Subhash Chander

Factors influencing early complications following Gamma Knife radiosurgery. A prospective study.

Purpose: The factors influencing early complications following Gamma Knife radiosurgery have not been definitely established. We report a prospective study evaluating the incidence of early complications (occurring within 3 months of radiosurgery) and various factors associated with early complications following stereotactic Gamma Knife radiosurgery for intracranial lesions. Patients and Methods: Seventy-nine previously unirradiated consecutive adult patients (82 lesions: arteriovenous malformations 35, benign tumors 43, metastases 4) treated by Gamma Knife radiosurgery were studied between May 1997 and August 1998. The median target volume was 4.8 cm3. The median dose of 15 Gy was prescribed to the 50% isodose. Patients were evaluated clinically and radiologically (with CT/MRI/SPECT) at 3-month intervals for the 1st year and 6 monthly thereafter. Complications were further divided as immediate (occurring within 24 h) or acute (occurring from 1 day to 3 months). Results: Early complications were observed in 19/79 (24.0%) patients. These included immediate in 10 (12.7%) and acute complications in 9 (11.3%) patients and were characterized by headache, nausea/vomiting, vertigo and seizures. No severe early complications were observed. Radiological changes in the form of perilesional edema were seen in 8/82 (9.8%) lesions. Maximum target diameter >25 mm was the only factor significantly associated with early complications by univariate analysis (p = 0.0335). Multivariate analysis revealed maximum target diameter >25 mm and prescribed dose >20 Gy to be significantly associated with early complications (p = 0.0442 and p = 0.0083, respectively). Conclusion: Up to one fourth of the patients undergoing Gamma Knife radiosurgery for intracranial lesions can experience self-limiting early toxicity. The selection of targets with small diameter and volume may reduce the risk of early complications following Gamma Knife radiosurgery.

Neoadjuvant chemotherapy with weekly paclitaxel and carboplatin followed by chemoradiation in locally advanced cervical carcinoma: A pilot study

OBJECTIVE To evaluate role of dose dense neo-adjuvant chemotherapy (NACT) prior to standard concurrent chemo-radiation (CCRT) in locally advanced cervical cancer. METHODS Between June 2010 and December 2011, 28 patients (median age - 51 years, range, 35 to 67 years) with locally advanced cervical cancer received NACT using paclitaxel (60 mg/m(2)) and carboplatin (AUC-2) weekly for 6 doses. After a mean interval of 15 days (range 7-23 days), the patients then received definitive radiation and concomitant weekly infusion of cisplatin (40 mg/m(2) for 6 doses). Response to concurrent chemo-radiation and toxicity were end points. RESULTS Following NACT, 67.8% of patients responded; complete (CR) - 2(7.1%), Partial (PR) - 17 (60.7%), stable 7 (25.0%) and 2 patients (7.1%) progressed. 24 of 28 patients received CCRT; 23/24 achieved CR. 22 of 23 complete responders continue to be in CR at a median follow-up of 12 months (range, 7 to 24 months). Grade III/IV neutropenia was the main hematological toxicity seen in 28.5% and 29% of patients, respectively during NACT and CCRT. CONCLUSIONS Neoadjuvant chemotherapy with dose dense weekly paclitaxel and carboplatin followed by standard CCRT is a feasible approach and is associated with a high response rate in locally advanced cervical cancer.

Total skin electron irradiation therapy in mycosis fungoides using high-dose rate mode: A preliminary experience

Introduction  Total skin electron irradiation (TSEI) therapy is the treatment of choice for mycosis fungoides. However, conventional TSEI therapy is time consuming as well as patient unfriendly. Therefore we used high‐dose rate (HDR) mode TSEI in these patients. High‐dose rate mode of TSEI is a technological innovation attached to a Linear Accelerator (Philips, SL‐20, Netherlands), which can deliver an electron beam of 30 Gy/min at the iso‐center. The iso‐center faces the patient, 100 cm away from the target of the linear accelerator. The patient is treated at a distance of 10 feet from the iso‐center of the linear accelerator. The dose delivered to the skin was 1.13 Gy/min, making the treatment execution much easier and patient compliance much better.

Radiation induced liver disease: A clinical update

Radiation-induced liver disease (RILD) or radiation hepatitis is a sub-acute form of liver injury due to radiation. It is one of the most dreaded complications of radiation which prevents radiation dose escalation and re-irradiation for hepatobiliary or upper gastrointestinal malignancies. This complication should be kept in mind whenever a patient is planned for irradiation of these malignancies. Although, incidence of RILD is decreasing due to better knowledge of liver tolerance, improved investigation modalities and modern radiation delivery techniques, treatment options are still limited. In this review article, we have focussed on patho-physiology, risk factors, prevention and management of RILD.

Comparative Evaluation of Two-dimensional Radiography and Three Dimensional Computed Tomography Based Dose-volume Parameters for High-dose-rate Intracavitary Brachytherapy of Cervical Cancer: A Prospective Study

BACKGROUND Dosimetric comparison of two dimensional (2D) radiography and three-dimensional computed tomography (3D-CT) based dose distributions with high-dose-rate (HDR) intracavitry radiotherapy (ICRT) for carcinoma cervix, in terms of target coverage and doses to bladder and rectum. MATERIALS AND METHODS Sixty four sessions of HDR ICRT were performed in 22 patients. External beam radiotherapy to pelvis at a dose of 50 Gray in 27 fractions followed by HDR ICRT, 21 Grays to point A in 3 sessions, one week apart was planned . All patients underwent 2D-orthogonal and 3D-CT simulation for each session. Treatment plans were generated using 2D-orthogonal images and dose prescription was made at point A. 3D plans were generated using 3D-CT images after delineating target volume and organs at risk. Comparative evaluation of 2D and 3D treatment planning was made for each session in terms of target coverage (dose received by 90%, 95% and 100% of the target volume: D90, D95 and D100 respectively) and doses to bladder and rectum: ICRU-38 bladder and rectum point dose in 2D planning and dose to 0.1cc, 1cc, 2cc, 5cc, and 10cc of bladder and rectum in 3D planning. RESULTS Mean doses received by 100% and 90% of the target volume were 4.24 ± 0.63 and 4.9 ± 0.56 Gy respectively. Doses received by 0.1cc, 1cc and 2cc volume of bladder were 2.88 ± 0.72, 2.5 ± 0.65 and 2.2 ± 0.57 times more than the ICRU bladder reference point. Similarly, doses received by 0.1cc, 1cc and 2cc of rectum were 1.80 ± 0.5, 1.48 ± 0.41 and 1.35 ± 0.37 times higher than ICRU rectal reference point. CONCLUSIONS Dosimetric comparative evaluation of 2D and 3D CT based treatment planning for the same brachytherapy session demonstrates underestimation of OAR doses and overestimation of target coverage in 2D treatment planning.

Cutaneous T-cell lymphoma treated with electron beam irradiation in Indian patients.

Abstract

Extrapulmonary Small Cell Carcinoma - a Case Series of Oropharyngeal and Esophageal Primary Sites Treated with Chemo-Radiotherapy

BACKGROUND The optimal sequence and extent of multimodality therapy remains to be defined for extrapulmonary small cell carcinoma because of its rarity. The purpose of our study was to assess the response to neoadjuvant chemotherapy followed by chemoradiation/radiation in patients with extrapulmonary small cell carcinoma. MATERIALS AND METHODS Four consecutively diagnosed patients were included in this study. The primary tumor site was oropharynx in three patients and esophagus in one. The patients with the limited disease were treated with chemotherapy followed by concurrent chemoradiation (n=2) or radiotherapy (n=1). The patient with the extensive disease with the primary site in vallecula was treated with chemotherapy and palliative radiotherapy to the metastatic site. RESULTS The median follow-up was 22.5 months (range, 8-24 months). Three patients with the limited disease (base of tongue, n=2; esophagus, n=1) were in complete remission. The patient with the extensive disease died of loco-regional tumor progression at 8 months from the time of diagnosis. CONCLUSIONS The combination of chemotherapy and radiotherapy is the preferred therapeutic approach for patients with extrapulmonary small cell carcinoma. Induction chemotherapy followed by concurrent chemoradiation or radiation provides a good loco-regional control in patients with limited disease.

Radiation Therapy in Paediatric Orbital Granulocytic Sarcomas: Experience from a Tertiary Cancer Center.

INTRODUCTION Orbital Granulocytic Sarcoma (OGS) is an uncommon manifestation associated with haematological malignancies. Chemotherapy remains the cornerstone of the treatment. The role of radiation is not well-defined. AIM To evaluate the effect of radiation in OGS and to define an optimal dose for achieving adequate local control. MATERIALS AND METHODS This was a retrospective analysis of 11 patients who received radiation therapy to orbit for Granulocytic Sarcoma (GS) between 2007 and 2014 at a tertiary cancer center in India. Radiotherapy was planned by three dimensional conformal (3DCRT) techniques. Demographic and disease characteristics, including clinical, imaging, histopathology and treatment details in this patient cohort were recorded and their response to therapy was assessed. RESULTS The median age was 7 years (Range: 2-16 years). There were 3 female and 8 male patients. Eight patients were diagnosed as Acute Myelogenous Leukemia (AML), two patients had Primary Orbital Granulocytic Sarcoma (POGS) and one had bi-phenotypic leukemia. Median dose was 24.5Gy (Range-15-45 Gy). Two anterior oblique field design were used most commonly. Out of 11 patients, 5 (45.4%) had complete response, 3 (27.27%) had partial response, 1 patient had stable disease (9%) and 2 developed progressive disease (18%). Median follow-up was 24 months (Range 24-84 months). At last follow-up, 7 (63.6%) patients were alive and 4 patients (37.4%) were dead due to progressive disease. CONCLUSION In patients with residual orbital disease after chemotherapy, low dose radiation can be used to improve local disease control and improve quality of life. Local conformal radiotherapy of 24-30 Gy in conventional fractionation appears optimal with excellent local control and minimal morbidity.

Non syndromic bilateral microdontia of maxillary second molars: a very rare finding.

Dental anomalies are the formative defects caused by genetic disturbances or environmental factors during tooth morphogenesis. The term microdontia is defined as the condition of having abnormally small teeth. Clinically, microdontia in the permanent dentition, excluding the third molars, is found in 0.8-8.4% of the population. One of the commonest forms of localized microdontia is that which affects the maxillary lateral incisor, a condition called Peg laterals. The next tooth which can be affected is the third molars. Few cases of microdontia in canines have been reported. Localised microdontia of maxillary second molar has never been reported in literature before.

Adjuvant Radiotherapy with Three-Dimensional Conformal Radiotherapy of Lacrimal Gland Adenoid Cystic Carcinoma.

BACKGROUND & AIM Adenoid cystic carcinoma (ACC) of lacrimal gland is a rare tumour with aggressive behaviour. There is sparse data to address optimum therapy for such tumours. So, the present study was aimed at evaluating the role of adjuvant three dimensional conformal radiotherapy (3D-CRT) in cases of incomplete (R1) resection along with review of literature pertaining to management of lacrimal adenoid cystic carcinoma. MATERIALS AND METHODS We retrospectively reviewed the demographic and treatment data of 10 biopsy proven ACC of lacrimal gland patients, treated from December 2006 to June 2013. They were treated with radiotherapy following surgical resection. Eight patients underwent gross total excision of the tumour mass (enbloc excision) followed by conformal radiotherapy to a dose of 60 Gray/30fractions/ 6 weeks. Two patients with advanced disease were treated with palliative radiotherapy after biopsy. RESULTS The median age was 32 years. There were equal numbers of male and female patients. The median duration of symptoms was 7 months. At a median follow up of 21 months, eight patients had no evidence of disease and had complete tumour response, two patients worsened, and one of the two had systemic failure with bone metastasis. CONCLUSION Despite a small sample size and short follow, enbloc surgical excision with adjuvant radiotherapy is well tolerated and shows good control in ACC of lacrimal gland.