న్యూక్లియర్ మెడిసిన్ & రేడియేషన్ థెరపీ

Currently, there are increasing interests in imaging tumor response to radiation therapy (RT) of hepatic cancer. Early detection of tumor response may allow a change in the treatment before completion of the prescribed therapy and maximize therapeutic efficacy of the treatment. Most importantly, once early tumor response indicates achievement of final tumor control, withholding treatment will prevent radiationinduced diseases. Response Evaluation Criteria in Solid Tumors (RECIST) which evaluates tumor response based on change in tumor size is a clinically adopted approach to determine solid tumor responses. But it may take several weeks for RECIST criteria to suggest success or failure of a treatment, which may lead to severe radiation toxicity or tumor progression due to inadequate radiation delivery. Advances of medical imaging allow high-sensitivity and high-specificity assessment of tumor biological process and, therefore, may provide surrogates of tumor response before morphological change occurs.

Increasing radiation dose for better hepatic cancer control from radiation therapy (RT) is limited by the development of radiationinduced liver disease (RILD). Clinical syndrome of RILD occurs typically 2 weeks to 4 months after completion of RT. In severe cases, RILD can lead to liver failure and death. Using the Lyman-Kutcher- Burman NTCP model, the likelihood of developing RILD can be estimated based on the planned dose on the normal liver [1]. However, the models solely based on dose distribution which ignores individual liver sensitivity to RT that may allow safe delivery of higher radiation dose on some patients. Imaging can quantitatively assess normal tissue response to RT, and thereby it may be able to characterize individual liver tolerance to radiation and provide surrogates to early predict the development of RILD.

Background: Aim was to evaluate the additional benefit of adjuvant chemotherapy in patients of early stage endometrial carcinoma (EC) with adverse features.

Materials and methods: Between June 2006 and July 2011, 56 patients with EC after surgery were randomized to receive either adjuvant radiotherapy (RT) [35 patients] or adjuvant sequential chemotherapy and radiotherapy (CRT) [21 patients]. Median age was 57.6 years (40-80). Predominant stages were FIGO IB (44.6%) and IIA (26.7%). Mean body mass index was 35.9 kg/m2 (23-72).

Results: Median follow-up was 55 months (6-60). The Kaplan-Meier estimates for loco regional control (LRC), distant metastasis control (DMC) and overall survival (OS) for RT and CRT arms were; 85.7% vs. 74.2% (p 0.04), 85.7% vs. 85.7% (p 0.9) and 82.8% vs. 81% (p 0.8) respectively. Patients in CRT arm had earlier and higher pelvic recurrences {hazard ratios of 2.21 (1.45-7.85)}. Acute hematological grade3 toxicity was higher in CRT arm (9.5%) and no difference in acute or delayed non-hematological toxicities was seen between two arms.

Conclusion: Adjuvant chemotherapy in patients with EC after surgery is associated with inferior LRC and no additional benefit in DMC and OS. If adjuvant chemotherapy is considered it shall be given after adjuvant radiotherapy.

Abstract Aim: To report mature outcomes of helical Tomotherapy (HT)-based image-guided intensity-modulated radiation therapy (IMRT) in benign/low-grade meningiomas.

Methods: Nineteen consecutive patients with 22 complex, irregular, residual, recurrent, or progressive benign/ low-grade meningiomas were treated on HT and followed up clinico-radiologically. Tumor control was defined as lack of evidence of tumor progression on serial imaging. Progression-free survival (PFS) was calculated from date of initiation of HT till imaging-defined progression or sustained neurologic worsening whichever occurred earlier.

Results: The median age of the study cohort was 40 years (range 15-72 years) and included 13 (68%) females. HT achieved excellent target volume coverage, good high-dose conformality and homogeneity with exquisite sparing of surrounding normal critical structures. Acute toxicity of HT was mild and self-limiting. Using standard response evaluation criteria, 18 of 22 (83%) lesions were stable on first response assessment, while 4 (17%) lesions showed partial response. Pre-existent neuro-deficits present in 13 patients prior to HT either improved or remained stable following irradiation in all but one patient. Only 1 patient (5%) developed cataract necessitating extraction. Two (10.5%) patients had clinical and/or radiological progression on follow-up. With a median follow-up of 32 months (inter-quartile range 27-45 months), the 5-year clinico-radiological PFS was 89.2%. All 19 patients were alive for a 5-year overall survival of 100%.

Conclusion: HT-based image-guided IMRT for benign/low-grade meningiomas achieves excellent high-dose conformality with minimal acute and late morbidity resulting in excellent long-term outcomes prompting its use in routine clinical practice

Background: Standard treatment for well differentiated thyroid cancer is surgery followed by adjuvant radioactive iodine-131 (RAI) therapy. To concentrate RAI in thyroid tissue, levothroxine therapy is withheld for 3-4 weeks prior to RAI therapy along with low iodine diet (LID), which results in short term hypothyroidism, which ultimately can result into mild to severe symptomatic hyponatremia with fatal complications. It is very rare complication; has been reported only in four case reports so far.

Case presentation: Here in we present a case report of 62 years Saudi, known hypertensive female on thiazide diuretic with diagnosis of papillary thyroid cancer (pT2N0M0), who was admitted for RAI therapy after total thyroidectomy. Patient was on low iodine diet for 3 weeks and she was given recombinant human thyrotropin (rhTSH) for two days prior to admission. On second day of admission (18 hours of RAI therapy), she was found confused, disoriented and was unable to recognise her family members. Blood chemistry showed low serum sodium concentration (105 mEq/L). Further investigations confirmed hypotonic hyponatremia and she was managed accordingly and she made full recovery within 48 hours of diagnosis.

Conclusion: Although low iodine diet related hyponatremia is rare complication, but consequences can be worse in patients undergoing RAI therapy, especially elderly patients who are on diuretics. Therefore, physicians should recognize this rare side effect for prompt intervention.

• Radiation oncology practised in public hospitals or private practice. • Adelaide Radiotherapy Centre is sole private practice provider of services in South Australia. • Corporate medicine not involved in radiation oncology. • Adelaide Radiotherapy Centre bought out by private company in 2008. • Rationale, benefits and disadvantages discussed.

Purpose: In this study the influence of clinical and morphological peculiarities of facial carcinoma on the results of treatment by means of Neodymium (Nd) laser radiation was estimated.

Methods: The light of high-energy mono pulsed Nd laser (λ = 1060 nm) was used to treat 2805 patients with 2940 histologically confirmed facial carcinoma, stages T1-2 N0 M0. Of those 2845 were classified as primary basal cell carcinoma (BCC) and 95 as squamous cells carcinoma (SCC). The patients were followed-up from 1 year to 13 years (median: 7 years) after treatment.

Results: The overall frequency of tumor recurrence after laser radiation was revealed in 2% of all irradiated tumors (median: 10.0 months). The rate of recurrence depended on type of tumors (1.9% in BCC and 5.3% in SCC), clinical peculiarities (3.5% in nodular-ulcerative and 4.5% infiltrative-ulcerative tumors), localization (3.2% in tumors located in nasolabial area) and tumor size.

Conclusion: Neodymium laser radiation is an effective method for treatment of facial carcinomas stages T1-2 N0 M0 whose results depend on tumor morphology, stage of the disease, clinical characteristics and localization

Background: We aimed to evaluate the outcomes and toxicity profile in patients with well differentiated thyroid carcinoma (WDTC) treated with intensity modulated radiation therapy (IMRT). Materials and methods: Between June 2007 and July 2011, 18 patients with WDTC received postoperative IMRT with mean radiation dose 66Gy (60-66) delivered with 7 dynamic beams. Median age was 50.5 years (23-66); of whom 10 were males (55.6%) and 8 were females (44.4%). Predominant histology was papillary in 17 patients (94.4%) and predominant T stage was T4 in 15 patients (83.3%). RAI therapy was given to all patients. Results: Median follow up was 53 months (6-55). At 48 months, the Kaplan-Meier estimates of locoregional control, distant control and overall survival were 88.9%, 83.2% and 89.4% respectively. Incomplete surgery, presence of lymphovascular invasion (LVI), and number of >4 positive lymph nodes were found as poor prognostic factors (0.0001). Acute grade 3 Mucositis was experienced in one patient (5.5%) and grade 3 skin toxicity was seen in 1 patient (5.5%). Late toxicities were few and of grade 2. Conclusion: Postoperative IMRT offers excellent locoregional and distant control rates and overall survival with minimal toxicity profile in the treatment of WDTC.

Adelaide Radiotherapy Centre is the private practice provider of radiation oncology services in South Australia. In 2004, it decided to have advanced trainees integrated into the practice. The purpose of this study is to - 1. Ascertain whether this has been a benefit for the trainees. 2. Decide whether the practice should continue with advanced training. 3. Decide methods to improve the training for trainees.

Esophagectomy is the main treatment for esophageal cancer. The 2 histologic subtypes of esophageal cancer are squamous cell carcinoma and adenocarcinoma; these subtypes have different biologic features and treatment strategies. Although the prognosis of patients treated with surgery alone remains unsatisfactory, neoadjuvant therapy helps to improve outcome. A meta-analysis revealed that neoadjuvant chemoradiotherapy provides survival benefits for both histologic types, while neoadjuvant chemotherapy is useful for adenocarcinoma. In Western countries, neoadjuvant chemoradiotherapy is a standard treatment for resectable advanced esophageal cancer, while neoadjuvant chemotherapy has become the standard treatment in Japan. Esophagectomy can be performed by several different approaches, including McKeown (cervico-thoraco-abdominal), Ivor-Lewis (thoraco-abdominal), and transhiatal approaches. It has been suggested that Minimally Invasive Esophagectomy (MIE) contributes to the reduction of pulmonary complications. Cervico-thoraco-abdominal 3-field lymphadenectomy may prolong survival, but a randomized control study on this subject has not been conducted. Mortality and morbidity rates after esophagectomy remain high. Several meta-analyses demonstrated that esophagectomy at low-volume hospitals was associated with a significant increase in the incidence of in-hospital and 30-day mortality. The influence of hospital volume on long-term outcome continues to be a subject of debate.

In conclusion, surgical resection remains the main treatment for potentially curable esophageal cancer. Neoadjuvant treatment can improve long-term outcome after esophagectomy. Furthermore, MIE may improve shortterm outcome, and 3-field lymph node dissection may reduce the risk of recurrence. The effects of these surgical procedures should be confirmed by randomized prospective studies.

Radiation therapy (RT) has demonstrated strong clinical benefits for patients who present a high relapse risk after breast conserving surgery or radical mastectomy. Unfortunately, the benefits of RT can be offset by its possible impacts on cardiac toxicity and increased risk of death from cardiac events. Additionally, recent radiological and radiotherapy techniques have allowed clinicians to better define target volumes and customize irradiation so that doses to the heart and left coronary artery can be accurately quantified. Alternative treatment positions, such as the lateral and prone positions are also being used. These positions can adapt to the patient’s anatomy and thus better protect the heart and lungs. This paper will report the outcomes for a patient who received breast cancer treatment after her treatment position and technique were optimized for ideal target volume coverage and minimum irradiation to organs at risk (OAR), particularly to the heart and lungs.

There are a number of codes, reports and protocols by national and international organizations, including IAEA, which provide physicists with a systematic approach to dosimetry of photon beams. Most of these dosimetry recommendations have explicitly recognized the advantages of using cylindrical ionization chambers for dosimetry of therapeutic beams, especially for photon beams with energies from kilo voltage (kV) to megavoltage (MV) x-ray. A commercial cylindrical ionization chamber (W-30001) was used as the reference chamber for compare measurements. The homemade 0.6cc ionization chamber (CC1) have been designed, fabricated, tested and calibrated. Measurements were made using a Farmer type 2670 electrometer together with these chambers. Leakage current, short-term stability, cable effect, repeatability and angular dependence of the CC1 and W-30001 were all tested and found to be in consistence with the international standard IEC 60731. Ion collection efficiency and polarity effect were determined during calibration of the chambers in Co-60. According to the preliminary test results the CC1 homemade chamber is found to be in consistence with the international standard IEC 60731. An advantage of CC1 chamber is a very low leakage current i.e. its specific insulation design and material.

Brain metastases are the most frequently observed cancerous lesions in the brain and their incidence has grown as advances in imaging technologies and the treatment of extracranial disease has allowed the life expectancy of cancer patients to increase. For this reason, determining optimal treatment regimens for specific subsets of patients with brain metastases is imperative for clinicians. The purpose of this article is to review the randomized controlled trials analyzing patients with brain metastases treated with neurosurgery, WBRT, and SRS to determine future research directions for physicians and scientists. For patients who have a Karnofsky Performance Status (KPS) ≥70 and a single, surgically accessible brain metastasis, surgical resection followed by post-operative WBRT has proven to be a superior treatment modality when compared to WBRT alone and surgical resection alone. Evidence suggests that the addition of WBRT to SRS results in increased levels of survival for patients who have a single brain metastasis and increased levels of local tumor control for patients who have 1 to 4 brain metastases. Questions remain regarding survival and tumor control in patients treated with SRS with or without WBRT, which warrants further clinical investigation into this controversial matter. Although several randomized controlled trials have been published assessing the clinical outcomes of patients with brain metastases treated with a variety of treatment modalities, many studies are limited by poor patient accrual and further randomized evidence is needed to guide clinicians in their future treatment decisions.

Purposes/Objective: Image-Guided Radiation Therapy has been shown to significantly decrease setup errors and correct for organ motions (by patient repositioning, referred to as shift here), thus allowing the use of a tight treatment margin. The objective of the present work is to show that our evidenced-based patient positioning technique (isocenter shift) can effectively reduce the overall setup error for the majority of prostate patients.

Methods and Materials: We reviewed and analyzed the pre-treatment CT scans of 87 prostate patients treated from 2005-2007. Each patient received 10-15 image-guided fractions in the first phase of the treatment course. By systematically analyzed the imaging data and comparing to the planning CT, the isocenter positioning in both the left-right and anterior-posterior directions in the second phase of the treatment course can be predicted, along with the selection of a patient specific posterior margin.

Results: For 90% of the patients, the isocenter correction can be predicted to within 95% confidence. 90% of the patients in the study have a posterior margin in the range 5-8 mm for the second phase of treatment. The outliers in the frequency distributions of the iso-shifts for both the left-right and anterior-posterior directions seems to indicate that more frequent image-guided sessions are required in order to improve the setup accuracy.

Conclusions: An adequate number of image-guided treatments provide a semi-pattern recognition approach for patient repositioning. This, together with the inclusion of a quasi-adaptive margin can accommodate the daily variance of the prostate positions and affords a 95% confidence limit for tumor coverage. Our evidence-based method can effectively reduce the systematic setup error which potentially could modify the cumulative dose distribution. The use of adaptive strategy as proposed in this work reduces the overall setup error.

This study aims at a method that employs deformable dose accumulation for the evaluation of the results of intensity-modulated radiation therapy (IMRT) in pelvic cases. Each fraction dose was derived from the planning dose through rigid transformation accounting for setup corrections. Daily cone-beam CT (CBCT) images were used to deform the daily fraction dose to a reference geometry, which in our study was the first fraction geometry. A commercial software system, MIMvista, was used to perform deformable image registration, dose deformation, and dose accumulation. The differences in distributions of accumulated dose and planned dose were observed. The application of deformable dose accumulation is particularly useful in final accumulated dose evaluation throughout radiotherapy treatment, especially for the cases where there are significant deformations of planning target volume (PTV) and organs at risk (OARs).