A simple clinical method for predicting the benefit of prone vs. supine positioning in reducing heart exposure during left breast radiotherapy

Background and purpose

The benefit of reduced radiation heart exposure in the prone vs. supine position individually differs. In this prospective cohort study, the goal was to develop a simple method for the operation of a validated model for the prediction of preferable treatment position during left breast radiotherapy.

Clinical use of stereoscopic X-ray positioning of patients treated with conformal radiotherapy for prostate cancer

PURPOSE: To evaluate accuracy and time requirements of a stereoscopic X-ray-based positioning system in patients receiving conformal radiotherapy to the prostate. METHODS AND MATERIALS: Setup errors of the isocenter with regard to the bony pelvis were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) and infrared marker (IR) based positioning in each of 261 treatments. In each direction, the random error represents the standard deviation and the systematic error the absolute value of the mean position. Time measurements were done in 75 treatments. RESULTS: Random errors with the X-ray positioning system in the anteroposterior (AP), lateral, and longitudinal direction were (average +/- 1 standard deviation) 2 +/- 0.6 mm, 1.7 +/- 0.6 mm, and 2.4 +/- 0.7 mm. The corresponding values of conventional as well as IR positioning were significantly higher (p < 0.01). Systematic errors for X-ray positioning were 1.1 +/- 1.2 mm AP, 0.6 +/- 0.5 mm laterally, and 1.5 +/- 1.6 mm longitudinally. Conventional and IR marker-based positioning showed significantly larger systematic errors AP and laterally, but longitudinally, the difference was not significant. Depending on the axis looked at, errors of >or=5 mm occurred in 2%-14% of treatments after X-ray positioning, 13%-29% using IR markers, and 28%-53% with conventional positioning. Total linac time for one treatment session was 14 min 51 s +/- 4 min 18 s, half of which was used for the X-ray-assisted positioning procedure. CONCLUSION: X-ray-assisted patient positioning significantly improves setup accuracy, at the cost of an increased treatment time.     

The effect of patient positioning (prone or supine) on the dose received by small bowel in pelvic radiotherapy in rectal cancer patients

PurposeThe small bowel is a main dose-limiting organ in pelvic radiotherapy in the patients with rectal cancer. Conventionally, pelvic radiotherapy of patients with rectal cancer is performed in the prone position.Material and MethodsThirty-nine patients underwent CT planning scan in the treatment position (20 patients in prone position group and 19 patients in supine position group). After radiation treatment planning optimization, the volumes of the irradiated small intestines were investigated.ResultsThe volume of irradiated small bowel was higher in the supine position (mean difference; 36,274 cm³). However, it was not statistically significant (P value = 0.187)ConclusionSupine position could be accepted for the patients undergoing preoperative rectal cancer chemo-radiation.     

Risk-adapted androgen deprivation and escalated three-dimensional conformal radiotherapy for prostate cancer: Does radiation dose influence outcome of patients treated with adjuvant androgen deprivation? A GICOR study.

PURPOSE: Multicenter study conducted to determine the impact on biochemical control and survival of risk-adapted androgen deprivation (AD) combined with high-dose three-dimensional conformal radiotherapy (3DCRT) for prostate cancer. Results of biochemical control are reported. PATIENTS AND METHODS: Between October 1999 and October 2001, 416 eligible patients with prostate cancer were assigned to one of three treatment groups according to their risk factors: 181 low-risk patients were treated with 3DCRT alone; 75 intermediate-risk patients were allocated to receive neoadjuvant AD (NAD) 4-6 months before and during 3DCRT; and 160 high-risk patients received NAD and adjuvant AD (AAD) 2 years after 3DCRT. Stratification was performed for treatment/risk group and total radiation dose. RESULTS: After a median follow-up of 36 months (range, 18 to 63 months), the actuarial biochemical disease-free survival (bDFS) at 5 years for all patients was 74%. The corresponding figures for low-risk, intermediate-risk, and high-risk disease were 80%, 73%, and 79%, respectively (P = .847). Univariate analysis showed that higher radiation dose was the only significant factor associated with bDFS for all patients (P = .0004). When stratified for treatment group, this benefit was evident for low-risk patients (P = .009) and, more interestingly, for high-risk patients treated with AAD. The 5-year bDFS for high-risk patients treated with AAD was 63% for radiation doses less than 72 Gy and 84% for those > or = 72 Gy (P = .003). CONCLUSION: The results of combined AAD plus high-dose 3DCRT are encouraging. To our knowledge, this is the first study showing an additional benefit of high-dose 3DCRT when combined with long-term AD for unfavorable disease.     

Influence of organ motion on conformal vs. intensity-modulated pelvic radiotherapy for prostate cancer

PURPOSE: To compare an intensity-modulated radiotherapy (IMRT) planning approach for prostate pelvic RT with a conformal RT (CRT) approach taking into account the influence of organ-at-risk (OAR) motion. METHODS AND MATERIALS: A total of 20 male patients, each with one planning computed tomography scan and five to eight treatment computed tomography scans, were used for simulation of IMRT and CRT for delivery of a prescribed dose of 50 Gy to the prostate, seminal vesicles, and pelvic lymph nodes. Planning was done in Eclipse without correcting for OAR motion. Evaluation was performed using the CRT and IMRT dose matrices and the planning and treatment OAR outlines. The generalized equivalent uniform dose (gEUD) was calculated for 894 OAR volumes using a volume-effect parameter of 4, 12, and 8 for bowel, rectum and bladder, respectively. For the bowel, the gEUD was normalized to a reference volume of 200 cm(3). For each patient and each OAR, an average of the treatment gEUDs (gEUD(treat)) was calculated for CRT and IMRT. The paired t test was used to compare IMRT with CRT and gEUD(treat) with gEUD(plan). RESULTS: The mean gEUD(treat) was reduced from 43 to 40 Gy, 47 to 46 Gy, and 48 to 45 Gy with IMRT for the bowel, rectum, and bladder, respectively (p < 0.001). Differences between the gEUD(plan) and gEUD(treat) were not significant (p > 0.05) for any OAR but was >6% for the bowel in 6 of 20 patients. CONCLUSION: Intensity-modulated RT reduced the bowel, rectum, and bladder gEUDs also under influence of OAR motion. Neither CRT nor IMRT was robust against bowel motion, but IMRT was not less robust than CRT.     

Dose-volume relationship for acute side effects during high dose conformal radiotherapy for prostate cancer.

PURPOSE: To determine acute and late complications for bladder and rectum and to determine dose-volume correlations. METHODS AND MATERIALS: Sixty-four patients received definitive treatment for prostate cancer between January 1995 and December 1998 using conformal three-dimensional radiotherapy. Doses ranged from 72 to 80Gy. The acute and late side effects were gathered retrospectively, and graded according to Radiotherapy and Oncology Group criteria (RTOG). The patients were divided into two groups: or=76Gy (Group B) and had a mean follow-up of 32 and 22 months, respectively. RESULTS: No grades 3-4 acute, urinary or rectal toxicity was reported. Acute grade 2 rectal complications were seen in 10 and 18% of the patients in Groups A and B, respectively. They were observed at a mean dose of 38Gy. Acute grade 2 urinary symptoms were 33 and 47% for Groups A and B, respectively. They were seen at a mean dose of 43Gy. Acute rectal symptoms were dose-volume related. Patients without diarrhea had a mean rectal volume receiving a dose of 70Gy or more of 8.5 cm(3). However, patients with RTOG 2 diarrhea had a volume of 16.5 cm(3) (P=0.042). No dose-volume relationship for acute bladder symptoms or late complications were seen. Grades 1-2 late rectal and bladder complications were seen in 11 and 8% of the patients, respectively. None required hospital admission or transfusion. CONCLUSION: Radiotherapy to the prostate can be given at 80Gy. No grades 3-4 acute, urinary or rectal toxicity was reported. Acute rectal symptoms are dose-volume related.     

The early toxicity of escalated versus standard dose conformal radiotherapy with neo-adjuvant androgen suppression for patients with localised prostate cancer: results from the MRC RT01 trial (ISRCTN47772397).

BACKGROUND: Five-year disease-free survival rates for localised prostate cancer following standard doses of conventional radical external beam radiotherapy are around 80%. Conformal radiotherapy (CFRT) raises the possibility that radiotherapy doses can be increased and long-term efficacy outcomes improved, with safety an important consideration. METHODS: MRC RT01 is a randomised controlled trial of 862 men with localised prostate cancer comparing Standard CFRT (64Gy/32f) versus Escalated CFRT (74Gy/37f), both administered with neo-adjuvant androgen suppression. Early toxicity was measured using physician-reported instruments (RTOG, LENT/SOM, Royal Marsden Scales) and patient-reported questionnaires (MOS SF-36, UCLA Prostate Cancer Index, FACT-P). RESULTS: Overall early radiotherapy toxicity was similar, apart from increased bladder, bowel and sexual toxicity, in the Escalated Group during a short immediate post-radiotherapy period. Toxicity in both groups had abated by week 12. Using RTOG Acute Toxicity scores, cumulative Grade 2 bladder and bowel toxicity was 38% and 30% for Standard Group and 39% and 33% in Escalated Group, respectively. Urinary frequency (Royal Marsden Scale) improved in both groups from pre-androgen suppression to 6 months post-radiotherapy (p<0.001), but bowel and sexual functioning deteriorated. This pattern was supported by patient-completed assessments. Six months after starting radiotherapy the incidence of RTOG Grade > or = 2 side-effects was low (<1%); but there were six reports of rectal ulceration (6 Escalated Group), six haematuria (5 Escalated Group) and eight urethral stricture (6 Escalated Group). CONCLUSIONS: The two CFRT schedules with neo-adjuvant androgen suppression have broadly similar early toxicity profiles except for the immediate post-RT period. At 6 months and compared to before hormone therapy, bladder symptoms improved, whereas bowel and sexual symptoms worsened. These assessments of early treatment safety will be complemented by further follow-up to document late side-effects and efficacy.     

Complications from radiotherapy dose escalation in prostate cancer: preliminary results of a randomized trial

OBJECTIVE: To compare early and late side effects in prostate cancer patients with Stage T1b-T3 disease randomized to receive 70 Gy or 78 Gy. METHODS: There were 189 patients randomized with a minimum follow-up of 2 years, that were available for this analysis. All patients were initially treated with a 4-field box to an isocenter dose of 46 Gy at 2 Gy per fraction. In the 70-Gy arm, treatment was continued to a reduced volume using a 4-field box technique. In the 78-Gy arm, treatment was continued to a reduced volume using a conformal 6-field arrangement. Side effects were graded on a 1-4 scale, adapted from Radiation Therapy Oncology Group and Late Effects Normal Tissue Task Force criteria. RESULTS: No significant differences in acute rectal or bladder toxicity were seen between the two treatment techniques (p > 0.6 for all comparisons). The 5-year Kaplan-Meier risks of Grade 2 or higher late bladder toxicity were 20% and 9% for 70-Gy and 78-Gy groups, respectively (log rank, p = 0.8). The 5-year risks of Grade 2 or higher late rectal toxicity were 14% and 21% for 70 Gy and 78 Gy, respectively (p = 0.4). Dose-volume histogram analysis of the 78-Gy patients showed a significant correlation between the percentage of rectum irradiated to 70 Gy or greater and the likelihood of developing late rectal complications. Patients with more than 25% of the rectum receiving 70 Gy or greater had a 5-year risk of Grade 2 or higher complications of 37% compared to 13% for patients with 25% or less (p = 0.05). All three Grade 3 complications occurred when greater than 30% of the rectum received 70 Gy or more. CONCLUSION: The overall rate of complications was similar in both treatment arms. However, there is evidence for a significant increase in late rectal complications when more than 25% of the rectum received 70 Gy or greater. This parameter may serve as a benchmark for the design of future three-dimensional conformal trials.     

A randomized trial of external beam radiotherapy versus cryoablation in patients with localized prostate cancer

BACKGROUND:

Localized prostate cancer can be treated several different ways, but head‐to‐head comparisons of treatments are infrequent. The authors of this report conducted a randomized, unblinded, noninferiority trial to compare cryoablation with external beam radiotherapy in these patients.

METHODS:

From December 1997 through February 2003, 244 men with newly diagnosed localized prostate cancer were assigned randomly to receive either cryoablation or radiotherapy (122 men in each arm). All received neoadjuvant antiandrogen therapy. The primary endpoint was disease progression at 36 months based on a trifecta definition: 1) radiologic evidence of metastatic disease, or 2) initiation of further antineoplastic therapy, or 3) biochemical failure. Two definitions of biochemical failure were used: 1) 2 consecutive rises in prostate‐specific antigen (PSA) with a final value >1.0 ng/mL, and 2) a rise above PSA nadir + 2 ng/mL. Secondary endpoints included overall survival, disease‐specific survival, and prostate biopsy at 36 months.

RESULTS:

The median follow‐up was 100 months. Disease progression at 36 months was observed in 23.9% (PSA nadir + 2 ng/mL, 17.1%) of men in the cryoablation arm and in 23.7% (PSA nadir + 2 ng/mL, 13.2%) of men in the radiotherapy arm. No difference in overall or disease‐specific survival were observed. At 36 months, more patients in the radiotherapy arm had a cancer‐positive biopsy (28.9%) compared with patients in the cryoablation arm (7.7%).

CONCLUSIONS:

The observed difference in disease progression at 36 months was small, 0.2%; however, because of the wide confidence interval, from ?10.8% to 11.2%, it was not possible to rule out inferiority (defined a priori as a 10% difference). With longer term follow‐up, the trend favors cryoablation. Significantly fewer positive biopsies were documented after cryoablation than after radiotherapy. Cancer 2010. © 2010 American Cancer Society.     

Internal organ motion in prostate cancer patients treated in prone and supine treatment position.

BACKGROUND AND PURPOSE: To compare supine and prone treatment positions for prostate cancer patients with respect to internal prostate motion and the required treatment planning margins. MATERIALS AND METHODS: Fifteen patients were treated in supine and fifteen in prone position. For each patient, a planning computed tomography (CT) scan was used for treatment planning. Three repeat CT scans were made in weeks 2, 4, and 6 of the radiotherapy treatment. Only for the planning CT scan, laxation was used to minimise the rectal content. For all patients, the clinical target volume (CTV) consisted of prostate and seminal vesicles. Variations in the position of the CTV relative to the bony anatomy in the four CT scans of each patient were assessed using 3D chamfer matching. The overall variations were separated into variations in the mean CTV position per patient (i.e. the systematic component) and the average 'day-to-day' variation (i.e. the random component). Required planning margins to account for the systematic and random variations in internal organ position and patient set-up were estimated retrospectively using coverage probability matrices. RESULTS: The observed overall variation in the internal CTV position was larger for the patients treated in supine position. For the supine and prone treatment positions, the random components of the variation along the anterior-posterior axis (i.e. towards the rectum) were 2.4 and 1.5 mm (I standard deviation (1 SD)), respectively; the random rotations around the left-right axis were 3.0 and 2.9 degrees (1 SD). The systematic components of these motions (1 SD) were larger: 2.6 and 3.3 mm, and 3.7 and 5.6 degrees, respectively. The set-up variations were similar for both treatment positions. Despite the smaller overall variations in CTV position for the patients in prone position, the required planning margin is equal for both groups (about 1 cm except for 0.5 cm in lateral direction) due to the larger impact of the systematic variations. However, significant time trends cause a systematic ventral-superior shift of the CTV in supine position only. CONCLUSIONS: For internal prostate movement, it is important to distinguish systematic from random variations. Compared to patients in supine position, patients in prone position had smaller random but somewhat larger systematic variations in the most important coordinates of the internal CTV position. The estimated planning margins to account for the geometrical uncertainties were therefore similar for the two treatment positions.     

A randomized trial of external beam radiotherapy versus cryoablation in patients with localized prostate cancer

BACKGROUND:

A recent randomized trial to compare external beam radiation therapy (EBRT) to cryoablation for localized disease showed cryoablation to be noninferior to external beam EBRT in disease progression and overall and disease‐specific survival. We report on the quality of life (QOL) outcomes for this trial.

METHODS:

From December 1997 through February 2003, 244 men with newly diagnosed localized prostate cancer were randomly assigned to cryoablation or EBRT (median dose 68 Gy). All patients received neoadjuvant antiandrogen therapy. Patients completed the EORTC QLQ C30 and the Prostate Cancer Index (PCI) before treatment and at 1.5, 3, 6, 12, 18, 24, and 36 months post‐treatment.

RESULTS:

Regardless of treatment arm, participants reported high levels of QOL with few exceptions. cryoablation was associated with more acute urinary dysfunction (mean PCI urinary function cryoablation = 69.4; mean EBRT = 90.7; P < .001), which resolved over time. No late arising QOL issues were observed. Both EBRT and cryoablation participants reported decreases in sexual function at 3 months with the cryoablation patients reporting poorer functioning (mean cryoablation = 7.2: mean EBRT = 32.9; P < .001). Mean sexual function score was 15 points lower at 3 years for the cryoablation group and 13% more of the cryoablation men said that sexuality was a moderate or big problem.

CONCLUSIONS:

In this randomized trial, no long‐term QOL advantage for either treatment was apparent with the exception of poorer sexual function reported by those treated with cryoablation. Men who wish to increase their odds of retaining sexual function might be counseled to choose EBRT over cryoablation. Cancer 2009. © 2009 American Cancer Society.     

Gastro-intestinal and genito-urinary morbidity after 3D conformal radiotherapy of prostate cancer: observations of a randomized trial.

BACKGROUND AND PURPOSE: The late morbidity of a randomized study was analyzed after a follow up of 2 years. The difference in intestinal morbidity was analyzed as a function of the treatment arm and dose volume parameters. The correlation with acute toxicity and (pre-existing) bowel complaints was investigated. PATIENTS AND METHODS: 266 T1-4N0M0 prostate cancer patients were randomized for conventional (open fields) and 3D conformal radiotherapy using beams eye view blocked fields with the same dose (66 Gy) and gross target volume-planning target volume margin (15 mm). Apart from the RTOG toxicity scoring system a patient self-assessment questionnaire was used to obtain detailed information on morbidity. RESULTS: At 2 years there is only a trend for less rectal toxicity (grade >/=1) in favor of the conformal radiotherapy (grade 1, 47 versus 40% and grade 2, 10 versus 7% for conventional and conformal radiotherapy, respectively (P=0.1). A significant relation was found between late rectal toxicity (grade >/=1) and the volume of the anus and rectum exposed to >/=90% tumor dose (TD). A highly significant relationship is observed between acute rectum and anal toxicity and late rectal toxicity. The patient self-assessment questionnaire analysis revealed that patients are most bothered by compliance related symptoms like urgency, soiling and fecal loss. In a multivariate analysis, all other variables loose significance, when anal volume exposed to >/=90% TD and pre-treatment defaecation frequency are accounted for. Late anal toxicity is low and related only to acute anal toxicity. Late bladder toxicity is related solely to pre-treatment frequency and overall urological symptoms. The incidence of grade 2 toxicity increases with a factor 2.5-4 when (stool or urine) frequency is unfavorable at the start of treatment. CONCLUSIONS: Conformal radiotherapy at the dose level of 66 Gy does not significantly decrease the incidence of rectal, anal and bladder toxicity compared to conventional radiotherapy. There is a significant relationship between acute and late toxicity and the anal volume exposed to 90% TD. Intestinal (and urological) symptoms at start have a major impact on late toxicity.     

Bladder opacification does not significantly influence dose distribution in conformal radiotherapy of prostate cancer.

PURPOSE: To compare the results of treatment planning with or without bladder contrast during simulation of three dimensional conformal radiotherapy (3D-CRT) for prostate cancer (18 MV X-rays, six field arrangement), and to assess the potential changes in dose distribution in the target and rectal volumes. METHODS AND MATERIALS: Based on CT-simulation using intravenous contrast media, 3-D conformal treatment planning was performed in five patients. To simulate a non-opacified bladder, the electron matrix density of the opacified bladder was virtually changed to water density. Two treatment plans were carried out, with and without bladder opacification. In each patient dose distributions were formally compared for both plans, and the increment in monitor units (MU) needed to compensate for the presence of contrast media was assessed. RESULTS: A mean dose variation of -0.03% (range, -0.03-0.14%) and -1.13% (range, -1.85-0%) was observed for the prostate and the rectum, respectively. The average mean MU increment without bladder contrast normalized to the case with bladder contrast was 0.31% +/- 0.52. CONCLUSIONS: Bladder opacification used during simulation does not significantly influence prostate or rectal dose distributions in prostate patients treated with 3D-CRT, 18 MV X-rays, and a six-beam arrangement.     

Initial clinical experience with infrared-reflecting skin markers in the positioning of patients treated by conformal radiotherapy for prostate cancer

PURPOSE: To evaluate an infrared (IR) marker-based positioning system in patients receiving conformal radiotherapy for prostate cancer. METHODS AND MATERIALS: During 553 treatments, the ability of the IR system to automatically position the isocenter was recorded. Setup errors were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) in 184 treatments. RESULTS: The standard deviation of anteroposterior (AP) and lateral setup errors was significantly reduced with IR marker positioning compared to conventional: 2 vs. 4.8 mm AP (p < 0.01) and 1.6 vs. 3.5 mm laterally (p < 0.01). Longitudinally, the difference was not significant (3.5 vs. 3.0 mm). Systematic errors were on the average smaller AP and laterally for the IR method: 4.1 vs. 7.8 mm AP (p = 0.01) and 3.1 vs. 5.6 mm lateral (p = 0.07). Longitudinally, the IR system resulted in somewhat larger systematic errors: 5.0 vs. 3.4 mm for conventional positioning (p = 0.03). The use of an off-line correction protocol, based on the average deviation measured over the first four fractions, allowed virtual elimination of systematic errors. Inability of the IR system to correctly locate the markers, leading to an executional failure, occurred in 21% of 553 fractions. CONCLUSION: IR marker-assisted patient positioning significantly improves setup accuracy along the AP and lateral axes. Executional failures need to be reduced.     

Survival advantage for prostate cancer patients treated with high-dose three-dimensional conformal radiotherapy.

PURPOSE: The value of treating prostate cancer has been questioned, and some insist that a survival benefit is demonstrated to justify treatment. Prospective dose-escalation studies with three-dimensional conformal radiotherapy technique have demonstrated improvement in biochemical freedom from disease and local control. We report the outcomes of high-dose treatment with three-dimensional conformal radiotherapy compared with low-dose treatment for biochemical freedom from disease, freedom from distant metastasis, cause-specific survival, and overall survival. PATIENTS AND METHODS: The study design was retrospective, involving pairs matched on independent prognostic variables in which each patient treated with low-dose radiotherapy was matched with a patient treated with high-dose radiotherapy. Outcomes were compared for two groups of patients: Group I: Three-dimensional conformal radiotherapy treatment--296 patients treated with more than 74 Gy matched on stage, grade, and prostate-specific antigen level, to 296 patients treated with less than 74 Gy. Group II: Three-dimensional conformal radiotherapy treatment--357 patients treated with more than 74 Gy matched on stage and grade to 357 patients treated with less than 74 Gy. RESULTS: Univariate analysis showed that dose is a significant predictor of biochemical freedom from disease, freedom from distant metastasis, and cause-specific survival for group I and biochemical freedom from disease, freedom from distant metastasis, cause-specific survival, and overall survival for group II. Multivariate analysis showed that dose is a significant independent predictor in group I for biochemical freedom from disease and freedom from distant metastasis and for biochemical freedom from disease, freedom from distant metastasis, cause-specific survival, and overall survival in group II. DISCUSSION: These data provide strong support for the definitive treatment of prostate cancer with high-dose (> 74 Gy) three-dimensional conformal radiotherapy. These doses can be safely delivered with three-dimensional conformal radiotherapy techniques. Various institutions and industry must collaborate to expand the technology allowing the use of high-dose three-dimensional conformal radiotherapy in the national practice beyond centers of technological excellence.     

Hypofractionated whole breast irradiation for patients with large breasts: A randomized trial comparing prone and supine positions

Background and purpose

Comparison of acute toxicity of whole-breast irradiation (WBI) in prone and supine positions.

Materials and methods

This non-blinded, randomized, prospective, mono-centric trial was undertaken between December 29, 2010, and December 12, 2012. One hundred patients with large breasts were randomized between supine multi beam (MB) and prone tangential field (TF) intensity modulated radiotherapy (IMRT). Dose–volume parameters were assessed for the breast, heart, left anterior descending coronary artery (LAD), ipsilateral lung and contralateral breast. The primary endpoint was acute moist skin desquamation. Secondary endpoints were dermatitis, edema, pruritus and pain.

Results

Prone treatment resulted in: improved dose coverage (p < 0.001); better homogeneity (p < 0.001); less volumes of over-dosage (p = 0.001); reduced acute skin desquamation (p < 0.001); a 3-fold decrease of moist desquamation p = 0.04 (chi-square), p = 0.07 (Fisher’s exact test)); lower incidence of dermatitis (p < 0.001), edema (p = 0.005), pruritus (p = 0.06) and pain (p = 0.06); 2- to 4-fold reduction of grades 2–3 toxicity; lower ipsilateral lung (p < 0.001) and mean LAD (p = 0.007) dose; lower, though statistically non-significant heart and maximum LAD.

Conclusions

This study provides level I evidence for replacing the supine standard treatment by prone IMRT for whole-breast irradiation in patients with large breasts. A confirmatory trial in a multi-institutional setting is warranted.