Clinical Outcomes and Dosimetric Evaluationof Interstitial Brachytherapyin Gynecological Malignancies.

BACKGROUND: In management of Carcinoma Cervix, Brachytherapy plays a crucial role. Most commonly used technique is Intracavitary Brachytherapy (ICBT). In cases where ICBT is not technically feasible or it may result in suboptimal dose distribution, Interstitial Brachytherapy (ISBT) is recommended. With this study we wanted to study the clinical outcome and dosimetric details of interstitial brachytherapy in gynecological cancers. MATERIALS & METHODS: We analysed clinicaloutcome and dosimetric details of interstitial brachytherapy (ISBT) done for gynecological malignancies in our institute during the period 1st January 2013 to 31st December 2020. RESULTS: Total of 42 interstitial brachytherapy (ISBT) details were analysed.37 patients had Carcinoma Cervix and 5 patients had Carcinoma Vagina. In the majority of the patients, ISBT dosage schedule was three fractions 7Gy each. D2cc to rectum, bladder, sigmoid and bowel were 4.88 Gy, 5.62 Gy, 3.57 Gy and 2.47 Gy respectively. Mean CTV volume was 129.89 cc. EQD2 dose to CTV combining EBRT and ISBT dose was 85.88 Gy. D90 and D100 to CTV from ISBT were 111.96% and 68.21 % of prescribed dose respectively. Grade III/IV toxicities were seen in 5 (12%) patients. Local control rates at 1year &2 years were 88% & 85.7% respectively. DFS at 1 year, 2 years and 3 years were 80.7%, 72.3% and 65.7% respectively. OS at 1year, 2 years, 4 years and 5 years were 92.5%, 65.5%, 59.5% and 42.3% respectively. CONCLUSION: 3D imagebased dosimetry with CT based planning using MUPIT implant is a feasible option for gynecological malignancies warranting interstitial brachytherapy. In view of good clinical outcomes in terms of toxicity profile, Local control, DFS and OS with acceptable GEC-ESTRO dosimetric data, we recommend routine use interstitial brachytherapy if facilities are available and in clinical situations were ISBT is indicated.

Beam Focal Spot Offset Determination for Linear Accelerators: A Phantom less Method.

The effectiveness of radiotherapy treatment is influenced by the position of beam focal spot; therefore, it is important to verify the beam focal spot periodically. In this study the beam focal spot offset is measured using an electronic portal imaging (EPID) based technique and co- rotational penumbra modulation technique(CPM). MATERIALS AND METHODS: This method utilizes one set of jaws and the multileaf collimator (MLC) to form a symmetric field and then a 180o collimator rotation was utilized to determine the radiation isocenter defined by the jaws and the MLC, respectively. The difference between these two isocentres is then directly correlated with the beam focal spot offset of the linear accelerator. In the current study, the method has been used for Varian ClinaciX and Elekta Versa HD linear accelerators. Since an Elektalinac with the Agility® head does not have two set of jaws, a modified method that making use of one set of diaphragms, the MLC and a full 360o collimator rotation is implemented. RESULT: The method is validated against CPM and found to be in agreement within 0.00923± 0.009360 mm ( SD) also the method has been found to be reproducible to within 0.0365 mm (SD). CONCLUSION: The method could be used for routine quality assurance (QA) to ensure that the beam focal spot offset is in tolerance.

Clinical Outcomes of Head and Neck Cancer Patients Treated with Palliative Oral Metronomic Chemotherapy at a Tertiary Cancer Center in Kerala, India.

BACKGROUND: Cetuximab-based chemotherapy is the standard palliative chemotherapy in head and neck cancers, but there is a limitation due to financial and logistic reasons, and where oral metronomic chemotherapy can be a successful alternate. Oral metronomic chemotherapy (MCT) can either be with Methotrexate alone or a combination of Methotrexate and Erlotinib. The study was aimed to assess the clinical outcome of oral MCT in head and neck cancer patients. MATERIALS AND METHODS: This was a retrospective review done at a tertiary cancer centre in India. The clinical outcomes of head and neck cancers patients started on palliative oral MCT from 1st August 2016 to 31st December 2017 were analyzed. The demographic details, toxicity profiles, response to MCT, disease progression status were analyzed. Univariate analysis was done to assess the factors associated with disease progression. Kaplan Meier curve was used for estimating progression free survival (PFS). RESULTS: Of the total 104 patients, the most common primary site of head and neck cancer was oral cavity (52%). MCT scheduled with Methotrexate and Erlotinib in 80 patients. Toxicity rate was 61%, with Grade 3-4 toxicity in 21%. Response rate was 56% and clinically meaningful response rate was 69%. Disease progression was observed in 55% patients. Median PFS rate was 134 Days. Oral MCT was permanently stopped in 73%, the most common reason being disease progression. DISCUSSION: Patients who underwent palliative oral MCT had a median PFS of 134 days which is considered as promising treatment method. Results confirmed more than 50% response rate with lower Grade 3-4 toxicities. CONCLUSION: Palliative oral MCT either with Methotrexate and Erlotinib or Methotrexate alone will be a feasible treatment option in patients with head and neck cancers treated with palliative intent.

Late toxicities among laryngopharyngeal cancers patients treated with different schedules of concurrent chemoradiation at a rural tertiary cancer care center.

BACKGROUND: Concurrent chemoradiation is the treatment of choice for laryngeal-pharyngeal cancers. Apart from survival organ preservation remains major aims of the treatment. Advanced radiation techniques like VMAT have shown to reduce morbidity. The purpose of our study is to assess the late toxicities in patients treated with concurrent chemoradiation and its association with dose to organs at risk. AIMS: Assessment of late toxicities following concurrent chemoradiation in patients with laryngopharyngeal cancers. MATERIALS AND METHODS: Retrospective study at a tertiary cancer centre on patients with laryngeal and pharyngeal cancers treated with concurrent chemoradiation with VMAT upto a total dose of 69.3 -70 Gy in 33-35 fractions and concurrent chemotherapy with Cisplatin was done. Severe late toxicities and its association with demographic and clinical parameters and dose to OAR were studied. Data was analysed using EpiData analysis v2.2.2.182. RESULTS: Of the 93 patients studied majority were males above 55 years. Oropharynx was the commonest site (58%) with T3 and N2 in majority. Late dysphagia and odynophagia was seen in 18(21%) and 23(27%) patients respectively. 16 (17%) had tube dependence and nine (9.6%) had aspiration pneumonia. D60, V50 and V60 along with site, node positivity and weight loss were found to be significantly associated with severe late toxicity. CONCLUSION: Oropharyngeal cancers, node positivity and weight loss were found to have significant grade III and above toxicities including tube dependency. Dose to larynx showed association with severe late toxicities, though dose to constrictors could not.

En Bloc Resection with Partial Sacrectomy Helps to Achieve R0 Resection in Locally Advanced Rectal Cancer, Experience from a Tertiary Cancer Center.

Partial sacrectomy is a radical procedure that benefits a select group of patients with locally advanced primary or recurrent rectal cancer with posterior extension and carries potential for significant morbidity. This study was done to evaluate the morbidity and oncological outcome of patients who underwent partial sacral resection for rectal cancer in a tertiary cancer center. Seventeen patients underwent partial sacrectomy during the period from 2011 to 2015. Eleven patients had primary and six had recurrent rectal cancer. All patients were evaluated with MRI pelvis and metastatic evaluation with CT scan of the chest and abdomen and PET scan in patients with recurrent cancer. All patients had resection below the level of S2/S3 junction or lower. Three patients were females and the remaining were males. Median age was 56 years. Overall morbidity was 76% and most common morbidity was wound related. The mean estimated relapse-free survival (RFS) for patients treated for primary rectal cancer was 20.3 months (95% confidence interval (CI), 12.8-27.9) and the mean estimated overall survival (OS) 23.9 months. Estimated mean RFS for patients who were operated for recurrent rectal cancer was 25.6 months (95% CI, 17.7-33.5) and the median RFS was yet to reach. Estimated mean OS was 29.7 months (95% CI, 15.5-43.8) and the median OS was 39.6 months. Partial sacrectomy below the level of S2/S3 junction is a safe approach to facilitate en bloc resection of locally advanced primary and recurrent rectal cancer extending posteriorly with loss of plane with sacrum. In selected patients, this approach can improve survival at the cost of high morbidity.

Improved survival among oral cancer patients: findings from a retrospective study at a tertiary care cancer centre in rural Kerala, India.

BACKGROUND: Oral cancer is very common in India. The reported 5-year survival of such patients is around 50% after treatment with surgery and radiotherapy, much lower than most of the developed countries. METHODS: A retrospective study of a prospective database of oral cancer patients undergoing surgery from June 2009 to June 2013 was conducted. Follow-up details were updated from case records and by phone calls. Data were double entered in EpiData Entry version 3.1 and were analysed using EpiData Analysis software 2.1.0.73. RESULTS: Two-hundred and twenty patients were analysed (136 males); 85% were consuming tobacco, mainly in chewable form. The majority (51.1%) had tongue cancer, of whom 75 patients (34.1%) had T4 tumours. Postoperative radiotherapy was given to 108 patients (49.1%). Forty had recurrence, of which 23 were in early stage. Of these, 19 showed node positivity (p < 0.01). Node-negative patients had 79% 5-year survival while node positive had 59% which is comparable to that reported in developed countries. Median disease-free survival duration was 48.2 months. CONCLUSIONS: Node positivity is the single factor affecting recurrence and survival. The overall survival and disease-free survival is better in patients without lymph node involvement and in patients with early stage of cancer as compared to the patients with node involvement and in advanced stages.