Comparative analysis of simultaneous integrated boost and sequential boost radiotherapy in node-positive cervical cancer: dosimetric and radiobiological considerations.

For locally advanced cervical cancer, the standard therapeutic approach involves concomitant chemoradiation therapy, supplemented by a brachytherapy boost. Moreover, an external beam radiotherapy (RT) boost should be considered for treating gross lymph node (LN) volumes. Two boost approaches exist with Volumetric Intensity Modulated Arc Therapy (VMAT): Sequential (SEQ) and Simultaneous Integrated Boost (SIB). This study undertakes a comprehensive dosimetric and radiobiological comparison between these two boost strategies. The study encompassed ten patients who underwent RT for cervical cancer with node-positive disease. Two sets of treatment plans were generated for each patient: SIB-VMAT and SEQ-VMAT. Dosimetric as well as radiobiological parameters including tumour control probability (TCP) and normal tissue complication probability (NTCP) were compared. Both techniques were analyzed for two different levels of LN involvement - only pelvic LNs and pelvic with para-aortic LNs. Statistical analysis was performed using SPSS software version 25.0. SIB-VMAT exhibited superior target coverage, yielding improved doses to the planning target volume (PTV) and gross tumour volume (GTV). Notably, SIB-VMAT plans displayed markedly superior dose conformity. While SEQ-VMAT displayed favorable organ sparing for femoral heads, SIB-VMAT appeared as the more efficient approach for mitigating bladder and bowel doses. TCP was significantly higher with SIB-VMAT, suggesting a higher likelihood of successful tumour control. Conversely, no statistically significant difference in NTCP was observed between the two techniques. This study's findings underscore the advantages of SIB-VMAT over SEQ-VMAT in terms of improved target coverage, dose conformity, and tumour control probability. In particular, SIB-VMAT demonstrated potential benefits for cases involving para-aortic nodes. It is concluded that SIB-VMAT should be the preferred approach in all cases of locally advanced cervical cancer.

Evaluation of survival outcome and prognostic factors for oral cavity cancer treated with volumetric arc therapy.

PURPOSE: This study aimed to evaluate the survival outcomes and identify prognostic factors for patients with oral cavity cancer (OCC) who underwent adjuvant treatment with volumetric arc therapy (VMAT) using simultaneous integrated boost (SIB). METHODS: Data was collected for post-operated patients of carcinoma of oral cavity who received adjuvant VMAT with SIB between June 2018 and December 2022. The data was entered and analyzed using SPSS software version 20.0. Survival rates were estimated using Kaplan Meier method. To determine survival difference between the groups, log rank test was used. Multivariate analyses were performed with Cox proportional hazard model and p value < 0.05 was considered as significant. RESULTS: A total of 178 patients were included in the study. The median follow-up period was 26 months (range 3-56 months). The 3-year OS, DFS, and LRC rates were 78% (95% CI 77-79%), 76% (95% CI 74-77%), and 81% (95% CI 80-82%), respectively. Univariate analysis identified age ≥ 50 years, lymph node involvement, extracapsular extension (ECE), and N2-N3 disease as significant adverse prognostic factors for OS, DFS, and LRC. Multivariate analysis confirmed age ≥ 50 years and nodal involvement as independent predictors of worse OS, DFS, and LRC. Additionally, ECE independently affected OS and DFS. CONCLUSION: Adjuvant treatment with VMAT using SIBin patients with OCC is effective. Age and nodal involvement had significant impact on LRC, DFSand OS while ECE on DFSand OS.

Survival outcome and prognostic factors post inadvertent hysterectomy in carcinoma cervix treated with salvage chemo-radiation.

INTRODUCTION: The standard of care for treating early invasive cervical cancer is radical hysterectomy or radiation alone while chemo-radiation is a definitive treatment for advanced disease. Occasionally, a simple hysterectomy is performed in the cancer cervix and these patients merit adjuvant treatment in view of the high chances of loco-regional recurrences. The aim of the study was to analyze the survival outcome of these patients treated with salvage chemo-radiotherapy and also to determine the prognostic factors affecting survival. MATERIALS AND METHODS: The medical records of all patients with cervical cancer post simple hysterectomy outside and who received salvage treatment in our department between 2014 and 2020 were retrieved. The data regarding clinical, treatment details and survival were analyzed. RESULTS: A total of 198 patients were included. Median follow-up duration was 45.5 months. Gross disease and lymphadenopathy were seen in 60% and 28% patients, respectively. The 5-year progression-free survival(PFS) and overall survival(OS) was 75% and 76%, respectively. Concurrent chemotherapy alone or in combination with induction chemotherapy using three-drug regimens showed better survival compared to those treated by radiation alone. On multivariate analysis, factors found to be adversely affecting OS and PFS were lymph node (LN) size of more than 2 cm, non-squamous histology, overall treatment time(OTT) of more than 12 weeks and use of non three-drug chemotherapy regimen. CONCLUSION: Subtotal hysterectomy results in a higher incidence of local recurrence of disease. Factors that impair the outcome in this sub-group of patients are gross lymphadenopathy, non-squamous histology and prolong OTT.

Hiccups: An atypical side effect experienced during chemo-radiotherapy in carcinoma nasopharynx.

ABSTRACT: Nasopharyngeal carcinoma is an uncommon cancer but has a distinct racial and geographic distribution. Patient presents with constellation of signs and symptoms due to its vicinity to critical structures and are best treated by conformal concurrent chemo-radiotherapy. We present a case of 45-year-old male diagnosed with carcinoma nasopharynx, referred to us for radiotherapy after three cycles of neoadjuvant chemotherapy. As per the prevailing standard of care, patient was planned for radiotherapy by volumetric arc technique with concurrent cisplatin. Initial days of treatment were uneventful. After fourth week of treatment, patient developed persistent hiccup which was not relieved on conservative medications. Plan was re-evaluated and it revealed maximum dose of 54.6 Gy to the brainstem. Radiotherapy induced edema that could have stimulated vagus nerve leading to hiccups was suspected. Patient was started on injectable steroid and chlorpromazine. There was prompt recovery from the symptom within five days of conservative treatment.

Clinico-epidemiological profile and treatment outcome in adolescents and young patients of rectal cancer attending a tertiary cancer center.

INTRODUCTION: The incidence of colorectal cancer in young adults is on an increasing trend. It is observed that this subgroup of patients has an aggressive disease and carries a poorer prognosis compared to its older counterpart. This study aimed to analyze the incidence, treatment outcome, and prognostic factors in adolescents and young adults with rectal cancer attending a tertiary cancer center in North India. MATERIALS AND METHODS: We retrospectively analyzed 50 patients of histologically proven rectal cancer, aged up to 30 years, treated at our center between 2015 and 2019. The clinical, demographic, and pathological parameters were studied in all these patients. Kaplan-Meier survival analysis was used to find out survival. Univariate analysis was performed to assess prognostic factors. RESULTS: The incidence was 26.4% at our center with a median age of 28 years. Bleeding per rectum was the commonest complaint. Most of them had signet ring cell histology (26%). The median overall survival was 16 months. Survival was significantly better in patients having bleeding per rectum as an initial complaint (P = 0.009), absence of lymphovascular invasion (LVI) (P = 0.005), and perineural invasion (PNI) (P = 0.002), who received complete planned treatment compared to patients who could not receive either of the modality (P < 0.001). Patients who did not receive radiotherapy (RT) had the worst outcomes compared to those who received RT in any form. RT dose of 50.4 Gy was found to be superior as compared to other schedules. There was no significant difference in survival with gender, tumor stage, grade, type of surgery, or chemotherapy regimen. CONCLUSION: The majority of patients presented in an advanced stage. Therefore, bleeding per rectum should be properly and timely investigated in all these young patients. Early detection and complete treatment are paramount to improving the outcome.

Evaluation of survival outcomes and prognostic factors of carcinoma anal canal at a tertiary cancer center.

CONTEXT: Concurrent chemoradiotherapy is considered a standard of care for patients with carcinoma anal canal. Being an unusual malignancy, there is limited Indian data regarding survival outcomes and prognostic factors. AIM: To evaluate survival outcomes and associated prognostic factors in patients with carcinoma anal canal treated with radical intent. METHODS AND MATERIAL: Patients with squamous cell carcinoma of the anal canal, treated with radical intent between 2015 and 2019 were included in the study. Data regarding the baseline characteristics of the patients and treatment outcomes were collected and analyzed. Survival rates were estimated using Kaplan-Meier method. To determine survival difference between the groups, log-rank test was used. Multivariate analyses were performed with Cox proportional hazard models and P value < 0.05 was considered significant. RESULTS: Forty-two patients were identified after applying suitable eligibility criteria. The median age was 55 years (range: 26-80 years).The median follow-up duration was 23.5 months (range: 1.9-51.9 months). The 3-year overall survival (OS), disease-free survival (DFS), and locoregional (LRC) were 78.5%, 53.1%, and 66.4%, respectively. On multivariate analysis, inferior DFS was significantly affected by lack of concurrent chemotherapy (CT) (hazard ratio [HR], 11.50; 95% confidence interval [CI], 1.92-68.78; P = 0.007) and radiotherapy (RT) dose of 45 Gy or less (HR, 35.96; 95% CI, 6.32-204.56; P = 0.000). CONCLUSION: For patients of carcinoma anal canal, concurrent CT and RT dose are independent prognostic factors influencing DFS.

Development and validation of an indigenous, radiobiological model-based tumor control probability and normal tissue complication probability estimation software for routine plan evaluation in clinics.

Purpose: Development and validation of a simple and convenient computational program in MATLAB environment for estimating the tumor control probability (TCP) and the normal tissue complication probability (NTCP), as a decision support system for routine plan evaluation. Materials and Methods: We developed an in-house software using MATLAB 2016b (Mathworks) for estimating TCP and NTCP named as RBMODELV1. The program contains Niemierko free equivalent uniform dose (EUD) program code provided in authors research article. For rest of radiobiological (RB) models in the software separate coding is performed. The program accepts cumulative dose-volume histogram file in (.txt) format containing two columns dose and volume. A set of two RB parameters were prepared, default and user-dependent in excel sheet named as RBDATA. We cross-validated results of RBMODELV1 software with BioSuite software for Poisson's TCP model and Lyman-Kutcher-Burman (LKB) model. A set of total 20 patient's data of head and neck site took under study and respective TCP and NTCP calculated by all the RB models and compared. Results: This is the first study in which we tried to establish correlation between the mean doses (EUD) received by parallel structure (parotid gland and oral cavity) and predicted percentage of NTCP values. It is found that mean dose in the range of 35-40 Gy for parotid gland can result in more than 50% NTCP predicted by all four RB models. Similarly oral cavity receiving mean dose in the range of 53-58 Gy can results in more than 35% NTCP predicted by all the four models. There is <3% variation observed between TCP calculated by BioSuite and RBMODELV1 software and <4% variation observed between predicted NTCP for parotid gland and oral cavity OAR from LKB model by both the software. Conclusion: We created simple software RBMODELV1 which can be used as a research tool as well as decision support system.

Feasibility of using polytetrafluoroethylene flexible implant tube for interstitial brachytherapy patients.

PURPOSE: To design the different Polytetrafluoroethylene (PTFE) based flexible implant tubes using an in-house developed device and to evaluate them for High dose rate (HDR) interstitial brachytherapy using computer tomography images. METHODS AND MATERIALS: PTFE hollow tube having a 2 mm (6 French) outer diameter (OD) and 1.4 mm inner diameter (ID) was used to design in-house single and/or double leader flexible catheters for interstitial brachytherapy implant. An in-house Plastic Wire Drawing Plate (PWDP) machine was developed. Customization of PTFE hollow flexible implant tube (FIT) was done through PWDP. Different percentages of BaSO4 (5%, 10%, & 15%) were added to Nylon 6 to make radiopaque button. Various quality assurance tests were performed with the PTFE tubes implanted in the brinjal (phantom) before using them on the patients. That is, coupling of brachytherapy machine transfer tube with flexible PTFE Tubes, CT scan artifacts, tube kinks, breast template, and free-hand compatibility. RESULTS: With the help of the PWDP machine, plastic wires of different lengths were made for single leader and double leader tubes. The different plastic leader ends of 1 cm to 50 cm lengths having 1 mm diameter were created. The radiopaque button of Nylon 6 in circular shape having 1 cm diameter and 0.5 cm thick was created. Developed radiopaque buttons were visible on CT scan images as well as on radiograph images. CONCLUSIONS: PTFE tubes of the desired length can be made depending upon the size of the brachytherapy implant and are inexpensive than commercially available flexible implant tubes.

Plan evaluation indices: A journey of evolution.

AIM: A systemic review and analysis of evolution journey of indices, such as conformity index (CI), homogeneity index (HI) and gradient index (GI), described in the literature. BACKGROUND: Modern radiotherapy techniques like VMAT, SRS and SBRT produce highly conformal plans and provide better critical structure and normal tissue sparing. These treatment techniques can generate a number of competitive plans for the same patients with different dose distributions. Therefore, indices like CI, HI and GI serve as complementary tools in addition to visual slice by slice isodose verification while plan evaluation. Reliability and accuracy of these indices have been tested in the past and found shortcomings and benefits when compared to one another. MATERIAL AND METHODS: Potentially relevant studies published after 1993 were identified through a pubmed and web of science search using words "conformity index", "Homogeneity index", "Gradient index"," Stereotactic radiosurgery"," stereotactic Body radiotherapy" "complexity metrics" and "plan evaluation index". Combinations of words "plan evaluation index conformity index" were also searched as were bibliographies of downloaded papers. RESULTS AND CONCLUSIONS: Mathematical definitions of plan evaluation indices modified with time. CI definitions presented by various authors tested at their own and could not be generalized. Those mathematical definitions of CI which take into account OAR sparing grant more confidence in plan evaluation. Gradient index emerged as a significant plan evaluation index in addition to CI whereas homogeneity index losing its credibility. Biological index base plan evaluation is becoming popular and may replace or alter the role of dosimetrical indices.

A Randomized Prospective Study of Concurrent Chemo-Radiotherapy vs Accelerated Hyperfractionation in Advanced Cancer of Head and Neck.

INTRODUCTION: Locally advanced unresectable squamous cell carcinoma of head and neck has poor locoregional control when treated with conventionally fractionated Radiation Therapy (RT) alone. However, Concurrent Chemo-Radiotherapy (CRT) and altered fractionated RT schedules like Accelerated Hyperfractionation (AHF) are two different treatment strategies that have shown to be associated with better efficacy as compared to conventional RT alone in such cases. AIM: Aim of the study was to compare these two treatment strategies i.e., CRT and AHF radiation treatment to know which is better in terms of clinical outcome and toxicity in patients of locally advanced unresectable squamous cell carcinoma of head and neck. MATERIALS AND METHODS: A prospective randomized trial was done to compare the effect of CRT and of AHF radiation treatment in locally advanced unresectable head and neck cancer on 15 patients in each arm and followed up over three months period. RESULTS: At the end of three months after completion of treatment protocol, complete response was 62% in CRT arm and 53% in AHF arm. In CRT arm and AHF arm, Grade 3 skin reactions were observed in 100% and 87%, grade 3 mucosal reactions were in 62% and 67% of cases, respectively. Three patients died in CRT arm (two due to myelosuppression and associated infection; one during the treatment and another after two weeks of treatment completion. The third patient expired after one month of treatment completion at his native place due to unknown reason). One patient died in AHF arm (during treatment due to cardiac event). CONCLUSION: Efficacy of AHF was comparable to CRT with lesser toxicity. So the present study suggests that AHF should be preferred over CRT in locally advanced, unresectable, squamous cell head and neck cancer followed over three months non-treatment period.

Retrospective Analysis of Efficacy and Toxicity of Hypo-fractionated Radiotherapy in Breast Carcinoma.

INTRODUCTION: The conventional dose fractionation of adjuvant radiotherapy (RT) to whole breast is 45-50 Gy in 25 fractions as 1.8-2.0-Gy per fraction. Lumpectomy cavity with a 1.5-2-cm margin receieves additional 10- 16 Gy doseas boost. Alternative dose fraction schedules used in various randomised trials have established the role of hypofractionated radiotherapy (HRT) in early breast cancer. HRT allows time and cost saving thus better patient compliance. However the efficacy and toxicity of HRT in locally advanced breast cancer is still under evaluation. AIM: To study the toxicity and efficacy of Hypofractionated Radiotherapy (HRT) as compared to Conventional Radiotherapy (CRT) in breast cancer at our centre. MATERIALS AND METHODS: A retrospective analysis of breast cancer patients treated between October 2012- September 2014 with adjuvant radiation therapy as CRT or HRT. The data of these patients was retrieved and analysed regarding demographic profile, stage at presentation, pathological type, extent of surgery, chemotherapy, efficacy and toxicity of HRT. The toxicity assessment was done as per RTOG toxicity criteria. The data were analysed using SPSS software version 20.0. RESULTS: A total of 100 patients with carcinoma breast who received radiotherapy over two years were analysed. Age ranged from 18-90 years, mean 49.15 ± 12.7 years. Fifty-five patients were post-menopausal, predominant clinical feature was painless lump in the breast (98%). Early stage (Stage I and II) constituted 41%, locally advanced disease in 59%. Modified radical mastectomy was done in 75%, breast conserving surgery in 25%. A 56 patients received HRT and 44 were treated with CRT. The most common acute toxicity was skin grade I. An 18% patients in HRT arm and 30% patients in conventional arm developed grade II skin toxicity (p=0.23). Dysphagia grade I was seen in 10% cases in CRT arm and 12% in HRT arm. The median follow-up period was 11.3 months with 2 loco-regional failures in each arm. CONCLUSION: HRT seems to be equally efficacious and no more toxic than CRT in carcinoma breast even in unselected sub-group of patients.