K.P. Haresh

Comparison of computed tomography and magnetic resonance based target volume in brain tumors

PURPOSE This study was mainly framed to study the difference in tumor volumes as seen on computed tomography (CT) and magnetic resonance (MR) and their significance in planning. MATERIALS AND METHODS Twenty-five patients with brain tumor of different diagnoses who underwent stereotactic radiotherapy were included in this study. CT and MR imaging was done for all the patients with 2.5 mm slice thickness. The CT tumor volume and MR tumor volume were measured and compared with each other. The center of mass (CM) of the tumor volume delineated on CT and MR were computed and the shift between the two CMs was determined. RESULTS The mean and median volume of the tumor as measured from MR scans was 19.67 cc +/- 13.73 and 16.13 cc (range: 3.25 cc-50.37 cc). Similarly, the mean and median volume of the tumor as measured from CT scans was 15.05 cc +/- 10.13 and 11.63 cc (range: 3.0 cc-36.25 cc) respectively. The mean and median CM shift between CT and MR was 5.47 mm and 5.21 mm respectively. CONCLUSION The study demonstrates that MR is an indispensable imaging modality in radiotherapy for planning brain tumors.

Osseous Hodgkin's lymphoma—review of literature and report of an unusual case presenting as a large ulcerofungating sternal mass

Osseous involvement in Hodgkins lymphoma is uncommon. The most common location is vertebral, primarily in the thoracolumbar region, followed by pelvis, ribs, femur, sternum, clavicle and skull in decreasing incidence. We herein illustrate the salient features of the disease citing a case of a disseminated Hodgkins lymphoma presenting as a large ulcerofungating sternal mass mimicking chronic tubercular osteomyelitis. The case report highlights the importance of clinical suspicion of unusual presentation of lymphohematopoietic tumors of the bone especially in developing countries, where chronic granulomatous disease is preponderant.

A prospective study evaluating surgery and chemo radiation in muscle invasive bladder cancer

AIM The aim of our study was to compare the two standard treatment approaches in muscle invasive carcinoma of urinary bladder--radical cystectomy and chemo radiation. MATERIALS AND METHODS Transitional cell carcinoma (TCC) of bladder of stages, T2 to T4, N0/N1/N2 and M0 were included in the study. Patients were allotted to two arms of the study. Arm A consisted of radical cystectomy. Adjuvant CMV chemotherapy was given for T3/T4 or Node positive disease only. Arm B received 2 cycles of neoadjuvant CMV chemo therapy followed by concurrent chemo radiation. RESULTS Forty-four patients were recruited into the study. Thirty patients in the surgical arm and 13 patients in the chemo radiation arm. The actuarial two-year survival rate in surgical arm is 56% while in chemo radiation arm it is 54%. There was no statistically significant difference in disease-free survival also between the two groups. CONCLUSION Chemo radiation yielded equivalent survival results with radical cystectomy. So it is worth giving preference to chemo radiation that will give a better quality of life for the patient.

Adjuvant radiotherapy in the treatment of gall bladder carcinoma: What is the current evidence

Gall bladder carcinoma (GBC) is considered the fifth most common one of the most aggressive gastro intestinal tract malignancies. Owing to their large incidence randomised controlled trials have hardly been conducted to look into their optimum treatment. Over the years surgical resection has been considered the only curative treatment of these tumors. However, the outcome still remains guarded. The predominant pattern of failure is loco-regional followed by systemic. Hence, local adjuvant radiation has been used by different institutes with concurrent and adjuvant chemotherapy. The large retrospective series with their limitations showed improved survival in patients with regional spread or tumors infiltrating the liver when treated with adjuvant radiotherapy. In the present era with modern radiation techniques and target delineation radiation may further improve upon the impact without adding to the toxicity profile. Hence, radiation in gall bladder cancer needs a relook to optimize treatment outcome of such aggressive disease.

Neoadjuvant treatment intensification or adjuvant chemotherapy for locally advanced carcinoma rectum: The optimum treatment approach remains unresolved.

BACKGROUND Rectal carcinoma [RC] is often managed with preoperative radiotherapy or radio-chemotherapy followed by total mesorectal excision (TME). Efforts are being made to improve outcome by intensifying the preoperative treatment. However, the optimum therapy remains unclear. There is ongoing controversy regarding the optimum radiation dose, chemotherapy regimen and schedule. In addition there exists growing disagreement regarding the role of adjuvant chemotherapy after neoadjuvant radiation or chemoradiation. METHODOLOGY We reviewed the recent land mark trials to find a road map in the management of locally advanced rectal carcinoma. RESULTS Preoperative short course radiotherapy has long been proven to improve local disease control. The initial trials with long course chemoradiotherapy, comparing short course radiotherapy have shown to increase local control and pathological complete response rates. Since then treatment intensification of this neoadjuvant schedule has been tried by many researchers. But initial results of these treatment intensification trials, show no significant benefit and are associated with increased toxicity. There is an unmet need to stratify patients depending on risk to assign them to long course chemoradiotherapy or short course radiotherapy. Current evidence does not support the use of adjuvant chemotherapy in patients who were treated with preoperative (chemo)radiotherapy. CONCLUSION Preoperative radiotherapy appears to improve disease control with favorable toxicity profile and there is very little to choose between long course chemoradiotherapy and short course radiotherapy. However, long course chemoradiotherapy may be beneficial for patients with high risk features like positive circumferential resection margin [CRM] and extramural spread of >5mm. There is no role for adjuvant chemotherapy in patients who were treated preoperative (chemo)radiotherapy.

A simple technique for cranio-spinal irradiation in pediatric patients

PURPOSE Field matching poses challenges in craniospinal irradiation (CSI) as it leads either to underdosage or overdosage in the junctional area. A simple technique for CSI in pediatric patients is proposed. MATERIALS AND METHODS Computed tomography scans were performed in the prone position. Two lateral cranial fields and a direct posterior spinal field were planned with a common central axis. Half-beam-blocked cranial fields with zero collimator rotation were used for treating the cranium. A half-beam-blocked field defined with jaws was used to treat the spinal column at an extended source-to-surface distance. Before treating the patient, matching of the cranial and spinal field junction along the central axis was verified with an extended dose range film. RESULTS AND CONCLUSION The technique described is simple and easy to implement and can be applied to pediatric patients undergoing CSI. This method has the potential to reduce daily setup time and setup errors. This technique is ideally suitable for patients with spinal fields less than 30 cm.

Simulation of dose to surrounding normal structures in tangential breast radiotherapy due to setup error.

Setup error plays a significant role in the final treatment outcome in radiotherapy. The effect of setup error on the planning target volume (PTV) and surrounding critical structures has been studied and the maximum allowed tolerance in setup error with minimal complications to the surrounding critical structure and acceptable tumor control probability is determined. Twelve patients were selected for this study after breast conservation surgery, wherein 8 patients were right-sided and 4 were left-sided breast. Tangential fields were placed on the 3-dimensional-computed tomography (3D-CT) dataset by isocentric technique and the dose to the PTV, ipsilateral lung (IL), contralateral lung (CLL), contralateral breast (CLB), heart, and liver were then computed from dose-volume histograms (DVHs). The planning isocenter was shifted for 3 and 10 mm in all 3 directions (X, Y, Z) to simulate the setup error encountered during treatment. Dosimetric studies were performed for each patient for PTV according to ICRU 50 guidelines: mean doses to PTV, IL, CLL, heart, CLB, liver, and percentage of lung volume that received a dose of 20 Gy or more (V20); percentage of heart volume that received a dose of 30 Gy or more (V30); and volume of liver that received a dose of 50 Gy or more (V50) were calculated for all of the above-mentioned isocenter shifts and compared to the results with zero isocenter shift. Simulation of different isocenter shifts in all 3 directions showed that the isocentric shifts along the posterior direction had a very significant effect on the dose to the heart, IL, CLL, and CLB, which was followed by the lateral direction. The setup error in isocenter should be strictly kept below 3 mm. The study shows that isocenter verification in the case of tangential fields should be performed to reduce future complications to adjacent normal tissues.

Primary pediatric mid-brain lymphoma: Report of a rare pediatric tumor in a rare location

Primary central nervous system lymphoma (PCNSL) is a rare disease in pediatric age group. A thirteen-year-old male child presented with complaints of headache for six months, vomiting and diplopia for three days. Magnetic resonance imaging of the brain showed a single lesion of 1.7 cm × 1.6 cm × 1.6 cm in the mid brain and tectum. He underwent a gross total resection of the tumor. The histopathological evaluation revealed B cell high grade non Hodgkin lymphoma. The patient was treated with High dose methotrexate and cranio spinal radiation. The patient was alive without disease 12 mo after completion of treatment. This case highlights importance of keeping PCNSL as differential in brain stem lesions of pediatric patients also. Radiation and chemotherapy remains the most important treatment for such patients.

Impact of post-operative radiation on coronary arteries in patients of early breast cancer: A pilot dosimetric study from a tertiary cancer care center from India

BACKGROUND The significant impact of postoperative radiotherapy (PORT) on cardiac morbidity in patients of early breast cancer (EBC) undergoing breast-conserving surgery has been shown in different studies. The present study was conducted to assess the impact of surgery and the side of involvement on radiation dose to left anterior descending artery (LAD) and Left circumflex coronary artery (LCx). MATERIALS AND METHODS Totally, 58 patients of EBC were randomly chosen for this dosimetric study and planned with tangential field technique without intensity modulation (IM). Heart, LAD, and LCx (n = 55) were contoured. Dose volume histograms were analyzed to determine the Dmax (maximum dose) and Dmean (mean dose) of LAD and LCx. Students t-test was used for comparative analysis of the means. RESULTS The mean Dmax of LAD for left (L) EBC was 3.17 Gray (Gy) while for right (R) EBC it was 0.86 Gy (P = 0.007; 95% C.I, 1.14-3.48). The mean Dmean of LAD for L-EBC and R-EBC were 1.97 Gy and 0.79 Gy, respectively (P = 0.029; 95% C.I, 0.77-1.60). The mean-Dmax of LCx for patients with L-EBC (2.9 Gy; range: 1.2-4.35 Gy) was statistically higher than that for R-EBC (1.3 Gy; range: 0.7-3.2 Gy) (P = 0.045). The mean-Dmean of LCx for L-EBC (2.1 Gy; range: 0.6-3.6 Gy) was also significantly higher than that of L-EBC (0.9 Gy; range: 0.7-2.1 Gy) (P = 0.03). There was no significant impact of the pattern of surgery on LAD dose, but significance was noted for LCx dose parameters (P = 0.04 and 0.08 for m-Dmax and m-Dmean of LCx). CONCLUSION This pilot dosimetric study confirms the assumption that patients with left-sided EBC are at higher risk of developing long-term cardiac morbidity when treated with PORT due to increased dose to LAD.

Modern chemoradiation practices for malignant tumors of the trachea: An institutional experience.

Background: Malignant tumors of the trachea are rare. A multimodality treatment approach is often necessary. Outcomes of radical non-surgical approaches are sparse. Radiation combined with sequential or concurrent chemotherapy is an important treatment option. Materials and Methods: We present an analysis of outcomes using modern radiotherapy and chemotherapy for tracheal tumors. Results: Radiation dose escalation using modern techniques is of benefit for these tumors. The results with chemotherapy are encouraging. Conclusions: Radiation plays a distinct role and should be a part of treatment for these tumors. The role of chemotherapy needs to be studied further.