cancer patients treated with contemporary RT techniques.

Risk-Adapted Target Delineation for Breast Cancer: Controversies and Considerations.

The advent of computed tomography-based planning coupled with modern tools for target delineation and hypofractionated treatment schedules has increased efficiency and throughput for patients with breast cancer. While the benefit of adjuvant radiation therapy (RT) in reducing locoregional recurrences is established, disentangling local versus regional recurrence risks with modern treatment protocols has become an area of active research to de-escalate treatment. Delineation guidelines for nodal regions either attempt to replicate results of conventional RT techniques by translating bony landmarks to clinical target volumes or use landmarks based on the fact that lymphatic channels run along the vasculature. Because direct comparisons of both approaches are implausible, mapping studies of nodal recurrences have reported on the proportion of nodes included in these delineation guidelines, and larger, bony, landmark-based guidelines appear intuitively appealing for patients with unfavorable risk factors. A pooled analysis of these studies is reported here, along with literature supporting the exclusion of the true chest wall from postmastectomy/breast-conserving surgery clinical target volumes and the selective (versus routine) use of bolus during postmastectomy RT. The risk-adapted approach suggested here accounts for the risk of recurrence as well as toxicity and endorses nuanced target volume delineation rather than a one-size-fits-all approach.

Effectiveness of Head-and-Neck Molecular Imaging Reporting and Data System Criterion in Head-and-Neck Squamous Cell Carcinoma PostConcurrent Chemoradiotherapy.

Purpose: Postconcurrent chemoradiotherapy (CRT) response assessment has been challenging in locally advanced head-and-neck squamous cell carcinoma (LA-HNSCC) due to prevailing postradiation changes. Molecular response methods have been encouraging, although further clarifications and validations were needed. We tested the effectiveness of a proposed semi-quantitative molecular response criterion in these patients. Materials and Methods: Two subspecialty-trained physicians evaluated 18F-fluorodeoxyglucose positron emission tomography/computed tomography of LA-HNSCC patients (n = 83) post 3 months CRT using a five points Head and Neck Molecular Imaging-Reporting and Data System (HAN-MI-RADS) criterion. Where available, histopathology examination with clinical and imaging interpretation was taken as a reference for the disease. A diagnostic accuracy comparison was done with the existing Hopkins score. Further effectiveness was analyzed with disease-free survival (DFI) and overall survival (OS). Results: Metastasis was developed in 11/83 patients at 3 months of evaluation. Of 72 patients, 39, 2, and 31 patients had a complete response, equivocal response, and partial response as per HAN-MI-RADS. Per patient sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for predicting loco-regional disease up to 1 and 2 years was 93.3%, 92.5%, 90.3%, 94.9%, 92.9%, and 84.9%, 91.9%, 90.3%, 87.2%, and 88.6% respectively. One year and two years DFI for each HAN-MI-RADS score showed a statistically significant difference while it was not for OS. The receiver operating characteristic curve analysis showed significantly better outcome predictability of HAN-MI-RADS (area under the curve [AUC] 0.884) than Hopkins (AUC 0.699). Conclusions: A five points HAN-MI-RADS criterion was found promising for response assessment with less equivocal results and statistically significant higher AUC than Hopkins for loco-regional recurrence prediction.

Tri-modality therapy in advanced esophageal carcinoma: long-term results and insights from a developing world, institutional cohort.

OBJECTIVE: To evaluate treatment outcomes in patients from a low-middle income country (LMIC) with esophageal carcinoma who underwent esophagectomy after neoadjuvant chemoradiation (NACRT/S). METHODS: Between 2010 and 2020, 254 patients (median follow-up: 53 months) met our inclusion criteria. Out-of-field nodal regions were determined by reviewing individual radiotherapy plans. Cox regression modelling was performed to analyze overall survival (OS) and recurrence-free survival (RFS), while pathological complete response (pCR) prediction utilized Poisson regression. RESULTS: The median OS was 71.4 months (interquartile range: 19.6-∞), RFS did not reach the median and pCR rate was 46%. On multivariable Cox regression, BMI [0.93 (0.89-0.98); 0.94 (0.89-0.99)] and absence of out-of-field node with extranodal extension (ENE)[0.22 (0.09-0.53); 0.30 (0.12-0.75)] influenced OS and RFS, respectively. Age [1.03 (1.01-1.06)], nodal stage [cN2-3 vs cN0: 2.67 (1.08-6.57)] and adventitial involvement [2.54 (1.36-4.72)] also influenced OS, while involved margins [3.12 (1.24-7.81)] influenced RFS. On multivariable Poisson regression, non-CROSS-chemotherapy regimens [0.65 (0.44-0.95)] and residual primary disease on pre-surgical imaging [0.73 (0.57-0.93)] were significantly associated with pCR. The most frequently involved in-field and out-of-field nodal regions were the periesophageal and perigastric (greater and lesser curvature) regions, respectively. CONCLUSION: NACRT/S is feasible and effective in patients from LMIC. Out-of-field ENE merits further investigation as a prognostic factor since it significantly influenced both OS and RFS. ADVANCES IN KNOWLEDGE: The results of clinical trials are replicable in LMICs. Out-of-field ENE is an independent prognostic factor for OS and RFS.

Dosimetric Influence of Acuros XB Dose-to-Medium and Dose-to-Water Reporting Modes on Carcinoma Cervix Using Intensity-Modulated Radiation Therapy and Volumetric RapidArc Technique.

Aim: We aimed to evaluate the dosimetric influence of Acuros XB (AXB) dose-to-medium (Dm) and dose-to-water (Dw) reporting mode on carcinoma cervix using intensity-modulated radiation therapy (IMRT) and RapidArc (RA) technique. Materials and Methods: A cohort of thirty patients cared for carcinoma cervix was retrospectively selected for the study. Plans were computed using analytical anisotropic algorithm (AAA), AXB-Dm, and AXB-Dw algorithms for dosimetric comparison. A paired t-test and Pitman-Morgan dispersion test were executed to appraise the difference in mean values and the inter-patient variability of the differences. Results: The dose-volume parameters were higher for AXB-Dw in contrast to AAA for IMRT and RA plans, excluding D98%, minimum dose to planning target volume (PTV) and rectum mean dose (RA). There was no systematic trend observed in dose-volume parameters for PTV and organs at risk (OARs) between AXB-Dm and AXB-Dw for IMRT and RA plans. The dose-volume parameters for target were higher for AXB-Dm in comparison to AAA in IMRT and RA plans, except D98% and minimum dose to PTV. Analysis envisaged less inter-patient variability while switching from AAA to AXB-Dm in comparison to those switching from AAA to AXB-Dw. Conclusions: The present study reveals the important difference between AAA, AXB-Dm, and AXB-Dw computations for cervix carcinoma using IMRT and RA techniques. The inter-patient variability and systematic difference in dose-volume parameters computed using AAA, AXB-Dm, and AXB-Dw algorithms present the possible impact on the dose prescription to PTV and their relative constraints to OARs for IMRT and RA techniques. This may help in the decision-making in clinic while switching from AAA to AXB (Dm or Dw) algorithm for cervix carcinoma using IMRT and RA techniques.

Combined Diagnostic Accuracy of Diffusion and Perfusion MR Imaging to Differentiate Radiation-Induced Necrosis from Recurrence in Glioblastoma.

We aimed to use quantitative values derived from perfusion and diffusion-weighted MR imaging (PWI and DWI) to differentiate radiation-induced necrosis (RIN) from tumor recurrence in Glioblastoma (GBM) and investigate the best parameters for improved diagnostic accuracy and clinical decision-making. Methods: A retrospective analysis of follow-up MRI with new enhancing observations was performed in histopathologically confirmed subjects of post-treated GBM, who underwent re-surgical exploration. Quantitative estimation of rCBV (relative cerebral blood volume) from PWI and three methods of apparent diffusion coefficient (ADC) estimation were performed, namely ADC R1 (whole cross-sectional area of tumor), ADC R2 (only solid enhancing lesion), and ADC R3 (central necrosis). ROC curve and logistic regression analysis was completed. A confusion matrix table created using Excel provided the best combination parameters to ameliorate false-positive and false-negative results. Results: Forty-four subjects with a mean age of 46 years (range, 19−70 years) underwent re-surgical exploration with RIN in 28 (67%) and recurrent tumor in 16 (33%) on histopathology. rCBV threshold of >3.4 had the best diagnostic accuracy (AUC = 0.93, 81% sensitivity and 89% specificity). A multiple logistic regression model showed significant contributions from rCBV (p < 0.001) and ADC R3 (p = 0.001). After analysis of confusion matrix ADC R3 > 2032 × 10−6 mm2 achieved 100% specificity with gain in sensitivity (94% vs. 56%). Conclusions: A combination of parameters had better diagnostic performance, and a stepwise combination of rCBV and ADC R3 obviated unnecessary biopsies in 10% (3/28), leading to improved clinical decision-making.

Immunotherapy in advanced non-small-cell lung cancer (NSCLC) after progression on chemotherapy: real-world results from a prospective institutional cohort.

Objective: To analyze the outcomes of patients receiving immunotherapy (IO) with advanced non-driver mutated non-small-cell lung cancer (NSCLC) after progression on systemic treatment. Methods: The overall survival (OS), progression-free survival (PFS) and best response to IO of 64 patients who met our inclusion criteria were analyzed. Results: Median follow-up, OS and PFS were 35.9, 7.1 and 3.2 months, respectively. On uni- and multi-variable analysis, better ECOG PS and fewer extra-thoracic metastases were associated with prolonged OS and PFS. Response to IO was associated with prolonged OS, while thoracic radiotherapy and isolated CNS involvement were associated with prolonged PFS. ECOG PS, thoracic radiotherapy and PDL1 status significantly influenced the likelihood of response to IO. Overall, 30% patients experienced any grade toxicity. Conclusion: Our results are concordant with reported trial outcomes and support the application of IO in Indian patients.

Several clinical trials have demonstrated favorable results with immunotherapy in patients with lung cancer who do not have a mutation in their tumors. However, clinical trials are often designed to provide the best chance for a trial drug/intervention to demonstrate effectiveness. Therefore, they usually include relatively healthier patients compared to what clinicians see in their practice. To demonstrate the efficacy of a drug outside a clinical trial, a real-world analysis is performed, which is reported in this article. We analyzed lung cancer patients treated with immunotherapy at our institution and found comparable efficacy to reported clinical trials. This was important because the trials did not include any patients from our country. We also found that patients with fewer sites of involvement outside the lung and those who received radiotherapy to the lung (either during or before receiving immunotherapy) survived longer without disease progression.

Dosimetric analysis of intensity-modulated radiation therapy and volumetric-modulated arc therapy in comparison with conventional box technique in the treatment of carcinoma cervix: An impact of prosthetic implant.

Introduction: The number of patients for carcinoma cervix with implanted hip prostheses has been increasing worldwide during the past several decades. Technological advancements are useful for delivering higher doses, i.e., dose escalation to the target, but the presence of high-density implanted hip prosthesis creates challenges for the planner. Materials and Methods: A population of 25 patients was selected for the study. Plans were generated using the MONACO treatment planning system keeping the isocenter same. The parameters evaluated for planning target volume (PTV) were D98%, D50%, D2%, Dmax, Dmean, V107%, and V110%. Similarly, the parameters Dmax, Dmean, and D2cc were evaluated for the delineated critical organs. Average monitor units (TMUmean) were also assessed. Results: D98% of PTV was 44.51 (standard deviation [SD]: 0.13) Gy, 44.41 (SD: 0.38) Gy, 44.58 (SD: 0.14) Gy, 44.08 (SD: 0.41) Gy and 44.46 (SD: 0.32) Gy for 4F, intensity-modulated radiation therapy (IMRT), IMRT_WP, volumetric-modulated arc therapy (VMAT), and VMAT_WP techniques, respectively, where WP stands for "without prosthesis". Volume of bowel receiving 45 Gy was 86.82 (SD: 66.38) cm3, 6.97 (SD: 5.77) cm3, 14.11 (SD: 14.29) cm3, 13.31 (SD: 6.57) cm3, and 10.31 (SD: 10.94) cm3 for 4F, IMRT, IMRT_WP, VMAT and VMAT_WP techniques, respectively. Discussion: Radiotherapy is standard care of practice for known cases of cervical malignancies. As per our investigations, VMAT has generated comparable plans in terms of target coverage (D98%) as compared to IMRT and 4F techniques (P = 0.015 and P = 0.002) and with prosthesis also (P = 0.024). The mean dose to the bladder was significantly lesser with IMRT and VMAT. Our results highlight that VMAT has reduced the mean dose to the rectum (P = 0.001) in presence of high-density implant. The mean dose to femoral heads was also reduced when compared with the 4-field technique. Conclusion: VMAT has an edge over other techniques in terms of target coverage and sparing of critical organs in the presence of metallic prosthesis. Information about the geometry and density of prosthesis will be beneficial for treatment planning.

Treatment Delay during Radiotherapy of Cancer Patients due to COVID-19 Pandemic.

PURPOSE: To analyze the impact of treatment delay caused by COVID-19 infection on patients scheduled for radiotherapy treatment. METHODS AND MATERIALS: In this descriptive study, we analyzed all patients who were COVID-19 positive during the scheduled radiotherapy course, those who had an infection while on neoadjuvant treatment period, or during surgery before the start of radiation. The study period was from June 2020 to May 2021. A treatment delay was defined as a delay in starting the radiation treatment, a gap during their scheduled radiation treatment, or treatment discontinuation. All patients who had a treatment delay were followed-up till November 2021. RESULTS: The median follow-up time of the study was 13 months. Ninety-four patients were selected for the study who met the inclusion criteria. Seventy-seven patients had a mild COVID-19 infection, while 17 had a moderate to severe illness. Of the entire cohort, 83 patients had a treatment delay. The median treatment delay (MTD) in days was 18 (6 to 47). Amongst those who had a treatment delay, 66 patients were treated with curative intent, of which 51 patients are on follow-up - 34 patients are disease-free (MTD - 18.5, 10 to 43), seven had either a residual disease or locoregional recurrence (MTD - 22, 10 to 32), seven had distant metastasis (MTD - 18, 15 to 47), and three patients died (MTD - 20, 8 to 27). Of three patients who died, only one died of COVID-19-related causes. CONCLUSIONS: Even though the mortality due to COVID-19 infection among those who underwent radiotherapy was low, a treatment delay might have caused adverse treatment outcomes. Longer follow-up of these patients is required to further establish this. It will remain debatable whether it was worth delaying radiotherapy for mild to moderate COVID-19 infection for a significant time to cause a potential cancer treatment failure.

To Study the Impact of Different Optimization Methods on Intensity-Modulated Radiotherapy and Volumetric-Modulated Arc Therapy Plans for Hip Prosthesis Patients.

Purpose: To study the impact of different optimization methods in dealing with metallic hip implant using intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques. Materials and Methods: A cohort of 16 patients having metallic implants was selected for the study. Three sets of IMRT and VMAT plans were generated. Set 1 IMRT (IM_Base), VMAT (VM_Base) without any restrictions on beam entry and exit, set 2 (IM_ENT and VM_ENT) optimizer restricts the beam entry and set 3 (IM_EXT+ENT), neither entry nor exit doses were allowed toward the metallic implant. Results: There was no significant difference in target (D95%) and organ-at-risk doses between IM_Base and IM_ENT. There were significant (P = 0.002) improvements in planning target volume (PTV) V95% and homogeneity from IM_EXT+ENT to IM_ENT. There was no significant difference in plan quality between VM_Base and VM_ENT. There were significant (P = 0.005) improvements in PTV, V95%, homogeneity from VM_EXT+ENT to VM_ENT. V40Gy, V30Gy for bladder, rectum, bowel, and bowel maximum dose decreases significantly (P < 0.005) in IM_ENT compared to IM_EXT+ENT, but not significant for VMAT plans. Similarly, there was a significant decrease in dose spill outside target (P < 0.05) comparing 40%, 50%, 60%, and 70% dose spills for IM_ENT compared to IM_EXT+ENT, but variations among VMAT plans are insignificant. VMAT plans were always superior to IMRT plans for the same optimization methods. Conclusion: The best approach is to plan hip prosthesis cases with blocked entry of radiation beam for IMRT and VMAT. The VMAT plans had more volumetric coverage, fewer hotspots, and lesser heterogeneity.

Depth of Invasion as an Independent Predictor of Survival in Patients of Stage III Squamous Cell Carcinoma of the Oral Tongue.

OBJECTIVE: Depth of invasion (DOI) has been incorporated in the new AJCC 8th classification. However, even with this new AJCC classification stage III oral tongue squamous cell carcinoma (OTSCC) remains a heterogenous group. The study aims at finding a discreet group within stage III using DOI as a cut-off of 10 mm. METHODS: The institutional database was reviewed from 2012 to 2018 for postoperative stage III OTSCC patients who subsequently received postoperative radiotherapy. Ninety-six patients matched the inclusion criteria. Two groups were created using a DOI cut-off of 10 mm (superficial and deep groups). The groups were analyzed for overall survival (OS) and relapse-free survival (RFS). RESULTS: The baseline and treatment characteristics were comparable between the groups except for the higher number of extensive surgeries, endophytic configuration, pT3 and, DOI in the deep group. For a median follow-up of 40.5 (range: 4-139) months, the median OS and RFS for the superficial group were not reached. The median OS and RFS for the deep group were 101 (range: 73.7-128.3) and 60 (range: 46.6-73.4) months, respectively. The difference was statistically significant for median RFS (P = .008) and trended toward significance for median OS (P = .066) for the superficial group. Multivariate Cox regression analysis showed DOI cut-off as a significant predictor for RFS but not for OS. CONCLUSION: DOI significantly predicts poor RFS. However, showed a trend toward poor OS. This study hints toward a possibility of sub-dividing stage III OTSCC based on DOI cut-off. LEVEL OF EVIDENCE: 3 (Retrospective cohort study) Laryngoscope, 132:1594-1599, 2022.

Role of 68Ga-Prostate-Specific Membrane Antigen PET/CT in Disease Assessment in Glioblastoma Within 48 Hours of Surgery.

Within 48 hours after surgery, disease assessment in glioblastoma is a challenge for both the clinician and the radiologist. Certain technical and logistical issues prevail in this period. Ga-prostate-specific membrane antigen PET/CT is a known molecular imaging marker in prostate cancer. Its role in high-grade gliomas has been recently discussed. We present a case of a 39-year-old man with recurrence glioblastoma of the right frontal lobe and underwent resurgery. After surgery, Ga-prostate-specific membrane antigen PET/CT showed residual disease along the posterior and inferior margin of the postoperative cavity.