Computed tomography/magnetic resonance based volume changes of the primary tumour in patients with prostate cancer with or without androgen deprivation

Optimizing planning CT using past CT images for prostate cancer volumetric modulated arc therapy

This study aimed to evaluate a new method to optimize planning computed tomography (CT) using three-dimensional (3D) displacement error between the planning and diagnosed past CT scans. Thirty-two patients undergoing volumetric modulated arc therapy for prostate cancer were evaluated for a 3D displacement error between bone- and prostate-matching spatial coordinates using multiple acquisition planning CT (MPCT) scans. Each MPCT image and a past CT image were used to perform rigid image registration (RIR) and deformable image registration (DIR), and the 3D displacement error was calculated. Correlations of the 3D displacement error in each MPCT scan and between the MPCT and past CT were evaluated based on RIR and DIR, respectively. The 3D displacement error in the MPCT images exhibited moderate correlation with the 3D displacement error between MPCT and past CT for both RIR (adjusted r² = 0.495) and DIR (adjusted r² = 0.398). In the correlation analysis between MPCT and past CT, image pairs with 3D displacement errors ≥ 6 mm were significantly different from those with errors < 6 mm (p < 0.0001). Past CT images were different from the planning CT images, which can be attributed to setup tools, flat-top plates, and physical differences due to the presence or absence of urine as well as prescription effects. The relationship between bone and prostate exhibited small deviations between the planning and past CT regardless of pretreatment. The prostate, which only has a slight effect on the displacement between it and bladder volume, was covered with a stiff pelvic bone. As a result, MPCT images exhibited correlations with past CT images of various difference states such as body positions. Finally, large 3D displacement errors in prostate position were caused by pelvic tension and stress, which can be detected using diagnosed past CT images instead of requiring MPCT scans. By comparing past and planning CT images, the random displacement error in the planning CT scan can be avoided by evaluating 3D displacement errors. The new method using the past CT images can estimate the displacement error of the prostate during the treatment period with 1 plan CT scan only, and it helps improve the treatment accuracy.

Can androgen-deprivation therapy obviate the need of channel transurethral resection of the prostate in advanced prostate cancer with urinary retention? A prospective study

Objective

To evaluate the efficacy of androgen-deprivation therapy (ADT) in relieving urinary retention in patients with advanced prostate cancer presenting with urinary retention or a high post-void residual urine volume (PVR).

Patients and methods

Patients with advanced prostate cancer with an indwelling catheter for acute/chronic urinary retention, or with a high PVR (>200 mL) who had not received any previous treatment were included in the study. Patients with localised prostate cancer eligible for receiving any therapy aimed at cure were excluded. All enrolled patients were managed by ADT (LHRH antagonist/agonist or orchidectomy) combined with α-adrenoceptor antagonist/combined therapy for at least 1 month to a maximum of 3 months; they were given their first trial of voiding without catheter after 1 month, and monthly thereafter.

Results

A total of 101 patients received ADT of which 97 were able to void successfully at the end of 3 months. In all, 27 patients could void in the first month, followed by 50 in the second month, and an additional 20 in the third month. There was a significant decrease in prostate volume, PVR, and International Prostate Symptom Score, and maximum urinary flow rates improved with normalisation of renal functions and resolution of upper tract changes noted on ultrasonography.

Conclusion

ADT can relieve retention and decrease PVR over a period of time obviating the need for channel transurethral resection of the prostate.

The diagnostic value of PET/CT imaging with the (68)Ga-labelled PSMA ligand HBED-CC in the diagnosis of recurrent prostate cancer

Purpose

Since the introduction of positron emission tomography (PET) imaging with ⁶⁸Ga-PSMA-HBED-CC (=⁶⁸Ga-DKFZ-PSMA-11), this method has been regarded as a significant step forward in the diagnosis of recurrent prostate cancer (PCa). However, published data exist for small patient cohorts only. The aim of this evaluation was to analyse the diagnostic value of ⁶⁸Ga-PSMA-ligand PET/CT in a large cohort and the influence of several possibly interacting variables.

Methods

We performed a retrospective analysis in 319 patients who underwent ⁶⁸Ga-PSMA-ligand PET/CT from 2011 to 2014. Potential influences of several factors such as prostate-specific antigen (PSA) level and doubling time (DT), Gleason score (GSC), androgen deprivation therapy (ADT), age and amount of injected tracer were evaluated. Histological verification was performed in 42 patients after the ⁶⁸Ga-PSMA-ligand PET/CT. Tracer uptake was measured in 901 representative tumour lesions.

Results

In 82.8 % of the patients at least one lesion indicative of PCa was detected. Tumor-detection was positively associated with PSA level and ADT. GSC and PSA-DT were not associated with tumor-detection. The average maximum standardized uptake value (SUV_max) of tumour lesions was 13.3 ± 14.6 (0.7–122.5). Amongst lesions investigated by histology, 30 were false-negative in 4 different patients, and all other lesions (n = 416) were true-positive or true-negative. A lesion-based analysis of sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) revealed values of 76.6 %, 100 %, 91.4 % and 100 %. A patient-based analysis revealed a sensitivity of 88.1 %. Of 116 patients available for follow-up, 50 received local therapy after ⁶⁸Ga-PSMA-ligand PET/CT.

Conclusion

⁶⁸Ga-PSMA-ligand PET/CT can detect recurrent PCa in a high number of patients. In addition, the radiotracer is highly specific for PCa. Tumour detection is positively associated with PSA and ADT. ⁶⁸Ga-PSMA-ligand PET/CT can help delay systemic therapy of PCa.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-014-2949-6) contains supplementary material, which is available to authorized users.

Anatomic variation and dosimetric consequences of neoadjuvant hormone therapy before radiation therapy for prostate cancer

PURPOSE

To characterize anatomic variation during neoadjuvant androgen deprivation (NAD) and determine a treatment planning strategy to maintain acceptable normal tissue dose while treating potential microscopic disease in the original (pre-NAD) tumor bed.

METHODS AND MATERIALS

We retrospectively examined the effects of treating the post-NAD anatomy with plans derived before and after NAD in a group of 44 patients enrolled in an institutional review board-approved protocol. An 8-field intensity modulated radiation therapy (IMRT) treatment plan was generated on anatomy both before and after NAD for the first 35 patients. The pre-NAD treatment plan was applied to the post-NAD anatomy to evaluate the effect of complete pre-NAD tumor bed treatment on normal tissue sparing, and the post-NAD treatment plan was applied to the pre-NAD anatomy to investigate whether microscopic disease might go untreated in the location of the pre-NAD tumor bed.

RESULTS

The prostate decreased in volume by an average of about 14 cm(3) (24.3%) and was correlated with NAD duration (P = .002). The prostate center of volume systematically shifted in the inferior direction (mean = 1.4 mm, P = .005) and inferior shift was correlated with absolute volume reduction of the prostate (P = .044) in a multivariate model containing rectal and bladder volume change and initial prostate volume. Pre-NAD treatment planning resulted in a significant increase in the bladder volume (P < .01) but little increase in the rectal volume treated to all dose levels. Post-NAD treatment planning resulted in decreased treatment of the prostate and seminal vesicles (on the pre-NAD anatomy) at the prescribed and 95% isodose levels (prostate: P = .033 and 0.025; seminal vesicles: P < .001).

CONCLUSIONS

Anisotropic volume reduction of the prostate was found during NAD and correlated with NAD duration. Post-NAD based treatment planning can minimize excess bladder and rectal dose.

Androgen deprivation therapy for prostate cancer-review of indications in 2010

The discovery of androgen deprivation therapy (ADT) has been one of the most important advances in the treatment of prostate cancer. Here, the indications for the use of ADT are reviewed, together with the data supporting each indication. The settings for ADT use include cytoreduction; combined ADT and radiotherapy; pathologic node-positive disease; and recurrent, metastatic, or progressive prostate cancer.

Comparison of peripheral zone and central gland volume in patients undergoing intensity-modulated radiotherapy

BACKGROUND AND PURPOSE

The shrinking effect of androgen deprivation therapy (ADT) and radiotherapy (RT) on prostate gland volume is a known clinical finding. Until now, it is not known which part of the prostate shrinks more. We examined patients with and without ADT undergoing intensity-modulated RT (IMRT) and performed 3-dimensional measurements of the peripheral zone (PZ) and central gland (CG) with magnetic resonance imaging (MRI).

METHODS AND MATERIALS

Prostate gland volumes of PZ and CG between planning MRI and first available follow-up MRI were retrospectively determined in 44 patients with localized prostate carcinoma. A total of 24 patients had ADT with a median time interval of 5 months (range, 1.5-24 months). Median time interval between both MRI time points was 132 days (range, 104-224 days). Two observers performed PZ and CG delineation in consensus using planimetry. Volume changes over time were determined and compared.

RESULTS

Patients who had ADT showed smaller prostate volume in the first MRI (mean [SD], 32 [16.7] mL), which was still present after IMRT (28.1 [16.7] mL). Patients who had no ADT started with 44.6 (16.9) mL and showed 37.5 (13.9) mL after IMRT. Shrinking effect in PZ was significantly larger than in CG for all patients (-18.3% vs -6.3%, P < 0.05).

CONCLUSIONS

Because, typically, most tumors are located in PZ and this area also shows the largest shrinkage effect after IMRT, this should be taken into account for planning purposes. Notably, there are only minor differences in the relative shrinking effects between patients with and without ADT, although they start with different volumes.

External beam radiotherapy for prostate cancer: urinary outcomes for men with high International Prostate Symptom Scores (IPSS)

PURPOSE

To report the urinary outcome of men treated for prostate cancer with external beam radiotherapy (EBRT) who have pretreatment obstructive urinary symptoms (International Prostate Symptom Score [IPSS] ≥ 15).

METHODS AND MATERIALS

We treated 368 patients with EBRT for localized prostate cancer, and pre- and post-radiotherapy (RT) IPSSs were recorded. In total, 80 men had an IPSS ≥ 15, 48% of whom were taking genitourinary (GU) medications before RT. The IPSS was followed over time and analyzed as a pretreatment factor against Radiation Therapy Oncology Group acute and late GU toxicity.

RESULTS

The median follow-up was 44 months. Among men with a pre-RT IPSS ≥ 15, the median IPSS at baseline, first follow-up, and last follow-up was 18 (range, 15 to 34), 17 (range, 0 to 32), and 13 (range, 0 to 34), respectively. The mean patient declines in IPSS from baseline to first and last follow-up were -3.6 points (p < 0.0004) and -6.9 points (p < 0.0001), respectively. At last follow-up, 43 men (54%) took GU medications. Pre-RT IPSS ≥ 15 vs. ≤ 14 was associated with a higher incidence of Grade ≥ 2 acute GU toxicity (64% vs. 42%, p = 0.0005), and 4-year freedom from Grade ≥ 2 late GU toxicity was 38% vs. 64% (p < 0.0001). There was no greatly increased risk of Grade ≥ 3 late GU toxicity for men with IPSS ≥ 15 (4-year freedom from Grade ≥ 3 late GU toxicity of 90% vs. 96%, p = 0.0964).

CONCLUSIONS

Although the improvement is not immediate, men with moderate to severe obstructive GU symptoms can have improvement in urinary function after EBRT, without significant risk for severe morbidity.

Rectal dose variation during the course of image-guided radiation therapy of prostate cancer

BACKGROUND AND PURPOSE

To investigate the change in rectal dose during the treatment course for intensity-modulated radiotherapy (IMRT) of prostate cancer with image-guidance.

MATERIALS AND METHODS

Twenty prostate cancer patients were recruited for this retrospective study. All patients have been treated with IMRT. For each patient, MR and CT images were fused for target and critical structure delineation. IMRT treatment planning was performed on the simulation CT images. Inter-fractional motion during the course of treatment was corrected using a CT-on-rails system. The rectum was outlined on both the original treatment plan and the subsequent daily CT images from the CT-on-rails by the same investigator. Dose distributions on these daily CT images were recalculated with the isocenter shifts relative to the simulation CT images using the leaf sequences/MUs based on the original treatment plan. The rectal doses from the subsequent daily CTs were compared with the original doses planned on the simulation CT using our clinical acceptance criteria.

RESULTS

Based on 20 patients with 139 daily CT sets, 28% of the subsequent treatment dose distributions did not meet our criterion of V(40) < 35%, and 27% did not meet our criterion of V(65) < 17%. The inter-fractional rectal volume variation is significant for some patients.

CONCLUSIONS

Due to the large inter-fractional variation of the rectal volume, it is more favorable to plan prostate IMRT based on an empty rectum and deliver treatment to patients with an empty rectum. Over 70% of actual treatments showed better rectal doses than our clinical acceptance criteria. A significant fraction (27%) of the actual treatments would benefit from adaptive image-guided radiotherapy based on daily CT images.

The effect of concurrent androgen deprivation and 3D conformal radiotherapy on prostate volume and clinical organ doses during treatment for prostate cancer

In this study, we investigated the shrinking effect of concurrent three-dimensional conformal radiotherapy (3D-CRT) and androgen deprivation (AD) on prostate volume, and its possible impact on the dose received by the rectum and bladder during the course of 3D-CRT. The difference between the prostatic volumes determined on pre-treatment planning CT (PL-CT) and post-treatment CT (PT-CT) following a 3D-CRT course was assessed in 52 patients with localised prostate carcinoma. The changes in mean prostate volume when compared with PL-CT and PT-CT-based measurements were assessed. The pre- and post-treatment mean prostate volumes for the whole study population were 49.7 cm(3) and 41.0 cm(3) (p _ 0.02), respectively. The study cohort was divided into two groups depending on the duration of neoadjuvant androgen deprivation (NAD): 23 patients (44.7%) were designated as "short NAD" (< or =3 months; SNAD) and the remaining 29 (55.3%) as "long NAD" (>3 months; LNAD). Patients on SNAD experienced a significantly greater reduction in prostate volume compared with those on LNAD (14.1% vs 5.1%; p _ 0.03). A significant increase in rectum V(40-60) values in PT-CT compared with PL-CT was demonstrated. LNAD patients had significantly higher rectal V(50-70) values at PT-CT compared with the SNAD group. There was a significant decline in V(30)-V(75) bladder values in PT-CT compared with PL-CT in the SNAD group. In conclusion, a higher prostate volume reduction during 3D-CRT was demonstrated when RT planning was performed within 3 months of NAD. However, this reduction and daily organ motion may lead to an unpredictable increase in rectal doses.

Neoadjuvant androgen deprivation for prostate volume reduction: the optimal duration in prostate cancer radiotherapy

OBJECTIVES

For locally advanced prostate cancer, the results of radiotherapy are improved by combination with androgen deprivation therapy. Volume reduction achieved with neoadjuvant hormonal treatment can facilitate dose escalation without increasing the toxicity. The optimal duration of hormonal treatment, however, is unknown. The endpoint of this study is the optimal duration of androgen deprivation for prostate volume reduction in a cohort of patients scheduled for external beam radiotherapy.

PATIENTS AND METHODS

Twenty patients scheduled for external beam radiotherapy with cT2-3No/xMo prostate cancer were treated with a luteinizing hormone releasing hormone agonist (busereline) and nonsteroidal anti-androgen (nilutamide) for 9 months consecutively. Repeated CT scan examination was performed 3-monthly to measure prostate volumes until the start of radiation therapy. The analysis of volume reduction was performed with the Wilcoxon signed ranks test.

RESULTS

The baseline median prostate volume for the cohort of patients was 82 cc (95% CI: 61-104 cc) with a median volume reduction of 31% (95% CI: 26%-35%) (P < 0.0001) after 3 months of androgen deprivation. Between 3 and 6 months, a median volume reduction of 9% (95% CI: 4%-14%) (P < 0.0001) was observed. The effect was more pronounced in large prostates (>60 cc) than in small prostates (≤60 cc). In the total cohort of patients no significant volume reduction occurred between 6 and 9 months of maximal androgen blockade (MAB).

CONCLUSIONS

In this study, we have shown that the most significant prostate volume reduction is achieved after 3 months of MAB with a maximum reduction after 6 months. Therefore, the optimal duration of neoadjuvant androgen deprivation to reduce prostate volume before prostate cancer radiotherapy is 6 months. In small prostates 3 months of hormonal treatment may be enough for maximal volume reduction.

Changes of prostate gland volume with and without androgen deprivation after intensity modulated radiotherapy - A follow-up study

BACKGROUND AND PURPOSE

The shrinking effect of androgen deprivation therapy (ADT) on prostate volume is a known finding, but data on volume changes during radiotherapy are inconsistent. We examined patients with and without ADT undergoing intensity modulated radiotherapy (IMRT) and performed follow-up examinations to study volume changes before and after radiotherapy.

METHODS AND MATERIALS

Prostate volumes between planning magnetic resonance imaging (MRI) and last available follow-up MRI were retrospectively determined in 39 patients. Median time interval between first and last MRI was 233days (range 126-813). Two observers performed volume measurements in consensus and were blind to the timing of MRI. Volume changes over MRI were determined using the ellipsoid formula. Data of patients with and without ADT were compared by a linear mixed model.

RESULTS

Of 39 patients, 22 had ADT with a median duration of 5months (range 1-24). ADT patients showed lower prostate volume throughout the study period (-28% to 38%). Although individual shrinking effect was highly variable, patients treated with IMRT but without ADT showed a significantly larger volume reduction (26.1%) than patients with ADT (12.9%, p<0.05).

CONCLUSIONS

Patients undergoing IMRT show definite prostate shrinkage. The rate is slowed down after 6months in both groups, whereas the volume reduction is significantly larger in patients without ADT. Nevertheless there is no adding effect of ADT+IMRT vs. IMRT alone.

10-Year Survival and Quality of Life in Patients With High-Risk PN0 Prostate Cancer Following Definitive Radiotherapy

PURPOSE

To evaluate long-term overall survival (OS), cancer-specific survival (CSS), clinical progression-free survival (cPFS), and health-related quality of life (HRQoL) following definitive radiotherapy (RT) given to T(1-4p)N(0)M(0) prostate cancer patients provided by a single institution between 1989 and 1996.

METHODS AND MATERIALS

We assessed outcome among 203 patients who had completed three-dimensional conformal RT (66 Gy) without hormone treatment and in whom staging by lymphadenectomy had been performed. OS was compared with an age-matched control group from the general population. A cross-sectional, self-report survey of HRQoL was performed among surviving patients.

RESULTS

Median observation time was 10 years (range, 1-16 years). Eighty-one percent had high-risk tumors defined as T(3-4) or Gleason score (GS) > or =7B (4+3). Among these, 10-year OS, CSS, and cPFS rates were 52%, 66%, and 39%, respectively. The corresponding fractions in low-risk patients (T(1-2) and GS < or =7A [3+4]) were 79%, 95%, and 73%, respectively. Both CSS and cPFS were predicted by GS and T-classification; OS was associated with GS only. High-risk, but not low-risk, patients had reduced OS compared with the general population (p < 0.0005). When pelvis-related side effects were included in multivariate analyzes together with physical function and pain, sexual, urinary, and bowel function were not independently associated with self-reported global quality of life.

CONCLUSIONS

Despite surgically proven (p)N(0), RT with dosage <70 Gy as monotherapy does not give satisfactory CSS rates after 10 years in patients with T(3-4) or GS > or =7B.

Predictors for rectal and intestinal acute toxicities during prostate cancer high-dose 3D-CRT: results of a prospective multicenter study

PURPOSE

To find predictors for rectal and intestinal acute toxicity in patients with prostate cancer treated with > or =70 Gy conformal radiotherapy.

METHODS AND MATERIALS

Between July 2002 and March 2004, 1,132 patients were entered into a cooperative study (AIROPROS01-02). Toxicity was scored using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale and by considering the changes (before and after treatment) of the scores of a self-administered questionnaire on rectal/intestinal toxicity. The correlation with a number of parameters was assessed by univariate and multivariate analyses. Concerning the questionnaire, only moderate/severe complications were considered.

RESULTS

Of 1,132 patients, 1,123 were evaluable. Of these patients, 375, 265, and 28 had Grade 1, 2, and 3 Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity, respectively. The mean rectal dose was the most predictive parameter (p = 0.0004; odds ratio, 1.035) for Grade 2 or worse toxicity, and the use of anticoagulants/antiaggregants (p = 0.02; odds ratio, 0.63) and hormonal therapy (p = 0.04, odds ratio, 0.65) were protective. The questionnaire-based scoring revealed that a greater mean rectal dose was associated with a greater risk of bleeding; larger irradiated volumes were associated with frequency, tenesmus, incontinence, and bleeding; hormonal therapy was protective against frequency and tenesmus; hemorrhoids were associated with a greater risk of tenesmus and bleeding; and diabetes associated highly with diarrhea.

CONCLUSION

The mean rectal dose correlated with acute rectal/intestinal toxicity in three-dimensional conformal radiotherapy for prostate cancer, and hormonal therapy and the use of anticoagulants/antiaggregants were protective. According to the moderate/severe injury scores on the self-assessed questionnaire, several clinical and dose-volume parameters were independently predictive for particular symptoms.

Impact of neoadjuvant hormonal therapy on dose-volume histograms in patients with localized prostate cancer under radical radiation therapy

INTRODUCTION

Prostate volume involves a defined toxicity predictor in the radiation therapy of localized prostate cancer. Neoadjuvant hormone therapy (nHT) can reduce prostate volume and, therefore, the planned volume. The objective of this study was to establish if the value of nHT reduces the planned volume and if this reduction correlates with a reduction of the dose received in the target organs.

MATERIAL AND METHODS

28 patients diagnosed of localized prostate cancer and referred to our departments for radiation therapy with radical intention, in the period ranging between April 2002 and October 2003, were included prospectively. The patients received nHT (triptorelin + flutamide) for 2 months and adjuvant HT until completing 2 years in the high-risk cases. A transrectal ultrasound study was performed in all patients, simulation CT and planning before the start of HT and after 2 months of treatment. The radiation therapy was carried out with 6 or 18 MV LINAC photons, with a dose fractioning scheme of 5 x 180-200 cGy, a total dosage of 66-72 Gy to prostate, 56 Gy to seminal vesicles and, in the high-risk cases, 46 Gy to pelvic lymph nodes.

RESULTS

The distribution according to risk group was: low risk 3.6%, intermediate risk 28.6% and high risk 67.9%. By transrectal ultrasound, prostate volume on diagnosis was 50.65 cc pre HT and 38.97 cc post HT (p < 0.001), which means a volume reduction of 24%. The comparative analysis of the dose-volume histograms of the first versus the second CT shows a reduction in the planned volume GTV1 (prostate) (81.33 cc vs 63.96 cc, p < 0.05), PTV1 (prostate and margin) (197.51 cc vs 168.38 cc, p < 0.001) and PTV2 (prostate, vesicles and margin) (340.5 cc vs 307.26 cc, p < 0.05), a reduction of the maximum dose in the seminal vesicles (70.2 versus 68.75 Gy, p < 0.05), a reduction of the mean dose in the seminal vesicles (65.07 Gy versus 63.07 Gy, p < 0.05), PTV2 (67.72 Gy versus 66.9 Gy, p < 0.01) and PTV3 (prostate, vesicles, pelvic lymph nodes and margin) (58.86 Gy versus 57.21 Gy, p < 0.01), a reduction of the D90 in the seminal vesicles (61.83 Gy versus 60.06 Gy, p < 0.05) and PTV2 (61.04 Gy versus 59.45 Gy, p < 0.05) and a reduction of V60 of the rectum (32.45% versus 28.22%, p < 0.05) and V60 of the bladder (41.78% versus 31.67%, p < 0.005).

CONCLUSIONS

Neoadjuvant hormone therapy reduces significantly prostate volume and as a result the planned volume and consequently the rectal and bladder V60 can be significantly reduced.

The Role of Recipient Sites in Fat-Graft Survival

The survival of fat grafts depends on many factors, 1 of the major being early revascularization. Early studies showed that adipose tissue has a low tolerance to ischemia. Some methods have been described to increase the tolerance of adipose tissue to ischemia. This study was designed to compare volume maintenance of the transplanted fat graft in different recipient sites of the rabbit face. Three groups of 5 New Zealand white rabbits were studied. Fat grafts harvested from the right inguinal fat pad were transplanted to the buccomandibular area of the rabbit's face. Three different recipient sites (subcutaneous, supramuscular, and submuscular) were dissected on each side of the face, and groups were formulated based on this difference of recipient sites. Morphometric, as well as histopathologic, analyses were done, and the results revealed a statistically significant increase of fat graft survival in supramuscular layer (81.95% +/- 4.40%) than in subcutaneous (41.62% +/- 3.29%) and submuscular layer (37.31% +/- 5.77%) (P<0.05). This study demonstrates that selection of an "appropriate recipient site" should enhance ultimate fat-graft survival.

Patient-reported acute gastrointestinal toxicity in men receiving 3-dimensional conformal radiation therapy for prostate cancer with or without neoadjuvant androgen suppression therapy

OBJECTIVE

To investigate the impact of 2 months of neoadjuvant and 2 months of concurrent hormonal therapy on the acute gastrointestinal (GI) toxicities associated with 3-dimensional conformal radiation therapy (3D-CRT) for prostate adenocarcinoma.

METHODS

The study cohort consisted of 80 men who underwent 3D-CRT with (n=40) or without (n=40) neoadjuvant and concurrent hormonal therapy. Computerized tomography-based planning occurred after neoadjuvant hormonal therapy. All patients completed a previously validated, quality-of-life self-assessment tool on 7 GI symptoms, including diarrhea, urgency, pain, rectal bleeding, cramping, mucus, and tenesmus, at baseline and weekly during radiation therapy.

RESULTS

Patients who received hormonal therapy were more likely to have T2b, T2c, T3a, or T3b (P<0.001) or Gleason score 7, 8, or 9 (P=0.02) disease compared to those that did not. The dose delivered to the planning target volume was 70 Gy for both groups. Median radiation treatment volume was numerically smaller for the hormone group but not to a statistically significant degree (949 vs. 1043 cc, P=0.30). Patients who received hormonal therapy had less rectal pain (P<0.01) and tenesmus (P=0.02) but more rectal mucus (P=0.03) compared to those who did not.

CONCLUSIONS

Prostate gland volume reduction after androgen suppression therapy may reduce patient-reported acute GI toxicities associated with 3D-CRT for prostate cancer.

Volume and hormonal effects for acute side effects of rectum and bladder during conformal radiotherapy for prostate cancer

PURPOSE

To identify dosimetric variables predictive of acute gastrointestinal (GI) and genitourinary (GU) toxicity and to determine whether hormonal therapy (HT) is independently associated with acute GI and GU toxicity in prostate cancer patients treated with conformal radiotherapy (RT).

METHODS AND MATERIALS

This analysis was performed on 336 patients participating in a multicenter (four hospitals) randomized trial comparing 68 Gy and 78 Gy. The clinical target volume consisted of the prostate with or without the seminal vesicles, depending on the risk of seminal vesicle involvement. The margin from the clinical target volume to the planning target volume was 1 cm. For these patients, the treatment plan for a total dose of 68 Gy was used, because nearly all toxicity appeared before the onset of the 10-Gy boost. Acute toxicity (<120 days) was scored according to the Radiation Therapy Oncology Group criteria. The dosimetric parameters were obtained from the relative and absolute dose-volume/surface histograms derived from the rectal wall (rectal wall volume receiving > or =5-65 Gy) and the bladder surface (bladder surface receiving > or =5-65 Gy). Additionally, relative and absolute dose-length histograms of the rectum were created, and the lengths of rectum receiving more than a certain dose over the whole circumference (rectal length receiving > or =5-65 Gy) were computed. The clinical variables taken into account for GI toxicity were neoadjuvant HT, hospital, and dose-volume group; for GU toxicity, the variables pretreatment GU symptoms, neoadjuvant HT, and transurethral resection of the prostate were analyzed. The variable neoadjuvant HT was divided into three categories: no HT, short-term neoadjuvant HT (started < or =3 months before RT), and long-term neoadjuvant HT (started >3 months before RT).

RESULTS

Acute GI toxicity Grade 2 or worse was seen in 46% of the patients. Patients with long-term neoadjuvant HT experienced less Grade 2 or worse toxicity (27%) compared with those receiving short-term neoadjuvant HT (50%) and no HT (50%). The volumes of the prostate and seminal vesicles were significantly smaller in both groups receiving neoadjuvant HT compared with those receiving no HT. In multivariate logistic regression analysis, including the two statistically significant clinical variables neoadjuvant HT and hospital, a volume effect was found for the relative, as well as absolute, rectal wall volumes exposed to intermediate and high doses. Of all the length parameters, the relative rectal length irradiated to doses of > or =5 Gy and > or =30 Gy and absolute lengths receiving > or =5-15 and 30 Gy were significant. Acute GU toxicity Grade 2 or worse was reported in 56% of cases. For patients with pretreatment GU symptoms, the rate was 93%. The use of short-term and long-term neoadjuvant HT resulted in more GU toxicity (73% and 71%) compared with no HT (50%). In multivariate analysis, containing the variables pretreatment symptoms and neoadjuvant HT, only the absolute dose-surface histogram parameters (absolute surface irradiated to > or =40, 45, and 65 Gy) were significantly associated with acute GU toxicity.

CONCLUSION

A volume effect was found for acute GI toxicity for relative, as well as absolute, volumes. With regard to acute GU toxicity, an area effect was found, but only for absolute dose-surface histogram parameters. Neoadjuvant HT appeared to be an independent prognostic factor for acute toxicity, resulting in less acute GI toxicity, but more acute GU toxicity. The presence of pretreatment GU symptoms was the most important prognostic factor for GU symptoms during RT.

The magnetic resonance detected intraprostatic lesion in prostate cancer: planning and delivery of intensity-modulated radiotherapy

BACKGROUND AND PURPOSE

Local relapse after radiotherapy for prostate cancer mostly originates at the original tumor location. Dose escalation reduces local relapse rates. It may be of benefit to focus the highest dose to the intraprostatic lesion (GTVMRI) using intensity-modulated radiotherapy (IMRT). Therefore, the visualization of the GTVMRI and its inclusion into computer optimization is mandatory.

MATERIALS AND METHODS

Fifteen patients with prostatic adenocarcinoma were referred for IMRT. All these patients had a palpable lesion on digital rectal examination (DRE) and/or a PSA >10.0 ng/ml. A T2-weighted MR examination of the prostate was performed in order to detect a GTV(MRI) and correlate the location of the GTV(MRI) with the site of the tumour-containing cylinder (biopsy). Two IMRT plans were compared: a plan without the inclusion of the GTV(MRI) (IMRT-CONV) versus a plan including the GTV(MRI) into the plan optimization (IMRT-GTV(MRI)). For comparison, both physical and biological endpoints of the GTV(MRI), CTV, PTV and rectum were taken into account. After the finalization of the planning study, the IMRT-GTV(MRI) plans were clinically delivered using step-and-shoot IMRT. Acute gastro-intestinal (GI) and genito-urinary (GU) toxicity were recorded.

RESULTS

In all cases, the location of the GTV(MRI) corresponded with the site of the tumor containing biopsy cylinder. The mean and median distance of the GTV(MRI) to the anterior rectal wall was 3 and 2mm, respectively (range: 0-12 mm). For the GTV(MRI), its inclusion in the optimization led to a significant increase of all physical endpoints (P<0.01), without compromising the dose to the CTV, PTV and rectum. Mean GTV(MRI) dose was 78.3 Gy (IMRT-GTV(MRI)) versus 76.9 Gy (IMRT-CONV) (P<0.00001). All IMRT treatments were successfully delivered within 6 min. We did not observe grade 3 acute GI toxicity. One patient developed grade 3 GU toxicity (nocturia), that disappeared after administration of medication. Grade 2 GI and GU toxicity was observed in, respectively, four and six patients.

CONCLUSION

Using T2-weighted MR, the visualization of an intraprostatic lesion is feasible. The inclusion of the GTV(MRI) into planning optimization leads to a modest increase in dose, without compromising the dose to the CTV, PTV and organs at risk. The clinical delivery of these plans runs without problems. Acute toxicity is mild.

Acute and late complications after radiotherapy for prostate cancer: results of a multicenter randomized trial comparing 68 Gy to 78 Gy

PURPOSE

To compare acute and late gastrointestinal (GI) and genitourinary (GU) side effects in prostate cancer patients randomized to receive 68 Gy or 78 Gy.

METHODS AND MATERIALS

Between June 1997 and February 2003, 669 prostate cancer patients were randomized between radiotherapy with a dose of 68 Gy and 78 Gy, in 2 Gy per fraction and using three-dimensional conformal radiotherapy. All T stages with prostate-specific antigen (PSA) <60 ng/mL were included, except any T1a and well-differentiated T1b-c tumors with PSA < or =4 ng/mL. Stratification was done for four dose-volume groups (according to the risk of seminal vesicles [SV] involvement), age, hormonal treatment (HT), and hospital. The clinical target volume (CTV) consisted of the prostate with or without the SV, depending on the estimated risk of SV invasion. The CTV-planning target volume (PTV) margin was 1 cm for the first 68 Gy and was reduced to 0.5 cm (0 cm toward the rectum) for the last 10 Gy in the 78 Gy arm. Four Dutch hospitals participated in this Phase III trial. Evaluation of acute and late toxicity was based on 658 and 643 patients, respectively. For acute toxicity (<120 days), the Radiation Therapy Oncology Group (RTOG) scoring system was used and the maximum score was reported. Late toxicity (>120 days) was scored according to the slightly adapted RTOG/European Organization for Research and Treatment of Cancer (EORTC) criteria.

RESULTS

The median follow-up time was 31 months. For acute toxicity no significant differences were seen between the two randomization arms. GI toxicity Grade 2 and 3 was reported as the maximum acute toxicity in 44% and 5% of the patients, respectively. For acute GU toxicity, these figures were 41% and 13%. No significant differences between both randomization arms were seen for late GI and GU toxicity, except for rectal bleeding requiring laser treatment or transfusion (p = 0.007) and nocturia (p = 0.05). The 3-year cumulative risk of late RTOG/EORTC GI toxicity grade > or =2 was 23.2% for 68 Gy, and 26.5% for 78 Gy (p = 0.3). The 3-year risks of late RTOG/EORTC GU toxicity grade > or =2 were 28.5% and 30.2% for 68 Gy and 78 Gy, respectively (p = 0.3). Factors related to acute GI toxicity were HT (p < 0.001), a higher dose-volume group (p = 0.01), and pretreatment GI symptoms (p = 0.04). For acute GU toxicity, prognostic factors were: pretreatment GU symptoms (p < 0.001), HT (p = 0.003), and prior transurethral resection of the prostate (TURP) (p = 0.02). A history of abdominal surgery (p < 0.001) and pretreatment GI symptoms (p = 0.001) were associated with a higher incidence of late GI grade > or =2 toxicity, whereas HT (p < 0.001), pretreatment GU symptoms (p < 0.001), and prior TURP (p = 0.006) were prognostic factors for late GU grade > or =2.

CONCLUSIONS

Raising the dose to the prostate from 68 Gy to 78 Gy resulted in higher incidences of acute and late GI and GU toxicity, but these differences were not significant, except for late rectal bleeding requiring treatment and late nocturia. Other factors than the studied dose levels appeared to be important in predicting toxicity after radiotherapy, especially previous surgical interventions (abdominal surgery or TURP), hormonal therapy, and the presence of pretreatment symptoms.

Acute morbidity related to treatment volume during 3D-conformal radiation therapy for prostate cancer

PURPOSE

To investigate the relation between acute toxicity and irradiated volume in the organs at risk during three-dimensional conformal radiation therapy for prostate cancer.

METHODS AND MATERIALS

From January to December 2001, we treated 132 prostate cancer patients to a prescribed target dose of 70 Gy. Twenty-six patients (20%) received irradiation to the prostate only (Group P), 86 patients (65%) had field arrangements encompassing the prostate and seminal vesicles (Group PSV) while 20 (15%) received modified pelvic fields (Group MPF). A four-field conformal box technique was used. Acute toxicity according to the RTOG scoring system was prospectively recorded throughout the course of treatment.

RESULTS

Overall, radiation was well tolerated with 11%, 16% and 35% Grade 2 gastro-intestinal (GI) toxicity and 19%, 34% and 35% Grade 2 or higher genito-urinary (GU) toxicity in Groups P, PSV and MPF, respectively. In univariate and multivariate analyses treatment group was a significant predictor for Grade 2 or higher acute morbidity. In multivariate logistic regression, the rectum dose-volume histogram parameters were correlated to the incidence of acute Grade 2 GI toxicity, with the fractional volumes receiving more than 37-40 Gy and above 70 Gy showing the statistically strongest correlation. The fractional bladder volume receiving more than 14-27 Gy showed the statistically strongest correlation with acute GU toxicity.

CONCLUSIONS

3D-CRT radiation therapy to 70 Gy for prostate cancer was well tolerated. Only two of the 132 patients in the cohort experienced acute bladder toxicity Grade 3, none had Grade 3 rectal toxicity. Uni- and multivariate analyses indicated that the volume treated was a significant factor for the incidence of Grade 2 or higher acute morbidity.

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.

Luteinising hormone releasing hormone analogues in the treatment of prostate cancer

The use of the luteinising hormone releasing hormone (LHRH) analogues--goserelin (Zoladex, AstraZeneca) and leuprorelin (Prostap, Wyeth)--is well established and forms the backbone of the treatment of locally advanced and metastatic prostate cancer. Comparable efficacy with orchidectomy and, historically, diethylstilbestrol (DES) is accepted, with the advantages of reversibility and limited thromboembolic and cardiovascular toxicity, respectively. Side effects such as hot flushes, loss of libido, lethargy and decreased bone mineral density have recently stimulated more interest in the use of non-steroidal anti-androgens such as bicalutamide (Casodex, AstraZeneca) in locally advanced disease. Although better tolerated, bicalutamide has significant problems with gynaecomastia and breast pain. Maximal androgen blockade using LHRH analogues and their adjuvant use with radiotherapy are discussed, as well as their experimental application in intermittent androgen suppression therapy. Similar side effect profiles are reported for the LHRH analogues but injection tolerability differs with the smaller 23G needle for Prostap 3 compared to the 16G needle for Zoladex LA. There is no evidence to suggest a difference in the efficacy between the LHRH analogues goserelin and leuprorelin, although no direct comparison has yet been undertaken.