Quality assurance of radiation therapy after breast-conserving surgery among patients in the BOOG 2013-08 trial

BACKGROUND AND PURPOSE

In the BOOG 2013-08 trial (NCT02271828), cT1-2N0 breast cancer patients were randomized between breast conserving surgery with or without sentinel lymph node biopsy (SLNB) followed by whole breast radiotherapy (WBRT). While awaiting primary endpoint results (axillary recurrence rate), this study aims to perform a quality assurance analysis on protocol adherence and (incidental) axillary radiation therapy (RT) dose.

MATERIALS AND METHODS

Patients were enrolled between 2015 and 2022. Data on prescribed RT and (in 25% of included patients) planning target volumes (PTV) parameters were recorded for axillary levels I-IV and compared between treatment arms. Multivariable linear regression analysis was performed to determine prognostic variables for incidental axillary RT dose.

RESULTS

1,439/1,461 included patients (98.5%) were treated according to protocol and 87 patients (5.9%) received regional RT (SLNB 10.9%, no-SLNB 1.5 %). In 326 patients included in the subgroup analysis, the mean incidental PTV dose at axilla level I was 59.5% of the prescribed breast RT dose. In 5 patients (1.5%) the mean PTV dose at level I was ≥95% of the prescribed breast dose. No statistically or clinically significant differences regarding incidental axillary RT dose were found between treatment arms. Tumour bed boost (yes/no) was associated with a higher incidental mean dose in level I (R2 = 0.035, F(6, 263) = 1.532, p 0.168).

CONCLUSION

The results indicate that RT-protocol adherence was high, and that incidental axillary RT dose was low in the BOOG 2013-08 trial. Potential differences between treatmentarms regarding the primary endpoint can thus not be attributed to different axillary radiation doses.

Postmastectomy Radiation Therapy Planning After Immediate Implant-based Reconstruction Using the European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice Consensus Guidelines for Target Volume Delineation

AIMS

To evaluate how common radiation therapy techniques perform in the setting of the new European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) delineation recommendations for immediate breast reconstruction (IBR).

MATERIALS AND METHODS

Seven Danish radiation therapy centres and six international European centres participated in this project. Two breast cancer cases (one left-sided and one right-sided) with a retropectoral implant were chosen for radiation therapy planning using deep-inspiration breath-hold. Target volumes were delineated according to ESTRO-ACROP delineation recommendations. The centres were asked to plan the cases using any radiation therapy technique according to the Danish Breast Cancer Group plan objectives.

RESULTS

In total, 35 treatment plans were collected. Half of the submitted plans, for both the left-sided and the right-sided case, used the field-in-field (FiF) technique (nine for each), a quarter used volumetric arc radiation therapy (VMAT; five for right-sided, four for left-sided) and the remaining quarter was a mix of inverse intensity-modulated radiation therapy (IMRT), helicoidal therapy and hybrid (combined open fields and VMAT) techniques. Mean clinical target volume doses were in the range 99-102% of the prescribed dose. The median FiF mean heart dose (MHD) for right-sided radiation therapy was 1 Gy (range 0.8-3.7) and 5.2 Gy for left-sided radiation therapy (range 2.2-6.5). For right-sided radiation therapy, the median VMAT MHD was 3.42 Gy, for IMRT was 2.3 Gy and for helicoidal therapy was 5.1 Gy. For left-sided radiation therapy, the median VMAT MHD was 6.3 Gy, for IMRT was 7.8 Gy and for helicoidal therapy was 7.3 Gy.

CONCLUSIONS

Different radiation therapy techniques could be used to plan radiation therapy in the setting of IBR. FiF provided good coverage with acceptable organ at risk doses. The best dose distribution results as a trade-off between the objectives of target volume coverage and high-dose organ at risk inclusion. The radiation therapy technique affects the interplay between these objectives.

Elicitation of preferences in the second half of the shared decision making process needs attention; a qualitative study

BACKGROUND

It is known that the use of a Patient Decision Aid (PtDA), combined with advice for professionals on how and when to use it, can enhance the involvement of patients in the treatment decision. However, we need more knowledge with respect to the intention-behaviour gap. This study aims to analyse patients' experiences with the Shared Decision Making (SDM) process to find clues to close this gap.

METHODS

This qualitative study was part of a pilot study aiming to implement SDM in early adopter breast cancer teams. Patients were given access to a personalised PtDA. Breast cancer teams were instructed on how and when to deliver the PtDA. We interviewed 20 patients about their experience with the PtDA and SDM in general.

RESULTS

Most patients experienced SDM, though to a certain extent. Choice talk and option talk were commonly experienced, however the elicitation of preferences and decision talk was rare. The PtDA was used by the majority of patients (N = 13), all indicating that it was useful, especially to recall all the information given. Patients appreciated the contribution of breast cancer nurses in the SDM process. They considered them as true case managers, easy to approach and supportive.

CONCLUSION

Although patients felt well-informed and satisfied about risk-communication, the elicitation of preferences appeared very limited to non-existent. We recommend that breast cancer teams divide tasks in the SDM process and reallocate the elicitation of preferences to the nurses in a well-defined clinical pathway.

What do patients and health care professionals view as important attributes in radiotherapy decisions? Input for a breast cancer patient decision aid

Background and aim

There is increased attention for shared decision making (SDM) when deciding on radiotherapy for selected patients with Stage 0–2 breast cancer. This study aimed to explore patients' and health care professionals’ experiences, decisional attributes and needs as input for the development of a patient decision aid to facilitate SDM.

Methods

Qualitative semi-structured interviews were held with fifteen breast cancer patients, being confronted with a radiotherapy decision one month to eight years earlier. Another fifteen interviews were held with professionals specialized in breast cancer care. Interviews were transcribed verbatim and independently coded by two researchers, who agreed upon relevant issues.

Results

Most patients made their decision by weighing the advantages of radiotherapy, i.e. comparing the decrease in recurrence risk with and without radiotherapy, and disadvantages, i.e. possible side effects. Patients and professionals agreed that recurrence risks should be communicated, but not on how to deal with uncertainty. There was wide variation in which, and how, side effects were explained by professionals. The most common side effects mentioned by both patients and professionals were skin toxicity, fatigue and breast deformity.

Conclusion

Patients and professionals appeared to agree on what type of attributes should be communicated during SDM on radiotherapy, but how this should be done is up for discussion. To ensure the patient's voice these attributes and needs need to be incorporated in the risk communication and value elicitation part of the patient decision aid. The format in which the attributes are communicated should be critically evaluated.

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Patients and professionals agree on most important attributes.

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These attributes need to be used in a patient decision aid.

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There is unwarranted inter doctor variation in informing about side effects.

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Professionals differ in opinion how to inform patients about epistemic uncertainties.

Effects and moderators of psychosocial interventions on quality of life, and emotional and social function in patients with cancer: An individual patient data meta-analysis of 22 RCTs

Objective

This individual patient data (IPD) meta‐analysis aimed to evaluate the effects of psychosocial interventions (PSI) on quality of life (QoL), emotional function (EF), and social function (SF) in patients with cancer, and to study moderator effects of demographic, clinical, personal, and intervention‐related characteristics.

Methods

Relevant studies were identified via literature searches in 4 databases. We pooled IPD from 22 (n = 4217) of 61 eligible randomized controlled trials. Linear mixed‐effect model analyses were used to study intervention effects on the post‐intervention values of QoL, EF, and SF (z‐scores), adjusting for baseline values, age, and cancer type. We studied moderator effects by testing interactions with the intervention for demographic, clinical, personal, and intervention‐related characteristics, and conducted subsequent stratified analyses for significant moderator variables.Results: PSI significantly improved QoL (β = 0.14,95%CI = 0.06;0.21), EF (β = 0.13,95%CI = 0.05;0.20), and SF (β = 0.10,95%CI = 0.03;0.18). Significant differences in effects of different types of PSI were found, with largest effects of psychotherapy. The effects of coping skills training were moderated by age, treatment type, and targeted interventions. Effects of psychotherapy on EF may be moderated by cancer type, but these analyses were based on 2 randomized controlled trials with small sample sizes of some cancer types.

Conclusions

PSI significantly improved QoL, EF, and SF, with small overall effects. However, the effects differed by several demographic, clinical, personal, and intervention‐related characteristics. Our study highlights the beneficial effects of coping skills training in patients treated with chemotherapy, the importance of targeted interventions, and the need of developing interventions tailored to the specific needs of elderly patients.

Preoperative breast radiation therapy: Indications and perspectives

Preoperative breast radiation therapy (RT) is not a new concept, but older studies failed to change practice. More recently, there has been interest in revisiting preoperative RT using modern techniques. This current perspective discusses the indications, summarises the published literature and then highlights current clinical trials, with particular attention to combining with novel drugs and optimising associated translational research.

Clinically node negative breast cancer patients undergoing breast conserving therapy, sentinel lymph node procedure versus follow-up: a Dutch randomized controlled multicentre trial (BOOG 2013-08)

BACKGROUND

Studies showed that axillary lymph node dissection can be safely omitted in presence of positive sentinel lymph node(s) in breast cancer patients treated with breast conserving therapy. Since the outcome of the sentinel lymph node biopsy has no clinical consequence, the value of the procedure itself is being questioned. The aim of the BOOG 2013-08 trial is to investigate whether the sentinel lymph node biopsy can be safely omitted in clinically node negative breast cancer patients treated with breast conserving therapy.

METHODS

The BOOG 2013-08 is a Dutch prospective non-inferiority randomized multicentre trial. Women with pathologically confirmed clinically node negative T1-2 invasive breast cancer undergoing breast conserving therapy will be randomized for sentinel lymph node biopsy versus no sentinel lymph node biopsy. Endpoints include regional recurrence after 5 (primary endpoint) and 10 years of follow-up, distant-disease free and overall survival, quality of life, morbidity and cost-effectiveness. Previous data indicate a 5-year regional recurrence free survival rate of 99% for the control arm and 96% for the study arm. In combination with a non-inferiority limit of 5% and probability of 0.8, this result in a sample size of 1.644 patients including a lost to follow-up rate of 10%. Primary and secondary endpoints will be reported after 5 and 10 years of follow-up.

DISCUSSION

If the sentinel lymph node biopsy can be safely omitted in clinically node negative breast cancer patients undergoing breast conserving therapy, this study will cost-effectively lead to a decreased axillary morbidity rate and thereby improved quality of life with non-inferior regional control, distant-disease free survival and overall survival.

TRIAL REGISTRATION

The BOOG 2013-08 study is registered in ClinicalTrials.gov since October 20, 2014, Identifier: NCT02271828. https://clinicaltrials.gov/ct2/show/NCT02271828.

Abstract P4-02-01: Only in lobular breast cancer MRI use is associated with a lower risk of positive surgical margins and a reduced number of mastectomies. A real-world analysis in The Netherlands

Background

The value of magnetic resonance imaging (MRI) for patients with breast cancer remains under debate. Breast MRI may contribute to the planning of local therapy, but also bears the risk of overtreatment. We analyzed the use of MRI and its impact on surgical treatment and risk of detecting contralateral breast cancer in the Netherlands.

Patients and methods

All patients who underwent primary surgery for stage I-III invasive breast cancer in the years 2011-2013 were identified through the Netherlands Cancer Registry. The following data were documented: year of diagnosis, hospital type and volume, age at diagnosis, clinical T and N stage, histological type and grade, presence of multifocality in resection specimen, hormone receptor status, HER2 status and use of MRI. We analyzed whether MRI use was related to type of surgery (primary or secondary mastectomy or breast conserving surgery), surgical margin involvement, and diagnosis of synchronous contralateral breast cancer.

Results

MRI was performed in 10,819 (29,8%) out of 36,333 patients newly diagnosed with invasive breast cancer and treated with primary surgery in the years 2011-2013 in the Netherlands. Use of MRI did not clearly increase in this period.

In the multivariate analysis, patients younger than 50 years of age compared to patients aged 70 years or older (OR 6.34, 95% CI 5.86-6.87), patients with lobular breast cancer compared to those with ductal carcinoma (OR 3.46; 95% CI 3.23-3.70) and patients with multifocal tumors compared to those without multifocality (OR 2.30, 95% CI 2.15-2.45) were more likely to undergo MRI. Hospital volume (<150 versus >150) was only marginally related to MRI use (OR 0.93; 95% CI 0.87-0.99).

Patients with invasive breast cancer undergoing MRI were more likely to undergo primary mastectomy than those without MRI (OR 1.21; 95% CI 1.15-1.28), but the subgroup with invasive lobular cancer undergoing MRI were less likely to undergo primary mastectomy (OR 0.85; 95% CI 0.75-0.98). A significantly lower risk of positive surgical margins was seen in patients with lobular breast cancer and breast conserving surgery who had undergone MRI as compared to those without MRI (OR 0.58, 95% CI 0.44-0.78) and, consequently, also a lower risk of secondary mastectomy (OR 0.60, 95% CI 0.41-0.87). Risk of positive surgical margins was not reduced by MRI use in patients with invasive ductal carcinoma (OR 0.91; 95% CI 0.77-1.07). Patients who underwent MRI were almost four times more frequently diagnosed with contralateral breast cancer, compared to those in whom MRI was not performed (OR 3.60, 95% CI 3.06-4.24).

Conclusion

Breast MRI was significantly more often used in younger patients, patients with lobular and/or multifocal breast cancer. Interestingly, MRI use was associated with less primary and secundary mastectomies in lobular invasive breast cancer, in contrast to an increased number of primary mastectomies in patients with invasive ductal cancer. MRI was further associated with an almost fourfold higher incidence of contralateral breast cancer.

Citation Format: Tjan-Heijnen VC, Lobbes MB, Vriens IJ, van Bommel AC, Nieuwenhuijzen GA, Smidt ML, Boersma LJ, van Dalen T, Smorenburg CH, Siesling S, Voogd AC. Only in lobular breast cancer MRI use is associated with a lower risk of positive surgical margins and a reduced number of mastectomies. A real-world analysis in The Netherlands. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-02-01.

Abstract P5-08-36: Contemporary risk of local breast cancer recurrence after neo-adjuvant chemotherapy: Results of a population-based cohort study

Introduction

Neo-adjuvant chemotherapy (NAC) is increasingly used in breast cancer to enable less extensive surgery and monitor the response to systemic therapy. Little is known about local recurrence (LR) in patients who received NAC. However, this information is important when deciding on optimal local treatment in these patients, especially since NAC is increasingly being offered to patients with smaller tumors. The aim of this study is to assess the contemporary rates of local breast cancer recurrence in patients that received NAC.

Methods

All women treated with NAC for primary invasive breast cancer in the years 2003-2008 were selected from the Netherlands Cancer Registry. The first event within five years after NAC was included for analyses. The 5-year local (LR) recurrence rate was calculated using Kaplan Meier estimates and the prognostic value of various clinicopathological and treatment factors was evaluated.

Results

A total of 2,457 patients were identified of whom 43% had cT1-2, 25% cT3 and 29% cT4 tumors. Two-thirds of the patients had metastatic lymph node involvement and 85% received adjuvant radiotherapy. The overall 5-year risk of LR was 6.7% and decreased from 2003-2008.

Table 1. Overall 5-year rate of local breast cancer recurrence in 2,457 breast cancer patients that received neo-adjuvant chemotherapy in the period 2003-2008.  Local recurrencea  NRate2003N=412309.6%2004N=429288.0%2005N=549398.1%2006N=604234.7%2007N=406164.7%2008N=489245.5%TotalN=2,4571606.7%aLocal recurrence defined as ipsilateral in-breast recurrence or new primary Rates represent Kaplan Meier estimates

The LR-rate was lower in hormone receptor positive (HR+) than HR-negative (HR-) tumors (3.3% vs. 12.9%) and increased with larger residual tumor size (from 1.2% in ypT0 to 13.0% in ypT3 and 16.1% in ypT4 tumors). The LR-rate also increased with the ypN-stage (4.1% in ypN0, 5.7% in ypN1 and 11.3% in ypN>1 patients) and was lower following breast-conserving surgery (BCS) than after mastectomy (4.8% vs. 7.2%).

Currently, we are working on the multivariate analyses, which will be available at the San Antonio Breast Cancer Symposium.

Conclusions

The rate of LR in patients treated with NAC has decreased over time. This will most likely be caused by enhanced imaging and radiotherapy techniques, as well as by increased insight in tumor biology resulting in improvements in both the development and application of systemic treatment modalities. Multivariate analyses will have to provide further insight into the risk of developing LR in patients treated with NAC, as well as into the prognostic value of different clinicopathological factors.

Citation Format: Aalders KC, Sonke GS, van der Heiden-van der Loo M, Boersma LJ, van Diest PJ, Siesling S, van Dalen T. Contemporary risk of local breast cancer recurrence after neo-adjuvant chemotherapy: Results of a population-based cohort study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-36.

Abstract P5-08-01: Contemporary local and regional recurrence rates in very young breast cancer patients

Introduction: Historically, young breast cancer patients proved to have a poorer prognosis regarding survival and locoregional recurrence. Over the last two decades, the survival of breast cancer patients has improved substantially, while at the same time locoregional recurrence rates decreased. The diminishing recurrence rates in the overall breast cancer population and acknowledgement of tumor biology and intrinsic subtypes in relation to age, raise the question whether the historically high locoregional recurrence risk in young women has decreased over a time where systemic treatment has evolved, particularly for the aggressive tumor types that occur frequently in young women. The aim of this study was to evaluate contemporary local and regional recurrence rates in very young breast cancer patients in relation to tumor biology in the shape of intrinsic subtypes.

Methods: Women <35 years of age who were operated for primary unilateral invasive breast cancer between 2003-2008 were selected from the Netherlands Cancer Registry. Patients were categorized according to intrinsic subtypes using hormone receptor and HER2 status. The 5-year risks of developing local recurrence (LR) and regional lymph node recurrence (RR) were estimated using Kaplan Meier statistics. The prognostic influence of different clinicopathological and treatment factors was assessed.

Results: A total of 1,000 patients were identified. The overall 5-year LR and RR rates were 3.5% and 3.7% respectively and a decreasing trend for both rates was observed over time.

Overall 5-year local, regional and distant recurrence rates over time in breast cancer patients <35 years (n=1,000)  Local recurrence*Regional recurrenceDistant metastases  NRateNRateNRate2003n=21384.2%116.1%3617.8%2004n=212105.6%105.1%3819.2%2005n=18232.0%53.1%2514.6%2006n=17053.2%21.2%138.2%2007•n=11722.1%10.9%98.1%2008•n=10633.2%44.4%1010.0%Totaln=1,000313.5%333.7%13113.9%*Local recurrence (ipsilateral in-breast recurrence + new primary) •Fewer patients were included in the years 2007-2008 compared to earlier years due to the fact that some hospitals did not provide data for those years. Rates represent Kaplan Meier estimates

Intrinsic subtype proved to be a prognostic factor for both LR and RR (P=0.0556 and P=0.0141, respectively). Particularly HR-/HER2+ tumors were associated with high LR and RR rates. Patients with lymph node metastases at time of diagnosis had a higher RR-risk in both the total population (P=0.0349) as well as within the different intrinsic subtypes, although only significantly in the triple negative group (P=0.0401). Type of surgery did not influence the rate of LR and RR in this study.

Conclusions: Overall, the LR and RR rates in very young breast cancer patients were relatively low and decreased over time. The higher recurrence rates in this population were associated with the presence of more aggressive intrinsic subtypes. We emphasize that tumor biology should guide decision-making towards optimal treatment in this specific population. Although longer follow-up is needed, especially for this very young patient population, the results of this study provide important insight in the locoregional recurrence risks for this historically high-risk population.

Citation Format: Aalders KC, Postma EL, Strobbe LJ, van der Heiden-van der Loo M, Sonke GS, Boersma LJ, van Diest PJ, Siesling S, van Dalen T. Contemporary local and regional recurrence rates in very young breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-01.

The value of completion axillary treatment in sentinel node positive breast cancer patients undergoing a mastectomy: a Dutch randomized controlled multicentre trial (BOOG 2013-07)

Background

Trials failed to demonstrate additional value of completion axillary lymph node dissection in case of limited sentinel lymph node metastases in breast cancer patients undergoing breast conserving therapy. It has been suggested that the low regional recurrence rates in these trials might partially be ascribed to accidental irradiation of part of the axilla by whole breast radiation therapy, which precludes extrapolation of results to mastectomy patients. The aim of the randomized controlled BOOG 2013–07 trial is therefore to investigate whether completion axillary treatment can be safely omitted in sentinel lymph node positive breast cancer patients treated with mastectomy.

Design

This study is designed as a non-inferiority randomized controlled multicentre trial. Women aged 18 years or older diagnosed with unilateral invasive clinically T1-2 N0 breast cancer who are treated with mastectomy, and who have a maximum of three axillary sentinel lymph nodes containing micro- and/or macrometastases, will be randomized for completion axillary treatment versus no completion axillary treatment. Completion axillary treatment can consist of completion axillary lymph node dissection or axillary radiation therapy. Primary endpoint is regional recurrence rate at 5 years. Based on a 5-year regional recurrence free survival rate of 98 % among controls and 96 % for study subjects, the sample size amounts 439 per arm (including 10 % lost to follow-up), to be able to reject the null hypothesis that the rate for study and control subjects is inferior by at least 5 % with a probability of 0.8. Results will be reported after 5 and 10 years of follow-up.

Discussion

We hypothesize that completion axillary treatment can be safely omitted in sentinel node positive breast cancer patients undergoing mastectomy. If confirmed, this study will significantly decrease the number of breast cancer patients receiving extensive treatment of the axilla, thereby diminishing the risk of morbidity and improving quality of life, while maintaining excellent regional control and without affecting survival.

Trial registration

The BOOG 2013–07 study is registered in the register of ClinicalTrials.gov since April 10, 2014, Identifier: NCT02112682.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1613-2) contains supplementary material, which is available to authorized users.

Economic evaluation of four follow-up strategies after curative treatment for breast cancer: results of an RCT

BACKGROUND

An economic evaluation was performed alongside a randomised controlled trial (ISRCTN 74071417) investigating the cost-effectiveness of nurse-led telephone follow-up instead of hospital visits, and of a short educational group programme (EGP) in the first year after breast cancer treatment.

METHOD

This economic evaluation (n = 299) compared the one-year costs and the effects of four follow-up strategies: (1) hospital follow-up; (2) nurse-led telephone follow-up; (3) hospital follow-up plus EGP; and (4) nurse-led telephone follow-up plus EGP. Costs were measured using cost diaries and hospital registrations. Quality-adjusted life years (QALYs) were measured using the EQ-5D. Outcomes were expressed in incremental cost-effectiveness ratios (ICERs) and cost-effectiveness acceptability curves.

RESULTS

Hospital follow-up plus EGP yielded most QALYs (0.776), but also incurred the highest mean annual costs (€4914). The ICER of this strategy versus the next best alternative, nurse-led telephone follow-up plus EGP (0.772 QALYs and €3971), amounted to €235.750/QALY. Hospital and telephone follow-up without EGP both incurred higher costs and less QALYs than telephone follow-up plus EGP and were judged inferior. Hospital follow-up plus EGP was not considered cost-effective, therefore, telephone follow-up plus EGP was the preferred strategy. The probability of telephone follow-up plus EGP being cost-effective ranged from 49% to 62% for different QALY threshold values. Secondary and sensitivity analyses showed that results were robust.

CONCLUSION

Nurse-led telephone follow-up plus EGP seems an appropriate and cost-effective alternative to hospital follow-up for breast cancer patients during their first year after treatment.

Nurse-led telephone follow-up and an educational group programme after breast cancer treatment: results of a 2 × 2 randomised controlled trial

OBJECTIVE

To investigate whether frequent hospital follow-up in the first year after breast cancer treatment might partly be replaced by nurse-led telephone follow-up without deteriorating health-related quality of life (HRQoL), and whether a short educational group programme (EGP) would enhance HRQoL.

PATIENTS AND METHODS

A multicentre pragmatic randomised controlled trial (RCT) with a 2×2 factorial design was performed among 320 breast cancer patients who were treated with curative intent. Participants were randomised to follow-up care as usual (3-monthly outpatient clinic visits), nurse-led telephone follow-up, or the former strategies combined with an educational group programme. The primary outcome for both interventions was HRQoL, measured by EORTC QLQ-C30. Secondary outcomes were role and emotional functioning and feelings of control and anxiety.

RESULTS

Data of 299 patients were available for evaluation. There was no significant difference in HRQoL between nurse-led telephone and hospital follow-up at 12 months after treatment (p = 0.42; 95% confidence interval (CI) for difference: -1.93-4.64) and neither between follow-up with or without EGP (p = 0.86; 95% CI for difference: -3.59-3.00). Furthermore, no differences between the intervention groups and their corresponding control groups were found in role and emotional functioning, and feelings of control and anxiety (all p-values > 0.05).

CONCLUSION

Replacement of most hospital follow-up visits in the first year after breast cancer treatment by nurse-led telephone follow-up does not impede patient outcomes. Hence, nurse-led telephone follow-up seems an appropriate way to reduce clinic visits and represents an accepted alternative strategy. An EGP does not unequivocally affect positive HRQoL outcomes.

Follow-up after curative treatment for breast cancer: Why do we still adhere to frequent outpatient clinic visits?

Follow-up after curative treatment for breast cancer consists of frequent outpatient clinic visits, scheduled at regular intervals. Its aim is primarily to detect local disease recurrence, or a second primary breast cancer, but also to provide information and psychosocial support. The cost-effectiveness of these frequent visits is being questioned however, leading to a search for less intensive follow-up strategies, such as follow-up by the general practitioner, patient-initiated or nurse-led follow-up or contact by telephone. These strategies are generally considered to be safe, but they are not yet widely accepted in clinical practice. Since brief interventions based on self-education and information have been shown to be able to improve quality of life, we hypothesise that these interventions may lead to a better acceptance of reduced follow-up by both patients and professionals.

Paradoxical effects of trichostatin A: inhibition of NF-Y-associated histone acetyltransferase activity, phosphorylation of hGCN5 and downregulation of cyclin A and B1 mRNA

Trichostatin A (TSA), an inhibitor of histone deacetylase (HDAC), is widely used to study the role of histone acetylation in gene expression, since genes that use histone acetylation as a means of regulating expression may be up regulated when TSA is added. In this study, however, we show that TSA has an unexpected paradoxical effect leading to inhibition of NF-Y-associated histone acetyl transferase (HAT) activity and phosphorylation of the HAT, hGCN5. TSA treatment of cells resulted in diminished levels of NF-Y-associated HAT activity without changes in NF-Y(A) amount. hGCN5 is one of the HATs known to associate with NF-Y. The association of hGCN5 with NF-Y was not altered by TSA treatment. The enzymatic activity of hGCN5 is known to be inhibited by phosphorylation. TSA treatment of Hela cells resulted in phosphorylation of hGCN5. Exposure of the NF-Y immunoprecipitates from TSA-treated cells to a phosphatase resulted in enhanced HAT activity. We have also shown that the mRNA levels of several genes, cyclin B1 and cyclin A, are downregulated by TSA; these effects do not require protein synthesis and the downregulation of cyclin B1 by TSA occurs through transcription. These results suggest that TSA can have contradictory effects, on one hand stimulating HAT activity in general by inhibition of HDACs, but also resulting in inhibition of NF-Y-associated HAT activity and phosphorylation of hGCN5.

Changes in local pulmonary injury up to 48 months after irradiation for lymphoma and breast cancer

PURPOSE

To assess the recovery from early local pulmonary injury after irradiation and to determine whether regional differences exist.

METHODS

For 110 patients treated for breast cancer or malignant lymphoma, single photon emission computed tomography (SPECT) perfusion and ventilation scans and CT scans were made before, 3, 18, and 48 months after radiotherapy. Dose-effect relations for changes in local perfusion, ventilation, and density were determined for each individual patient using spatially correlated SPECT and CT data sets, for each follow-up period. Average dose-effect relations for both subgroups were determined, as well as dose-effect relations for different regions.

RESULTS

In general, partial improvement of local pulmonary injury was observed between 3 and 18 months for each of the three endpoints. After 18 months, no further improvement was seen. Patients with breast cancer and malignant lymphoma showed a similar improvement (except for the perfusion parameter), which was attributed to a recovery from the early radiation response and could not be explained by contraction effects of fibrosis of lung parenchyma. No regional differences in radiosensitivity 18 months after treatment were observed, except for the dorsal versus ventral region. This difference was attributed to a gravity-related effect in the measuring procedure.

CONCLUSION

For all patients, a partial recovery from early local perfusion, ventilation, and density changes, was seen between 3 and 18 months after radiotherapy. After 18 months, local lung function did not further improve (lymphoma patients).

Radiation dose-effect relations and local recovery in perfusion for patients with non-small-cell lung cancer

PURPOSE

To determine local dose-effect relations for lung perfusion and density changes due to irradiation for patients with non-small-cell lung cancer (NSCLC) and to quantify the effect of reperfusion.

METHODS AND MATERIALS

For 25 NSCLC patients and a reference group of 81 patients with healthy lungs, registered single photon emission computed tomography (SPECT) lung perfusion and CT scans were made, before and after radiotherapy. Average dose-effect relations for perfusion and CT-density changes were calculated and compared with the dose-effect relation of the reference group. On the basis of these dose-effect relations, the post-RT perfusion was predicted for each patient and compared to the measured post-RT perfusion.

RESULTS

Well-perfused lung regions of the NSCLC patients showed the same dose-effect relation as the reference patients. By comparing predicted and measured post-treatment perfusion scans, regions of reperfusion could be determined for 18 of 25 NSCLC patients but for none of the reference patients.

CONCLUSION

Well-perfused lung tissue of patients with NSCLC behaves like healthy lung tissue with respect to radiation. The dose-effect relation for perfusion and CT density was extended for doses up to 80 Gy. Radiation damage in poorly perfused lung regions was less than predicted as a consequence of local reperfusion.

Effect of radiotherapy and chemotherapy on pulmonary function after treatment for breast cancer and lymphoma: A follow-up study

PURPOSE

To determine the changes in pulmonary function tests (PFTs) 0 to 48 months after treatment for breast cancer and lymphoma.

PATIENTS AND METHODS

The alveolar volume (V(A)), vital capacity, forced expiratory volume in 1 second, and corrected transfer factor of carbon monoxide (T(L,COc)) were measured in 69 breast cancer and 41 lymphoma patients before treatment and 3, 18, and 48 months after treatment with radiotherapy alone or radiotherapy in combination with chemotherapy (mechlorethamine, vincristine, procarbazine, prednisone, doxorubicin, bleomycin, vinblastine; cyclophosphamide, epidoxorubicin, fluorouracil; cyclophosphamide, thiotepa, carboplatin; cyclophosphamide, methotrexate, fluorouracil). The three-dimensional dose distribution in the lung of each patient was converted to the mean lung dose. Statistical analysis was used to evaluate the changes in PFT values over time in relation to age, sex, smoking, chemotherapy, and the mean lung dose.

RESULTS

After an initial reduction in PFT values at 3 months, significant recovery was seen at 18 months for all patients. Thereafter, no further improvement could be demonstrated. Reductions in spirometry values and V(A) were related to the mean lung dose only (0.9% per Gy at 3 months and 0.4% per Gy mean dose at 18 months). T(L,COc) decreased 1. 1% per Gy mean dose and additionally decreased 6% when chemotherapy was given after radiotherapy. Chemotherapy administered before radiotherapy reduced baseline T(L,COc) values by 8% to 21%. All patients showed an improvement of 5% at 18 months.

CONCLUSION

On the basis of the mean lung dose and the chemotherapy regimen, the changes in PFT values can be estimated before treatment within 10% of the values actually observed in 72% to 85% of our patients with healthy lungs.

Prediction of overall pulmonary function loss in relation to the 3-D dose distribution for patients with breast cancer and malignant lymphoma

PURPOSE

To predict the changes in pulmonary function tests (PFTs) 3-4 months after radiotherapy based on the three-dimensional (3-D) dose distribution and taking into account patient- and treatment-related factors.

METHODS

For 81 patients with malignant lymphoma and breast cancer, PFTs (VA, VC, FEV1 and TL,COc) were performed prior to and 3-4 months after irradiation and dose-effect relations for early changes in local perfusion, ventilation and air-filled fraction were determined using correlated CT and SPECT data. The 3-D dose distribution of each patient was converted into four different dose-volume parameters, i.e. the mean dose in the lung and three overall response parameters (ORPs, which represent the average local injury over the complete lung). ORPs were determined using the dose-effect relations for early changes in local perfusion, ventilation and air-filled fraction. Correlation coefficients were calculated between these dose-volume parameters and the changes in PFTs. In addition, the impact of the variables chemotherapy (MOPP/ABV and CMF), tamoxifen, smoking, age and gender on the relation between the mean lung dose and the relative changes in PFTs following radiotherapy was studied using multiple regression analysis.

RESULTS

The mean lung dose proved to be the easiest parameter to predict the reduction in PFTs 3-4 months following radiotherapy. For all patients the relation between the mean lung dose and the changes in PFTs could be described with one regression line through the origin and a slope of 1% reduction in PFT for each increase of 1 Gy in mean lung dose. Smoking and CMF chemotherapy influenced the reduction in PFTs significantly for VA and TL,COc, respectively. Patients treated with MOPP/ABV prior to radiotherapy had lower pre-radiotherapy PFTs than other patient groups, but did not show further deterioration after radiotherapy (at 3-4 months).

CONCLUSIONS

The relative reduction in VA, VC, FEV1 and TL,COc 3-4 months after radiotherapy for breast cancer and malignant lymphoma can be estimated before radiotherapy based on the mean lung dose of each individual patient and taking into account the use of chemotherapy and smoking habits of the patient.

Evaluation of two dose-volume histogram reduction models for the prediction of radiation pneumonitis

PURPOSE

To evaluate the similarities between the mean lung dose and two dose-volume histogram (DVH) reduction techniques of 3D dose distributions of the lung.

PATIENTS AND METHODS

DVHs of the lungs were calculated from 3D dose distributions of patients treated for malignant lymphoma (44), breast cancer (42) and lung cancer (20). With a DVH reduction technique, a DVH is summarized by the equivalent uniform dose (EUD), a quantity which is directly related to the normal tissue complication probability (NTCP). Two DVH reduction techniques were used. The first was based on an empirical model proposed by Kutcher et al. (Kutcher, G.J., Burman, C., Brewster, M.S., Goitein, M. and Mohan, R. Histogram reduction method for calculating complication probabilities for three-dimensional treatment planning evaluations. Int. J. Radiat. Oncol. Biol. Phys. 21: 137-146, 1991), which needs a volume exponent n. Several values for n were tested. The second technique was based on a radiobiological model, the parallel functional subunit model developed by Niemierko et al. (Niemierko, A. and Goitein, M. Modeling of normal tissue response to radiation: the critical volume model. Int. J. Radiat. Oncol. Biol. Phys. 25: 135-145, 1993) and Jackson et al. (Jackson, A., Kutcher, G.J. and Yorke, E.D. Probability of radiation-induced complications for normal tissues with parallel architecture subject to non-uniform irradiation. Med. Phys. 20: 613-625, 1993), for which a local dose-effect relation needed to be specified. This relation was obtained from an analysis of perfusion and ventilation SPECT data.

RESULTS

It can be shown analytically that the two DVH reduction techniques are identical, if the local dose-effect relation obeys a power-law relationship in the clinical dose range. Local dose-effect relations based on perfusion and ventilation SPECT data can indeed be fitted with a power-law relationship in the range 0-80 Gy, from which values of n = 0.8-0.9 were deduced. These correspond to the commonly used value of n = 0.87 for lung tissue and yielded EUDn=0.87 values which were almost identical to the mean lung doses. For other n values, for which no experimental data are present, differences exist between EUD and mean dose values. Six patients with malignant lymphoma (6/44) and none of the breast cancer patients (0/42) developed radiation pneumonitis. These cases occurred only at high values for the mean lung dose.

CONCLUSION

The two DVH reduction techniques are identical for lung and are very similar to mean dose calculations. The two techniques are also relatively similar for other model parameter values.

Dose-effect relations for early local pulmonary injury after irradiation for malignant lymphoma and breast cancer

PURPOSE

To quantify the influence of treatment- and patient-related factors on the severity of early local pulmonary injury and to establish whether regional differences are present for local dose-effect relations for early radiation-induced pulmonary injury.

METHODS

Forty-two patients with malignant lymphoma and 40 breast cancer patients were examined prior to and 3 months after radiotherapy. The lymphoma patients were irradiated with mantle fields to an average dose of 38 Gy and the breast cancer patients were irradiated with internal mammary node fields with or without tangential breast fields to an average dose of 50 Gy. Dose-effect relations for local perfusion, ventilation and density changes were determined using correlated single photon emission computed tomography (SPECT) and CT data. A multivariate analysis was performed to study the influence of irradiated volume, chemotherapy (CMF and MOPP/ABV), smoking, age and gender. In addition, dose-effect relations for different regions in the lung were determined.

RESULTS

A similar and almost linear increase of early functional changes as a function of radiation dose was observed for perfusion and ventilation, whereas the shape of the dose-effect relation and the magnitude of early structural changes were different for density. For the three end-points studied, regional differences in radiosensitivity could not be demonstrated. For the posterior lung region compared to the anterior lung region, however, a difference was observed, which could be attributed to a gravity-related effect in the measuring procedure. Local structural changes (density) were significantly smaller for smokers (P = 0.002) and young patients (P = 0.007), whereas the CMF chemotherapy regimen given after radiotherapy (P = 0.017) significantly increased the amount of functional changes (perfusion). The magnitude of local pulmonary changes was independent of the irradiated volume, the MOPP/ABV chemotherapy regimen and gender.

CONCLUSION

The dose-effect relations for early radiation-induced local pulmonary changes were independent of the irradiated volume, MOPP/ABV, gender and lung region. CMF, smoking and age influenced the magnitude of early pulmonary changes and should be taken into account in dose-escalation protocols.

Automatic three-dimensional matching of CT-SPECT and CT-CT to localize lung damage after radiotherapy

The aim of this study was to develop a fast and clinically robust automatic method to register SPECT and CT scans of the lungs.

METHODS

CT and SPECT scans were acquired in the supine position from 20 patients with healthy lungs. After partial irradiation of the lungs by radiotherapy, the scans were repeated. Two matching methods were compared: a conventional method with external skin markers and a new method using chamfer matching of the lung contours. In the latter method, a unique value for the SPECT threshold, needed for segmentation of the SPECT lungs, was determined by iteratively applying the chamfer matching algorithm.

RESULTS

The new technique for CT-SPECT matching could be implemented in a fully automatic manner and required less than 2 min. No large systematic shifts or rotations were present between the matches obtained with the marker method and the lung contour method for healthy or partially irradiated lungs. For healthy lungs, the number of ventilation SPECT counts outside the CT-defined lung was taken as a measure for a good match. This number of outside counts was slightly lower for the new method than for the conventional method, which indicates that the accuracy of the new method is at least comparable to the conventional method. For ventilation, a systematic difference between the results of the matching methods, a small translation in the anterior --> posterior direction, could be attributed to an inconsistency of the marker positions (2 mm). For perfusion, a somewhat larger anterior --> posterior shift was found, which was attributed to the gravity force. CT-CT correlation on the lung contours using chamfer matching was tested with the same dataset. For accurate matching, the CT slices encompassing the diaphragm had to be deleted.

CONCLUSION

The new method based on lung contour matching is a fast, automatic procedure and allows accurate clinical follow-up.

Estimation of the incidence of late bladder and rectum complications after high-dose (70-78 GY) conformal radiotherapy for prostate cancer, using dose-volume histograms

PURPOSE

To investigate whether Dose-Volume Histogram (DVH) parameters can be used to identify risk groups for developing late gastrointestinal (GI) and genitourinary (GU) complications after conformal radiotherapy for prostate cancer.

METHODS AND MATERIALS

DVH parameters were analyzed for 130 patients with localized prostate cancer, treated with conformal radiotherapy in a dose-escalating protocol (70-78 Gy, 2 Gy per fraction). The incidence of late (>6 months) GI and GU complications was classified using the RTOG/EORTC and the SOMA/LENT scoring system. In addition, GI complications were divided in nonsevere and severe (requiring one or more laser treatments or blood transfusions) rectal bleeding. The median follow-up time was 24 months. We investigated whether rectal and bladder wall volumes, irradiated to various dose levels, correlated with the observed actuarial incidences of GI and GU complications, using volume as a continuous variable. Subsequently, for each dose level in the DVH, the rectal wall volumes were dichotomized using different volumes as cutoff levels. The impact of the total radiation dose, and the maximum radiation dose in the rectal and bladder wall was analyzed as well.

RESULTS

The actuarial incidence at 2 years for GI complications > or =Grade II was 14% (RTOG/EORTC) or 20% (SOMA/LENT); for GU complications > or =Grade III 8% (RTOG/EORTC) or 21% (SOMA/LENT). Neither for GI complications > or =Grade II (RTOG/EORTC or SOMA/LENT), nor for GU complications > or =Grade III (RTOG/EORTC or SOMA/LENT), was a significant correlation found between any of the DVH parameters and the actuarial incidence of complications. For severe rectal bleeding (actuarial incidence at 2 years 3%), four consecutive volume cutoff levels were found, which significantly discriminated between high and low risk. A trend was observed that a total radiation dose > or = 74 Gy (or a maximum radiation dose in the rectal wall >75 Gy) resulted in a higher incidence of severe rectal bleeding (p = 0.07).

CONCLUSIONS

These data show that dose escalation up to 78 Gy, using a conformal technique, is feasible. However, these data have also demonstrated that the incidence of severe late rectal bleeding is increased above certain dose-volume thresholds.

Recovery of overall and local lung function loss 18 months after irradiation for malignant lymphoma

PURPOSE

To determine the local and overall pulmonary injury 3 to 18 months after irradiation and to investigate whether the changes in overall lung function can be predicted using the three-dimensional (3-D) dose distribution in combination with dose-effect relations for local injury; and to study the influence of chemotherapy on the injury.

PATIENTS AND METHODS

Local perfusion (Q), ventilation (V), and tissue density were measured in 25 patients treated for malignant lymphoma, before, 3 to 4 months after, and 18 months after irradiation. Dose-effect relations for local injury, calculated using correlated single-photon emission computed tomographic (SPECT) and computed tomographic (CT) data, were combined with the 3-D dose distribution, to calculate the estimated mean local changes over the complete lung for each patient. The result was correlated with the actual changes in pulmonary function.

RESULTS

A dose-dependent increase with injury was observed at 3 to 4 months after irradiation, which at 18 months had recovered by approximately 50% to 60%. The estimated mean relative reduction of local Q predicted the change in overall lung function within 10% of the actually observed values in 63% to 73% of patients. Chemotherapy given before radiotherapy enhanced radiation-induced reduction of local Q significantly, with dose-modifying factors of 1.22 and 1.37 at 3 to 4 months and 18 months, respectively.

CONCLUSION

Partial recovery of radiation-induced reduction of local and overall lung function was observed at 18 months after irradiation. The overall functional outcome of most patients could be well predicted, based on the estimated mean local injury over the complete lung. Chemotherapy given before radiotherapy enhanced the radiation-induced reduction of local Q.

Radiation pneumonitis imaged with indium-111-pentetreotide

Early recognition of radiation pneumonitis enables adequate treatment with a reasonable chance to prevent late sequelae. The feasibility of 111In-pentetreotide in detecting this condition was explored in this study.

METHODS

The degree of lung uptake of 111In-pentetreotide, evaluated both visually and quantitatively by irradiated-to-nonirradiated area ratios (INIA ratio) from planar images after 24 hr, was analyzed in relation to the radiation field and compared with ventilation/perfusion (V/Q) images and chest radiographs or CT in 11 patients who had received radiotherapy to the mediastinum or to the internal mammary nodes, 10 of whom were suspected of having clinical radiation pneumonitis. Additional SPECT studies were used to map lung uptake distribution.

RESULTS

Indium-111-pentetreotide scans were positive in nine symptomatic patients examined 2-5 mo after radiotherapy; strongly or moderately positive in eight patients, one of whom was receiving steroid therapy without clinical response; and weakly positive in one patient with good steroid response. Indium-111-pentetreotide studies were negative in one asymptomatic patient examined 1 mo after radiotherapy and in one symptomatic patient, with subsequent diagnosis of aspecific viral pneumonitis, examined 4 mo after irradiation. Positive 111In-pentetreotide scans delineated areas of radiation pneumonitis that adequately correlated with areas of decreased ventilation/perfusion and x-ray abnormalities. INIA ratios varied from 1.01 to 2.16 and, in irradiated areas with visible uptake, the lowest value was 1.29. SPECT showed lung uptake in both superficial and deep lying areas in patients with mantle irradiation fields whereas distribution was limited to anterior areas in internal mammary lymph node chain irradiation.

CONCLUSION

Indium-111-pentetreotide can detect radiation pneumonitis and may have a role in both the differential diagnosis of patients who have complaints after radiotherapy, and when supported by quantification in the monitoring of response to steroid therapy.

Estimation of overall pulmonary function after irradiation using dose-effect relations for local functional injury

PURPOSE

To predict the pulmonary function 3-4 months after irradiation for malignant lymphoma from the three-dimensional (3-D) dose distribution.

METHODS

Dose-effect relations for the relative reduction of local perfusion (Q) and local ventilation (V), were calculated in 25 patients, using correlated SPECT (Single Photon Emission Computed Tomography) and CT data. By combining the 3-D dose distribution of an individual patient with the dose-effect relations averaged over all patients, the average reduction of local Q and V (i.e., the overall response parameters) in the whole lung was estimated for each patient. Correlation coefficients were calculated between these overall response parameters and the change in standard lung function tests. In addition, the relation between the overall response parameters and the incidence of radiation pneumonitis was determined.

RESULTS

The overall response parameter for perfusion was correlated with the change in standard lung function tests, with correlation coefficients varying between 0.53 (p = 0.007) and 0.71 (p < 0.001) for the change of Vital Capacity and Forced Expiratory Volume at 1 s, respectively. For the overall response parameter for ventilation similar correlations were observed. Four out of the 25 patients developed radiation pneumonitis; in these four patients the overall response parameter for perfusion was on average somewhat higher (13.2 +/- 1.4% (1 standard error of the mean)) than in patients without radiation pneumonitis (10.5 +/- 1.0%), but this difference was not significant. A higher incidence of radiation pneumonitis was observed for larger values of the overall response parameter for perfusion; in patient groups with an overall response parameter for perfusion of 0-5%, 5-10%, 10-15%, and 15-20%, the incidence of radiation pneumonitis was 0 (0/1), 10 (1/10), 13 (1/8) and 33% (2/6), respectively.

CONCLUSION

By combining the 3-D dose distribution with the average dose-effect relations for local perfusion or ventilation, an overall response parameter can be calculated prior to irradiation, which is predictive for the radiation-induced change in the overall pulmonary function, and possibly for the incidence of radiation pneumonitis, in this group of patients.

Dose-effect relations for local functional and structural changes of the lung after irradiation for malignant lymphoma

PURPOSE

To estimate the dose-effect relations for local functional (ventilation and perfusion) and structural (density) changes of the lung, 3-4 months after irradiation.

METHODS

Twenty-five patients with malignant lymphoma were irradiated with a (modified) mantle field to an average dose of 38 Gy, given in 21 fractions. Single photon emission computed tomography (SPECT) ventilation (V) and perfusion (Q) scans, and CT scans were performed before and 3-4 months after radiation treatment. The three-dimensional dose distribution was calculated using the CT data. After correlation of SPECT and CT data sets, the average post-treatment value of V, Q and lung density per voxel was calculated relative to the pre-treatment value, per dose interval of 4 Gy. Subsequently, the dose-effect relations in each patient were normalized to the average value per voxel in the dose interval of 0-12 Gy. In addition, in each dose interval of 4 Gy the fraction of patients with changes larger than 20% was calculated for all three parameters. The dose-effect relations for perfusion and ventilation normalized to the low-dose regions, and the dose-incidence curves for the fraction of patients with changes larger than 20% were fitted for all three parameters, using a logistic model.

RESULTS

Marked changes in the distribution of V and Q were found after irradiation. Prior to normalization to the low-dose regions, a change in V and Q was found in most patients in the dose interval of 0-12 Gy, varying from an increase of 37% to a decrease of 10%, which was followed by a decreasing trend at higher doses. The increase in the low-dose regions indicated a redistribution phenomenon, the magnitude of which was dependent of the irradiated volume. The logistic fit of the dose-effect relations for Q and V, normalized to the low-dose regions, resulted in values for D50 of 51 Gy and 54 Gy (given in 21 fractions on average), respectively, and for the steepness parameter k of 4.2 and 4.0, respectively. The logistic fit for the dose-incidence curves for Q, V and lung density resulted in values for D50 and k of 38 Gy, 37 Gy, 44 Gy and 10.3, 7.8 and 9.4, respectively.

CONCLUSIONS

With the combined use of SPECT and CT scans, we have obtained dose-effect relations for local functional and structural damage in the lung, 3-4 months after irradiation.

Quantifying local lung perfusion and ventilation using correlated SPECT and CT data

A clinically applicable method for quantifying lung perfusion and ventilation on a subregional (local) scale from SPECT scans in order to estimate local lung function in patients with pre-existing pulmonary disease and to monitor local treatment effects was developed and evaluated.

METHODS

SPECT 99mTc perfusion and 81mKr ventilation images were corrected for photon attenuation and scatter effect with a postreconstruction correction method incorporating a variable-effective linear-attenuation coefficient calculated from spatially-correlated CT data. A new algorithm was developed to quantify local ventilation from the SPECT data, which, in contrast with other algorithms, makes no assumptions on ventilation homogeneity over the lung. The quantification procedure was applied to clinical data from patients with a normal lung function and from patients suffering from radiation-induced pulmonary dysfunction.

RESULTS

The calculated attenuation correction factors on the observed number of counts in the lung range from 2.0 to 3.0 and 2.3 to 3.5 for 81mKr and 99mTc, respectively, showing a systematic increase from the diaphragm to the lung apex. As a result of this correction, the values of local perfusion and ventilation differ 10%-15% from values calculated without attenuation correction. The calculated values of the local ventilation are 10%-50% lower than those found by quantification algorithms which assume homogeneous ventilation.

CONCLUSIONS

The methods presented here are robust with respect to uncertainties in the input parameters and yield realistic values for perfusion and ventilation distribution in the lung with an intrinsic accuracy (largely determined by count statistics) of about 10%.

A new method to determine dose-effect relations for local lung-function changes using correlated SPECT and CT data

PURPOSE

To determine dose-effect relations for regional lung-function changes after radiotherapy.

METHODS

Single Photon Emission Computed Tomography (SPECT) was performed to quantify regional ventilation and perfusion. CT scans were used to calculate the three-dimensional (3-D) dose distribution. Both SPECT and CT scans were performed prior to radiotherapy and 5 months after the start of the treatment. To obtain combined 3-D information on ventilation, perfusion and dose, the SPECT data were correlated with the corresponding CT data. The relative changes in ventilation and perfusion were calculated in each SPECT voxel (voxel size about 6 x 6 x 6 mm) and related to the dose in that voxel. The average relative changes were determined per dose interval of 4 Gy. This procedure was evaluated using the data from five patients treated for Hodgkin's disease with mantle field irradiation with a prescribed total dose of 40-42 Gy.

RESULTS

Dose-effect relations for perfusion were observed in all patients, while in four of the five patients, a dose-effect relation was found for ventilation. The maximal uncertainty of the calculated radiation dose was 11%: a difference between the position of the patient during treatment and during CT scanning caused a maximal dose uncertainty of 6%, while the accuracy of the dose calculation algorithm itself was estimated to be within 5%.

CONCLUSION

The results indicate that the combined use of SPECT and CT information is an effective method for determining dose-effect relations for regional lung function parameters in each individual patient.

Pulmonary morbidity 10-18 years after irradiation for Hodgkin's disease

Pulmonary function tests were performed in 78 patients who had been curatively treated for Hodgkin's disease with mantle field irradiation 10-18 years ago. Mean values of the total lung capacity (95.2%), vital capacity (VC) (95.9%), forced expiratory volume in 1 s (FEV1) (90.6%), and carbon monoxide diffusing capacity per unit alveolar volume (82.7%) showed significant deviations from the predicted normal values, standardised for age, sex, race and height. In a multiple regression analysis the normalised total dose of irradiation, the field of irradiation, and the interval since irradiation had independent negative effects on the test results. Patients reported more coughing, wheezing and dyspnoea on exertion in comparison with hospital-visitors. Their smoking habits and reported pulmonary disease were not different. It is concluded that small, but significant impairment of pulmonary function exists after a follow-up of 14 (2) years [mean (S.D.)]. The clinical impact of these findings seems, however, minimal. Further avoidance of pulmonary toxicity requires a careful quantitative study of the effects of the radiation dose and irradiated volume.