Long-Term Variations of Global Solar Radiation and Its Potential Effects at Dome C (Antarctica).

An empirical model to predict hourly global solar irradiance under all-sky conditions as a function of absorbing and scattering factors has been applied at the Dome C station in the Antarctic, using measured solar radiation and meteorological variables. The calculated hourly global solar irradiance agrees well with measurements at the ground in 2008-2011 (the model development period) and at the top of the atmosphere (TOA). This model is applied to compute global solar irradiance at the ground and its extinction in the atmosphere caused by absorbing and scattering substances during the 2006-2016 period. A sensitivity study shows that the responses of global solar irradiance to changes in water vapor and scattering factors (expressed by water vapor pressure and S/G, respectively; S and G are diffuse and global solar irradiance, respectively) are nonlinear and negative, and that global solar irradiance is more sensitive to changes in scattering than to changes in water vapor. Applying this empirical model, the albedos at the TOA and the surface in 2006-2016 are estimated and found to agree with the satellite-based retrievals. During 2006-2016, the annual mean observed and estimated global solar exposures decreased by 0.05% and 0.09%, respectively, and the diffuse exposure increased by 0.68% per year, associated with the yearly increase of the S/G ratio by 0.57% and the water vapor pressure by 1.46%. The annual mean air temperature increased by about 1.80 °C over the ten years, and agrees with the warming trends for all of Antarctica. The annual averages were 316.49 Wm-2 for the calculated global solar radiation, 0.332 for S/G, -46.23 °C for the air temperature and 0.10 hPa for the water vapor pressure. The annual mean losses of solar exposure due to absorbing and scattering substances and the total loss were 4.02, 0.19 and 4.21 MJ m-2, respectively. The annual mean absorbing loss was much larger than the scattering loss; their contributions to the total loss were 95.49% and 4.51%, respectively, indicating that absorbing substances are dominant and play essential roles. The annual absorbing, scattering and total losses increased by 0.01%, 0.39% and 0.28% per year, respectively. The estimated and satellite-retrieved annual albedos increased at the surface. The mechanisms of air-temperature change at two pole sites, as well as a mid-latitude site, are discussed.

The 2020 Arctic ozone depletion and signs of its effect on the ozone column at lower latitudes.

The present study discusses the effect of the ozone depletion that occurred over the Arctic in 2020 on the ozone column in central and southern Europe by analysing a data set obtained from ground-based measurements at six stations placed from 79 to 42°N. Over the northernmost site (Ny-Ålesund), the ozone column decreased by about 45% compared to the climatological average at the beginning of April, and its values returned to the normal levels at the end of the month. Southwards, the anomaly gradually reduced to nearly 15% at 42°N (Rome) and the ozone minimum was detected with a delay from about 6 days at 65°N to 20 days at 42°N. At the same time, the evolution of the ozone column at the considered stations placed below the polar circle corresponded to that observed at Ny-Ålesund, but at 42°-46°N, the ozone column turned back to the typical values at the end of May. This similarity in the ozone evolutional patterns at different latitudes and the gradually increasing delay of the minimum occurrences towards the south allows the assumption that the ozone columns at lower latitudes were affected by the phenomenon in the Arctic. The ozone decrease observed at Aosta (46°N) combined with predominantly cloud-free conditions resulted in about an 18% increase in the erythemally weighted solar ultraviolet irradiance reaching the Earth's surface in May.

Long-Term Performance Assessment of Low-Cost Atmospheric Sensors in the Arctic Environment.

The Arctic is an important natural laboratory that is extremely sensitive to climatic changes and its monitoring is, therefore, of great importance. Due to the environmental extremes it is often hard to deploy sensors and observations are limited to a few sparse observation points limiting the spatial and temporal coverage of the Arctic measurement. Given these constraints the possibility of deploying a rugged network of low-cost sensors remains an interesting and convenient option. The present work validates for the first time a low-cost sensor array (AIRQino) for monitoring basic meteorological parameters and atmospheric composition in the Arctic (air temperature, relative humidity, particulate matter, and CO2). AIRQino was deployed for one year in the Svalbard archipelago and its outputs compared with reference sensors. Results show good agreement with the reference meteorological parameters (air temperature (T) and relative humidity (RH)) with correlation coefficients above 0.8 and small absolute errors (≈1 °C for temperature and ≈6% for RH). Particulate matter (PM) low-cost sensors show a good linearity (r2 ≈ 0.8) and small absolute errors for both PM2.5 and PM10 (≈1 µg m-3 for PM2.5 and ≈3 µg m-3 for PM10), while overall accuracy is impacted both by the unknown composition of the local aerosol, and by high humidity conditions likely generating hygroscopic effects. CO2 exhibits a satisfying agreement with r2 around 0.70 and an absolute error of ≈23 mg m-3. Overall these results, coupled with an excellent data coverage and scarce need of maintenance make the AIRQino or similar devices integrations an interesting tool for future extended sensor networks also in the Arctic environment.

Variations in total ozone column and biologically effective solar UV exposure doses in Bologna, Italy during the period 2005-2010.

Variations in total ozone column and sun exposures able to cause erythema and damage the DNA molecules were observed by the narrow-band filter radiometer UV-RAD in Bologna, Italy from 2005 to 2010. The ozone columns determined from the UV-RAD measurements were found to be close to those provided by the satellite Ozone Monitoring Instrument (OMI) showing an average discrepancy of 1% with standard deviation of ± 6%. Analysis of the data highlights a well-marked annual cycle of the ozone column variations while the oscillations with periods of 8, 18 and 34 months present much smaller amplitudes. The influence of the frequency of solar irradiance measurements on the accuracy of the evaluated daily exposure dose has been studied and it was found that time intervals no longer than 5-10 min between the measurements of erythema and DNA damage effective UV irradiances provide a satisfactory assessment of the corresponding daily exposures. The latter do not present significant year-to-year variations for the period under study, while their annual distributions show slight changes likely due to the specific cloud cover and ozone column variability for different years. The annual erythemal exposure dose for 2007-2010 varied between 603.7 and 638.1 kJ m(-2), while the corresponding sun exposure affecting DNA changed from 6.38 to 7.91 kJ m(-2).

Preliminary assessment of the risks associated with solar ultraviolet-A exposure.

An approach is proposed to assess the periods of human skin exposure to solar ultraviolet-A (UV-A, 315-400 nm) irradiance in natural conditions that are able to yield doses found to trigger carcinogenesis in laboratory experiments. Weighting functions, adopted to perform such estimate are constructed, allowing for a comparison between environmental and laboratory doses. Furthermore, the impact of stratum corneum (SC) thickness on the studied environmental doses was investigated. Based on laboratory studies, it was found that exposure periods of less than a month, at mid-latitudes, could provide irradiance doses capable of causing tumor formation. The duration of these exposure periods closely depends on the exposure regime, atmospheric conditions and SC thickness. It is believed that the presented evaluations could provide a useful preliminary estimation of the risk associated with environmental UV-A exposure prior to the formulation of the corresponding action spectra and determination of the threshold doses.

Quality assurance of solar UV irradiance in the Arctic.

The first Arctic intercomparison of three solar ultraviolet (UV) spectroradiometers and two multifilter radiometers was held in May and June 2009 at Ny-Alesund, Svalbard, Norway. The transportable reference spectroradiometer QASUME acted as reference instrument for this intercomparison. The measurement period extended over eleven days, comprising clear sky and overcast weather conditions. Due to the high latitude, measurements could be performed throughout the day during this period. The intercomparison demonstrated that the solar UV measurements from all instruments agreed to within +/-15% during the whole measurement period, while the spectroradiometer from the Alfred-Wegener Institute agreed to better than +/-5%. This intercomparison has demonstrated that solar UV measurements can be performed reliably in the high-latitude Arctic environment with uncertainties comparable to mid-latitude sites.

Does treatment of the pelvic nodes with IMRT increase late rectal toxicity over conformal prostate-only radiotherapy to 76 Gy?

PURPOSE: To compare late rectal toxicity rates after three-dimensional conformal radiotherapy to the prostate alone (P-3D-CRT) and whole-pelvis intensity-modulated radiotherapy along with a prostate boost (WP-IMRT/PB) to the same nominal total dose to the prostate. PATIENTS AND METHODS: 68 patients treated with conformal radiotherapy to the prostate only to 76 Gy at the National Institute for Cancer Research, Genoa, Italy, represented the first group (P-3D-CRT). The second group consisted of 45 patients treated at the University of Texas Medical Branch (UTMB), Galveston, TX, USA, with IMRT covering the pelvic nodes and seminal vesicles to 54 Gy at 1.8 Gy per fraction and the prostate to 60 Gy in the same 30 fractions. A separate phase boosted the prostate to 76 Gy (WP-IMRT/PB). Major aspects of planning were remarkably similar at both institutions leaving the inclusion or not of pelvic nodes as the main treatment-related difference between the two groups. Late rectal toxicity was prospectively scored according to the RTOG scale. All patients have a 12-month minimum follow-up, and mean follow-up, similar in both groups, is 25.9 months (SD [standard deviation]: 8.4 months). RESULTS: At 2 years, the estimated cumulative incidence of grade 2 late rectal toxicity is 6%+/-4% for WP-IMRT/PB and 21.2%+/-6% for P-3D-CRT (p=0.06). The difference became significant (HR [hazard ratio]=0.1, 95% CI [confidence interval]: 0.0-0.6; p=0.01) at multivariate analysis. None of the patients developed grade 3+ toxicity. CONCLUSION: Despite the larger treated volume, WP-IMRT/PB allows more rectal sparing than P-3D-CRT.

Narrowband filter radiometer for ground-based measurements of global ultraviolet solar irradiance and total ozone.

The ultraviolet narrowband filter radiometer (UV-RAD) designed by the authors to take ground-based measurements of UV solar irradiance, total ozone, and biological dose rate is described, together with the main characteristics of the seven blocked filters mounted on it, all of which have full widths at half maxima that range 0.67 to 0.98 nm. We have analyzed the causes of cosine response and calibration errors carefully to define the corresponding correction terms, paying particular attention to those that are due to the spectral displacements of the filter transmittance peaks from the integer wavelength values. The influence of the ozone profile on the retrieved ozone at large solar zenith angles has also been examined by means of field measurements. The opportunity of carrying out nearly monochromatic irradiance measurements offered by the UV-RAD allowed us to improve the procedure usually followed to reconstruct the solar spectrum at the surface by fitting the computed results, using radiative transfer models with field measurements of irradiance. Two long-term comparison campaigns took place, showing that a mean discrepancy of +0.3% exists between the UV-RAD total ozone values and those given by the Brewer #63 spectroradiometer and that mean differences of +0.3% and -0.9% exist between the erythemal dose rates determined with the UV-RAD and those obtained with the Brewer #63 and the Brewer #104 spectroradiometers, respectively.

Very late nonfatal consequences of fractionated TBI in children undergoing bone marrow transplant.

PURPOSE: To describe long-term late consequences in children who received total body irradiation (TBI) for hematopoietic stem cell transplantation 10 years earlier. METHODS AND MATERIALS: A cohort of 42 children treated with TBI between 1985 and 1993, still alive at least 10 years after fractionated TBI (FTBI), was evaluated. Twenty-five patients received FTBI at 330 cGy/day for 3 days (total dose 990 cGy), whereas 17 children were administered fractions of 200 cGy twice daily for 3 days (total dose 1200 cGy). Twenty-seven patients received autologous and 16 allogeneic hematopoietic stem cell transplantation. Median age at TBI was 6.3 years, and 18.4 years at most recent follow-up. RESULTS: Cataract was diagnosed in 78% of patients after a median of 5.7 years. Hypothyroidism was detected in 12%, whereas thyroid nodules were observed in 60% of our population after a median interval of 10.2 years. Patients treated with 990 cGy developed thyroid nodules more frequently than those treated with 1200 cGy (p = 0.0002). Thyroid carcinoma was diagnosed in 14% of the total population. Females who received FTBI after menarche more frequently developed temporary ovarian dysfunction than those treated before menarche, but cases of persistent ovarian dysfunction did not differ between the two groups. Indirect signs of germinal testicular dysfunction were detected in 87% of males. Restrictive pulmonary disease was observed in 74% of patients. Osteochondroma was found in 29% of patients after a median interval of 9.2 years. This latter complication appeared more frequently in patients irradiated before the age of 3 years (p < 0.001). CONCLUSIONS: This study shows that late effects that are likely permanent, although not fatal, are frequent in survivors 10 years after TBI. However, some of the side effects observed shortly after TBI either disappeared or remained unchanged without signs of evolution. Monitoring is recommended to pursue secondary prevention strategies and counseling on family planning.

Improved algorithm for calculations of Rayleigh-scattering optical depth in standard atmospheres.

Precise calculations of the total Rayleigh-scattering optical depth have been performed at 88 wavelengths ranging from 0.20 to 4.00 microm for the six well-known standard atmosphere models by integrating the volume Rayleigh-scattering coefficient along the vertical atmospheric path from sea level to a 120-km height. The coefficient was determined by use of an improved algorithm based on the Ciddor algorithm [Appl. Opt. 35, 1566 (1996)], extended by us over the 0.20-0.23-microm wavelength range to evaluate the moist air refractive index as a function of wavelength, air pressure, temperature, water-vapor partial pressure, and CO2 volume concentration. The King depolarization factor was also defined taking into account the moisture conditions of air. The results indicate that the influence of water vapor on Rayleigh scattering cannot be neglected at tropospheric altitudes: for standard atmospheric conditions represented in terms of the U.S. Standard Atmosphere (1976) model, the relative variations produced by water vapor in the Rayleigh scattering parameters at a 0.50-microm wavelength turn out to be equal to -0.10% in the moist air refractivity at sea level (where the water-vapor partial pressure is equal to approximately 7.8 hPa), -0.04% in the sea-level King factor, -0.24% in the sea-level Rayleigh-scattering cross section, and -0.06% in the Rayleigh-scattering optical depth.

Audit of effectiveness of routine follow-up clinics after radiotherapy for cancer: a report of the REACT working group of ESTRO.

BACKGROUND AND PURPOSE: The European Society for Therapeutic Radiology and Oncology was funded by the EU for a project on recording providing education, and ameliorating the consequences of treatment (REACT). An European audit was carried out as part of which to assess the usefulness of current follow-up practices. PATIENTS AND METHODS: Over a 4-month period in 15 cancer centres in 10 countries, patients attending for routine follow-up completed a questionnaire covering their expectations of and satisfaction with the visit. This was matched with a questionnaire completed by the physician about the content and usefulness of the consultation. The feasibility of a short toxicity scale developed by Dische and Saunders was also investigated. RESULTS: In total, 2303 matched questionnaires were analysed. Forty percent of the patients had symptoms or medical problems related to their disease. In 18% there was a positive finding on clinical examination. In 28% investigations were undertaken part of departmental routine practice. Ten percent of the investigations showed an abnormal result. Ninety nine percent of physicians and 85% of the patients expressed satisfaction. Using the short toxicity scale rates of recording toxicity could be increased from 28 to 93%. CONCLUSIONS: There is wide variation in follow-up practices among European centres. There was a low incidence of positive findings clinically or with routine investigations. A simple scale for recording morbidity has proved easy to use by departments, which have not routinely used one of the standard measures. Further work will attempt to produce an European guideline for effective routine follow-up after radiotherapy.

Is there a "curative" role of radiotherapy for clinically localized hormone refractory prostate cancer?

Whether definitive radiotherapy (RT) is still an option for patients with clinically prostate-confined prostate cancer treated with androgen deprivation (AD) alone who develop a rising prostate-specific antigen (PSA) is not clear. In this retrospective series, we report the outcome of 29 such patients treated with "curative" radiotherapy at our institution between 1991 and 2000. At initial diagnosis, all patients had evidence of prostate-confined disease and for several reasons underwent AD alone. Afterward all patients developed rising PSA, but again, without clinical evidence of distant/pelvic node disease. All underwent RT with curative intent up to 70 Gy (66 to 76 Gy). Median follow-up after radiotherapy is 33.1 month (range: 7-134.2 months). For living patients, minimum and median follow-ups are 30.4 and 55.4 months, respectively. Twenty-three patients (79%) developed overt clinical disease, most of which (19/23, 83%) involved distant sites, whereas isolated locoregional failure was observed in only 4 patients (4/23, 17%). The estimates of locoregional control rate (LRC), actuarial incidence of distant metastases, and overall survival at 5 years are 89 +/- 7%, 68 +/- 9%, and 28 +/- 9%, respectively. Although we were unable to find any predictor of LRC at univariate analysis, patients with low Gleason score at diagnosis, lower PSA at RT, lower risk category and advanced age were less likely to develop distant disease. RT has a palliative role, because most patients with still presumed localized hormone refractory prostate cancer will develop distant metastases. A subset of patients, those with more differentiated tumor at diagnosis and with pre-RT PSA less than 20 ng/mL, might be considered for a more aggressive locoregional approach.

Contralateral parotid-sparing radiotherapy in patients with unilateral squamous cell carcinoma of the head and neck: technical methodology and preliminary results.

AIMS AND BACKGROUND: Radiation-induced permanent xerostomia occurs frequently in patients affected by squamous cell carcinoma of the head and neck treated by parallel opposed lateral fields. An ipsilateral technique by using co-planar multiple-field arrangement was designed to restrict treatment to the primary tumor and neck on the same side for patients with selected lateralized squamous cell carcinoma of the head and neck. METHODS: From November 2001 till December 2002, 30 patients affected by squamous cell carcinoma of tonsillar fossa, retromolar trigone, alveolar ridge and oropharyngeal lateral wall were included in this investigational trial and treated with an ipsilateral multiple field technique: in detail, oblique opposed two upper half fields were planned ipsilaterally to the squamous cell carcinoma site to cover PTV1 and PTV2, whereas an anterior-lower half field was planned to encompass the lower neck node area above clavicles. On CT scans, the contralateral parotid gland was outlined as organ at risk and the contralateral upper lymph node area was contoured as volume of interest. In selected cases, convergent oblique two wedge-pair half fields were added to opposed oblique two-field technique in order to cover only PTV2: generally, in these patients, PTV1 received 1.8 Gy per fraction and PTV2 2.2 Gy per fraction up to total doses of 54 Gy and 66 Gy, respectively. RESULTS: Ten patients received radical radiotherapy, 9 patients radical alternating chemo-radiotherapy, and 11 patients adjuvant radiotherapy. At the end of treatment, unilateral confluent mucositis was recorded in 13 (43%) patients and unilateral moist skin epidermolysis in 14 (46%) patients. Six months after the end of radiotherapy, grade 0 xerostomia was recorded in 20 (67%) patients. No patient experienced grade 2+ xerostomia. At a median follow-up of 12 months, 26 (86%) patients were alive and well; 2 patients (6%) developed contralateral neck node failure, both 4 months after the end of ipsilateral radiotherapy. CONCLUSIONS: These results, although preliminary, suggest that by using an ipsilateral radiotherapy technique, symptomatic xerostomia may be avoided in selected patients with lateralized squamous cell carcinoma of the head and neck without an increased short-term risk of contralateral nodal failure.

Sucralfate versus mesalazine versus hydrocortisone in the prevention of acute radiation proctitis during conformal radiotherapy for prostate carcinoma. A randomized study.

PURPOSE: To assess whether the topical use of steroids or 5-aminosalicylic acid (5-ASA) is superior to sucralfate in preventing acute rectal toxicity during three-dimensional conformal radiotherapy (3DCRT) to 76 Gy. PATIENTS AND METHODS: Patients undergoing 3DCRT for prostate carcinoma at our institution were offered to be randomized to sucralfate 3 g in 15 ml suspension enema (Antepsin, mesalazine 4 g gel enema (Enterasyn, or hydrocortisone 100 mg foam enema (Colifoam. Randomization was blind to the treating physician but not to the patient. Sucralfate was chosen as control arm. Topical treatment had to be performed once daily, starting on day 1 of 3DCRT. Acute rectal toxicity was scored weekly according to RTOG criteria. Time to occurrence of grade 2+ acute rectal toxicity was taken as endpoint. RESULTS: The trial was opened in August 1999, and after the first 24 patients had been treated, arm 2 was discontinued because of eight patients receiving mesalazine, seven actually developed acute rectal toxicity (five patients grade 3 and two patients grade 2). Until May 2001, 134 consecutive patients were randomly assigned to sucralfate (63 patients), mesalazine (eight patients) or hydrocortisone (63 patients). The cumulative incidence of acute rectal toxicity at the end of treatment by arm is 61.9 +/- 6.1%, 87.5 +/- 11.7%, and 52.4 +/- 6.2% for arms 1, 2, and 3, respectively. The difference between the mesalazine group and the sucralfate group is highly significant (hazard ratio [HR] 2.5, 95% confidence interval [CI] 1.1-5.7; p = 0.03). At both uni- and multivariate analysis taking into account several patients and treatment covariates, the difference between hydrocortisone and sucralfate is not significant (HR 0.7, 95% CI 0.5-1.2; p = 0.2). CONCLUSION: Topical mesalazine is contraindicated during radiotherapy. Hydrocortisone enema is not superior to sucralfate in preventing acute rectal toxicity.

Neoadjuvant androgen deprivation and prostate gland shrinkage during conformal radiotherapy.

PURPOSE: The shrinking effect of 3-month neoadjuvant androgen deprivation (NAD) on preradiotherapy prostate gland volume is well documented. However, recently, it has been shown that the cancerous prostate gland keeps shrinking up to 12 months after NAD start. Thus, if such a reduction is not taken into account, a larger than planned portion of the surrounding normal tissues might shift in the high-dose region during conformal radiotherapy (3DCRT) course. The present study was undertaken to quantify this issue. MATERIALS AND METHODS: Prostate gland volume reduction between planning CT (plCT) and the last week of 3DCRT (tmtCT) was prospectively assessed in 33 consecutive patients with localized prostate carcinoma. The median time interval between plCT and tmtCT was 2.5 months (2.1-2.7 months). A single observer was asked to draw on each slice prostate gland volume as appropriate. The observer was 'blind' to the timing of CT (plCT vs. tmtCT). In order to estimate intra-observer variability, prostate gland delineation was repeated twice for each data set. Mean prostate gland change, plCT and tmtCT cumulative dose volume histogram (DVH) calculations for the rectum were analyzed for each patient. Results were correlated to AD status and its duration before plCT. Means were compared by non-parametric rank tests. RESULTS: Based on an internal protocol, 14 patients (42%) did not receive AD, while 19 patients (58%) had undergone neoadjuvant and concomitant AD. The median duration of AD before plCT ranged from 0.2 to 6 months (median: 2.9 months). Although individual data were highly variable, compared to plCT volume, mean prostate gland volume change at the end of 3DCRT was similar for patients receiving (-7.3%) or not (-7%) androgen deprivation (P=0.77). However, within the group of patients treated with hormones, patients starting AD within 3 months from plCT had a significantly larger reduction in prostate volume (-14.2%) than patients with longer NAD duration (-1.1%, P=0.03). At tmtCT, on average, patients undergoing 3DCRT within 3 months from AD start showed an increase of the amount of rectum receiving 40-75 Gy compared to plCT values. At 40 Gy (V40) the mean difference between tmtCT and plCT was +7.5%. In the other two groups, average variations of V40-70 were within +/-2% of plCT values. However, these differences are not significant. CONCLUSION: For patients who undergo plCT and 3DCRT shortly after AD start, prostate gland shrinkage may be substantial. In some of these patients, this might lead to an unexpected increase of the percentage of rectal wall exposed to intermediate doses.

Late local treatment morbidity after accelerated radiotherapy or alternating chemoradiotherapy for advanced head and neck carcinoma.

BACKGROUND: To report local long-term morbidity after concomitant boost radiotherapy (AFRT) or alternating chemoradiotherapy (CTRT), we analyzed the toxicity data recorded in 168 patients with advanced head and neck squamous cell carcinoma treated at our institution within phase II-III studies. PATIENTS AND METHODS: All patients enrolled in three consecutive phase II-III studies and followed for a minimum of three months after the end of treatment were included in the present analysis. Local late reactions were scored prospectively. The actuarial incidence of grade 2 or more (2-4) late local toxicity according to RTOG/EORTC was taken as endpoint. The median follow-up is 32.0 months (range, 3.3-138.1 months). For living patients the minimum and median follow-up are 12.1 and 69.3 months, respectively. RESULTS: The five-year actuarial incidence of grade 2+ and grade 3+ toxicity are 56.7 +/- 5% and 21 +/- 4%, respectively. At multivariate analysis, acute mucositis grade, complementary surgery, primary site and performance status proved to be independent predictive factors of grade 2+ late toxicity with P values of <0.001, 0.009, 0.022 and 0.033, respectively. No effect was found for treatment itself on the incidence of late toxicity, although patients treated with accelerated radiotherapy had a higher probability of confluent mucositis than patients treated with alternating chemoradiotherapy (68% vs 32%, P <0.01). CONCLUSIONS: A substantial proportion of surviving patients develops late complications, although severe irreversible reactions occur in a minority of patients. Acute local toxicity can be used to predict local late toxicity that arises within five years of the end of treatment.

Bladder cancer.

Bladder cancer is the second most frequent tumour of the urogenital tract. Tobacco smoke has been shown to increase the risk of bladder cancer two- to fivefold as well as the exposure to metabolites of aniline dyes and other aromatic amines. Seventy-five per cent of bladder cancers are superficial at initial presentation, limited to the mucosa, submucosa, or lamina propria. Recurrence rates after initial treatment are 50-80%, with progression to muscle-invading tumour in 10-25%. In muscle-invading bladder cancers, there is a 50% risk of distant metastases. Surgery is the mainstay of standard treatment both in the form of transurethral endoscopic resection, mainly for superficial disease, and in the form of open ablative surgery with urinary diversion for muscle invasive disease. Endovesical administration of BCG has been employed after endoscopic resection as the most effective agent for both prophylaxis of disease recurrence and progression from superficial to invasive disease. The accepted treatment for muscle infiltrative disease is radical cystectomy. Response rates to combination chemotherapy regimens of up to 70% in patients with advanced metastatic disease have led to an investigation of its use for locally invasive disease in combination with conventional modalities of treatment.

Radiotherapy after prostatectomy.

AIMS AND BACKGROUND: The role of radiotherapy after prostatectomy is controversial. This paper tries to give some guidelines for everyday practice through an analysis of literature data. METHODS: The potential role of radiotherapy in the adjuvant and salvage setting is discussed. We also report and interpret available literature data for both settings. RESULTS: As regards an increase in or detectable prostate-specific antigen (PSA) after radical prostatectomy, about 40-50% of patients are rendered bNED with local salvage radiotherapy, but only 10-50% are long-term (5 years) biochemically controlled. A timely salvage treatment is crucial to optimize control probability. As regards adjuvant radiotherapy for undetectable postoperative PSA in patients at high risk of failure as judged on pathology, results are more encouraging. Recent data report bNED rates > 70% at 5 years. CONCLUSIONS: Although results are far from satisfactory, salvage radiotherapy should be considered for every patient with an increased or detectable PSA after surgery. Adjuvant radiotherapy seems preferable to salvage radiotherapy for patients at high (> 30%) risk of failure.