Lower abdominal and pelvic radiation and testicular germ cell tumor risk.

BACKGROUND: Testicular germ cell tumor (TGCT) incidence has increased in recent decades along with the use and dose of diagnostic radiation. Here we examine the association between reported exposure to diagnostic radiation and TGCT risk. METHODS: We conducted a case-control study of men with and without TGCT recruited from hospital- and population-based settings. Participants reported on exposures to 1) x-ray or CT below the waist and 2) lower GI series or barium enema, which consists of a series of x-rays of the colon. We also derived a combined measure of exposure. We used logistic regression to determine the risk of developing TGCT according to categories of exposures (0, 1-2, or ≥3 exposures) and age at first exposure, adjusting for age, year of birth, race, county, body mass index at diagnosis, family history of TGCT, and personal history of cryptorchidism. RESULTS: There were 315 men with TGCT and 931 men without TGCT in our study. Compared to no exposures, risk of TGCT was significantly elevated among those reporting at least three exposures to x-ray or CT (OR≥3 exposures, 1.78; 95% CI, 1.15-2.76; p = 0.010), lower GI series or barium enema (OR≥3 exposures, 4.58; 95% CI, 2.39-8.76; p<0.001), and the combined exposure variable (OR≥3 exposures, 1.59; 95% CI, 1.05-2.42; p = 0.029). The risk of TGCT was elevated for those exposed to diagnostic radiation at age 0-10 years, compared to those first exposed at age 18 years or later, although this association did not reach statistical significance (OR, 2.00; 95% CI, 0.91-4.42; p = 0.086). CONCLUSIONS: Exposure to diagnostic radiation below the waist may increase TGCT risk. If these results are validated, efforts to reduce diagnostic radiation doses to the testes should be prioritized.

Intensity-modulated Radiotherapy for Anal Cancer: Dose-Volume Relationship of Acute Gastrointestinal Toxicity and Disease Outcomes.

AIMS: Intensity-modulated radiotherapy (IMRT) is increasingly used in the treatment delivery of chemoradiotherapy in anal cancer with the ability to reduce toxicity. We report on 4 year outcomes since the introduction of IMRT and identify the most predictive bowel organ at risk that correlates with acute diarrhoea. MATERIALS AND METHODS: Fifty-eight patients receiving definitive chemoradiotherapy for squamous or basaloid cell anal carcinoma (T1-4NanyM0) were reviewed. Fifty-four per cent of patients had stage III disease and most (79%) were treated with a dose of 54 Gy in 30 fractions. Patient acute gastrointestinal toxicity was recorded using Common Terminology Criteria of Adverse Events (CTCAE) diarrhoea grading. Four different methods of bowel were re-contoured for each patient and correlated with acute diarrhoea. Locoregional control and overall survival were analysed. RESULTS: CTCAE grade 3 or more diarrhoea occurred in 11/58 patients (19%). Seven patients did not complete treatment; 10 patients (17%) required a treatment break of 3 or more days. 'Bowel cavity' was the best predictor of acute grade 3 toxicity using volume (P = 0.002) or volume to bowel cavity in 5 Gy bins (V5-V50Gy); P < 0.05. Bowel cavity V30Gy ≤ 300 cm3 predicts a 6% grade 3 diarrhoea risk versus > 300 cm3 predicts a 42% risk. Four year progression-free survival was 84% (95% confidence interval 73-92%) and overall survival was 88% (95% confidence interval 75-95%). CONCLUSION: Chemoradiation using IMRT provides excellent local control and acceptable acute gastrointestinal toxicity. Bowel cavity is the most sensitive predictor for grade 3 versus grade 0-2 diarrhoea, with any volume receiving 5-50 Gy discriminatory.

Can We Spare the Pancreas and Other Abdominal Organs at Risk? A Comparison of Conformal Radiotherapy, Helical Tomotherapy and Proton Beam Therapy in Pediatric Irradiation.

OBJECTIVES: Late abdominal irradiation toxicity during childhood included renal damage, hepatic toxicity and secondary diabetes mellitus. We compared the potential of conformal radiotherapy (CRT), helical tomotherapy (HT) and proton beam therapy (PBT) to spare the abdominal organs at risk (pancreas, kidneys and liver- OAR) in children undergoing abdominal irradiation. METHODS: We selected children with abdominal tumors who received more than 10 Gy to the abdomen. Treatment plans were calculated in order to keep the dose to abdominal OAR as low as possible while maintaining the same planned target volume (PTV) coverage. Dosimetric values were compared using the Wilcoxon signed-rank test. RESULTS: The dose distribution of 20 clinical cases with a median age of 8 years (range 1-14) were calculated with different doses to the PTV: 5 medulloblastomas (36 Gy), 3 left-sided and 2 right-sided nephroblastomas (14.4 Gy to the tumor + 10.8 Gy boost to para-aortic lymphnodes), 1 left-sided and 4 right-sided or midline neuroblastomas (21 Gy) and 5 Hodgkin lymphomas (19.8 Gy to the para-aortic lymphnodes and spleen). HT significantly reduced the mean dose to the whole pancreas (WP), the pancreatic tail (PT) and to the ipsilateral kidney compared to CRT. PBT reduced the mean dose to the WP and PT compared to both CRT and HT especially in midline and right-sided tumors. PBT decreased the mean dose to the ispilateral kidney but also to the contralateral kidney and the liver compared to CRT. Low dose to normal tissue was similar or increased with HT whereas integral dose and the volume of normal tissue receiving at least 5 and 10 Gy were reduced with PBT compared to CRT and HT. CONCLUSION: In children undergoing abdominal irradiation therapy, proton beam therapy reduces the dose to abdominal OAR while sparing normal tissue by limiting low dose irradiation.

[Impact of abdominal cavity open EHF irradiation on activity of adhesive process in peritonitis].

In experiment on 45 rats a purulent peritonitis was simulated. There was established, that on background of a standard therapy for peritonitis application of abdominal cavity open irradiation of extreme high frequency (EHF) have promoted rapid stabilization of the lipid metabolism indices and the blood coagulation system, the reduction of intensity of lipids peroxidal oxidation processes and severity of systemic inflammatory reaction. Under the influence of complex treatment the severity of adhesive process was reduced in 5.4 times, comparing with such in animals, to whom a standard treatment was conducted only. The revealed pathogenetic aspects of the adhesions formation witnesses the expediency to add EHF irradiation to complex therapy of peritonitis.

Combined external and intracavitary irradiation in treatment of advanced cervical carcinomas: predictive factors for treatment outcome and early and late radiation reactions.

OBJECTIVE: The objective of this study was to find out predictive factors of tumor control as well as acute and late radiation reactions in treatment of advanced cervical carcinomas. METHODS: In a series of 134 primary cervical carcinomas in International Federation of Gynecology and Obstetrics stages I to IV treated with combined external pelvic and intraluminal cervical-vaginal brachytherapy, predictive and prognostic factors were analyzed with regard to tumor control, recurrences, survival data, and adverse effects. Concomitant chemotherapy was given to 48 patients (35.8%). The external beam therapy was given with a 4-field technique (50-60 Gy) and brachytherapy was given with a high-dose rate (iridium-192) afterloading technique using a ring applicator set. A computed tomographically based 3-dimensional dose-planning system was used for the external beam therapy and for the brachytherapy planning. The mean age of the patients was 65 years. A total of 110 tumors were squamous cell carcinomas and 24 were adenocarcinomas or adenosquamous carcinomas. A total of 111 tumors were in International Federation of Gynecology and Obstetrics stages I to II; 23 tumors, in stages III to IV. RESULTS: The primary control rate of the complete series was 92.5%. Tumor size, the brachytherapy dose, the combined external and brachytherapy dose, as well as the number of days of interruption (delay) of irradiation were all significant predictive factors for local tumor control. Forty recurrences (30%) were recorded. Early radiation reactions were recorded in 67% (mostly grade 1) and were associated with the widths of the anterior-posterior and lateral pelvic fields. Serious late radiations reactions (grade 3-4) were noted in 11%. CONCLUSIONS: The width of the lateral pelvic fields, left point A and B doses, dose to the rectal reference point, as well as asymmetry of the dose distribution were associated with late severe reactions. Prior abdominal and pelvic surgery was also a high-risk factor for late tissue reactions. Concomitant chemotherapy did not increase the risk for acute or late toxicity.

An improved approach to external beam radiation therapy for intra-abdominal cavity lesions for rural cancer centers.

Radiation therapy of abdominal lesions is problematic at best. The proximity of highly critical structures, tumor locations, and necessary margins combine to make prescription dose delivery with conventional 3-dimensional (3D) conformal techniques difficult. Others have tried to overcome these hurdles with newer modalities including intra-operative radiation therapy (IORT), intensity modulated radiation therapy (IMRT), and heavy particle irradiation. These techniques have had moderate success but are not readily available and are therefore limited in application. These factors have lead to the development of a modified, noncoplanar 4-field box technique that demonstrates significant improvement in critical structure sparing, i.e., kidney(s), bowel, and liver doses reduced while simultaneously improving isodose coverage to the target.

Radiation risk assessment in neonatal radiographic examinations of the chest and abdomen: a clinical and Monte Carlo dosimetry study.

Seeking to assess the radiation risk associated with radiological examinations in neonatal intensive care units, thermo-luminescence dosimetry was used for the measurement of entrance surface dose (ESD) in 44 AP chest and 28 AP combined chest-abdominal exposures of a sample of 60 neonates. The mean values of ESD were found to be equal to 44 +/- 16 microGy and 43 +/- 19 microGy, respectively. The MCNP-4C2 code with a mathematical phantom simulating a neonate and appropriate x-ray energy spectra were employed for the simulation of the AP chest and AP combined chest-abdominal exposures. Equivalent organ dose per unit ESD and energy imparted per unit ESD calculations are presented in tabular form. Combined with ESD measurements, these calculations yield an effective dose of 10.2 +/- 3.7 microSv, regardless of sex, and an imparted energy of 18.5 +/- 6.7 microJ for the chest radiograph. The corresponding results for the combined chest-abdominal examination are 14.7 +/- 7.6 microSv (males)/17.2 +/- 7.6 microSv (females) and 29.7 +/- 13.2 microJ. The calculated total risk per radiograph was low, ranging between 1.7 and 2.9 per million neonates, per film, and being slightly higher for females. Results of this study are in good agreement with previous studies, especially in view of the diversity met in the calculation methods.