Comparison of Acute Toxicities, Overall Treatment Time and Quality of Life in Head and Neck Cancer Patients Treated with IMRT and Helical Tomotherapy.

INTRODUCTION: Technical innovations in radiation therapy treatment planning and delivery over the last two decades have changed the practice of radiation therapy dramatically. The benefit of improved dose homogeneity and better sparing of critical structures in helical tomotherapy compared with conventional linac-based IMRT has been reported. This study was conducted to compare acute toxicities (skin, mucous membrane, salivary gland and hematological) during treatment and overall treatment time in Head and Neck Cancer patients treated with IMRT and Helical Tomotherapy and to assess the quality of life of patients during treatment between two groups. MATERIALS AND METHODS: The study involved thirty patients with histologically proven Squamous cell carcinomas of Head and Neck. They were treated with concurrent chemoradiotherapy, to a dose of 60-70 Gray in 30-35 fractions. The study consists of 2 arms which are standard IMRT and Tomotherapy arm. Fifteen consecutive patients were treated under IMRT and 15 patients were treated under Helical tomotherapy, along with concurrent chemotherapy. After completion of planning, plans were evaluated and dose to the targets, organs at risk were tabulated. Patients were assessed weekly for acute toxicities (skin reactions, mucositis, xerostomia, haematological toxicities) during the course of the treatment as per RTOG criteria. Quality of life of patients were assessed using FACT/ NCCN HNSI questionnaire in local language at day 1, day 21 and at completion of radiotherapy. RESULTS: Grade 2-3 skin reactions, mucositis, anemia, leukopenia and thrombocytopenia were predominant in both arms. Treatment time from start of radiotherapy to completion of radiotherapy varied from 39 days to 68 days. Majority of patients completed radiotherapy within 50-56 days. Mean quality of life score did not show much difference between IMRT and tomotherapy arms. CONCLUSION: The study did not show any statistically significant difference in overall treatment time, acute toxicities- skin reactions, xerostomia, mucositis& hematological toxicities and quality of life of patients during radiotherapy between IMRT and Helical Tomotherapy. Dosimetric benefits of Tomotherapy over IMRT do not translate into clinical benefit in terms of reduced acute toxicities, lesser overall treatment time and better quality of life of patients. KEY WORDS: Head and Neck Carcinoma, IMRT, Tomotherapy, RTOG, toxicity, FACT/ NCCN HNSI, quality of life.

Comparison of dosimetric analysis of organs at risk and target volumes for ovoids and cylinders in endometrial carcinoma.

Purpose: To compare dose volume parameters of target and organs at risk in vaginal vault brachytherapy using ovoids or cylinder in post-operative endometrial carcinoma. Material and methods: The study was done among 25 histologically proven post-operative endometrial carcinoma patients requiring vaginal brachytherapy. All patients underwent both cylinder and ovoids application alternatively on weekly basis. Ovoids size ranged from 2 to 3 cm diameter. Diameters of cylinder ranged between 2.5 and 3.5 cm. Bladder, rectum, urethra, and clinical target volume (CTV) were contoured on CT simulation images. Prescribed dose was 6-7 Gy in 2-3 fractions at 0.5 cm from the surface of applicator. Results: The mean values of D90, D50, V150, V100, V90, and V50 of CTV were comparable between cylinder and ovoids plans. The mean dose of CTV was significantly higher with cylinder than with ovoids, and D100 was significantly higher with ovoids (mean = 15.63 Gy vs. 14.64 Gy, p = 0.016, and D100 = 37.82% vs. 42.86%, p = 0.042, for cylinder vs. ovoids). In the dosimetry of the vault, D90, D50, V100, V90, V50, and mean of the vault did not show any significant difference between cylinder and ovoids. The V150 was significantly higher with cylinder plans than ovoids, and D100 of the vault was significantly higher with ovoids plans (V150 = 14.81% vs. 6.86%, p = 0.02, and D100 = 37.77% vs. 44.80%, p = 0.029, for cylinder vs. ovoids). D0.1cc, D1cc, D2cc, and mean for the bladder, rectum, and urethra were comparable between the cylinder and ovoid plans. Conclusions: The present study showed that the dose to organs at risk, most of the dosimetric parameters of CTV, and vault were comparable between the cylinder and ovoid plans. Both applicators provide good reproducibility. The choice of applicator will ultimately depend on the institutional policies and oncologist decision. However, in patients with dog-ear configuration of the vagina, ovoids may be preferred as per ABS guidelines.